The Selenge River Basin(SRB)in Mongolia has faced ecosystem degradation because of climate change and overloading.The dynamics of the pastoral system and the extent of overload under future scenarios have not been doc...The Selenge River Basin(SRB)in Mongolia has faced ecosystem degradation because of climate change and overloading.The dynamics of the pastoral system and the extent of overload under future scenarios have not been documented.This study aims to answer the following questions:Will the typical soums in the SRB become more overgrazed in the future?What optimal strategy should be implemented?Multisource data were integrated and utilized to model the pastoral system of typical soums using a system dynamics approach.Future scenarios under three SSP-RCPs were projected using the model.The conclusions are as follows:(1)From upstream to downstream,rational scenarios for pastoral system transferred from SSP1-RCP2.6 to SSP2-RCP4.5,which reflect improved productivity at the expense of ecosystem stability.(2)Compared with that during the historical period of 2000-2020,the projected carrying capacity of the soums decreases by 15.2%-37.3%,whereas the number of livestock continues to increase.Consequently,the stocking rate is expected to increase from 0.32-1.16 during 2000-2020 to 1.26-2.02 during 2021-2050,indicating that rangeland will become more overloaded.(3)A livestock reduction strategy based on future livestock stock and grassland carrying capacity scenarios was proposed to maintain a dynamic forage-livestock equilibrium.It is suggested that reducing livestock is a practical option for harmonizing grassland conservation with livestock husbandry development.展开更多
Human activities have significantly impacted the land surface temperature(LST),endangering human health;however,the relationship between these two factors has not been adequately quantified.This study comprehensively ...Human activities have significantly impacted the land surface temperature(LST),endangering human health;however,the relationship between these two factors has not been adequately quantified.This study comprehensively constructs a Human Activity Intensity(HAI)index and employs the Maximal Information Coefficient,four-quadrant model,and XGBoostSHAP model to investigate the spatiotemporal relationship and influencing factors of HAI-LST in the Yellow River Basin(YRB)from 2000 to 2020.The results indicated that from 2000 to 2020,as HAI and LST increased,the static HAI-LST relationship in the YRB showed a positive correlation that continued to strengthen.This dynamic relationship exhibited conflicting development,with the proportion of coordinated to conflicting regions shifting from 1:4 to 1:2,indicating a reduction in conflict intensity.Notably,only the degree of conflict in the source area decreased significantly,whereas it intensified in the upper and lower reaches.The key factors influencing the HAI-LST relationship include fractional vegetation cover,slope,precipitation,and evapotranspiration,along with region-specific factors such as PM_(2.5),biodiversity,and elevation.Based on these findings,region-specific ecological management strategies have been proposed to mitigate conflict-prone areas and alleviate thermal stress,thereby providing important guidance for promoting harmonious development between humans and nature.展开更多
Effective conservation relies on robust assessments;however,the lack of waterbird data in the Yellow River Basin(YRB)has led to an underestimation of key habitat significance.This study addressed this gap by evaluatin...Effective conservation relies on robust assessments;however,the lack of waterbird data in the Yellow River Basin(YRB)has led to an underestimation of key habitat significance.This study addressed this gap by evaluating YRB wetland conservation importance using waterbirds as indicators and applying Ramsar,Important Bird Areas(IBA),and East Asian-Australasian Flyway(EAAF)criteria.We integrated coordinated surveys with citizen science data,creating a framework that tackles data deficiencies along the under-monitored Central Asian Flyway(CAF).Our analysis identified 75 priority wetlands,supporting 15 threatened species and 49 exceeding global/flyway 1%thresholds,highlighting the basin's biodiversity.We observed strong seasonal habitat use,with high-altitude wetlands vital for breeding and migration,and the Yellow River Delta providing year-round refuge.This research also provided data to refine Baer's Pochard population estimates.Alarmingly,one-third of the identified priority areas,primarily rivers and lakes,remain unprotected.To address this,we recommend systematic surveys,enhanced protected areas,OECMs,and targeted wetland restoration.This study underscores the YRB's role in regional conservation and provides essential data for adaptive management,particularly emphasizing the CAF's importance.展开更多
The hydrological system in Central Asia is highly sensitive to global climate change,significantly affecting water supply and energy production.In Tajikistan,the Vakhsh River—one of the main tributaries of the Amu Da...The hydrological system in Central Asia is highly sensitive to global climate change,significantly affecting water supply and energy production.In Tajikistan,the Vakhsh River—one of the main tributaries of the Amu Darya—plays a key role in the region’s hydropower and irrigation.However,research on long-term hydrological changes in its two top large basins—the Surkhob and Khingov river basins—remains limited.Therefore,this study analyzed long-term climate and hydrological changes in the Vakhsh River,including its main tributaries—the Surkhob and Khingov rivers—which are vital for the water resource management in Tajikistan and even in Central Asia.Using long-term hydrometeorological observations,the change trends of temperature(1933–2020),precipitation(1970–2020),and runoff(1940–2018)were examined to assess the impact of climate change on the regional water resources.The analysis revealed the occurrence of significant warming and a spatially uneven increase in precipitation.The temperature changes across three climatic periods(1933–1960,1960–1990,and 1990–2020)indicated that there was a transition from baseline level to accelerated warming.The precipitation showed a 2.99 mm/a increase in the Khingov River Basin and a 2.80 mm/a increase in the Surkhob River Basin during 1970–2020.Moreover,there was a gradual shift toward wetter conditions in recent decades.Despite the relatively stable annual mean runoff,seasonal redistribution occurred,with increased runoff in spring and reduced runoff in summer,due to the compensation of glacier melting.Moreover,this study forecasted runoff change during 2019–2040 using the exponential triple smoothing(ETS)method and revealed the occurrence of alternating wet and dry phases,emphasizing the sensitivity of the Vakhsh River Basin’s hydrological system to climate change and the necessity of adaptive water resource management in mountainous regions of Central Asia.Therefore,this study can provide evidence-based insights that are critical for future water resources planning,climate-resilient hydropower development,and regional adaptation strategies in climate-vulnerable basins in Central Asia.展开更多
