[Objective] This study aimed to study on influence of rainfall runoff on non-point pollution and to reduce the pollution through control of the contamination produced from rainfall runoff. [Method] In order to explore...[Objective] This study aimed to study on influence of rainfall runoff on non-point pollution and to reduce the pollution through control of the contamination produced from rainfall runoff. [Method] In order to explore effective methods to decrease non-point pollution, we conducted analysis on hydrological process of rainfall runoff, interaction mechanism between the process and non-point pollutants, the influence on non-point pollution and hydrological model application in the research. [Result] It was proved that rainfall runoff was the main factor of non-point pollution. Control from source strengthened clearing and controlling of non-point pollutants on the ground. Growing plants in slope effectively reduced the scour and erosion of rainfall runoff on soil. The study became simple thanks for the hydrological process. [Conclusion] The research indicated that non-point pollution would be effectively reduced through control of rainfall runoff.展开更多
In this study,effects of elevated air temperatures on thermal and hydrologic process of the shallow soil in the active layer were investigated. Open-top chambers(OTCs)were utilized to increase air temperatures 1-2℃ i...In this study,effects of elevated air temperatures on thermal and hydrologic process of the shallow soil in the active layer were investigated. Open-top chambers(OTCs)were utilized to increase air temperatures 1-2℃ in OTC-1 and 3-5℃ in OTC-2 in the alpine meadow ecosystem on the Qinghai- Tibetan Plateau.Results show that the annual air temperatures under OTC-1 and OTC-2 were 1.21℃ and 3.62℃ higher than the Control,respectively.The entirely-frozen period of shallow soil in the active layer was shortened and the fully thawed period was prolonged with temperature increase.The maximum penetration depth and duration of the negative isotherm during the entirely-frozen period decreased, and soil freezing was retarded in the local scope of the soil profile when temperature increased.Meanwhile, the positive isotherm during the fully-thawed period increased,and the soil thawing was accelerated.Soil moisture under different manipulations decreased with the temperature increase at the same depth. During the early freezing period and the early fully- thawed period,the maximum soil moisture under the Control manipulation was at 0.2 m deep,whereas under OTC-1 and OTC-2 manipulations,the maximum soil moisture were at 0.4-0.5 m deep. These results indicate that elevated temperatures led to a decrease of the moisture in the surface soil.The coupled relationship between soil temperature and moisture was significantly affected by the temperature increase.During the freezing and thawing processes, the soil temperature and moisture under different manipulations fit the regression model given by the equationθV=a/{1+exp[b(TS+c)]}+d.展开更多
During extensive gully land consolidation projects on China's Loess Plateau,many loess-bedrock fill slopes were formed,which frequently experience shallow landslides induced by rainfall.However,studies on loess-be...During extensive gully land consolidation projects on China's Loess Plateau,many loess-bedrock fill slopes were formed,which frequently experience shallow landslides induced by rainfall.However,studies on loess-bedrock slope failure triggered by continuous heavy rainfall are limited,and the role of the soilerock interface between the original bedrock slope and fill slope in the hydrological and failure process of the slope remains unclear.In this study,we conducted a continuous rainfall model test on a loess-bedrock fill slope.During the test,the responses of volume water content,pore pressure,micro deformation,and movement of the infiltration front were observed.The hydrological process and failure mechanism were then analysed.The findings suggest that the soilerock interface is a predominant infiltration surface within the slope.Rainfall infiltration rates at the interface reach 1.24-2.80 times those of the fill slope,with peak interfacial pore water pressure exceeding that of the loess fill.Furthermore,the infiltration front moves rapidly along the interface toward the bottom of the slope,reducing interfacial cohesion between bedrock and loess.The slope failure modes are summarised into three phases:local failure→flow slide and crack penetration→multistage block retrogressive slides.The cracks generated at the slope surface serve as key determinants of the geometry and scale of shallow landslides.Therefore,we recommend targeted engineering interventions to mitigate the instability and erosion of loessebedrock fill slopes.展开更多
Hydrological process factors are a reflection of the physical mechanism of basin hydrology,which can provide important basis for the use and protection of water resources.Taking Heihe River Mountain Basin as the study...Hydrological process factors are a reflection of the physical mechanism of basin hydrology,which can provide important basis for the use and protection of water resources.Taking Heihe River Mountain Basin as the study area,the hydrological simulation was made based on SWAT-GIS integrated model platform.The calculation methods of hydrological process factors using SWAT model were described based on the simulation results of runoff from 1990 to 2000.Hydrological process factors in the study area were analyzed by using GIS technology.The spatial and temporal characteristics of precipitation,runoff,infiltration,evapotranspiration and snowmelt in the basin were calculated and analyzed.展开更多
In the arid inland river basins of northwestern China,human activities control almost all the surface hydrologic processes.The potential effects of these altered hydrologic processes are gradually becoming clear,espec...In the arid inland river basins of northwestern China,human activities control almost all the surface hydrologic processes.The potential effects of these altered hydrologic processes are gradually becoming clear,especially since the 2000 implementation of the integrated water resources management projects in the Shiyang River,the Heihe River,the Tarim River,and the Shuler River.While the appearance of these eco-hydrology changes and consequent environmental effects in the oasis has attracted broad attention,related research is still lacking.Eco-hydrological process changes in the desert-oasis ecotone were investigated in the Pingchuan irrigation district in the middle reaches of the Heihe River.The results showed that the annual average amount of surface water irrigation during the past 20 years has decreased by 1.498×107 m3,while the annual average amount of well irrigation has increased by 1.457×107 m3,since 2000,when the State Council of China approved the water diversion scheme for the Heihe River Basin.The groundwater depth before the water diversion scheme generally varied between2.44–3.19 m(average 2.73±0.24 m),while that after the water diversion scheme has varied between 3.08–4.01 m(average3.79±0.62 m).The distribution area of<3 m groundwater depth decreased from 3612 to 394 hm2;while the distribution area of>3 m groundwater depth increased from 853 to 3843 hm2.However,although the hydrologic processes changed dramatically,no significant effects on vegetation productivity in the desert-oasis ecotone were detected during the study period.展开更多
In the paper, the development of precipitation isotope observation networks in China was reviewed, and recent achievements in isoscape and environmental effect of precipitation stable isotopes were summarized; the hyd...In the paper, the development of precipitation isotope observation networks in China was reviewed, and recent achievements in isoscape and environmental effect of precipitation stable isotopes were summarized; the hydrological process studies based on precipitation isotopes in China during recent decade were also reviewed. In past decades, the spatial and seasonal patterns of precipitation isotopes have been investigated nationwide, especially after the participation in GNIP（Global Network of Isotopes in Precipitation） and the establishment of CHNIP（Chinese Network of Isotopes in Precipitation）, although long-term measurements are still limited; besides the nationwide network, a series of regional networks has been widely established across China. From the traditional manual drawing to the computer-aided mapping, and then to the simulation using isotope-equipped models, the productions of precipitation isoscape have been improved. The main factors controlling precipitation isotopes were summarized, and the potential significances of isotopes in climate proxies were mentioned. The recent studies about influence of raindrop sub-cloud secondary evaporation on isotopes were reviewed; based on the precipitation isotope and other parameters, the contribution of recycled moisture（evaporation and transpiration） in local precipitation can be estimated using three- or two-component mixing models. Finally, some prospects of precipitation isotope studies in China were presented.展开更多
