Glacial meltwater constitutes a vital component of the water supply in arid and semi-arid areas.However,the influence of glacial melting on runoff and evapotranspiration under global warming remains insufficiently und...Glacial meltwater constitutes a vital component of the water supply in arid and semi-arid areas.However,the influence of glacial melting on runoff and evapotranspiration under global warming remains insufficiently understood.Previous studies coupling the Soil and Water Assessment Tool(SWAT)model with glacier modules often failed to consider the spatial heterogeneity of temperature during glacial melting,potentially leading to biased estimates of meltwater volume.In this study,we developed a glacier-coupled SWAT(SWAT-glacier)model considering the digital elevation model(DEM)based temperature-driven glacial melt processes to elucidate the impact of glacial melting on hydrological processes across four river basins(Dongda,Xiying,Jinta,and Zamu)of the upper Shiyang River Basin(SYRB)in northwestern China from 1986 to 2021.Compared with the standard SWAT model,the proposed SWAT-glacier model significantly improved the simulation accuracy for both runoff and evapotranspiration.Specifically,in comparison with the standard SWAT model,the Nash-Sutcliffe efficiency of the SWAT-glacier model showed a relative improvement of approximately 0.42%–9.16%and 1.50%–10.15%for runoff and evapotranspiration,respectively,in the four river basins during the validation period.Annual glacial runoff occurred predominantly from May to October,whereas glacial melt-induced evapotranspiration peaked between June and August.From 1986 to 2021,the average contributions of glacial melt to runoff were 6.97%for Dongda,3.06%for Xiying,2.70%for Jinta,and 0.67%for Zamu,whereas its contributions to evapotranspiration were 9.06%,5.14%,3.21%,and 1.59%,respectively.This study presents a SWAT-glacier modeling framework that enhances the simulation of hydrological processes in cold regions.The proposed methodology can be extended to other glacierized basins to provide valuable insights into water resource management under climate change.展开更多
China has implemented large-scale hydraulic engineering projects in arid regions where water resources are severely scarce to efficiently maximize limited water resources for production and domestic needs.The processe...China has implemented large-scale hydraulic engineering projects in arid regions where water resources are severely scarce to efficiently maximize limited water resources for production and domestic needs.The processes and consequences of how the change of hydrological factors affects vegetation distribution remain unclear.This study employed multi-source remote sensing data to investigate the impact of hydrological factors on vegetation distribution in the Shiyang River Basin(SRB)in the arid region in Northwestern China.The results indicate that:(1)The NDVI values in the SRB showed a fluctuating upward trend of(0.0014/yr),with vegetation increase occurring in 62.71%of the area while vegetation degradation was observed in only 6.44%of the area.(2)The Surface Water Storage Anomaly(SWSA)shows an increasing trend of(0.112 mm/month),while Terrestrial Water Storage Anomaly(TWSA)and Groundwater Storage Anomaly(GWSA)exhibit significant declines at rates of-0.124 mm/month and-0.236 mm/month,respectively.(3)Vegetation growth on agricultural land and in planted forests has shown significant growth,in contrast to the general degradation of natural vegetation that is dependent on groundwater.In addition,surface water inputs directly catalyze vegetation growth dynamics.However,the complex mechanisms linking vegetation increase and decreasing terrestrial water reserves in arid regions still need to be studied in depth.The potential negative ecological impacts that may result from the continuous decline of terrestrial and groundwater reserves should not be taken lightly.展开更多
Pollen analysis of 30 modem water samples from the Shivang River, an internal river system located between the Tengger and Badain Jaran deserts, Northwest China was carried out to examine the river's capacity to c...Pollen analysis of 30 modem water samples from the Shivang River, an internal river system located between the Tengger and Badain Jaran deserts, Northwest China was carried out to examine the river's capacity to carry pollen and spores, and to assess the contribution of the water-borne pollen to pollen assemblages in lake sediments at the end of the river system. Results indicate the pollen assemblages in water samples consist of both local and upland pollen. Percentages of upland pollen reach 30% - 60%, and pollen assemblages in water samples do not indicate the nature of local vegetation at the sampling sites. Fluvial currents have the capacity to transport large quantities of pollen long distances, and the contribution of this fluvial transported pollen is relatively high, For example, percentages of Picea Dietr. pollen in water samples at sampling sites 130 km and 145 km away from Picea forests reach 16.5% and 7.7%, respectively. Fluvial pollen transport occurs primarily during flood periods, and pollen concentrations from the flood samples are 17.1 - 12.5 times those from normal fluvial flow. Reservoirs affect pollen transportation since pollen is deposited at reservoir inlets and pollen concentrations are much reduced at reservoir outlets. Human activity can thus change natural features of pollen transportation and deposition. The main factors influencing pollen concentrations and assemblages are sampling time, sampling location, and rainfall intensity.展开更多
Based on 35 a meteorological data and main crops planting data in Shiyang River basin meteorological station,the agricultural climate change,agricultural production,hydrology change and the influences on the crops lay...Based on 35 a meteorological data and main crops planting data in Shiyang River basin meteorological station,the agricultural climate change,agricultural production,hydrology change and the influences on the crops layout,planting in the basin were discussed.The results showed that the linear inclined rates of ≥0 ℃,10 ℃ accumulated temperature increase in the north-central part were bigger than in the south,and the heat resources increased evidently.The annual precipitation increased in the linear inclined rate which was 4.719 mm/10 a,and the annual runoff decreased in 0.274×109 m3/10 a velocity.The climate productivity increased in 134.62 kg/(hm2·10 a) velocity.In late spring and early summer,the regional drought increased evidently,and the frostless period prolonged.The sand storm decreased evidently.The gale in the south increased and decreased in the north-central part.The agricultural climate change made that the spring wheat planting zone advanced to the high-altitude area.The seeding date advanced,and the growth period shortened.It didn't favor for the yield formation.However,it was favorable to improve the yield and quality of thermophilous crops such as the corn,cotton and wine grape and so on.展开更多
Ecosystem risk is a new concept in understanding environmental problems. It is important to study and develop quantitative methods for regional ecosystem risk analysis. In this study, some new indicators and methods f...Ecosystem risk is a new concept in understanding environmental problems. It is important to study and develop quantitative methods for regional ecosystem risk analysis. In this study, some new indicators and methods for measuring oasis ecosystem risk were established using reliability theory. These indicators are linked to water resource, which is the key restricting factor in arid area oasis ecosystems. They have clear meanings and can also be compared in different arid area oases. A case study in the Liangzhou oasis of the Shiyang River Basin in China shows how to calculate these ecosystem risk indicators. The results of the case study are as follows： the reliability indicator, risk indicator, stability indicator, and integrated loss indicator of the Liangzhou oasis are 0.686, 0.314, 0.743, and 0.301, respectively. This means that the reliability degree of the oasis＇s ecosystem safety is 68.6%; the degree of risk that it is unsafe is 31.4%; the stability degree is 74.3%; and 30.1% of the oasis＇s area is supported by over-exploiting underground water and damaging the lower reaches of the ecosystem. This result can be used as a guide in controlling and managing ecosystem risk in the research area.展开更多