Clarifying the mechanisms that control the evolution of territorial space patterns is essential for regulating and optimizing the geographical structure and processes related to sustainable development.Using the Guang...Clarifying the mechanisms that control the evolution of territorial space patterns is essential for regulating and optimizing the geographical structure and processes related to sustainable development.Using the Guangdong and Guangxi sections of the Pearl River Basin as examples,the transfer-matrix method and standard deviation ellipse model were applied to characterize the evolution of territorial space patterns from 1990 to 2020.A trend surface analysis and the Theil index were used to analyze regional differences in the evolution process,and geodetectors were used to identify the underlying mechanisms of the changes.There were three key results.(1)In these critical areas of the Pearl River Basin,agricultural and ecological spaces have rapidly declined due to urban expansion,with transfers between these spaces dominating the evolution of territorial space patterns.Spatial pattern changes in the Guangdong section were more intense than in the Guangxi section.(2)Regional differences in urban space have decreased,whereas differences in agricultural and ecological spaces have intensified.Driven by socio-economic growth,the cross-regional transfers of territorial space have created a“high in the east,while low in the west”inter-regional difference,and a“high in the south,while low in the north”intra-regional difference shaped by natural conditions.The regional differences in space patterns were greater in Guangdong than in Guangxi.(3)The evolution of watershed territorial space patterns resulted from scale changes,locational shifts,structural reorganizations,and directional changes driven by multiple factors.Natural environment,social life,economic development,and policy factors played foundational,leading,key driving,and guiding roles,respectively.Additionally,the regional differences in the evolution of watershed territorial space patterns originated from the differential transmission of the influence of various factors affecting spatial evolution.Enhancing urban space efficiency,restructuring agricultural space,and optimizing ecological space are key strategies for building a complementary and synergistic territorial space pattern in the basin.展开更多
Wetlands play a critical role in the global environment.The Middle Yangtze River Basin(MYRB),known for its abundant wetland resources,has experienced notable changes resulting from the complex interplay of environment...Wetlands play a critical role in the global environment.The Middle Yangtze River Basin(MYRB),known for its abundant wetland resources,has experienced notable changes resulting from the complex interplay of environmental factors.Therefore,we investigated the spatiotemporal characteristics of wetland ecological quality in the MYRB from 2001 to 2020.Utilizing the random forest(RF)regression algorithm and patch-generated land-use simulation(PLUS)model,we forecasted variations in wetland habitat quality and their determinants under the Shared Socioeconomic Pathway-Representative Concentration Pathway(SSPRCP)framework from 2035 to 2095.The main findings are as follows:(1)The RF algorithm was optimal for land-use and land-cover(LULC)classification in the MYRB from 2001 to 2020,when notable changes were observed in water bodies and buildings.However,the forested area exhibited an increase and decrease of 3.9%and 1.2%under the SSP1-2.6 and SSP5-8.5 scenarios,respectively,whereas farmland exhibited a diminishing trend.(2)Wetlands were primarily concentrated in the central and eastern MYRB,with counties in the southwest exhibiting superior ecological-environmental quality from 2001 to 2020.Notably,wetland coverage revealed significantly high level,significant changes,frequent but relatively minor changes under the SSP1-2.6,SSP2-4.5,and SSP 5-8.5 scenarios,respectively.(3)Regions with lower habitat quality were primarily concentrated in urbanized areas characterized by frequent human activities,indicating a clear degradation in habitat quality across different scenarios.In conclusion,we established a foundational framework for future investigations into the eco-hydrological processes and ecosystem quality of watersheds.展开更多
Climate change is significantly impacting cotton production in the Tarim River Basin.The study investigated the climate change characteristics from 2021 to 2100 using climate change datasets simulated per the coupled ...Climate change is significantly impacting cotton production in the Tarim River Basin.The study investigated the climate change characteristics from 2021 to 2100 using climate change datasets simulated per the coupled model inter-comparison project phase six(CMIP6)climatic patterns under the shared socioeconomic pathways SSP2-4.5 and SSP5-8.5.The DSSAT-CROPGROCotton model,along with stepwise multiple regression analyses,was used to simulate changes in the potential yield of seed cotton due to climate change.The results show that while future temperatures in the Tarim River Basin will rise significantly,changes in precipitation and radiation during the cotton-growing season are minimal.Seed cotton yields are more sensitive to low temperatures than to precipitation and radiation.The potential yield of seed cotton under the SSP2-4.5 scenario would increase by 14.8%,23.7%,29.0%,and 29.4%in the 2030S,2050S,2070S,and 2090S,respectively.In contrast,under the SSP5-8.5 scenario,the potential yield of seed cotton would see increases of 17.5%,27.1%,30.1%,and 22.6%,respectively.Except for the 2090s under the SSP5-8.5 scenario,future seed cotton production can withstand a 10%to 20%deficit in irrigation.These findings will help develop climate change adaptation strategies for cotton cultivation.展开更多
The horizontal ecological compensation plays an important role in balancing the interests of all parties and coordinating regional development in the basin.However,the mechanism of ecological compensation based on emb...The horizontal ecological compensation plays an important role in balancing the interests of all parties and coordinating regional development in the basin.However,the mechanism of ecological compensation based on embodied carbon emissions is still poorly understood.Here,taking the Yellow River Basin as the research area,we use the multi-regional input-output(MRIO)model to measure the embodied carbon transfers between its seven urban agglomerations in 2012 and 2017 from the viewpoint of value-added trade benefits.Further,for the first time,the green trade benefits and ecological compensation amounts are analyzed.The results indicate that:(1)The transfer of trade-embodied carbon among the urban agglomerations in the basin showed obvious spatial heterogeneity and geographic proximity effects,and trade-embodied carbon outflows(inflows)had a pattern of"highest in the midstream,second in the downstream,and lowest in the upstream".(2)The industry composition of the urban agglomerations in relation to embodied carbon outflows(inflows)was similar,mainly in the service and heavy manufacturing industries.(3)The spatial pattern of green trade benefits in the basin had shifted from"high in the north and low in the surrounding area"to"high in the east-central part and low in the west".(4)The pattern of ecological compensation in the basin had shifted from the upstream surplus,the middle and downstream deficit to the midstream deficit,and the upstream and downstream surplus.Therefore,we recommend improving energy structures in high-demand urban agglomerations by adopting clean energy,focusing on decarbonization and energy efficiency in resource-rich regions.Additionally,promoting low-carbon economies,especially in the service and heavy manufacturing industries,implementing differentiated emission reduction strategies,and optimizing carbon compensation mechanisms considering regional disparities and resource endowments are crucial.It is expected that the study can enrich the scientific basis of horizontal ecological compensation and increase the fairness of regional carbon emission rights allocation.展开更多