On the basis of Digital Elevation Model data, the raster flow vectors, watershed delineation, and spatial topological relationship are generated by the Martz and Garbrecht method for the upper area of Huangnizhuang st...On the basis of Digital Elevation Model data, the raster flow vectors, watershed delineation, and spatial topological relationship are generated by the Martz and Garbrecht method for the upper area of Huangnizhuang station in the Shihe Catchment with 805 km<SUP>2</SUP> of area, an intensified observation field for the HUBEX/GAME Project. Then, the Xin’anjiang Model is applied for runoff production in each grid element where rain data measured by radar at Fuyang station is utilized as the input of the hydrological model. The elements are connected by flow vectors to the outlet of the drainage catchment where runoff is routed by the Muskingum method from each grid element to the outlet according to the length between each grid and the outlet. The Nash-Sutcliffe model efficiency coefficient is 92.41% from 31 May to 3 August 1998, and 85.64%, 86.62%, 92.57%, and 83.91%, respectively for the 1st, 2nd, 3rd, and 4th flood events during the whole computational period. As compared with the case where rain-gauge data are used in simulating the hourly hydrograph at Huangnizhuang station in the Shihe Catchment, the index of model efficiency improvement is positive, ranging from 27.56% to 69.39%. This justifies the claim that radar-measured data are superior to rain-gauge data as inputs to hydrological modeling. As a result, the grid-based hydrological model provides a good platform for runoff computation when radar-measured rain data with highly spatiotemporal resolution are taken as the input of the hydrological model.展开更多
The hydrological processes of mountainous watersheds in inland river basins are complicated.It is absolutely significant to quantify mountainous runoff for social,economic and ecological purposes.This paper takes the ...The hydrological processes of mountainous watersheds in inland river basins are complicated.It is absolutely significant to quantify mountainous runoff for social,economic and ecological purposes.This paper takes the mountainous watershed of the Heihe Mainstream River as a study area to simulate the hydrological processes of mountainous watersheds in inland river basins by using the soil and water assessment tool(SWAT)model.SWAT simulation results show that both the Nash–Sutcliffe efficiency and the determination coefficient values of the calibration period(January 1995 to December 2002)and validation period(January 2002 to December 2009)are higher than 0.90,and the percent bias is controlled within±5%,indicating that the simulation results are satisfactory.According to the SWAT performance,we discussed the yearly and monthly variation trends of the mountainous runoff and the runoff components.The results show that from 1996 to 2009,an indistinctive rising trend was observed for the yearly mountainous runoff,which is mainly recharged by lateral flow,and followed by shallow groundwater runoff and surface runoff.The monthly variation demonstrates that the mountainous runoff decreases slightly from May to July,contrary to other months.The mountainous runoff is mainly recharged by shallow groundwater runoff in January,February,and from October to December,by surface runoff in March and April,and by lateral flow from May to September.展开更多
Hydrological processes were compared, with and without the influence of precipita- tion on discharge, to identify the differences between glacierized and non-glacierized catchments in the Urumqi River source region, o...Hydrological processes were compared, with and without the influence of precipita- tion on discharge, to identify the differences between glacierized and non-glacierized catchments in the Urumqi River source region, on the northern slope of the eastern Tianshan Mountains, during the melting season （May-September） in 2011. The study was based on hydrological data observed at 10-min intervals, meteorological data observed at 15-min intervals, and glacier melting and snow observations from the Empty Cirque, Zongkong, and Urumqi Glacier No.1 gauging stations. The results indicated that the discharge differed markedly among the three gauging stations. The daily discharge was more than the nightly discharge at the Glacier No.1 gauging station, which contrasted with the patterns observed at the Zongkong and Empty Cirque gauging stations. There was a clear daily variation in the discharge at the three gauging stations, with differences in the magnitude and duration of the peak discharge. When precipitation was not considered, the time-lags between the maximum discharge and the highest temperature were 1-3 h, 10-16 h, and 5-11 h at the Glacier No.l, Empty Cirque, and Zongkong gauging stations, respectively. When precipitation was taken into consideration, the corresponding time-lags were 0-1 h, 13 h, and 6-7 h, respectively. Therefore, the duration from the generation of discharge to confluence was the shortest in the glacierized catchment and the longest in the catchment where was mainly covered by snow. It was also shown that the hydrological process from the generation of discharge to confluence shortened when precipitation was considered. The factors influencing changes in the discharge among the three gauging stations were different. For Glacier No.1 station, the discharge was mainly controlled by heat conditions in the glacierized region, and the discharge displayed an accelerated growth when the temperature exceeded 5℃ in the melt season. It was found that the englacial and subglacial drainage channel of Glacier No.1 had become simpler during the past 20 years. Its weaker retardance and storage of glacier melting water resulted in rapid discharge confluence. It was also shown that the discharge curve and the time-lag between the maximum discharge and the highest temperature could be used to reveal the evolution of the drainage system and the process of glacier and snow melting at different levels of glacier coverage.展开更多
Causes of land salinization were determined via land cover and hydrological process change detection in a typical part of Songnen Plain. The area of saline land increased from 4627 km2 in 1980 to 5416 km2 in 2000, and...Causes of land salinization were determined via land cover and hydrological process change detection in a typical part of Songnen Plain. The area of saline land increased from 4627 km2 in 1980 to 5416 km2 in 2000, and then decreased to 5198 km2 in 2015. The transformation between saline land and other land covers happened mainly before 2000, and saline land had transformation relationship mainly with cropland, grassland, and water body. From 1979 to 2007, groundwater depth fluctuated to increase and was mainly deeper than 3.3 m. Spatially, the area of the region where groundwater depth was deeper than 3.3 m increased from 46.7% in 1980 to 84% in 2000, while the area of the region almost occupied the whole region after 2000. Precipitation and evaporation changed little, while runoff decreased substantially. Shallow groundwater, change of cropland, grassland, and water body induced from human activities and decrease of runoff and increase of irrigation and water transfer from outer basin were the main reasons for land salinization before 2000. After 2000, groundwater with relatively great depth could not exert great influence on land salinization. Protection of grassland and wetland prevented the increase of the area of saline land.展开更多