The study employs slope, aspect, relief degree of land surface, land use, vegetation index, hydrology and climate, as evaluation indexes to set up the Human Settlements Environmental Index （HEI） model to evaluate th...The study employs slope, aspect, relief degree of land surface, land use, vegetation index, hydrology and climate, as evaluation indexes to set up the Human Settlements Environmental Index （HEI） model to evaluate the environmental suitability for human settlements in the Shiyang River Basin. By using GIS spatial analysis technology, such as spatial overlay analysis, buffer analysis and density analysis, the environmental suitability of the human set- tlement spatial situation and spatial pattern are established to analyze their spatial distribution The results show that the index of suitability for human settlements in the Shiyang River Basin is between 17.13 and 84.32. In general, suitability for human settlements decreases from the southwest to the northeast. Seen from an area pattern, the suitable region is mainly distributed in the Minqin oasis, Wuwei oasis and Changning basin, which are about 1080.01 km2 and account for 2.59% of the total area. Rather and comparatively suitable region is mainly distributed around the counties of Gulang, Yongchang and north of Tianzhu, which is about 1100.30 km2. The common suitable region is mainly distributed outside the counties of Yongchang, Jinchuan and most parts of Minqin County, which are about 23328.04 km2, accounting for 56.08% of the total area. The unsuitable region is mainly distributed upstream and to the north of the river, which is about 9937.60 km2, accounting for 23.89% of the total area. Meanwhile, the least suitable region is distributed around the Qilian Mountains, which are covered by snow and cold desert and lie in the intersecting area between the Tengger Desert and Badain Jaran Desert. The total area is about 6154.05 km2, accounting for 14.79% of the total area. Suitable regions for human habitation are mainly distributed around rivers in the form of ribbons and batches, while others are scattered. The distribution pattern is iden- tical to the residential spatial pattern. In addition, the relationships between HEI and other factors have been analyzed. There is a clear logarithmic correlation between the residential environment and population, that is, the correlation coefficient between the evaluation valueand population density reaches 0.851. There is also a positive correlation between the residential environment and economy, which reaches an evaluation value of 0.845 between the residential environment and GDP. Results also show that the environment is out of bearing with the existing population in Shiyang River Basin. Spatial distribution of population is pro- foundly affected by severe environmental problems, such as the expanded deserts, the hilly terrain and the changing climate. Surface water shortage and slow economic growth are bot- tlenecks for suitable human settlement in the Shiyang River Basin. Combining these prob- lems with planning for construction of new country and the exploitation of local land, some residential areas should be relocated to improve the residential environment.展开更多
Glacier runoff in mountain areas of the Shiyang River Basin(SRB), Qilian Mountain, western China is important for the river and water supply downstream. Small glaciers with area of less than 1km2 are dominant(87%) in ...Glacier runoff in mountain areas of the Shiyang River Basin(SRB), Qilian Mountain, western China is important for the river and water supply downstream. Small glaciers with area of less than 1km2 are dominant(87%) in the SRB. A modified monthly degree-day model was applied to quantify the glacier mass balance, area, and changes in glacier runoff in the SRB during 1961–2050. The comparison between the simulated and observed snow line altitude, annual glacier runoff, and mass balance from1961 to 2008 suggests that the degree-day model may be used to analyze the long-term change of glacier mass balance and runoff in the SRB. The glacier accumulation shows a significant(p<0.01) decreasing trend of-0.830 mm a-1. The mass balance also shows a significant(p<0.01) decreasing trend of-5.521 mm a-1. The glacier total runoff has significantly(p<0.05)increased by 0.079 × 105 m3 from 1961 to 2008. The monthly precipitation and air temperature are projected to significant(p<0.005) increase during2015 to 2050 under three different scenarios. The ablation is projected to significant(p<0.001) increase,while the accumulation has no significant(p=0.05)trend. The mass balance is projected to decrease, theglacier area is projected to decrease, and the glacier runoff depth is projected to increase. However, the glacier total runoff is projected to decrease. These results indicate that the glacier total runoff over glacier areas observed in 1970 reached its peak in the 2000 s. This will exacerbate the contradiction between water supply and downstream water demands in the SRB.展开更多
Land use and cover change(LUCC)is the most direct manifestation of the interaction between anthropological activities and the natural environment on Earth's surface,with significant impacts on the environment and ...Land use and cover change(LUCC)is the most direct manifestation of the interaction between anthropological activities and the natural environment on Earth's surface,with significant impacts on the environment and social economy.Rapid economic development and climate change have resulted in significant changes in land use and cover.The Shiyang River Basin,located in the eastern part of the Hexi Corridor in China,has undergone significant climate change and LUCC over the past few decades.In this study,we used the random forest classification to obtain the land use and cover datasets of the Shiyang River Basin in 1991,1995,2000,2005,2010,2015,and 2020 based on Landsat images.We validated the land use and cover data in 2015 from the random forest classification results(this study),the high-resolution dataset of annual global land cover from 2000 to 2015(AGLC-2000-2015),the global 30 m land cover classification with a fine classification system(GLC_FCS30),and the first Landsat-derived annual China Land Cover Dataset(CLCD)against ground-truth classification results to evaluate the accuracy of the classification results in this study.Furthermore,we explored and compared the spatiotemporal patterns of LUCC in the upper,middle,and lower reaches of the Shiyang River Basin over the past 30 years,and employed the random forest importance ranking method to analyze the influencing factors of LUCC based on natural(evapotranspiration,precipitation,temperature,and surface soil moisture)and anthropogenic(nighttime light,gross domestic product(GDP),and population)factors.The results indicated that the random forest classification results for land use and cover in the Shiyang River Basin in 2015 outperformed the AGLC-2000-2015,GLC_FCS30,and CLCD datasets in both overall and partial validations.Moreover,the classification results in this study exhibited a high level of agreement with the ground truth features.From 1991 to 2020,the area of bare land exhibited a decreasing trend,with changes primarily occurring in the middle and lower reaches of the basin.The area of grassland initially decreased and then increased,with changes occurring mainly in the upper and middle reaches of the basin.In contrast,the area of cropland initially increased and then decreased,with changes occurring in the middle and lower reaches.The LUCC was influenced by both natural and anthropogenic factors.Climatic factors and population contributed significantly to LUCC,and the importance values of evapotranspiration,precipitation,temperature,and population were 22.12%,32.41%,21.89%,and 19.65%,respectively.Moreover,policy interventions also played an important role.Land use and cover in the Shiyang River Basin exhibited fluctuating changes over the past 30 years,with the ecological environment improving in the last 10 years.This suggests that governance efforts in the study area have had some effects,and the government can continue to move in this direction in the future.The findings can provide crucial insights for related research and regional sustainable development in the Shiyang River Basin and other similar arid and semi-arid areas.展开更多
Understanding the response of vegetation variation to climate change and human activities is critical for addressing future conflicts between humans and the environment,and maintaining ecosystem stability.Here,we aime...Understanding the response of vegetation variation to climate change and human activities is critical for addressing future conflicts between humans and the environment,and maintaining ecosystem stability.Here,we aimed to identify the determining factors of vegetation variation and explore the sensitivity of vegetation to temperature(SVT)and the sensitivity of vegetation to precipitation(SVP)in the Shiyang River Basin(SYRB)of China during 2001-2022.The climate data from climatic research unit(CRU),vegetation index data from Moderate Resolution Imaging Spectroradiometer(MODIS),and land use data from Landsat images were used to analyze the spatial-temporal changes in vegetation indices,climate,and land use in the SYRB and its sub-basins(i.e.,upstream,midstream,and downstream basins)during 2001-2022.Linear regression analysis and correlation analysis were used to explore the SVT and SVP,revealing the driving factors of vegetation variation.Significant increasing trends(P<0.05)were detected for the enhanced vegetation index(EVI)and normalized difference vegetation index(NDVI)in the SYRB during 2001-2022,with most regions(84%)experiencing significant variation in vegetation,and land use change was determined as the dominant factor of vegetation variation.Non-significant decreasing trends were detected in the SVT and SVP of the SYRB during 2001-2022.There were spatial differences in vegetation variation,SVT,and SVP.Although NDVI and EVI exhibited increasing trends in the upstream,midstream,and downstream basins,the change slope in the downstream basin was lower than those in the upstream and midstream basins,the SVT in the upstream basin was higher than those in the midstream and downstream basins,and the SVP in the downstream basin was lower than those in the upstream and midstream basins.Temperature and precipitation changes controlled vegetation variation in the upstream and midstream basins while human activities(land use change)dominated vegetation variation in the downstream basin.We concluded that there is a spatial heterogeneity in the response of vegetation variation to climate change and human activities across different sub-basins of the SYRB.These findings can enhance our understanding of the relationship among vegetation variation,climate change,and human activities,and provide a reference for addressing future conflicts between humans and the environment in the arid inland river basins.展开更多