The Yellow River Basin in Sichuan Province(YRS)is undergoing severe soil erosion and exacerbated ecological vulnerability,which collectively pose formidable challenges for regional water conservation(WC)and sustainabl...The Yellow River Basin in Sichuan Province(YRS)is undergoing severe soil erosion and exacerbated ecological vulnerability,which collectively pose formidable challenges for regional water conservation(WC)and sustainable development.While effectively enhancing WC necessitates a comprehensive understanding of its driving factors and corresponding intervention strategies,existing studies have largely neglected the spatiotemporal heterogeneity of both natural and socio-economic drivers.Therefore,this study explored the spatiotemporal heterogeneity of WC drivers in YRS using multi-scale geographically weighted regression(MGWR)and geographically and temporally weighted regression(GTWR)models from an eco-hydrological perspective.We discovered that downstream regions,which are more developed,achieved significantly better WC than upstream regions.The results also demonstrated that the influence of temperature and wind speed is consistently dominant and temporally stable due to climate stability,while the influence of vegetation shifted from negative to positive around 2010,likely indicating greater benefits from understory vegetation.Economic growth positively impacted WC in upstream regions but had a negative effect in the more developed downstream regions.These findings highlight the importance of targeted water conservation strategies,including locally appropriate revegetation,optimization of agricultural and economic structures,and the establishment of eco-compensation mechanisms for ecological conservation and sustainable development.展开更多
Nebkhas,which play a fundamental role in stabilizing ecosystems in arid and semi-arid regions,are currently threatened by global warming and anthropogenic activities.This study focuses on a tamarisk-nebkha profile sit...Nebkhas,which play a fundamental role in stabilizing ecosystems in arid and semi-arid regions,are currently threatened by global warming and anthropogenic activities.This study focuses on a tamarisk-nebkha profile situated in the lower reaches of the Shule River Basin,an arid region in northwestern China.Using radioactive dating and the physicochemical properties of sediments,this study reconstructed changes in the nebkha’s hydro-ecological conditions over the past decades.The results revealed a significant decline in fine particle fraction,carbonate content,and low-frequency magnetic susceptibility,along with a notable increase in the Si_(2)O_(3)/Al_(2)O_(3) ratio,since the 1990s.These findings indicate the intensification of the desertification process and the degradation of hydrological conditions within the nebkha.Primary factors contributing to these transformations include the steadily rising temperature,which leads to an increased evaporation rate,and a substantial rise in human water consumption.These indicate an elevated risk of future nebkha reactivation.This reactivation,in turn,could potentially accelerate the process of regional desertification and lead to an ecological crisis.展开更多
Based on the meteorological observation data from 1994 to 2023,the spatiotemporal distribution characteristics and periodic changes of extreme precipitation were analyzed.The extreme precipitation showed a fluctuating...Based on the meteorological observation data from 1994 to 2023,the spatiotemporal distribution characteristics and periodic changes of extreme precipitation were analyzed.The extreme precipitation showed a fluctuating upward trend,and reached a peak of 713.5 mm in 2010.The frequency of events increased from 7 times in 1994-2000 to 56 times in 2020-2023,with significant periodicity of 3-4 and 7-8 a.In terms of spatial distribution,the precipitation intensity in the upper reaches was significantly higher than that in the middle and lower reaches,reaching 421.6 and 405.7 mm respectively.The lowest was in downstream Wuchuan City(268.3 mm),showing a decreasing trend from upstream to downstream.Extreme precipitation was mainly concentrated from July to October,especially in September(accounting for 25.8%).Typhoon was the main cause,with 80%of the TOP10 records related to typhoons,and the average precipitation intensity of typhoons reached 501.6 mm.The average precipitation intensity from 2020 to 2023 reached 442.8 mm.The correlation coefficient between 12-h rainfall intensity and flood level was 0.85,and the accuracy of flood warning based on rainfall intensity threshold was 78%,which had guiding significance for flood control and disaster reduction.展开更多
The Tarim River Basin(TRB)is a vast area with plenty of light and heat and is an important base for grain and cotton production in Northwest China.In the context of climate change,however,the increased frequency of ex...The Tarim River Basin(TRB)is a vast area with plenty of light and heat and is an important base for grain and cotton production in Northwest China.In the context of climate change,however,the increased frequency of extreme weather and climate events is having numerous negative impacts on the region's agricultural production.To better understand how unfavorable climatic conditions affect crop production,we explored the relationship of extreme weather and climate events with crop yields and phenology.In this research,ten indicators of extreme weather and climate events(consecutive dry days(CDD),min Tmax(TXn),max Tmin(TNx),tropical nights(TR),warm days(Tx90p),warm nights(Tn90p),summer days(SU),frost days(FD),very wet days(R95p),and windy days(WD))were selected to analyze the impact of spatial and temporal variations on the yields of major crops(wheat,maize,and cotton)in the TRB from 1990 to 2020.The three key findings of this research were as follows:extreme temperatures in southwestern TRB showed an increasing trend,with higher extreme temperatures at night,while the occurrence of extreme weather and climate events in northeastern TRB was relatively low.The number of FD was on the rise,while WD also increased in recent years.Crop yields were higher in the northeast compared with the southwest,and wheat,maize,and cotton yields generally showed an increasing trend despite an earlier decline.The correlation of extreme weather and climate events on crop yields can be categorized as extreme nighttime temperature indices(TNx,Tn90p,TR,and FD),extreme daytime temperature indices(TXn,Tx90p,and SU),extreme precipitation indices(CDD and R95p),and extreme wind(WD).By using Random Forest(RF)approach to determine the effects of different extreme weather and climate events on the yields of different crops,we found that the importance of extreme precipitation indices(CDD and R95p)to crop yield decreased significantly over time.As well,we found that the importance of the extreme nighttime temperature(TR and TNx)for the yields of the three crops increased during 2005-2020 compared with 1990-2005.The impact of extreme temperature events on wheat,maize,and cotton yields in the TRB is becoming increasingly significant,and this finding can inform policy decisions and agronomic innovations to better cope with current and future climate warming.展开更多