Continental Flood Basalts(CFB)occupy one fourth of the world’s land area.Hence,it is important to discern the hydrological processes in this complex hydrogeological setup for the sustainable water resources developme...Continental Flood Basalts(CFB)occupy one fourth of the world’s land area.Hence,it is important to discern the hydrological processes in this complex hydrogeological setup for the sustainable water resources development.A model assisted isotope,geochemical,geospatial and geophysical study was conducted to understand the monsoonal characteristics,recharge processes,renewability and geochemical evolution in one of the largest continental flood basalt provinces of India.HYSPLIT modelling and stable isotopes were used to assess the monsoonal characteristics.Rayleigh distillation model were used to understand the climatic conditions at the time of groundwater recharge.Lumped parameter models(LPM)were employed to quantify the mean transit time(MTT)of groundwater.Statistical and geochemical models were adopted to understand the geochemical evolution along the groundwater flow path.A geophysical model was used to understand the geometry of the aquifer.The back trajectory analysis confirms the isotopic finding that precipitation in this region is caused by orographic uplifting of air masses originating from the Arabian Sea.Stable isotopic data of groundwater showed its meteoric origin and two recharge processes were discerned;(i)quick and direct recharge by precipitation through fractured and weathered basalt,(ii)low infiltration through the clayey black cotton soil and subjected to evaporation prior to the recharge.Tritium data showed that the groundwater is a renewable source and have shorter transit times(from present day to<30 years).The hydrogeochemical study indicated multiple sources/processes such as:the minerals dissolution,silicate weathering,ion exchange,anthropogenic influences etc.control the chemistry of the groundwater.Based on the geo-electrical resistivity survey,the potential zones(weathered and fractured)were delineated for the groundwater development.Thus,the study highlights the usefulness of model assisted isotopic hydrogeochemical techniques for understanding the recharge and geochemical processes in a basaltic aquifer system.展开更多
Against the backdrop of global warming,the dynamics of glaciers and their water resources have significant implications for hydrological processes in the arid regions of Northwest China.The Aksu River,which is an esse...Against the backdrop of global warming,the dynamics of glaciers and their water resources have significant implications for hydrological processes in the arid regions of Northwest China.The Aksu River,which is an essential inland river enriched by substantial meltwater contributions,plays a pivotal role in the economic,ecological,and social development of the region.Based on 231 water samples collected during the period of intense glacial ablation in 2023,this study conducted a comprehensive analysis of the hydrochemical and stable isotopic characteristics of the Little Kurgan glacial basin in the Aksu River source region.A Piper diagram classified the hydrochemical type of the river water as Calcium-Bicarbonate.Analysis based on a Gibbs diagram indicated that rock weathering is the predominant factor affecting the hydrochemical properties within the studied basin.Through application of principal component analysis and end-member mixing analysis,it was determined that the glacier meltwater contribution to runoff was 67%,61%,and 55%in July,August,and September,respectively.The findings of this study reveal that glacier meltwater is the principal component of the river water,and highlight the critical impact of alterations in glacier ablation on the hydrological cycle within the Aksu River source region,which is vitally important for sustainable water resource management.展开更多
In this paper, a novel and efficient study on the hydrological processes of storm runoff from catchments of different land uses is conducted. The motivation is to precisely simulate the hydrological processes of storm...In this paper, a novel and efficient study on the hydrological processes of storm runoff from catchments of different land uses is conducted. The motivation is to precisely simulate the hydrological processes of storm runoff in the agricultural catchments with different patterns of land uses, i.e., forest, paddy, and upland, respectively. As it is discussed in this paper, different land use leads to different characteristics of storm runoff. In order to understand the changes in the hydrological processes of storm runoff from catchments of different land uses, the effects of rainfall intensity, initial soil moisture deficit, evapotranspiration rate, percolation rate, and retention capacity on hydrological processes of the catchments are taken into consideration. According to the principle of water balance, a general model to connect the separate hydrological processes is developed; then, the individual hydrological process is studied in detail： Firstly, the daily evaporation is calculated according to the relation between the actual evapotranspiration and the potential evapotranspiration rate; Secondly, the retention of storm runoff is plotted against the total rainfall, and the maximum storage is calculated; Thirdly, the percolation rate is calculated for each catchment.展开更多
Englacial and subglacial drainage systems of temperate glaciers have a strong influence on glacier dynamics, glacier-induced floods, glacier-weathering processes, and runoff from glacierized drainage basins. Proglacia...Englacial and subglacial drainage systems of temperate glaciers have a strong influence on glacier dynamics, glacier-induced floods, glacier-weathering processes, and runoff from glacierized drainage basins. Proglacial discharge is partly controlled by the geometry of the glacial drainage network and by the process of producing meltwater. The glacial-drainage system of some alpine glaciers has been characterized using a model based on proglacial discharge analysis. In this paper, we apply cross-correlation analysis to hourly hydro-climatic data collected from China＇s Hailuogou Glacier, a typical temperate glacier in Mt. Gongga, to study the seasonal status changes of the englacial and subglacial drainage systems by discharge-temperature （Q-T） time lag analy-sis. During early ablation season （April-May） of 2003, 2004 and 2005, the change of englacial and subglacial drainage system usually leads several outburst flood events, which are also substantiated by observing the leakage of supraglacial pond and cre-vasses pond water during field works in April, 2008. At the end of ablation season （October-December）, the glacial-drainage net-works become less hydro-efficient. Those events are evidenced by hourly hydro-process near the terminus of Hailuogou Glacier, and the analysis of Q-T time lags also can be a good indicator of those changes. However, more detailed observations or experi-ments, e.g. dye-tracing experiment and recording borehole water level variations, are necessary to describe the evolutionary status and processes of englacial and subglacial drainage systems evolution during ablation season.展开更多
The impact mechanism of vegetation on slope soil water infiltration and stability in the loess areas of the northeastern Qinghai-Tibet Plateau remains unclear.Understanding this mechanism is crucial for regional ecolo...The impact mechanism of vegetation on slope soil water infiltration and stability in the loess areas of the northeastern Qinghai-Tibet Plateau remains unclear.Understanding this mechanism is crucial for regional ecological restoration and shallow geological disaster prevention.This study investigated slopes covered by Caragana korshinskii Kom.by employing double-ring infiltration tests to explore the permeability characteristics and influencing factors of root-containing soils and to propose an appropriate infiltration model.Considering the synergistic effects of the canopy and roots,the hydrological response and stability of vegetation-covered slopes under rainfall infiltration conditions were evaluated through numerical simulation analysis.The results revealed that within the main root distribution layer(0-0.5 m),the initial and average infiltration rates and the permeability coefficient of the root-soil composite were significantly higher than those of bare land.Coarse roots with diameters of>5 mm were the key contributors to enhancement of the infiltration capacity.The dry density,fine particle content,and initial water content of the soil around the roots were negatively correlated with the infiltration process.The Horton model effectively reproduced the infiltration process under the canopy and on bare land.The roots significantly accelerated the advance of the slope wetting front during rainfall infiltration,whereas the canopy delayed its onset and progression.The rainfall infiltration process on vegetation-covered slopes was divided into three stages:the equilibrium infiltration stage,optimal infiltration stage beneath the canopy,and secondary equilibrium stage.Vegetation enhances slope stability through coupling of the canopy and root,with an order of canopy-root mode>root mode>bare slope.Under heavy rainfall conditions,the direct contribution of canopy interception to slope stability is limited,and its primary role is to delay the occurrence of instability.During this period,the mechanical effect of roots becomes the dominant mechanism in slope protection.展开更多