The research on the present situation of soil and water development and utilization in Shiyang River Basin shows that water resources and eco-environment situation in this area are near the edge of collapse. Since the...The research on the present situation of soil and water development and utilization in Shiyang River Basin shows that water resources and eco-environment situation in this area are near the edge of collapse. Since the water crises occurred in the 1970s, problems caused by continuous decrease of water resources have been becoming serious year by year and eco-environment crisis occurred as a consequence. Up to now, 10 380ha of irrigated lands have been abandoned due to sand coverage and water shortage in the basin. Ground water was over exploded in Wuwei and Minqin because of water shortage. Ground water table in many places dropped under 5m （which is the ecology water table level）, thus about 3000ha ofElaeagnus angustifolia forest come to dead and another 5800ha become feeble, and wind-drift sand near the oasis become alive. According to the current situation, if water utilization scope was not enlarged, a water transfer volume of 600×10^6m^3/a from other areas will be suitable to keep water resources and eco-environment safety in the basin, and also 70×10^6m^3/a will be left as spare water. Under this condition the water resources and eco-environment of the basin can reach the critical safety line of 2.032×10^6m^3/a; or if 180×10^6m^3 of water can be transferred from other areas, the water resources can reach the safety warning line of 1.732×10^9m^3/a.展开更多
[Objectives] To study structural characteristics of Lycium ruthenicum community and soil properties on different types of desert rangeland in the lower reaches of Shiyang River, and provide theoretical basis for ecolo...[Objectives] To study structural characteristics of Lycium ruthenicum community and soil properties on different types of desert rangeland in the lower reaches of Shiyang River, and provide theoretical basis for ecological protection and management in the lower reaches of Shiyang River. [Methods] One-way ANOVA analysis and correlation analysis were carried out with the aid of SPSS19.0 software for different types of desert rangeland soils. [Results](i) Among the communities surveyed, there are 31 species belonging to 9 families and 28 genera, including 12 shrub plants, 8 perennial herbs and 11 annual herbs. There are more single genus, occupying 50% of total genus. L. ruthenicum occupies an important position in the community with relatively higher importance value. It plays a dominated role in the community.(ii) In the soils with depths of 0-10 cm, 10-20 cm, 20-40 cm and 40-60 cm in different types of desert rangeland, the organic carbon contents in the saline alkali soil were the highest, with the values of 1.08%, 0.98%, 0.89% and 0.972%, respectively. Compared with that in sandy land, soil organic carbon in saline alkali land(0-10 cm) had the significant difference(P<0.05), available soil potassium in saline alkali land(except the depth of 20-40 cm) and the total phosphorus content in saline alkali land(0-10 cm) had the significant difference(P<0.05), the total soil nitrogen, alkali-hydrolyzable nitrogen, available phosphorus and the total potassium content had no significant difference(P>0.05). Soil organic carbon, available soil phosphorus in saline alkali land, total soil potassium on sand dune and total soil phosphorus in saline alkali land and gravel in different soil layers of the same type of desert rangeland had distinct aggregation effect.(iii) The soil microbial biomass in different types of desert rangeland displayed from high to low as saline alkali land > sandy land > fixed and semi fixed sandy land > gravel. The discrepancy of soil microbial biomass varied in different types of desert rangeland. The four soil enzyme activities in salinization was the highest. Soil invertase activity in saline alkali land in different soil layers were the highest. For different soil layers in the same type of desert rangeland, soil microbial biomass and invertase decreased gradually with the deepening of soil layer.(iv) There was a significant positive correlation between soil organic matter and microbial biomass carbon, microbial biomass nitrogen, phosphatase and sucrase(P<0.01), and a significant positive correlation with urease and catalase(P<0.05). Phosphorus content was significant positively correlated with urease, phosphatase and invertase(P<0.01), and positively correlated with microbial biomass carbon(P<0.05). Soil available potassium content was significant positively correlated with microbial and phosphatase(P<0.01). [Conclusions] The species of L. ruthenicum community and soil properties on different types of desert rangeland in the lower reaches of Shiyang River clearly shows that most species belong to a few families, and a few species belong to most families, and many species are single genus or single family. Soil organic carbon, soil available phosphorus, total phosphorus, soil microbial biomass and enzyme activity in salinization land had distinct surface aggregation effects, so salinization land provides excellent growth environment for the growth of L. ruthenicum, which is of great significance for the protection of L. ruthenicum population.展开更多
The Shiyang River is an important ecological pillar in northwest China,sustaining Minqin oasis and its surrounding society.However,the basin has long been plagued by water scarcity and ecological fragility.Although th...The Shiyang River is an important ecological pillar in northwest China,sustaining Minqin oasis and its surrounding society.However,the basin has long been plagued by water scarcity and ecological fragility.Although the river classification is critical for understanding the complexity,diversity,and ecological functions of rivers,and the foundation of river management and watershed ecological restoration,it has not received adequate attention in this region.To obtain a deeper and comprehensive understanding of the Shiyang River,this study utilizes the Rosgen stream classification system to assess the river morphology,geomorphic features,and hydrologic processes.The results showed that seven first-level and fourteen second-level river types can be identified along 53 river sections of the Shiyang River.Further comparison analysis on the hydrologic parameters for each river type demonstrated a strong positive correlation between discharge and all river parameters.As discharge increased,channels with moderate to high width/depth ratios experienced significant lateral adjustments.A consistent channel gradient,coupled with higher discharge,facilitated the transition from single to multiple channels.Braiding tendencies were more pronounced in rivers where riverbeds were wider and shallower with higher stream power.Additionally,water-flow shear stress decreased with the increase in the width/depth ratio.This study offered critical insights into the Shiyang River’s forms and processes and for the river management and ecological restoration practices.展开更多
With the increase of population and the development of social economy, contradiction between water supply and demand of Shiyang River Basin become more outstanding. Unreasonable exploitation and utilization of water r...With the increase of population and the development of social economy, contradiction between water supply and demand of Shiyang River Basin become more outstanding. Unreasonable exploitation and utilization of water resources cause the serious deterioration of ecological environment. According to the present ecoligical situation, by analyzing some actual problems of the ecosystem of Shiyang River Basin, a series of feasible control countermeasures are proposed. The article provide theoretical basis for the treatment and recovery of the degradation of ecological environment of Shiyang Rive Basin.展开更多
On the basis of the study on areal differentiation of the natural environment of oasis agriculture ecosystems in the Shiyang River Basin, this paper comparatively analyzes the natural productivities, water economic be...On the basis of the study on areal differentiation of the natural environment of oasis agriculture ecosystems in the Shiyang River Basin, this paper comparatively analyzes the natural productivities, water economic benefits, production efficiency, ecological stabilities and developmental conditions of the Wuwei Oasis agricultural ecosystem in the middle reaches of the river basin and the Minqin Oasis agricultural ecosystem in the lower reaches. Under a same management level and investment of . material and energy, primary productiveness and economic benefits of the former are higher than those of the latter. Construction directions of Wuwei and Minqin oases should be different in order to alleviate the water- use contradiction between the middle and lower reaches. The construction objective of Wuwei Oasis should be efficient irrigated farming production system and Minqin Oasis should become a mixed forestry-pastoral-farming ecosystem taking ecological protection as its major function.展开更多
Due to the uncertainties posed by climate change,resilience has become an increasingly important variable for evaluating regional ecosystem stability.The assessment of Ecological Network Resilience(ENR)is crucial for ...Due to the uncertainties posed by climate change,resilience has become an increasingly important variable for evaluating regional ecosystem stability.The assessment of Ecological Network Resilience(ENR)is crucial for establishing mitigation strategies and sustainable socioeconomic development in arid regions.Shiyang River Basin is an arid watershed in Northwest China with complex characteristics,its ENR and spatial differentiation characteristics in 2020 were investigated in this work based on the Complex Adaptive System(CAS)theory.The results indicated that the mean Ecological Network Resilience Index(ENRI)value for the Shiyang River Basin was 0.390 in 2020,and the mean values in the southern mountainous,middle oasis,and northern desert regions of the basin were 0.598,0.461,and 0.237,respectively,demonstrating evident spatial differences.Additionally,the ENR of the basin exhibited distinct distribution characteristics across different dimension,whereas the trend of the integrated ENR of the basin was consistent with that of elemental,structural,and functional resilience,indicating the constructed three-region ENR model based on the logical relationship of element-structure-function was suitable for evaluation of the ENR in arid inland river watersheds.Furthermore,strategies for enhancing regional ENR were proposed from the perspective of adapting to climate change.展开更多