Since the 1950's,212 earth fissures have been discovered in the Wei River Basin.During a field survey in 2016,an additional 48 earth fissures were discovered in Anren area,northeast of the Wei River Basin.The char...Since the 1950's,212 earth fissures have been discovered in the Wei River Basin.During a field survey in 2016,an additional 48 earth fissures were discovered in Anren area,northeast of the Wei River Basin.The characteristics and formation mechanisms of these fissures were studied through field investigations,measurements,trench excavation,and drilling.On-site investigations indicated that these earth fissures were distributed along a fault-controlled geomorphic boundary.Fissures trended at 60°-80°NE and were divided into five groups.Trenches revealed multiple secondary fissures,exposing severe soil ruptures in the shallow earth surfaces.Drilling profiles revealed that earth fissures dislocated several strata,and resembled synsedimentary faults.Seismic reflection profiles revealed buried faults beneath the earth fissures.The Anren area fissures formed in the following three stages:regional extension that initially generated multiple buried faults;seismic activity rupturing multiple strata,resulting in multiple buried fractures;and finally,erosion processes that propagated the buried fractures to the surface,forming the current earth fissures.展开更多
The geogenic enrichment of arsenic(As)extensively occurred in the riverine systems from the Qinghai-Tibetan Plateau under active geothermal discharge and chemical weathering conditions,while little is known about how ...The geogenic enrichment of arsenic(As)extensively occurred in the riverine systems from the Qinghai-Tibetan Plateau under active geothermal discharge and chemical weathering conditions,while little is known about how dissolved organic matter(DOM)transformation regulates the aquatic As concentrations.The present study revealed that the DOM components from the Singe Tsangpo River(STR)basin primarily consisted of protein-like components(81.30%±6.48%),with the microbially-endogenous production being a predominant source under the control of temperature and glacier-runoff recharge along the river flow path.Notably,the chemical weathering processes have significantly facilitated the enhancement of humic-like components in the river water.Besides,the groundwater DOM characteristics were predominantly influenced by the mobilization of sedimentary organic matter and the introduction of allochthonous DOM resulting from surface-water recharge.Interestingly,humic-like components facilitated As enrichment through complexation and competitive adsorption effects in both surface water and groundwater under oxidizing conditions,whichwas supported by the significant positive correlations between As and humiclike component(R^(2)=0.31/0.65,P<0.05/0.01)and the concurrent mobilization of As and humic-like components from sediment incubation experiments.Moreover,the Structural Equation Modeling analysis revealed a stronger contribution of humic-like components to the As enrichment in the groundwater compared with surface water,possibly due to the relatively strongermicrobial activity and enhanced mobilization of humic-like components in alluvial aquifers.The present study thus provided new insights into the transformation of DOM and its important role in facilitating As enrichment in the aquatic environment from alpine river basins.展开更多
Machine learning-based Debris Flow Susceptibility Mapping(DFSM)has emerged as an effective approach for assessing debris flow likelihood,yet its application faces three critical challenges:insufficient reliability of ...Machine learning-based Debris Flow Susceptibility Mapping(DFSM)has emerged as an effective approach for assessing debris flow likelihood,yet its application faces three critical challenges:insufficient reliability of training samples caused by biased negative sampling,opaque decision-making mechanisms in models,and subjective susceptibility mapping methods that lack quantitative evaluation criteria.This study focuses on the Yalong River basin.By integrating high-resolution remote sensing interpretation and field surveys,we established a refined sample database that includes 1,736 debris flow gullies.To address spatial bias in traditional random negative sampling,we developed a semi-supervised optimization strategy based on iterative confidence screening.Comparative experiments with four treebased models(XGBoost,CatBoost,LGBM,and Random Forest)reveal that the optimized sampling strategy improved overall model performance by 8%-12%,with XGBoost achieving the highest accuracy(AUC=0.882)and RF performing the lowest(AUC=0.820).SHAP-based global-local interpretability analysis(applicable to all tree models)identifies elevation and short-duration rainfall as dominant controlling factors.Furthermore,among the tested tree-based models,XGBoost optimized with semisupervised sampling demonstrates the highest reliability in debris flow susceptibility mapping(DFSM),achieving a comprehensive accuracy of 83.64%due to its optimal generalization-stability equilibrium.展开更多
The Kulsi River basin,situated in the South Kamrup district of Assam,India,is noted for its rich fish diversity and significant deposits of Pre-Cambrian quality sand in its headstreams.These deposits gradually make th...The Kulsi River basin,situated in the South Kamrup district of Assam,India,is noted for its rich fish diversity and significant deposits of Pre-Cambrian quality sand in its headstreams.These deposits gradually make their way downstream,acting as a catalyst for local livelihoods.However,the intricate ecosystem fos-tered by the Kulsi River is under significant ecological threat due to urbanization,population growth,and associated environmental stressors such as rampant sand mining,deforestation,and soil erosion.These changes pose a risk to the basin's ecological sustainability,increasing its vulnerability.This study employs the Analytical Hierarchical Process(AHP),a GIS-based multi-criteria decision analysis method,to assess and monitor the basin's ecological vulnerability.It seeks sustainable methods to rejuvenate ecological sustainability in the basin.Criteria such as slope,C factor,stream density,proximity to roads,soil erosion,literacy rate,soil erodibility factor,and rainfall were analyzed.The findings reveal varied vulnerability across the Kulsi River basin,with 6.24%of the area classified as extremely vulnerable,25.56%as highly vulnerable,24.56%as moderately vulnerable,32.67%as low vulnerable,and 10.94%as non-vulnerable.Highly vulnerable zones are notably in newly developed suburban areas adjacent to national highways.However,non-vulnerable zones are primarily in the upper river course and its surrounding regions in the southern direction.The findings highlight the urgent need for targeted mitigation strategies to address the adverse effects of human activities and natural processes on the basin's ecological integ-rity.This study maps the vulnerability of the Kulsi River basin.It provides valuable insights into sustainable management and hazard mitigation.The study highlights the link between human activity,ecological sustainability,and geomorphological hazards.展开更多
Compound extreme climate events may profoundly affect human activity in the Yangtze River Basin.This study analyzed the long-term spatiotemporal distribution characteristics of compound heatwave-drought and heatwave-w...Compound extreme climate events may profoundly affect human activity in the Yangtze River Basin.This study analyzed the long-term spatiotemporal distribution characteristics of compound heatwave-drought and heatwave-waterlogging events in the Yangtze River Basin using multi-period historical observation data and future scenario climate model data.It also examined the changes in population exposure to compound extreme climate events in the basin and their driving factors by combining population statistics and forecast data.The results show that the occurrence days of compound heatwave-drought and heatwave-waterlogging events in the Yangtze River Basin have shown a significant upward trend both in historical periods and future scenarios,accompanied by a marked expansion in the affected areas.Compared to historical periods,population exposure in the Yangtze River Basin under future scenarios is expected to increase by 1.5–2 times,primarily concentrated in the key urban areas of the basin.The main factors driving the changes in population exposure are the increased frequency of extreme climate events and population decline in future scenarios.These findings provide scientific evidence for early mitigation of meteorological disasters in the Yangtze River Basin.展开更多