This paper investigates the hydrological interactions in the atmosphere-evegetation-soil system by using the bucket model and several new simplified intermediately complex models. The results of mathematical analysis ...This paper investigates the hydrological interactions in the atmosphere-evegetation-soil system by using the bucket model and several new simplified intermediately complex models. The results of mathematical analysis and numerical simulations show that these models, despite their simplicity, can very clearly reveal the essential features of the rather complex hydrological system of atmosphere-ecosystem-soil. For given atmospheric variables, these models clearly demonstrate multiple timescales, the ＂red shift＂ of response spectra, multi-equilibria and limit cycles, bifurcation, abrupt change, self-organization, recovery, ＂desertification＂, and chaos. Most of these agree with observations. Especially, the weakening of ＂shading effect＂ of living canopy and the wilted biomass might be a major mechanism leading to the desertification in a relatively short period due to overgrazing, and the desertification in a relatively long period or in climate of change might be due to both Charney＇s mechanism and the shading effect. These ideas could be validated with further numerical simulations. In the paper, some methods for improving the estimation of timescales in the soil water evolution responding to the forcing are also proposed.展开更多
Based on previous research results on river re-distribution models, a modification on the effects of topographic slopes for a runoff parameterization was proposed and implemented to the NCAR's land sur- face model...Based on previous research results on river re-distribution models, a modification on the effects of topographic slopes for a runoff parameterization was proposed and implemented to the NCAR's land sur- face model (LSM). This modification has two aspects firstly, the topographic slopes cause outflows from higher topography and inflows into the lower topography points; secondly, topographic slopes also cause decrease of infiltration at higher topography and increases of infiltration at lower topography. Then changes in infiltration result in changes in soil molsture, surface fluxes and then in surface temperature, and eventual- ly in the upper atmosphere and the climate. This mechanism is very clearly demonstrated in the point bud- gets analysis at the Andes Mountains vicinities. Analysis from a regional scale perspective in the Mackenzie GEWEX Study (MAGS) area, the focus of the ongoing Canadian GEWEX program, shows that the modi- fied runoff parameterization does bring significant changes in the regional surface climate More important- ly, detailed analysis from a global perspective shows many encouraging improvements introduced by the modified LSM over the original model in simulating basic atmospheric climate properties such as thermodynamic features (temperature and humidity). All of these improvements in the atmospheric climate simulation illustrate that the inclusion of topographic effects in the LSM can force the AGCM to produce a more realistic model climate.展开更多
The study on the coupling relationship and hydrology mechanism between ecosystem and hydrological process in a basin has recently become the international research frontier in hydrology.Runoff separation is still an i...The study on the coupling relationship and hydrology mechanism between ecosystem and hydrological process in a basin has recently become the international research frontier in hydrology.Runoff separation is still an important subject and possibly cutting edge process in hydrology.This paper summarizes the progress of national and international research,and comments on the advantages and disadvantages of recent,diverse base flow separation methods.This paper also presents research on hydrological process and eco-hydrological function in different landscape zones,combining isotopic technology with hydrochemical methods.Based on the runoff separation of different water bodies,this paper probes into the coupling relationship and hydrology mechanism between ecosystem pattern and eco-hydrological process,and makes analysis on water conservation,regulation and storage mechanism,and eco-hydrological function in different landscape zones.This report also examines future trends in research on hydrological process and eco-hydrological function in mountainous areas.展开更多
The hydrological characteristics of the Heihe River Basin in the arid inland area of northwest China were investigated.The spatial distribution of annual precipitation in the basin indicates that it decreases from eas...The hydrological characteristics of the Heihe River Basin in the arid inland area of northwest China were investigated.The spatial distribution of annual precipitation in the basin indicates that it decreases from east to west and from south to north,and increases with elevation by a gradient of 24.4 mm per hundred meters below 2,810 m a.s.l.,but decreases with elevation by that of 37.0 mm per hundred meters above 2,810 m a.s.l.For the last 50 years,the mountain runoff of the ba-sin has a tendency of increase.Except in the mountain area,the aridity is very high in the basin,and the aridity index ranges from 1.6 to 7.0 at the piedmont,to 9.0～20.0 in the midstream area and up to 40.0 in the downstream Ejin region.It is estimated for the last 50 years that a 1oC increment of annual temperature causes a 21.5 mm increase of evaporation in the mountain area,and the equivalent reduction of mountain runoff is 0.215×109 m3/yr at the Yingluoxia Hydrometric Sta-tion.The estimation shows also that a 1oC increment of annual temperature causes 1,842 mm increase of farmland evapotranspiration in the midstream area,an equivalent of 0.298×109 m3/yr more water consumption.The anthropogenic influence on the hydrological processes and water resources is then discussed.展开更多
There are complex landscape pattern and hydrological process(LPHP)interactions,which exhibit different coupling mechanisms across multiple temporal and spatial scales.However,in-depth understanding of the LPHP interac...There are complex landscape pattern and hydrological process(LPHP)interactions,which exhibit different coupling mechanisms across multiple temporal and spatial scales.However,in-depth understanding of the LPHP interactions is currently lacking.This research conducted a systematic review of 198 empirical studies to explore the LPHP interactions.The findings reveal that:1)global LPHP research was concentrated in temperate regions,with tropical and cold regions underrepresented;2)LPHP interactions showed temporal and spatial scales differentiation,with the majority of studies occurring at long-term local and regional scales,and the relationship between agricultural land expansion and surface runoff was a key point.This research proposed a dual-path driving model that captures both landscape pattern-driven hydrological processes and hydrological process-reshaping landscape patterns.In natural areas,high cohesion and aggregation patterns should be protected and enhanced.In urban areas,landscape fragmentation should be controlled and green infrastructure should be promoted to strengthen hydrological resilience.Additionally,soil erosion and floods not only alter the landscape composition but may also trigger dynamic changes in landscape configuration,forming feedback loops,which are particularly pronounced at the local scale.Identifying these key pathways enhances the understanding of the coupled human-nature system,facilitating more robust predictions and responses to future changes and challenges.展开更多
基金Supported by Major Special Fund of National Technology Program of China(2008ZX07421-002,2008ZX07421-004)the National High Technology Research and Development Program of China(2008AA06A412)Project Studied and Developed by Ministry of Housing and Urban-Rural Construction(2009-K7-4)~~
文摘[Objective] This study aimed to study on influence of rainfall runoff on non-point pollution and to reduce the pollution through control of the contamination produced from rainfall runoff. [Method] In order to explore effective methods to decrease non-point pollution, we conducted analysis on hydrological process of rainfall runoff, interaction mechanism between the process and non-point pollutants, the influence on non-point pollution and hydrological model application in the research. [Result] It was proved that rainfall runoff was the main factor of non-point pollution. Control from source strengthened clearing and controlling of non-point pollutants on the ground. Growing plants in slope effectively reduced the scour and erosion of rainfall runoff on soil. The study became simple thanks for the hydrological process. [Conclusion] The research indicated that non-point pollution would be effectively reduced through control of rainfall runoff.