Meteorological data of 5 weather stations in the Shiyang River Basin on the eastern section of Hexi Corridor from 1961 to 2014 were analyzed using statistical analysis techniques such as linear trend and variance sign...Meteorological data of 5 weather stations in the Shiyang River Basin on the eastern section of Hexi Corridor from 1961 to 2014 were analyzed using statistical analysis techniques such as linear trend and variance signifi cance test. The results showed that as the low temperature rose generally, temperature in stations nearby desert showed higher increase rate; annual extreme maximum temperature in stations nearby mountains showed more signifi cant increase, and annual extreme minimum temperature in stations nearby desert showed more signifi cant increase, and the increase tendency of extreme minimum temperature was more obvious than that of extreme maximum temperature; annual extreme maximum temperature in stations in desert showed higher instability; instability of annual extreme minimum temperature in all sampling points increased, and showed no obvious regularity between desert and mountain.展开更多
The Shiyang River Basin is an area of China that is severly affected by aeolian desertification.Thus,we established an aeolian desertified land classification system for visual interpretation,which classified the Aeol...The Shiyang River Basin is an area of China that is severly affected by aeolian desertification.Thus,we established an aeolian desertified land classification system for visual interpretation,which classified the Aeolian Desertified Land(ADL)into Slight(SL),Moderate(M),Severe(S)and Extremely Severe(ES)according to the severity.Imagery of Landsat series(acquired in 1975,1990,2000 and 2010)were employed to monitor the status,trend and spatial pattern of aeolian desertification,especially to map the overall spatial pattern of ADL dynamics by proposing a new Dynamic Index(DI)in the Shiyang River Basin from 1975 to 2010.The results show a generally decreasing trend from 1975 to 2010.However,the ES ADL kept increasing throughout the whole study period.Moreover,the area of ADLs with different severity increased with increasing severity,this S and ES ADLs dominated characteristics of aeolian desertification was contrary to those sandy lands in eastern China where was dominated by SL and M ADLs.Among the three sub-periods of 1975−1990,1990−2000 and 2000−2010,the first two were the restoration stage,while the last one was the expansion stage of aeolian desertification.Moreover,all these new ADLs occurred in Minqin County during 2000−2010,indicating a detrimental increase of aeolian desertification in Minqin,and the concentration of ADLs toward the lower reaches of the Shiyang River Basin.The DI works well to identify areas with desertification changes no matter the sub-periods.Moreover,DI results disclosed a stable status of aeolian desertification,and the DI decreased with increasing ADL severity.These results indicate that it will be difficult to control the expansion of aeolian desertification in Minqin County over an extended period of time.Thus,we suggest effective and long-lasting aeolian desertification control programs in the Shiyang River Basin,especially in Minqin,and SL and MADLs should have priority in facilitating a quick reversal of aeolian desertification.展开更多
In recent years, the population size and scale of the Shiyang River Basin unceasingly expanding lead to a series of ecological environment: surface water reducing, land desertification and Ground water levels fall, et...In recent years, the population size and scale of the Shiyang River Basin unceasingly expanding lead to a series of ecological environment: surface water reducing, land desertification and Ground water levels fall, etc. Research evolution characteristics of population distribution and migration growth of Shiyang River Basin contribute to river water resources and the industrial development of the comprehensive management. The article using the distribution of population structure index, population distribution center of gravity model and the population migration growth analysis model analyzes the distribution of the population evolution characteristics and population migration growth characteristics of Shiyang River Basin in 2000 to 2010. The results show that: 1) Considering Shiyang River Basin, population density is generally low, population distribution difference is bigger and concentration distribution in the middle corridor plain and three big population distribution center of Minqin oasis area, presenting a “point-areas-ribbon” structure characteristics. 2) The population distribution trend of Shiyang River Basin is constantly concentration, but the change is slow;the population distribution of Minqin is in the highest concentration degree, but the trend has been declining. 3) The focus of population density in river basin locates in Liangzhou district of Daliu country;in ten years, it migrates about 1209 m to southwest Wuwei City direction, but migration along the direction things is bigger than the north and south direction. The focus of population density and the basin geometry center is far away. 4) For ten years, at the township for basic statistics unit, each level population migration change within the overall is not significant: township level > prefecture-level cities level > counties level. 5) For ten years, there are significant changes in population migration between watershed township units, Wuwei City and Gulang Town are the two main concentrations of population centers.展开更多
Last century 50 - 70 years, the dam construction of Shiyang Inland River Basin (SIRB) profound impact on the distribution of water resources and arable land in the basin. Through data collection, field surveys and rem...Last century 50 - 70 years, the dam construction of Shiyang Inland River Basin (SIRB) profound impact on the distribution of water resources and arable land in the basin. Through data collection, field surveys and remote sensing image interpretation, we analysis the use of land and water resources change process in the middle and lower reaches of SIRB in recent decades. The results show: (1) The cultivated area of SIRB has been an upward trend in recent decades, The whole basin cultivated area has increased total 229,000 hm<sup>2</sup> from 1973 to 2010 and mainly in the middle and lower reaches. Midstream increased by 149,700 hm<sup>2</sup> accounting for 65.36 percent of total, downstream increased by 70,000 hm<sup>2</sup> accounting for 30.70 percent of total. (2) The amount of surface water resources of downstream reduce significantly gradually since dam construction, and the water table sharp decline. While the volume of surface water resources come downstream from the 1950s accounted for 30 to 40 percent of the total gradually reduced to less than 10% in 2012;(3) since the arable land area of middle and lower reaches of SIRB basin substantial increase, so the surface water resource does not meet irrigation needs. Agricultural irrigation relies heavily on exploitation of groundwater to supplement, resulting in Regional Groundwater Depth dropped rapidly, and forming several huge funnel groundwater settlements. 20 years from 1981 to 2001 the groundwater level of midstream dropped from around 5m to around 10m in Wuwei, and in Minqin dam-region of downstream along faster rate of decline in 20 years fell from 8.52 m to 22.68 m. Dam construction project has changed the pattern of the basin water cycle, the middle reaches closure a large number of surface water resources led to downstream sharp decline. Downstream continued exploitation of groundwater formed a few huge funnel groundwater settlements, it caused serious ecological problems. The basin should adjust the industrial structure and develop water saving irrigation, promote a virtuous cycle of water resources, to achieve sustainable development, seek a sustainable development ways conversion natural oasis to artificial oasis efficiency in arid zone.展开更多
Agricultural water allocation system based on priority rights has caused regional conflicts and downstream ecological degradation. It is the urgent need to introduce the concept of the initial water rights and establi...Agricultural water allocation system based on priority rights has caused regional conflicts and downstream ecological degradation. It is the urgent need to introduce the concept of the initial water rights and establish benefits compensation mechanism to resolve such problems. This paper takes the Shiyang River basin as an example to calculate the opportunity cost of 0.97×10^8 m^3 of agricultural water encroached by the middle reach based on initial water right allocation system under which water is allocated in accordance with the ratio between agricultural population of two different regions concerning the downstream ecological reconstruction needs with Bio-economic model （BEM）. The results suggest that the total economic loss of Minqin County for ecological reconstruction amounts to 2.5 7×10^8 yuan, of which 1.68×10^8 yuan is ecological compensation, representing the economic loss Minqin suffered for ecological reconstruction which shouM burden beneficial groups of ecological reconstruction and 0.89 ×10^8 yuan is the economic loss Minqin suffered due to Liangzhou＇s encroachment behavior which should be compensated by Liangzhou.展开更多
基金supported by the National Key Research and Development Program of China(2022YFD1900501)the Gansu Provincial Water Conservancy Scientific Experimental Research and Technology Extension Project(25GSLK044,26GSLK093).