[Objectives]This study was conducted to investigate water pollution in the Huanghou Underground River Basin.[Methods]Five representative water quality indicators,ammonia nitrogen(NH+4-N),nitrate nitrogen(NO_(3)^(-)-N)...[Objectives]This study was conducted to investigate water pollution in the Huanghou Underground River Basin.[Methods]Five representative water quality indicators,ammonia nitrogen(NH+4-N),nitrate nitrogen(NO_(3)^(-)-N),permanganate index(COD Mn),total phosphorus(TP),and nitrite nitrogen(NO_(2)^(-)-N),were selected.The single-factor pollution index(P i),Nemerow pollution index(P N),and water quality index(WQI)were calculated to quantitatively assess pollution characteristics and evaluate water quality in the basin.[Results]The overall water quality in the Huanghou Underground River Basin fell within the"slightly polluted to good"range,with pollution primarily concentrated in the upstream areas.The downstream water quality was generally better,as most pollutants from the upstream were diluted or degraded during migration,resulting in little impact on the downstream areas.[Conclusions]This study provides a theoretical basis for understanding the pollution characteristics and evaluation of water quality in the Huanghou Underground River Basin.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
This study employs the Long Short-Term Memory(LSTM)rainfall-runoff model to simulate and predict runoff in typical basins of the Jiziwan Region of the Yellow River,aiming to overcome the shortcomings of traditional hy...This study employs the Long Short-Term Memory(LSTM)rainfall-runoff model to simulate and predict runoff in typical basins of the Jiziwan Region of the Yellow River,aiming to overcome the shortcomings of traditional hydrological models in complex nonlinear environments.The Jiziwan Region of the Yellow River is affected by human activities such as urbanization,agricultural development,and water resource management,leading to increasingly complex hydrological processes.Traditional hydrological models struggle to effectively capture the relationship between rainfall and runoff.The LSTM rainfall-runoff model,using deep learning techniques,automatically extracts features from data,identifies complex patterns and long-term dependency in time series,and provides more accurate and reliable runoff predictions.The results demonstrate that the LSTM rainfall-runoff model adapts well to the complex hydrological characteristics of the Jiziwan Region,showing superior performance over traditional hydrological models,especially in addressing the changing trends under the influence of climate change and human activities.By analyzing the interannual and within-year variations of runoff under different climate change scenarios,the model can predict the evolution trends of runoff under future climate conditions,providing a scientific basis for water resource management and decision-making.The results indicate that under different climate change scenarios,the runoff in several typical basins of the Jiziwan Region exhibits different variation trends.Under SSP1-2.6 and SSP2-4.5,some basins,such as the Wuding River Basin,Tuwei River Basin,and Gushanchuan Basin,show a decreasing trend in annual runoff.For example,in the Wuding River Basin,the average runoff from 2025 to 2040 is 12.48 m^(3)/s(SSP1-2.6),with an annual decrease of 0.10 m^(3)/s;in the Tuwei River Basin,the runoff from 2025 to 2040 is 12.96 m^(3)/s(SSP1-2.6),with an annual decrease of 0.10 m^(3)/s.In contrast,under SSP3-7.0 and SSP5-8.5,with climate warming and changes in precipitation patterns,runoff in some basins shows an increasing trend,particularly during the snowmelt period and with increased summer precipitation,leading to a significant rise in runoff.展开更多
基金National Natural Science Foundation of China,No.32161143025,No.42371283,No.W2412155National Key R&D Program of China,No.2022YFE0119200。
文摘The Selenge River Basin(SRB)in Mongolia has faced ecosystem degradation because of climate change and overloading.The dynamics of the pastoral system and the extent of overload under future scenarios have not been documented.This study aims to answer the following questions:Will the typical soums in the SRB become more overgrazed in the future?What optimal strategy should be implemented?Multisource data were integrated and utilized to model the pastoral system of typical soums using a system dynamics approach.Future scenarios under three SSP-RCPs were projected using the model.The conclusions are as follows:(1)From upstream to downstream,rational scenarios for pastoral system transferred from SSP1-RCP2.6 to SSP2-RCP4.5,which reflect improved productivity at the expense of ecosystem stability.(2)Compared with that during the historical period of 2000-2020,the projected carrying capacity of the soums decreases by 15.2%-37.3%,whereas the number of livestock continues to increase.Consequently,the stocking rate is expected to increase from 0.32-1.16 during 2000-2020 to 1.26-2.02 during 2021-2050,indicating that rangeland will become more overloaded.(3)A livestock reduction strategy based on future livestock stock and grassland carrying capacity scenarios was proposed to maintain a dynamic forage-livestock equilibrium.It is suggested that reducing livestock is a practical option for harmonizing grassland conservation with livestock husbandry development.
基金Shanxi Province Graduate Research Practice Innovation Project,No.2023KY465Project on the Reform of Graduate Education and Teaching in Shanxi Province,No.2021YJJG146+1 种基金Research Project of Shanxi Provincial Cultural Relics Bureau,No.22-8-14-1400-119National Key R&D Program of China,No.2021YFB3901300。
文摘Human activities have significantly impacted the land surface temperature(LST),endangering human health;however,the relationship between these two factors has not been adequately quantified.This study comprehensively constructs a Human Activity Intensity(HAI)index and employs the Maximal Information Coefficient,four-quadrant model,and XGBoostSHAP model to investigate the spatiotemporal relationship and influencing factors of HAI-LST in the Yellow River Basin(YRB)from 2000 to 2020.The results indicated that from 2000 to 2020,as HAI and LST increased,the static HAI-LST relationship in the YRB showed a positive correlation that continued to strengthen.This dynamic relationship exhibited conflicting development,with the proportion of coordinated to conflicting regions shifting from 1:4 to 1:2,indicating a reduction in conflict intensity.Notably,only the degree of conflict in the source area decreased significantly,whereas it intensified in the upper and lower reaches.The key factors influencing the HAI-LST relationship include fractional vegetation cover,slope,precipitation,and evapotranspiration,along with region-specific factors such as PM_(2.5),biodiversity,and elevation.Based on these findings,region-specific ecological management strategies have been proposed to mitigate conflict-prone areas and alleviate thermal stress,thereby providing important guidance for promoting harmonious development between humans and nature.