基金founded by The National Science Foundation of China(No.40730634 andNo.40925002)
文摘In this study,effects of elevated air temperatures on thermal and hydrologic process of the shallow soil in the active layer were investigated. Open-top chambers(OTCs)were utilized to increase air temperatures 1-2℃ in OTC-1 and 3-5℃ in OTC-2 in the alpine meadow ecosystem on the Qinghai- Tibetan Plateau.Results show that the annual air temperatures under OTC-1 and OTC-2 were 1.21℃ and 3.62℃ higher than the Control,respectively.The entirely-frozen period of shallow soil in the active layer was shortened and the fully thawed period was prolonged with temperature increase.The maximum penetration depth and duration of the negative isotherm during the entirely-frozen period decreased, and soil freezing was retarded in the local scope of the soil profile when temperature increased.Meanwhile, the positive isotherm during the fully-thawed period increased,and the soil thawing was accelerated.Soil moisture under different manipulations decreased with the temperature increase at the same depth. During the early freezing period and the early fully- thawed period,the maximum soil moisture under the Control manipulation was at 0.2 m deep,whereas under OTC-1 and OTC-2 manipulations,the maximum soil moisture were at 0.4-0.5 m deep. These results indicate that elevated temperatures led to a decrease of the moisture in the surface soil.The coupled relationship between soil temperature and moisture was significantly affected by the temperature increase.During the freezing and thawing processes, the soil temperature and moisture under different manipulations fit the regression model given by the equationθV=a/{1+exp[b(TS+c)]}+d.
基金supported by the National Key R&D Program of China(Grant No.2023YFC3008404)the National Key Research and Development Program,China(Grant No.2017YFD0800501)the National Natural Science Foundation of China(No.41790443).
文摘During extensive gully land consolidation projects on China's Loess Plateau,many loess-bedrock fill slopes were formed,which frequently experience shallow landslides induced by rainfall.However,studies on loess-bedrock slope failure triggered by continuous heavy rainfall are limited,and the role of the soilerock interface between the original bedrock slope and fill slope in the hydrological and failure process of the slope remains unclear.In this study,we conducted a continuous rainfall model test on a loess-bedrock fill slope.During the test,the responses of volume water content,pore pressure,micro deformation,and movement of the infiltration front were observed.The hydrological process and failure mechanism were then analysed.The findings suggest that the soilerock interface is a predominant infiltration surface within the slope.Rainfall infiltration rates at the interface reach 1.24-2.80 times those of the fill slope,with peak interfacial pore water pressure exceeding that of the loess fill.Furthermore,the infiltration front moves rapidly along the interface toward the bottom of the slope,reducing interfacial cohesion between bedrock and loess.The slope failure modes are summarised into three phases:local failure→flow slide and crack penetration→multistage block retrogressive slides.The cracks generated at the slope surface serve as key determinants of the geometry and scale of shallow landslides.Therefore,we recommend targeted engineering interventions to mitigate the instability and erosion of loessebedrock fill slopes.
基金Supported by National Natural Science Foundation of China(40972207)National S&T Major Project(2009ZX05039-004)~~
文摘Hydrological process factors are a reflection of the physical mechanism of basin hydrology,which can provide important basis for the use and protection of water resources.Taking Heihe River Mountain Basin as the study area,the hydrological simulation was made based on SWAT-GIS integrated model platform.The calculation methods of hydrological process factors using SWAT model were described based on the simulation results of runoff from 1990 to 2000.Hydrological process factors in the study area were analyzed by using GIS technology.The spatial and temporal characteristics of precipitation,runoff,infiltration,evapotranspiration and snowmelt in the basin were calculated and analyzed.
基金supported by the National Natural Science Foundation of China(Grant No.41125002)
文摘In the arid inland river basins of northwestern China,human activities control almost all the surface hydrologic processes.The potential effects of these altered hydrologic processes are gradually becoming clear,especially since the 2000 implementation of the integrated water resources management projects in the Shiyang River,the Heihe River,the Tarim River,and the Shuler River.While the appearance of these eco-hydrology changes and consequent environmental effects in the oasis has attracted broad attention,related research is still lacking.Eco-hydrological process changes in the desert-oasis ecotone were investigated in the Pingchuan irrigation district in the middle reaches of the Heihe River.The results showed that the annual average amount of surface water irrigation during the past 20 years has decreased by 1.498×107 m3,while the annual average amount of well irrigation has increased by 1.457×107 m3,since 2000,when the State Council of China approved the water diversion scheme for the Heihe River Basin.The groundwater depth before the water diversion scheme generally varied between2.44–3.19 m(average 2.73±0.24 m),while that after the water diversion scheme has varied between 3.08–4.01 m(average3.79±0.62 m).The distribution area of<3 m groundwater depth decreased from 3612 to 394 hm2;while the distribution area of>3 m groundwater depth increased from 853 to 3843 hm2.However,although the hydrologic processes changed dramatically,no significant effects on vegetation productivity in the desert-oasis ecotone were detected during the study period.
基金National Natural Science Foundation of China,No.41461003,No.41161012National Basic Research Program of China,No.2013CBA01801
文摘In the paper, the development of precipitation isotope observation networks in China was reviewed, and recent achievements in isoscape and environmental effect of precipitation stable isotopes were summarized; the hydrological process studies based on precipitation isotopes in China during recent decade were also reviewed. In past decades, the spatial and seasonal patterns of precipitation isotopes have been investigated nationwide, especially after the participation in GNIP（Global Network of Isotopes in Precipitation） and the establishment of CHNIP（Chinese Network of Isotopes in Precipitation）, although long-term measurements are still limited; besides the nationwide network, a series of regional networks has been widely established across China. From the traditional manual drawing to the computer-aided mapping, and then to the simulation using isotope-equipped models, the productions of precipitation isoscape have been improved. The main factors controlling precipitation isotopes were summarized, and the potential significances of isotopes in climate proxies were mentioned. The recent studies about influence of raindrop sub-cloud secondary evaporation on isotopes were reviewed; based on the precipitation isotope and other parameters, the contribution of recycled moisture（evaporation and transpiration） in local precipitation can be estimated using three- or two-component mixing models. Finally, some prospects of precipitation isotope studies in China were presented.