文摘Glacial meltwater constitutes a vital component of the water supply in arid and semi-arid areas.However,the influence of glacial melting on runoff and evapotranspiration under global warming remains insufficiently understood.Previous studies coupling the Soil and Water Assessment Tool(SWAT)model with glacier modules often failed to consider the spatial heterogeneity of temperature during glacial melting,potentially leading to biased estimates of meltwater volume.In this study,we developed a glacier-coupled SWAT(SWAT-glacier)model considering the digital elevation model(DEM)based temperature-driven glacial melt processes to elucidate the impact of glacial melting on hydrological processes across four river basins(Dongda,Xiying,Jinta,and Zamu)of the upper Shiyang River Basin(SYRB)in northwestern China from 1986 to 2021.Compared with the standard SWAT model,the proposed SWAT-glacier model significantly improved the simulation accuracy for both runoff and evapotranspiration.Specifically,in comparison with the standard SWAT model,the Nash-Sutcliffe efficiency of the SWAT-glacier model showed a relative improvement of approximately 0.42%–9.16%and 1.50%–10.15%for runoff and evapotranspiration,respectively,in the four river basins during the validation period.Annual glacial runoff occurred predominantly from May to October,whereas glacial melt-induced evapotranspiration peaked between June and August.From 1986 to 2021,the average contributions of glacial melt to runoff were 6.97%for Dongda,3.06%for Xiying,2.70%for Jinta,and 0.67%for Zamu,whereas its contributions to evapotranspiration were 9.06%,5.14%,3.21%,and 1.59%,respectively.This study presents a SWAT-glacier modeling framework that enhances the simulation of hydrological processes in cold regions.The proposed methodology can be extended to other glacierized basins to provide valuable insights into water resource management under climate change.
基金financially supported by the National Natural Science Foundation of China(42371040,41971036)Key Natural Science Foundation of Gansu Province(23JRRA698)+2 种基金Key Research and Development Program of Gansu Province(22YF7NA122)Cultivation Program of Major key projects of Northwest Normal University(NWNU-LKZD-202302)Oasis Scientific Research achievements Breakthrough Action Plan Project of Northwest normal University(NWNU-LZKX-202303).
文摘China has implemented large-scale hydraulic engineering projects in arid regions where water resources are severely scarce to efficiently maximize limited water resources for production and domestic needs.The processes and consequences of how the change of hydrological factors affects vegetation distribution remain unclear.This study employed multi-source remote sensing data to investigate the impact of hydrological factors on vegetation distribution in the Shiyang River Basin(SRB)in the arid region in Northwestern China.The results indicate that:(1)The NDVI values in the SRB showed a fluctuating upward trend of(0.0014/yr),with vegetation increase occurring in 62.71%of the area while vegetation degradation was observed in only 6.44%of the area.(2)The Surface Water Storage Anomaly(SWSA)shows an increasing trend of(0.112 mm/month),while Terrestrial Water Storage Anomaly(TWSA)and Groundwater Storage Anomaly(GWSA)exhibit significant declines at rates of-0.124 mm/month and-0.236 mm/month,respectively.(3)Vegetation growth on agricultural land and in planted forests has shown significant growth,in contrast to the general degradation of natural vegetation that is dependent on groundwater.In addition,surface water inputs directly catalyze vegetation growth dynamics.However,the complex mechanisms linking vegetation increase and decreasing terrestrial water reserves in arid regions still need to be studied in depth.The potential negative ecological impacts that may result from the continuous decline of terrestrial and groundwater reserves should not be taken lightly.
文摘Pollen analysis of 30 modem water samples from the Shivang River, an internal river system located between the Tengger and Badain Jaran deserts, Northwest China was carried out to examine the river's capacity to carry pollen and spores, and to assess the contribution of the water-borne pollen to pollen assemblages in lake sediments at the end of the river system. Results indicate the pollen assemblages in water samples consist of both local and upland pollen. Percentages of upland pollen reach 30% - 60%, and pollen assemblages in water samples do not indicate the nature of local vegetation at the sampling sites. Fluvial currents have the capacity to transport large quantities of pollen long distances, and the contribution of this fluvial transported pollen is relatively high, For example, percentages of Picea Dietr. pollen in water samples at sampling sites 130 km and 145 km away from Picea forests reach 16.5% and 7.7%, respectively. Fluvial pollen transport occurs primarily during flood periods, and pollen concentrations from the flood samples are 17.1 - 12.5 times those from normal fluvial flow. Reservoirs affect pollen transportation since pollen is deposited at reservoir inlets and pollen concentrations are much reduced at reservoir outlets. Human activity can thus change natural features of pollen transportation and deposition. The main factors influencing pollen concentrations and assemblages are sampling time, sampling location, and rainfall intensity.
基金Supported by The Special Project of Public Welfare Industry(Meteorology) Science Research(GYHY200806021)
文摘Based on 35 a meteorological data and main crops planting data in Shiyang River basin meteorological station,the agricultural climate change,agricultural production,hydrology change and the influences on the crops layout,planting in the basin were discussed.The results showed that the linear inclined rates of ≥0 ℃,10 ℃ accumulated temperature increase in the north-central part were bigger than in the south,and the heat resources increased evidently.The annual precipitation increased in the linear inclined rate which was 4.719 mm/10 a,and the annual runoff decreased in 0.274×109 m3/10 a velocity.The climate productivity increased in 134.62 kg/(hm2·10 a) velocity.In late spring and early summer,the regional drought increased evidently,and the frostless period prolonged.The sand storm decreased evidently.The gale in the south increased and decreased in the north-central part.The agricultural climate change made that the spring wheat planting zone advanced to the high-altitude area.The seeding date advanced,and the growth period shortened.It didn't favor for the yield formation.However,it was favorable to improve the yield and quality of thermophilous crops such as the corn,cotton and wine grape and so on.
基金Project supported by the China Scholarship Council and the National Basic Research Program (973) of China (No. 2002CCA00300).
文摘Ecosystem risk is a new concept in understanding environmental problems. It is important to study and develop quantitative methods for regional ecosystem risk analysis. In this study, some new indicators and methods for measuring oasis ecosystem risk were established using reliability theory. These indicators are linked to water resource, which is the key restricting factor in arid area oasis ecosystems. They have clear meanings and can also be compared in different arid area oases. A case study in the Liangzhou oasis of the Shiyang River Basin in China shows how to calculate these ecosystem risk indicators. The results of the case study are as follows： the reliability indicator, risk indicator, stability indicator, and integrated loss indicator of the Liangzhou oasis are 0.686, 0.314, 0.743, and 0.301, respectively. This means that the reliability degree of the oasis＇s ecosystem safety is 68.6%; the degree of risk that it is unsafe is 31.4%; the stability degree is 74.3%; and 30.1% of the oasis＇s area is supported by over-exploiting underground water and damaging the lower reaches of the ecosystem. This result can be used as a guide in controlling and managing ecosystem risk in the research area.