基金The Science and Technology Basic Resources Survey Project,No.2021FY101002Wetland Protection and Restoration in China Funded by the Palson Institute and Laoniu Foundation,UNDP-GEF Flyway Project,No.PIMS ID:6110。
文摘Effective conservation relies on robust assessments;however,the lack of waterbird data in the Yellow River Basin(YRB)has led to an underestimation of key habitat significance.This study addressed this gap by evaluating YRB wetland conservation importance using waterbirds as indicators and applying Ramsar,Important Bird Areas(IBA),and East Asian-Australasian Flyway(EAAF)criteria.We integrated coordinated surveys with citizen science data,creating a framework that tackles data deficiencies along the under-monitored Central Asian Flyway(CAF).Our analysis identified 75 priority wetlands,supporting 15 threatened species and 49 exceeding global/flyway 1%thresholds,highlighting the basin's biodiversity.We observed strong seasonal habitat use,with high-altitude wetlands vital for breeding and migration,and the Yellow River Delta providing year-round refuge.This research also provided data to refine Baer's Pochard population estimates.Alarmingly,one-third of the identified priority areas,primarily rivers and lakes,remain unprotected.To address this,we recommend systematic surveys,enhanced protected areas,OECMs,and targeted wetland restoration.This study underscores the YRB's role in regional conservation and provides essential data for adaptive management,particularly emphasizing the CAF's importance.
基金supported by the National Natural Science Foundation of China(W2412135).
文摘The hydrological system in Central Asia is highly sensitive to global climate change,significantly affecting water supply and energy production.In Tajikistan,the Vakhsh River—one of the main tributaries of the Amu Darya—plays a key role in the region’s hydropower and irrigation.However,research on long-term hydrological changes in its two top large basins—the Surkhob and Khingov river basins—remains limited.Therefore,this study analyzed long-term climate and hydrological changes in the Vakhsh River,including its main tributaries—the Surkhob and Khingov rivers—which are vital for the water resource management in Tajikistan and even in Central Asia.Using long-term hydrometeorological observations,the change trends of temperature(1933–2020),precipitation(1970–2020),and runoff(1940–2018)were examined to assess the impact of climate change on the regional water resources.The analysis revealed the occurrence of significant warming and a spatially uneven increase in precipitation.The temperature changes across three climatic periods(1933–1960,1960–1990,and 1990–2020)indicated that there was a transition from baseline level to accelerated warming.The precipitation showed a 2.99 mm/a increase in the Khingov River Basin and a 2.80 mm/a increase in the Surkhob River Basin during 1970–2020.Moreover,there was a gradual shift toward wetter conditions in recent decades.Despite the relatively stable annual mean runoff,seasonal redistribution occurred,with increased runoff in spring and reduced runoff in summer,due to the compensation of glacier melting.Moreover,this study forecasted runoff change during 2019–2040 using the exponential triple smoothing(ETS)method and revealed the occurrence of alternating wet and dry phases,emphasizing the sensitivity of the Vakhsh River Basin’s hydrological system to climate change and the necessity of adaptive water resource management in mountainous regions of Central Asia.Therefore,this study can provide evidence-based insights that are critical for future water resources planning,climate-resilient hydropower development,and regional adaptation strategies in climate-vulnerable basins in Central Asia.
基金National Social Science Foundation Program,No.22VRC163National Natural Science Foundation of China,No.42061043+1 种基金Postgraduate Research&Practice Innovation Program of Jiangsu Province,No.KYCX24_1008Innovation Project of Guangxi Graduate Education,No.YCSW2024473。
文摘Clarifying the mechanisms that control the evolution of territorial space patterns is essential for regulating and optimizing the geographical structure and processes related to sustainable development.Using the Guangdong and Guangxi sections of the Pearl River Basin as examples,the transfer-matrix method and standard deviation ellipse model were applied to characterize the evolution of territorial space patterns from 1990 to 2020.A trend surface analysis and the Theil index were used to analyze regional differences in the evolution process,and geodetectors were used to identify the underlying mechanisms of the changes.There were three key results.(1)In these critical areas of the Pearl River Basin,agricultural and ecological spaces have rapidly declined due to urban expansion,with transfers between these spaces dominating the evolution of territorial space patterns.Spatial pattern changes in the Guangdong section were more intense than in the Guangxi section.(2)Regional differences in urban space have decreased,whereas differences in agricultural and ecological spaces have intensified.Driven by socio-economic growth,the cross-regional transfers of territorial space have created a“high in the east,while low in the west”inter-regional difference,and a“high in the south,while low in the north”intra-regional difference shaped by natural conditions.The regional differences in space patterns were greater in Guangdong than in Guangxi.(3)The evolution of watershed territorial space patterns resulted from scale changes,locational shifts,structural reorganizations,and directional changes driven by multiple factors.Natural environment,social life,economic development,and policy factors played foundational,leading,key driving,and guiding roles,respectively.Additionally,the regional differences in the evolution of watershed territorial space patterns originated from the differential transmission of the influence of various factors affecting spatial evolution.Enhancing urban space efficiency,restructuring agricultural space,and optimizing ecological space are key strategies for building a complementary and synergistic territorial space pattern in the basin.