基金The research is jointly supported financially by the National Natural Science Foundation of China under Grant No. 40171016 and 49794030.
文摘On the basis of Digital Elevation Model data, the raster flow vectors, watershed delineation, and spatial topological relationship are generated by the Martz and Garbrecht method for the upper area of Huangnizhuang station in the Shihe Catchment with 805 km<SUP>2</SUP> of area, an intensified observation field for the HUBEX/GAME Project. Then, the Xin’anjiang Model is applied for runoff production in each grid element where rain data measured by radar at Fuyang station is utilized as the input of the hydrological model. The elements are connected by flow vectors to the outlet of the drainage catchment where runoff is routed by the Muskingum method from each grid element to the outlet according to the length between each grid and the outlet. The Nash-Sutcliffe model efficiency coefficient is 92.41% from 31 May to 3 August 1998, and 85.64%, 86.62%, 92.57%, and 83.91%, respectively for the 1st, 2nd, 3rd, and 4th flood events during the whole computational period. As compared with the case where rain-gauge data are used in simulating the hourly hydrograph at Huangnizhuang station in the Shihe Catchment, the index of model efficiency improvement is positive, ranging from 27.56% to 69.39%. This justifies the claim that radar-measured data are superior to rain-gauge data as inputs to hydrological modeling. As a result, the grid-based hydrological model provides a good platform for runoff computation when radar-measured rain data with highly spatiotemporal resolution are taken as the input of the hydrological model.
基金supported by the National Natural Science Foundation of China(41240002,91125025,91225302,Y211121001)the National Science and Technology Support Projects(2011BAC07B05)
文摘The hydrological processes of mountainous watersheds in inland river basins are complicated.It is absolutely significant to quantify mountainous runoff for social,economic and ecological purposes.This paper takes the mountainous watershed of the Heihe Mainstream River as a study area to simulate the hydrological processes of mountainous watersheds in inland river basins by using the soil and water assessment tool(SWAT)model.SWAT simulation results show that both the Nash–Sutcliffe efficiency and the determination coefficient values of the calibration period(January 1995 to December 2002)and validation period(January 2002 to December 2009)are higher than 0.90,and the percent bias is controlled within±5%,indicating that the simulation results are satisfactory.According to the SWAT performance,we discussed the yearly and monthly variation trends of the mountainous runoff and the runoff components.The results show that from 1996 to 2009,an indistinctive rising trend was observed for the yearly mountainous runoff,which is mainly recharged by lateral flow,and followed by shallow groundwater runoff and surface runoff.The monthly variation demonstrates that the mountainous runoff decreases slightly from May to July,contrary to other months.The mountainous runoff is mainly recharged by shallow groundwater runoff in January,February,and from October to December,by surface runoff in March and April,and by lateral flow from May to September.
基金National Science and Technology Support Plan Projects,No.2012BAC19B07Scientific Research Project of Higher Learning Institution in Gansu Province,No.2013A-018Project of Scientific Ability Promoting of Young Teachers of Northwest Normal University,No.NWNU-LKQN-12-20
文摘Hydrological processes were compared, with and without the influence of precipita- tion on discharge, to identify the differences between glacierized and non-glacierized catchments in the Urumqi River source region, on the northern slope of the eastern Tianshan Mountains, during the melting season （May-September） in 2011. The study was based on hydrological data observed at 10-min intervals, meteorological data observed at 15-min intervals, and glacier melting and snow observations from the Empty Cirque, Zongkong, and Urumqi Glacier No.1 gauging stations. The results indicated that the discharge differed markedly among the three gauging stations. The daily discharge was more than the nightly discharge at the Glacier No.1 gauging station, which contrasted with the patterns observed at the Zongkong and Empty Cirque gauging stations. There was a clear daily variation in the discharge at the three gauging stations, with differences in the magnitude and duration of the peak discharge. When precipitation was not considered, the time-lags between the maximum discharge and the highest temperature were 1-3 h, 10-16 h, and 5-11 h at the Glacier No.l, Empty Cirque, and Zongkong gauging stations, respectively. When precipitation was taken into consideration, the corresponding time-lags were 0-1 h, 13 h, and 6-7 h, respectively. Therefore, the duration from the generation of discharge to confluence was the shortest in the glacierized catchment and the longest in the catchment where was mainly covered by snow. It was also shown that the hydrological process from the generation of discharge to confluence shortened when precipitation was considered. The factors influencing changes in the discharge among the three gauging stations were different. For Glacier No.1 station, the discharge was mainly controlled by heat conditions in the glacierized region, and the discharge displayed an accelerated growth when the temperature exceeded 5℃ in the melt season. It was found that the englacial and subglacial drainage channel of Glacier No.1 had become simpler during the past 20 years. Its weaker retardance and storage of glacier melting water resulted in rapid discharge confluence. It was also shown that the discharge curve and the time-lag between the maximum discharge and the highest temperature could be used to reveal the evolution of the drainage system and the process of glacier and snow melting at different levels of glacier coverage.
基金Key Deployment Project of CAS,No.KFZD-SW-314National Natural Science Foundation of China,No.91547114
文摘Causes of land salinization were determined via land cover and hydrological process change detection in a typical part of Songnen Plain. The area of saline land increased from 4627 km2 in 1980 to 5416 km2 in 2000, and then decreased to 5198 km2 in 2015. The transformation between saline land and other land covers happened mainly before 2000, and saline land had transformation relationship mainly with cropland, grassland, and water body. From 1979 to 2007, groundwater depth fluctuated to increase and was mainly deeper than 3.3 m. Spatially, the area of the region where groundwater depth was deeper than 3.3 m increased from 46.7% in 1980 to 84% in 2000, while the area of the region almost occupied the whole region after 2000. Precipitation and evaporation changed little, while runoff decreased substantially. Shallow groundwater, change of cropland, grassland, and water body induced from human activities and decrease of runoff and increase of irrigation and water transfer from outer basin were the main reasons for land salinization before 2000. After 2000, groundwater with relatively great depth could not exert great influence on land salinization. Protection of grassland and wetland prevented the increase of the area of saline land.