基金National Natural Science Foundation of China, No.41261104 No.40971078+1 种基金 National Social Science Foundation Youth Project of China, No.12CTJ001 Youth Fund Projects of Science and Technology from Gansu Province, No.1107RJYA077
文摘The study employs slope, aspect, relief degree of land surface, land use, vegetation index, hydrology and climate, as evaluation indexes to set up the Human Settlements Environmental Index （HEI） model to evaluate the environmental suitability for human settlements in the Shiyang River Basin. By using GIS spatial analysis technology, such as spatial overlay analysis, buffer analysis and density analysis, the environmental suitability of the human set- tlement spatial situation and spatial pattern are established to analyze their spatial distribution The results show that the index of suitability for human settlements in the Shiyang River Basin is between 17.13 and 84.32. In general, suitability for human settlements decreases from the southwest to the northeast. Seen from an area pattern, the suitable region is mainly distributed in the Minqin oasis, Wuwei oasis and Changning basin, which are about 1080.01 km2 and account for 2.59% of the total area. Rather and comparatively suitable region is mainly distributed around the counties of Gulang, Yongchang and north of Tianzhu, which is about 1100.30 km2. The common suitable region is mainly distributed outside the counties of Yongchang, Jinchuan and most parts of Minqin County, which are about 23328.04 km2, accounting for 56.08% of the total area. The unsuitable region is mainly distributed upstream and to the north of the river, which is about 9937.60 km2, accounting for 23.89% of the total area. Meanwhile, the least suitable region is distributed around the Qilian Mountains, which are covered by snow and cold desert and lie in the intersecting area between the Tengger Desert and Badain Jaran Desert. The total area is about 6154.05 km2, accounting for 14.79% of the total area. Suitable regions for human habitation are mainly distributed around rivers in the form of ribbons and batches, while others are scattered. The distribution pattern is iden- tical to the residential spatial pattern. In addition, the relationships between HEI and other factors have been analyzed. There is a clear logarithmic correlation between the residential environment and population, that is, the correlation coefficient between the evaluation valueand population density reaches 0.851. There is also a positive correlation between the residential environment and economy, which reaches an evaluation value of 0.845 between the residential environment and GDP. Results also show that the environment is out of bearing with the existing population in Shiyang River Basin. Spatial distribution of population is pro- foundly affected by severe environmental problems, such as the expanded deserts, the hilly terrain and the changing climate. Surface water shortage and slow economic growth are bot- tlenecks for suitable human settlement in the Shiyang River Basin. Combining these prob- lems with planning for construction of new country and the exploitation of local land, some residential areas should be relocated to improve the residential environment.
基金supported by the Global Change Research Program of China (Grant No. 2013CBA01806)the China National Natural Science Foundation (Grants Nos. 41130641, 41130638, and 41271090)Shanxi key science and technology innovation team (2014KCT-27)
文摘Glacier runoff in mountain areas of the Shiyang River Basin(SRB), Qilian Mountain, western China is important for the river and water supply downstream. Small glaciers with area of less than 1km2 are dominant(87%) in the SRB. A modified monthly degree-day model was applied to quantify the glacier mass balance, area, and changes in glacier runoff in the SRB during 1961–2050. The comparison between the simulated and observed snow line altitude, annual glacier runoff, and mass balance from1961 to 2008 suggests that the degree-day model may be used to analyze the long-term change of glacier mass balance and runoff in the SRB. The glacier accumulation shows a significant(p<0.01) decreasing trend of-0.830 mm a-1. The mass balance also shows a significant(p<0.01) decreasing trend of-5.521 mm a-1. The glacier total runoff has significantly(p<0.05)increased by 0.079 × 105 m3 from 1961 to 2008. The monthly precipitation and air temperature are projected to significant(p<0.005) increase during2015 to 2050 under three different scenarios. The ablation is projected to significant(p<0.001) increase,while the accumulation has no significant(p=0.05)trend. The mass balance is projected to decrease, theglacier area is projected to decrease, and the glacier runoff depth is projected to increase. However, the glacier total runoff is projected to decrease. These results indicate that the glacier total runoff over glacier areas observed in 1970 reached its peak in the 2000 s. This will exacerbate the contradiction between water supply and downstream water demands in the SRB.
基金supported by the Central Government to Guide Local Technological Development(23ZYQH0298)the Science and Technology Project of Gansu Province(20JR10RA656,22JR5RA416)the Science and Technology Project of Wuwei City(WW2202YFS006).
文摘Land use and cover change(LUCC)is the most direct manifestation of the interaction between anthropological activities and the natural environment on Earth's surface,with significant impacts on the environment and social economy.Rapid economic development and climate change have resulted in significant changes in land use and cover.The Shiyang River Basin,located in the eastern part of the Hexi Corridor in China,has undergone significant climate change and LUCC over the past few decades.In this study,we used the random forest classification to obtain the land use and cover datasets of the Shiyang River Basin in 1991,1995,2000,2005,2010,2015,and 2020 based on Landsat images.We validated the land use and cover data in 2015 from the random forest classification results(this study),the high-resolution dataset of annual global land cover from 2000 to 2015(AGLC-2000-2015),the global 30 m land cover classification with a fine classification system(GLC_FCS30),and the first Landsat-derived annual China Land Cover Dataset(CLCD)against ground-truth classification results to evaluate the accuracy of the classification results in this study.Furthermore,we explored and compared the spatiotemporal patterns of LUCC in the upper,middle,and lower reaches of the Shiyang River Basin over the past 30 years,and employed the random forest importance ranking method to analyze the influencing factors of LUCC based on natural(evapotranspiration,precipitation,temperature,and surface soil moisture)and anthropogenic(nighttime light,gross domestic product(GDP),and population)factors.The results indicated that the random forest classification results for land use and cover in the Shiyang River Basin in 2015 outperformed the AGLC-2000-2015,GLC_FCS30,and CLCD datasets in both overall and partial validations.Moreover,the classification results in this study exhibited a high level of agreement with the ground truth features.From 1991 to 2020,the area of bare land exhibited a decreasing trend,with changes primarily occurring in the middle and lower reaches of the basin.The area of grassland initially decreased and then increased,with changes occurring mainly in the upper and middle reaches of the basin.In contrast,the area of cropland initially increased and then decreased,with changes occurring in the middle and lower reaches.The LUCC was influenced by both natural and anthropogenic factors.Climatic factors and population contributed significantly to LUCC,and the importance values of evapotranspiration,precipitation,temperature,and population were 22.12%,32.41%,21.89%,and 19.65%,respectively.Moreover,policy interventions also played an important role.Land use and cover in the Shiyang River Basin exhibited fluctuating changes over the past 30 years,with the ecological environment improving in the last 10 years.This suggests that governance efforts in the study area have had some effects,and the government can continue to move in this direction in the future.The findings can provide crucial insights for related research and regional sustainable development in the Shiyang River Basin and other similar arid and semi-arid areas.
基金National Natural Science Foundation of China(42230720).
文摘Understanding the response of vegetation variation to climate change and human activities is critical for addressing future conflicts between humans and the environment,and maintaining ecosystem stability.Here,we aimed to identify the determining factors of vegetation variation and explore the sensitivity of vegetation to temperature(SVT)and the sensitivity of vegetation to precipitation(SVP)in the Shiyang River Basin(SYRB)of China during 2001-2022.The climate data from climatic research unit(CRU),vegetation index data from Moderate Resolution Imaging Spectroradiometer(MODIS),and land use data from Landsat images were used to analyze the spatial-temporal changes in vegetation indices,climate,and land use in the SYRB and its sub-basins(i.e.,upstream,midstream,and downstream basins)during 2001-2022.Linear regression analysis and correlation analysis were used to explore the SVT and SVP,revealing the driving factors of vegetation variation.Significant increasing trends(P<0.05)were detected for the enhanced vegetation index(EVI)and normalized difference vegetation index(NDVI)in the SYRB during 2001-2022,with most regions(84%)experiencing significant variation in vegetation,and land use change was determined as the dominant factor of vegetation variation.Non-significant decreasing trends were detected in the SVT and SVP of the SYRB during 2001-2022.There were spatial differences in vegetation variation,SVT,and SVP.Although NDVI and EVI exhibited increasing trends in the upstream,midstream,and downstream basins,the change slope in the downstream basin was lower than those in the upstream and midstream basins,the SVT in the upstream basin was higher than those in the midstream and downstream basins,and the SVP in the downstream basin was lower than those in the upstream and midstream basins.Temperature and precipitation changes controlled vegetation variation in the upstream and midstream basins while human activities(land use change)dominated vegetation variation in the downstream basin.We concluded that there is a spatial heterogeneity in the response of vegetation variation to climate change and human activities across different sub-basins of the SYRB.These findings can enhance our understanding of the relationship among vegetation variation,climate change,and human activities,and provide a reference for addressing future conflicts between humans and the environment in the arid inland river basins.