基金National Natural Science Foundation of China,No.42207078CUG Scholar-Scientific Research Funds at China University of Geosciences(Wuhan),No.2022166+1 种基金China Scholarship Council,No.202306410026Opening Fund of State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin,China Institute of Water Resources and Hydropower Research,No.IWHR-SKL-KF202217。
文摘Wetlands play a critical role in the global environment.The Middle Yangtze River Basin(MYRB),known for its abundant wetland resources,has experienced notable changes resulting from the complex interplay of environmental factors.Therefore,we investigated the spatiotemporal characteristics of wetland ecological quality in the MYRB from 2001 to 2020.Utilizing the random forest(RF)regression algorithm and patch-generated land-use simulation(PLUS)model,we forecasted variations in wetland habitat quality and their determinants under the Shared Socioeconomic Pathway-Representative Concentration Pathway(SSPRCP)framework from 2035 to 2095.The main findings are as follows:(1)The RF algorithm was optimal for land-use and land-cover(LULC)classification in the MYRB from 2001 to 2020,when notable changes were observed in water bodies and buildings.However,the forested area exhibited an increase and decrease of 3.9%and 1.2%under the SSP1-2.6 and SSP5-8.5 scenarios,respectively,whereas farmland exhibited a diminishing trend.(2)Wetlands were primarily concentrated in the central and eastern MYRB,with counties in the southwest exhibiting superior ecological-environmental quality from 2001 to 2020.Notably,wetland coverage revealed significantly high level,significant changes,frequent but relatively minor changes under the SSP1-2.6,SSP2-4.5,and SSP 5-8.5 scenarios,respectively.(3)Regions with lower habitat quality were primarily concentrated in urbanized areas characterized by frequent human activities,indicating a clear degradation in habitat quality across different scenarios.In conclusion,we established a foundational framework for future investigations into the eco-hydrological processes and ecosystem quality of watersheds.
基金supported by the Science and Technology Program of Xinjiang Construction Corps(No.2024AB064)the National Natural Science Foundation of China(Nos.41975044,42001314)。
文摘Climate change is significantly impacting cotton production in the Tarim River Basin.The study investigated the climate change characteristics from 2021 to 2100 using climate change datasets simulated per the coupled model inter-comparison project phase six(CMIP6)climatic patterns under the shared socioeconomic pathways SSP2-4.5 and SSP5-8.5.The DSSAT-CROPGROCotton model,along with stepwise multiple regression analyses,was used to simulate changes in the potential yield of seed cotton due to climate change.The results show that while future temperatures in the Tarim River Basin will rise significantly,changes in precipitation and radiation during the cotton-growing season are minimal.Seed cotton yields are more sensitive to low temperatures than to precipitation and radiation.The potential yield of seed cotton under the SSP2-4.5 scenario would increase by 14.8%,23.7%,29.0%,and 29.4%in the 2030S,2050S,2070S,and 2090S,respectively.In contrast,under the SSP5-8.5 scenario,the potential yield of seed cotton would see increases of 17.5%,27.1%,30.1%,and 22.6%,respectively.Except for the 2090s under the SSP5-8.5 scenario,future seed cotton production can withstand a 10%to 20%deficit in irrigation.These findings will help develop climate change adaptation strategies for cotton cultivation.
基金supported by the National Natural Science Foundation of China(Grant number 42201302)the"Double First-Class"University Construction Project of Lanzhou University(Grant number:561120213)。
文摘The horizontal ecological compensation plays an important role in balancing the interests of all parties and coordinating regional development in the basin.However,the mechanism of ecological compensation based on embodied carbon emissions is still poorly understood.Here,taking the Yellow River Basin as the research area,we use the multi-regional input-output(MRIO)model to measure the embodied carbon transfers between its seven urban agglomerations in 2012 and 2017 from the viewpoint of value-added trade benefits.Further,for the first time,the green trade benefits and ecological compensation amounts are analyzed.The results indicate that:(1)The transfer of trade-embodied carbon among the urban agglomerations in the basin showed obvious spatial heterogeneity and geographic proximity effects,and trade-embodied carbon outflows(inflows)had a pattern of"highest in the midstream,second in the downstream,and lowest in the upstream".(2)The industry composition of the urban agglomerations in relation to embodied carbon outflows(inflows)was similar,mainly in the service and heavy manufacturing industries.(3)The spatial pattern of green trade benefits in the basin had shifted from"high in the north and low in the surrounding area"to"high in the east-central part and low in the west".(4)The pattern of ecological compensation in the basin had shifted from the upstream surplus,the middle and downstream deficit to the midstream deficit,and the upstream and downstream surplus.Therefore,we recommend improving energy structures in high-demand urban agglomerations by adopting clean energy,focusing on decarbonization and energy efficiency in resource-rich regions.Additionally,promoting low-carbon economies,especially in the service and heavy manufacturing industries,implementing differentiated emission reduction strategies,and optimizing carbon compensation mechanisms considering regional disparities and resource endowments are crucial.It is expected that the study can enrich the scientific basis of horizontal ecological compensation and increase the fairness of regional carbon emission rights allocation.
基金supported by the funding provided by the State Key Laboratory of Hydraulics and Mountain River Engineering(SKHL2210)National Natural Science Foundation of China(42171304)+1 种基金the Sichuan Science and Technology Program(2023YFS0380)Natural Science Foundation of Jiangsu Province of China(BK20242018)。
文摘The Yellow River Basin in Sichuan Province(YRS)is undergoing severe soil erosion and exacerbated ecological vulnerability,which collectively pose formidable challenges for regional water conservation(WC)and sustainable development.While effectively enhancing WC necessitates a comprehensive understanding of its driving factors and corresponding intervention strategies,existing studies have largely neglected the spatiotemporal heterogeneity of both natural and socio-economic drivers.Therefore,this study explored the spatiotemporal heterogeneity of WC drivers in YRS using multi-scale geographically weighted regression(MGWR)and geographically and temporally weighted regression(GTWR)models from an eco-hydrological perspective.We discovered that downstream regions,which are more developed,achieved significantly better WC than upstream regions.The results also demonstrated that the influence of temperature and wind speed is consistently dominant and temporally stable due to climate stability,while the influence of vegetation shifted from negative to positive around 2010,likely indicating greater benefits from understory vegetation.Economic growth positively impacted WC in upstream regions but had a negative effect in the more developed downstream regions.These findings highlight the importance of targeted water conservation strategies,including locally appropriate revegetation,optimization of agricultural and economic structures,and the establishment of eco-compensation mechanisms for ecological conservation and sustainable development.