文摘Continental Flood Basalts(CFB)occupy one fourth of the world’s land area.Hence,it is important to discern the hydrological processes in this complex hydrogeological setup for the sustainable water resources development.A model assisted isotope,geochemical,geospatial and geophysical study was conducted to understand the monsoonal characteristics,recharge processes,renewability and geochemical evolution in one of the largest continental flood basalt provinces of India.HYSPLIT modelling and stable isotopes were used to assess the monsoonal characteristics.Rayleigh distillation model were used to understand the climatic conditions at the time of groundwater recharge.Lumped parameter models(LPM)were employed to quantify the mean transit time(MTT)of groundwater.Statistical and geochemical models were adopted to understand the geochemical evolution along the groundwater flow path.A geophysical model was used to understand the geometry of the aquifer.The back trajectory analysis confirms the isotopic finding that precipitation in this region is caused by orographic uplifting of air masses originating from the Arabian Sea.Stable isotopic data of groundwater showed its meteoric origin and two recharge processes were discerned;(i)quick and direct recharge by precipitation through fractured and weathered basalt,(ii)low infiltration through the clayey black cotton soil and subjected to evaporation prior to the recharge.Tritium data showed that the groundwater is a renewable source and have shorter transit times(from present day to<30 years).The hydrogeochemical study indicated multiple sources/processes such as:the minerals dissolution,silicate weathering,ion exchange,anthropogenic influences etc.control the chemistry of the groundwater.Based on the geo-electrical resistivity survey,the potential zones(weathered and fractured)were delineated for the groundwater development.Thus,the study highlights the usefulness of model assisted isotopic hydrogeochemical techniques for understanding the recharge and geochemical processes in a basaltic aquifer system.
基金National Natural Science Foundation of China,No.42071076,No.41501085Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions,No.PAPD-20181105Jiangsu Normal University Support Fund for Doctoral Teachers Research,No.17XLR002。
文摘Against the backdrop of global warming,the dynamics of glaciers and their water resources have significant implications for hydrological processes in the arid regions of Northwest China.The Aksu River,which is an essential inland river enriched by substantial meltwater contributions,plays a pivotal role in the economic,ecological,and social development of the region.Based on 231 water samples collected during the period of intense glacial ablation in 2023,this study conducted a comprehensive analysis of the hydrochemical and stable isotopic characteristics of the Little Kurgan glacial basin in the Aksu River source region.A Piper diagram classified the hydrochemical type of the river water as Calcium-Bicarbonate.Analysis based on a Gibbs diagram indicated that rock weathering is the predominant factor affecting the hydrochemical properties within the studied basin.Through application of principal component analysis and end-member mixing analysis,it was determined that the glacier meltwater contribution to runoff was 67%,61%,and 55%in July,August,and September,respectively.The findings of this study reveal that glacier meltwater is the principal component of the river water,and highlight the critical impact of alterations in glacier ablation on the hydrological cycle within the Aksu River source region,which is vitally important for sustainable water resource management.
基金Supported by the Natural Science Foundation of Hubei Province (2005ABA290)
文摘In this paper, a novel and efficient study on the hydrological processes of storm runoff from catchments of different land uses is conducted. The motivation is to precisely simulate the hydrological processes of storm runoff in the agricultural catchments with different patterns of land uses, i.e., forest, paddy, and upland, respectively. As it is discussed in this paper, different land use leads to different characteristics of storm runoff. In order to understand the changes in the hydrological processes of storm runoff from catchments of different land uses, the effects of rainfall intensity, initial soil moisture deficit, evapotranspiration rate, percolation rate, and retention capacity on hydrological processes of the catchments are taken into consideration. According to the principle of water balance, a general model to connect the separate hydrological processes is developed; then, the individual hydrological process is studied in detail： Firstly, the daily evaporation is calculated according to the relation between the actual evapotranspiration and the potential evapotranspiration rate; Secondly, the retention of storm runoff is plotted against the total rainfall, and the maximum storage is calculated; Thirdly, the percolation rate is calculated for each catchment.
基金supported by the National Natural Science Foundation of China (Grant No. 40801030 and 40801025)the Major State Basic Research Development Program of China (973 Program) (2007CB411506)+1 种基金the Innovation Project of Chinese Academy Sciences (Kzcx2-yw-301)the National Basic Work Program of Chinese MST (Glacier Inventory of China Ⅱ, Grant No. 2006FY110200)
文摘Englacial and subglacial drainage systems of temperate glaciers have a strong influence on glacier dynamics, glacier-induced floods, glacier-weathering processes, and runoff from glacierized drainage basins. Proglacial discharge is partly controlled by the geometry of the glacial drainage network and by the process of producing meltwater. The glacial-drainage system of some alpine glaciers has been characterized using a model based on proglacial discharge analysis. In this paper, we apply cross-correlation analysis to hourly hydro-climatic data collected from China＇s Hailuogou Glacier, a typical temperate glacier in Mt. Gongga, to study the seasonal status changes of the englacial and subglacial drainage systems by discharge-temperature （Q-T） time lag analy-sis. During early ablation season （April-May） of 2003, 2004 and 2005, the change of englacial and subglacial drainage system usually leads several outburst flood events, which are also substantiated by observing the leakage of supraglacial pond and cre-vasses pond water during field works in April, 2008. At the end of ablation season （October-December）, the glacial-drainage net-works become less hydro-efficient. Those events are evidenced by hourly hydro-process near the terminus of Hailuogou Glacier, and the analysis of Q-T time lags also can be a good indicator of those changes. However, more detailed observations or experi-ments, e.g. dye-tracing experiment and recording borehole water level variations, are necessary to describe the evolutionary status and processes of englacial and subglacial drainage systems evolution during ablation season.
基金funded by Science and Technology Program of Qinghai Province of China(2024-SF-129)the National Natural Science Foundation of China(42002283).
文摘The impact mechanism of vegetation on slope soil water infiltration and stability in the loess areas of the northeastern Qinghai-Tibet Plateau remains unclear.Understanding this mechanism is crucial for regional ecological restoration and shallow geological disaster prevention.This study investigated slopes covered by Caragana korshinskii Kom.by employing double-ring infiltration tests to explore the permeability characteristics and influencing factors of root-containing soils and to propose an appropriate infiltration model.Considering the synergistic effects of the canopy and roots,the hydrological response and stability of vegetation-covered slopes under rainfall infiltration conditions were evaluated through numerical simulation analysis.The results revealed that within the main root distribution layer(0-0.5 m),the initial and average infiltration rates and the permeability coefficient of the root-soil composite were significantly higher than those of bare land.Coarse roots with diameters of>5 mm were the key contributors to enhancement of the infiltration capacity.The dry density,fine particle content,and initial water content of the soil around the roots were negatively correlated with the infiltration process.The Horton model effectively reproduced the infiltration process under the canopy and on bare land.The roots significantly accelerated the advance of the slope wetting front during rainfall infiltration,whereas the canopy delayed its onset and progression.The rainfall infiltration process on vegetation-covered slopes was divided into three stages:the equilibrium infiltration stage,optimal infiltration stage beneath the canopy,and secondary equilibrium stage.Vegetation enhances slope stability through coupling of the canopy and root,with an order of canopy-root mode>root mode>bare slope.Under heavy rainfall conditions,the direct contribution of canopy interception to slope stability is limited,and its primary role is to delay the occurrence of instability.During this period,the mechanical effect of roots becomes the dominant mechanism in slope protection.