文摘The research on the present situation of soil and water development and utilization in Shiyang River Basin shows that water resources and eco-environment situation in this area are near the edge of collapse. Since the water crises occurred in the 1970s, problems caused by continuous decrease of water resources have been becoming serious year by year and eco-environment crisis occurred as a consequence. Up to now, 10 380ha of irrigated lands have been abandoned due to sand coverage and water shortage in the basin. Ground water was over exploded in Wuwei and Minqin because of water shortage. Ground water table in many places dropped under 5m （which is the ecology water table level）, thus about 3000ha ofElaeagnus angustifolia forest come to dead and another 5800ha become feeble, and wind-drift sand near the oasis become alive. According to the current situation, if water utilization scope was not enlarged, a water transfer volume of 600×10^6m^3/a from other areas will be suitable to keep water resources and eco-environment safety in the basin, and also 70×10^6m^3/a will be left as spare water. Under this condition the water resources and eco-environment of the basin can reach the critical safety line of 2.032×10^6m^3/a; or if 180×10^6m^3 of water can be transferred from other areas, the water resources can reach the safety warning line of 1.732×10^9m^3/a.
基金Supported by Regional Fund Project of Gansu Province,China(31560128,31760709,31860175,31460134,31460223)Open Fund Project of Key Laboratory of Gansu Province(GSDC201506)Youth Science and Technology Project of Gansu Province(18JR3RA019)
文摘[Objectives] To study structural characteristics of Lycium ruthenicum community and soil properties on different types of desert rangeland in the lower reaches of Shiyang River, and provide theoretical basis for ecological protection and management in the lower reaches of Shiyang River. [Methods] One-way ANOVA analysis and correlation analysis were carried out with the aid of SPSS19.0 software for different types of desert rangeland soils. [Results](i) Among the communities surveyed, there are 31 species belonging to 9 families and 28 genera, including 12 shrub plants, 8 perennial herbs and 11 annual herbs. There are more single genus, occupying 50% of total genus. L. ruthenicum occupies an important position in the community with relatively higher importance value. It plays a dominated role in the community.(ii) In the soils with depths of 0-10 cm, 10-20 cm, 20-40 cm and 40-60 cm in different types of desert rangeland, the organic carbon contents in the saline alkali soil were the highest, with the values of 1.08%, 0.98%, 0.89% and 0.972%, respectively. Compared with that in sandy land, soil organic carbon in saline alkali land(0-10 cm) had the significant difference(P<0.05), available soil potassium in saline alkali land(except the depth of 20-40 cm) and the total phosphorus content in saline alkali land(0-10 cm) had the significant difference(P<0.05), the total soil nitrogen, alkali-hydrolyzable nitrogen, available phosphorus and the total potassium content had no significant difference(P>0.05). Soil organic carbon, available soil phosphorus in saline alkali land, total soil potassium on sand dune and total soil phosphorus in saline alkali land and gravel in different soil layers of the same type of desert rangeland had distinct aggregation effect.(iii) The soil microbial biomass in different types of desert rangeland displayed from high to low as saline alkali land > sandy land > fixed and semi fixed sandy land > gravel. The discrepancy of soil microbial biomass varied in different types of desert rangeland. The four soil enzyme activities in salinization was the highest. Soil invertase activity in saline alkali land in different soil layers were the highest. For different soil layers in the same type of desert rangeland, soil microbial biomass and invertase decreased gradually with the deepening of soil layer.(iv) There was a significant positive correlation between soil organic matter and microbial biomass carbon, microbial biomass nitrogen, phosphatase and sucrase(P<0.01), and a significant positive correlation with urease and catalase(P<0.05). Phosphorus content was significant positively correlated with urease, phosphatase and invertase(P<0.01), and positively correlated with microbial biomass carbon(P<0.05). Soil available potassium content was significant positively correlated with microbial and phosphatase(P<0.01). [Conclusions] The species of L. ruthenicum community and soil properties on different types of desert rangeland in the lower reaches of Shiyang River clearly shows that most species belong to a few families, and a few species belong to most families, and many species are single genus or single family. Soil organic carbon, soil available phosphorus, total phosphorus, soil microbial biomass and enzyme activity in salinization land had distinct surface aggregation effects, so salinization land provides excellent growth environment for the growth of L. ruthenicum, which is of great significance for the protection of L. ruthenicum population.
基金funded by The Second Tibetan Plateau Scientific Expedition and Research Program(STEP)(Grant No.2019QZKK0205)the National Natural Science Foundation of China(Grant No.42171002)the Science and technology Project of Tibet Autonomous Region(Grant No.XZ202401ZY0069).
文摘The Shiyang River is an important ecological pillar in northwest China,sustaining Minqin oasis and its surrounding society.However,the basin has long been plagued by water scarcity and ecological fragility.Although the river classification is critical for understanding the complexity,diversity,and ecological functions of rivers,and the foundation of river management and watershed ecological restoration,it has not received adequate attention in this region.To obtain a deeper and comprehensive understanding of the Shiyang River,this study utilizes the Rosgen stream classification system to assess the river morphology,geomorphic features,and hydrologic processes.The results showed that seven first-level and fourteen second-level river types can be identified along 53 river sections of the Shiyang River.Further comparison analysis on the hydrologic parameters for each river type demonstrated a strong positive correlation between discharge and all river parameters.As discharge increased,channels with moderate to high width/depth ratios experienced significant lateral adjustments.A consistent channel gradient,coupled with higher discharge,facilitated the transition from single to multiple channels.Braiding tendencies were more pronounced in rivers where riverbeds were wider and shallower with higher stream power.Additionally,water-flow shear stress decreased with the increase in the width/depth ratio.This study offered critical insights into the Shiyang River’s forms and processes and for the river management and ecological restoration practices.
文摘With the increase of population and the development of social economy, contradiction between water supply and demand of Shiyang River Basin become more outstanding. Unreasonable exploitation and utilization of water resources cause the serious deterioration of ecological environment. According to the present ecoligical situation, by analyzing some actual problems of the ecosystem of Shiyang River Basin, a series of feasible control countermeasures are proposed. The article provide theoretical basis for the treatment and recovery of the degradation of ecological environment of Shiyang Rive Basin.
文摘On the basis of the study on areal differentiation of the natural environment of oasis agriculture ecosystems in the Shiyang River Basin, this paper comparatively analyzes the natural productivities, water economic benefits, production efficiency, ecological stabilities and developmental conditions of the Wuwei Oasis agricultural ecosystem in the middle reaches of the river basin and the Minqin Oasis agricultural ecosystem in the lower reaches. Under a same management level and investment of . material and energy, primary productiveness and economic benefits of the former are higher than those of the latter. Construction directions of Wuwei and Minqin oases should be different in order to alleviate the water- use contradiction between the middle and lower reaches. The construction objective of Wuwei Oasis should be efficient irrigated farming production system and Minqin Oasis should become a mixed forestry-pastoral-farming ecosystem taking ecological protection as its major function.