基金This work was supported by the China National Science foundation （Grant No, 40233027） N0AA 0ffice of Global Programs, NASA （NAGA-13322）+1 种基金the U. S. National Science foundation （ATM 0301188） the Chinese Academy of Sciences＇ 0verseas Assessor＇s Grant and Well-Known 0verseas Chinese Scholar Grant.
文摘This paper investigates the hydrological interactions in the atmosphere-evegetation-soil system by using the bucket model and several new simplified intermediately complex models. The results of mathematical analysis and numerical simulations show that these models, despite their simplicity, can very clearly reveal the essential features of the rather complex hydrological system of atmosphere-ecosystem-soil. For given atmospheric variables, these models clearly demonstrate multiple timescales, the ＂red shift＂ of response spectra, multi-equilibria and limit cycles, bifurcation, abrupt change, self-organization, recovery, ＂desertification＂, and chaos. Most of these agree with observations. Especially, the weakening of ＂shading effect＂ of living canopy and the wilted biomass might be a major mechanism leading to the desertification in a relatively short period due to overgrazing, and the desertification in a relatively long period or in climate of change might be due to both Charney＇s mechanism and the shading effect. These ideas could be validated with further numerical simulations. In the paper, some methods for improving the estimation of timescales in the soil water evolution responding to the forcing are also proposed.
文摘Based on previous research results on river re-distribution models, a modification on the effects of topographic slopes for a runoff parameterization was proposed and implemented to the NCAR's land sur- face model (LSM). This modification has two aspects firstly, the topographic slopes cause outflows from higher topography and inflows into the lower topography points; secondly, topographic slopes also cause decrease of infiltration at higher topography and increases of infiltration at lower topography. Then changes in infiltration result in changes in soil molsture, surface fluxes and then in surface temperature, and eventual- ly in the upper atmosphere and the climate. This mechanism is very clearly demonstrated in the point bud- gets analysis at the Andes Mountains vicinities. Analysis from a regional scale perspective in the Mackenzie GEWEX Study (MAGS) area, the focus of the ongoing Canadian GEWEX program, shows that the modi- fied runoff parameterization does bring significant changes in the regional surface climate More important- ly, detailed analysis from a global perspective shows many encouraging improvements introduced by the modified LSM over the original model in simulating basic atmospheric climate properties such as thermodynamic features (temperature and humidity). All of these improvements in the atmospheric climate simulation illustrate that the inclusion of topographic effects in the LSM can force the AGCM to produce a more realistic model climate.
基金supported by the West Action Program of Chinese Academy of Sciences (KZCX2-XB2-04-03)the Chinese National Natural Science Fund (40801021)+1 种基金the West Light Foundation of West Doctor of CASthe China Postdoctoral Science Foundation (200801244, 20070420135)
文摘The study on the coupling relationship and hydrology mechanism between ecosystem and hydrological process in a basin has recently become the international research frontier in hydrology.Runoff separation is still an important subject and possibly cutting edge process in hydrology.This paper summarizes the progress of national and international research,and comments on the advantages and disadvantages of recent,diverse base flow separation methods.This paper also presents research on hydrological process and eco-hydrological function in different landscape zones,combining isotopic technology with hydrochemical methods.Based on the runoff separation of different water bodies,this paper probes into the coupling relationship and hydrology mechanism between ecosystem pattern and eco-hydrological process,and makes analysis on water conservation,regulation and storage mechanism,and eco-hydrological function in different landscape zones.This report also examines future trends in research on hydrological process and eco-hydrological function in mountainous areas.
基金supported by a grant from National Natural Sciences Foundation of China (No.40725001 No.40671010)+1 种基金the Key Project (KZCX2-XB2-04-02) of the Chinese Academy of Sciences,the National Key Technology R & D Program (No. 2007BAD46B01)
文摘The hydrological characteristics of the Heihe River Basin in the arid inland area of northwest China were investigated.The spatial distribution of annual precipitation in the basin indicates that it decreases from east to west and from south to north,and increases with elevation by a gradient of 24.4 mm per hundred meters below 2,810 m a.s.l.,but decreases with elevation by that of 37.0 mm per hundred meters above 2,810 m a.s.l.For the last 50 years,the mountain runoff of the ba-sin has a tendency of increase.Except in the mountain area,the aridity is very high in the basin,and the aridity index ranges from 1.6 to 7.0 at the piedmont,to 9.0～20.0 in the midstream area and up to 40.0 in the downstream Ejin region.It is estimated for the last 50 years that a 1oC increment of annual temperature causes a 21.5 mm increase of evaporation in the mountain area,and the equivalent reduction of mountain runoff is 0.215×109 m3/yr at the Yingluoxia Hydrometric Sta-tion.The estimation shows also that a 1oC increment of annual temperature causes 1,842 mm increase of farmland evapotranspiration in the midstream area,an equivalent of 0.298×109 m3/yr more water consumption.The anthropogenic influence on the hydrological processes and water resources is then discussed.
文摘There are complex landscape pattern and hydrological process(LPHP)interactions,which exhibit different coupling mechanisms across multiple temporal and spatial scales.However,in-depth understanding of the LPHP interactions is currently lacking.This research conducted a systematic review of 198 empirical studies to explore the LPHP interactions.The findings reveal that:1)global LPHP research was concentrated in temperate regions,with tropical and cold regions underrepresented;2)LPHP interactions showed temporal and spatial scales differentiation,with the majority of studies occurring at long-term local and regional scales,and the relationship between agricultural land expansion and surface runoff was a key point.This research proposed a dual-path driving model that captures both landscape pattern-driven hydrological processes and hydrological process-reshaping landscape patterns.In natural areas,high cohesion and aggregation patterns should be protected and enhanced.In urban areas,landscape fragmentation should be controlled and green infrastructure should be promoted to strengthen hydrological resilience.Additionally,soil erosion and floods not only alter the landscape composition but may also trigger dynamic changes in landscape configuration,forming feedback loops,which are particularly pronounced at the local scale.Identifying these key pathways enhances the understanding of the coupled human-nature system,facilitating more robust predictions and responses to future changes and challenges.