基金Under the Major Special Science and Technology Project of Gansu Province(No.23ZDKA0004)。
文摘Due to the uncertainties posed by climate change,resilience has become an increasingly important variable for evaluating regional ecosystem stability.The assessment of Ecological Network Resilience(ENR)is crucial for establishing mitigation strategies and sustainable socioeconomic development in arid regions.Shiyang River Basin is an arid watershed in Northwest China with complex characteristics,its ENR and spatial differentiation characteristics in 2020 were investigated in this work based on the Complex Adaptive System(CAS)theory.The results indicated that the mean Ecological Network Resilience Index(ENRI)value for the Shiyang River Basin was 0.390 in 2020,and the mean values in the southern mountainous,middle oasis,and northern desert regions of the basin were 0.598,0.461,and 0.237,respectively,demonstrating evident spatial differences.Additionally,the ENR of the basin exhibited distinct distribution characteristics across different dimension,whereas the trend of the integrated ENR of the basin was consistent with that of elemental,structural,and functional resilience,indicating the constructed three-region ENR model based on the logical relationship of element-structure-function was suitable for evaluation of the ENR in arid inland river watersheds.Furthermore,strategies for enhancing regional ENR were proposed from the perspective of adapting to climate change.
基金Sponsored by Preliminary Project of State 973 Program(2014CB460611)National Natural Science Foundation of China(41261102)
文摘Meteorological data of 5 weather stations in the Shiyang River Basin on the eastern section of Hexi Corridor from 1961 to 2014 were analyzed using statistical analysis techniques such as linear trend and variance signifi cance test. The results showed that as the low temperature rose generally, temperature in stations nearby desert showed higher increase rate; annual extreme maximum temperature in stations nearby mountains showed more signifi cant increase, and annual extreme minimum temperature in stations nearby desert showed more signifi cant increase, and the increase tendency of extreme minimum temperature was more obvious than that of extreme maximum temperature; annual extreme maximum temperature in stations in desert showed higher instability; instability of annual extreme minimum temperature in all sampling points increased, and showed no obvious regularity between desert and mountain.
基金The National Key R&D Program of China(2016YFC0500909)the International Partnership Program of Chinese Academy of Sciences(No.131B62KYSB20170031).
文摘The Shiyang River Basin is an area of China that is severly affected by aeolian desertification.Thus,we established an aeolian desertified land classification system for visual interpretation,which classified the Aeolian Desertified Land(ADL)into Slight(SL),Moderate(M),Severe(S)and Extremely Severe(ES)according to the severity.Imagery of Landsat series(acquired in 1975,1990,2000 and 2010)were employed to monitor the status,trend and spatial pattern of aeolian desertification,especially to map the overall spatial pattern of ADL dynamics by proposing a new Dynamic Index(DI)in the Shiyang River Basin from 1975 to 2010.The results show a generally decreasing trend from 1975 to 2010.However,the ES ADL kept increasing throughout the whole study period.Moreover,the area of ADLs with different severity increased with increasing severity,this S and ES ADLs dominated characteristics of aeolian desertification was contrary to those sandy lands in eastern China where was dominated by SL and M ADLs.Among the three sub-periods of 1975−1990,1990−2000 and 2000−2010,the first two were the restoration stage,while the last one was the expansion stage of aeolian desertification.Moreover,all these new ADLs occurred in Minqin County during 2000−2010,indicating a detrimental increase of aeolian desertification in Minqin,and the concentration of ADLs toward the lower reaches of the Shiyang River Basin.The DI works well to identify areas with desertification changes no matter the sub-periods.Moreover,DI results disclosed a stable status of aeolian desertification,and the DI decreased with increasing ADL severity.These results indicate that it will be difficult to control the expansion of aeolian desertification in Minqin County over an extended period of time.Thus,we suggest effective and long-lasting aeolian desertification control programs in the Shiyang River Basin,especially in Minqin,and SL and MADLs should have priority in facilitating a quick reversal of aeolian desertification.
文摘In recent years, the population size and scale of the Shiyang River Basin unceasingly expanding lead to a series of ecological environment: surface water reducing, land desertification and Ground water levels fall, etc. Research evolution characteristics of population distribution and migration growth of Shiyang River Basin contribute to river water resources and the industrial development of the comprehensive management. The article using the distribution of population structure index, population distribution center of gravity model and the population migration growth analysis model analyzes the distribution of the population evolution characteristics and population migration growth characteristics of Shiyang River Basin in 2000 to 2010. The results show that: 1) Considering Shiyang River Basin, population density is generally low, population distribution difference is bigger and concentration distribution in the middle corridor plain and three big population distribution center of Minqin oasis area, presenting a “point-areas-ribbon” structure characteristics. 2) The population distribution trend of Shiyang River Basin is constantly concentration, but the change is slow;the population distribution of Minqin is in the highest concentration degree, but the trend has been declining. 3) The focus of population density in river basin locates in Liangzhou district of Daliu country;in ten years, it migrates about 1209 m to southwest Wuwei City direction, but migration along the direction things is bigger than the north and south direction. The focus of population density and the basin geometry center is far away. 4) For ten years, at the township for basic statistics unit, each level population migration change within the overall is not significant: township level > prefecture-level cities level > counties level. 5) For ten years, there are significant changes in population migration between watershed township units, Wuwei City and Gulang Town are the two main concentrations of population centers.
文摘Last century 50 - 70 years, the dam construction of Shiyang Inland River Basin (SIRB) profound impact on the distribution of water resources and arable land in the basin. Through data collection, field surveys and remote sensing image interpretation, we analysis the use of land and water resources change process in the middle and lower reaches of SIRB in recent decades. The results show: (1) The cultivated area of SIRB has been an upward trend in recent decades, The whole basin cultivated area has increased total 229,000 hm<sup>2</sup> from 1973 to 2010 and mainly in the middle and lower reaches. Midstream increased by 149,700 hm<sup>2</sup> accounting for 65.36 percent of total, downstream increased by 70,000 hm<sup>2</sup> accounting for 30.70 percent of total. (2) The amount of surface water resources of downstream reduce significantly gradually since dam construction, and the water table sharp decline. While the volume of surface water resources come downstream from the 1950s accounted for 30 to 40 percent of the total gradually reduced to less than 10% in 2012;(3) since the arable land area of middle and lower reaches of SIRB basin substantial increase, so the surface water resource does not meet irrigation needs. Agricultural irrigation relies heavily on exploitation of groundwater to supplement, resulting in Regional Groundwater Depth dropped rapidly, and forming several huge funnel groundwater settlements. 20 years from 1981 to 2001 the groundwater level of midstream dropped from around 5m to around 10m in Wuwei, and in Minqin dam-region of downstream along faster rate of decline in 20 years fell from 8.52 m to 22.68 m. Dam construction project has changed the pattern of the basin water cycle, the middle reaches closure a large number of surface water resources led to downstream sharp decline. Downstream continued exploitation of groundwater formed a few huge funnel groundwater settlements, it caused serious ecological problems. The basin should adjust the industrial structure and develop water saving irrigation, promote a virtuous cycle of water resources, to achieve sustainable development, seek a sustainable development ways conversion natural oasis to artificial oasis efficiency in arid zone.
基金supported by the "100 Talents Pro-gramme" of Chinese Academy of Sciences.
文摘Agricultural water allocation system based on priority rights has caused regional conflicts and downstream ecological degradation. It is the urgent need to introduce the concept of the initial water rights and establish benefits compensation mechanism to resolve such problems. This paper takes the Shiyang River basin as an example to calculate the opportunity cost of 0.97×10^8 m^3 of agricultural water encroached by the middle reach based on initial water right allocation system under which water is allocated in accordance with the ratio between agricultural population of two different regions concerning the downstream ecological reconstruction needs with Bio-economic model （BEM）. The results suggest that the total economic loss of Minqin County for ecological reconstruction amounts to 2.5 7×10^8 yuan, of which 1.68×10^8 yuan is ecological compensation, representing the economic loss Minqin suffered for ecological reconstruction which shouM burden beneficial groups of ecological reconstruction and 0.89 ×10^8 yuan is the economic loss Minqin suffered due to Liangzhou＇s encroachment behavior which should be compensated by Liangzhou.