基金National Natural Science Foundation of ChinaNo.41401005,No.42307555+3 种基金Chinese Academy of Geological Sciences Basal Research FundNo.JKYQN202418,No.YK202405Project of the China Geological SurveyNo.DD20230459。
文摘Nebkhas,which play a fundamental role in stabilizing ecosystems in arid and semi-arid regions,are currently threatened by global warming and anthropogenic activities.This study focuses on a tamarisk-nebkha profile situated in the lower reaches of the Shule River Basin,an arid region in northwestern China.Using radioactive dating and the physicochemical properties of sediments,this study reconstructed changes in the nebkha’s hydro-ecological conditions over the past decades.The results revealed a significant decline in fine particle fraction,carbonate content,and low-frequency magnetic susceptibility,along with a notable increase in the Si_(2)O_(3)/Al_(2)O_(3) ratio,since the 1990s.These findings indicate the intensification of the desertification process and the degradation of hydrological conditions within the nebkha.Primary factors contributing to these transformations include the steadily rising temperature,which leads to an increased evaporation rate,and a substantial rise in human water consumption.These indicate an elevated risk of future nebkha reactivation.This reactivation,in turn,could potentially accelerate the process of regional desertification and lead to an ecological crisis.
文摘Based on the meteorological observation data from 1994 to 2023,the spatiotemporal distribution characteristics and periodic changes of extreme precipitation were analyzed.The extreme precipitation showed a fluctuating upward trend,and reached a peak of 713.5 mm in 2010.The frequency of events increased from 7 times in 1994-2000 to 56 times in 2020-2023,with significant periodicity of 3-4 and 7-8 a.In terms of spatial distribution,the precipitation intensity in the upper reaches was significantly higher than that in the middle and lower reaches,reaching 421.6 and 405.7 mm respectively.The lowest was in downstream Wuchuan City(268.3 mm),showing a decreasing trend from upstream to downstream.Extreme precipitation was mainly concentrated from July to October,especially in September(accounting for 25.8%).Typhoon was the main cause,with 80%of the TOP10 records related to typhoons,and the average precipitation intensity of typhoons reached 501.6 mm.The average precipitation intensity from 2020 to 2023 reached 442.8 mm.The correlation coefficient between 12-h rainfall intensity and flood level was 0.85,and the accuracy of flood warning based on rainfall intensity threshold was 78%,which had guiding significance for flood control and disaster reduction.
基金funded by the Tianshan Yingcai Program of the Xinjiang Uygur Autonomous Region(2022TSYCCX0038)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Y2022108)the Postdoctoral Fellowship Program of Chinese Postdoctoral Science Foundation(CPSF)(GZC20232962).
文摘The Tarim River Basin(TRB)is a vast area with plenty of light and heat and is an important base for grain and cotton production in Northwest China.In the context of climate change,however,the increased frequency of extreme weather and climate events is having numerous negative impacts on the region's agricultural production.To better understand how unfavorable climatic conditions affect crop production,we explored the relationship of extreme weather and climate events with crop yields and phenology.In this research,ten indicators of extreme weather and climate events(consecutive dry days(CDD),min Tmax(TXn),max Tmin(TNx),tropical nights(TR),warm days(Tx90p),warm nights(Tn90p),summer days(SU),frost days(FD),very wet days(R95p),and windy days(WD))were selected to analyze the impact of spatial and temporal variations on the yields of major crops(wheat,maize,and cotton)in the TRB from 1990 to 2020.The three key findings of this research were as follows:extreme temperatures in southwestern TRB showed an increasing trend,with higher extreme temperatures at night,while the occurrence of extreme weather and climate events in northeastern TRB was relatively low.The number of FD was on the rise,while WD also increased in recent years.Crop yields were higher in the northeast compared with the southwest,and wheat,maize,and cotton yields generally showed an increasing trend despite an earlier decline.The correlation of extreme weather and climate events on crop yields can be categorized as extreme nighttime temperature indices(TNx,Tn90p,TR,and FD),extreme daytime temperature indices(TXn,Tx90p,and SU),extreme precipitation indices(CDD and R95p),and extreme wind(WD).By using Random Forest(RF)approach to determine the effects of different extreme weather and climate events on the yields of different crops,we found that the importance of extreme precipitation indices(CDD and R95p)to crop yield decreased significantly over time.As well,we found that the importance of the extreme nighttime temperature(TR and TNx)for the yields of the three crops increased during 2005-2020 compared with 1990-2005.The impact of extreme temperature events on wheat,maize,and cotton yields in the TRB is becoming increasingly significant,and this finding can inform policy decisions and agronomic innovations to better cope with current and future climate warming.
基金the CMEC Technology Incubation Project(No.CMEC-KJFH-2018-02)the National Science Foundation of China(No.41877250)+2 种基金the Fundamental Research Funds for the Central Universities,CHD(Nos.300102263512 and 300102260401)Shaanxi Science and Technology Coordination Innovation Project(No.2011KTZB03-02-02)the National Geological Survey of China(No.DD20160264)。
文摘Since the 1950's,212 earth fissures have been discovered in the Wei River Basin.During a field survey in 2016,an additional 48 earth fissures were discovered in Anren area,northeast of the Wei River Basin.The characteristics and formation mechanisms of these fissures were studied through field investigations,measurements,trench excavation,and drilling.On-site investigations indicated that these earth fissures were distributed along a fault-controlled geomorphic boundary.Fissures trended at 60°-80°NE and were divided into five groups.Trenches revealed multiple secondary fissures,exposing severe soil ruptures in the shallow earth surfaces.Drilling profiles revealed that earth fissures dislocated several strata,and resembled synsedimentary faults.Seismic reflection profiles revealed buried faults beneath the earth fissures.The Anren area fissures formed in the following three stages:regional extension that initially generated multiple buried faults;seismic activity rupturing multiple strata,resulting in multiple buried fractures;and finally,erosion processes that propagated the buried fractures to the surface,forming the current earth fissures.
基金supported by the National Natural Science Foundation of China(No.42107094)Sichuan Science and Technology Program(No.2023NSFSC0806)the Geology Bureau project of Xinjiang Uygur Autonomous Region(Nos.XGMB202356 and XGMB202358).
文摘The geogenic enrichment of arsenic(As)extensively occurred in the riverine systems from the Qinghai-Tibetan Plateau under active geothermal discharge and chemical weathering conditions,while little is known about how dissolved organic matter(DOM)transformation regulates the aquatic As concentrations.The present study revealed that the DOM components from the Singe Tsangpo River(STR)basin primarily consisted of protein-like components(81.30%±6.48%),with the microbially-endogenous production being a predominant source under the control of temperature and glacier-runoff recharge along the river flow path.Notably,the chemical weathering processes have significantly facilitated the enhancement of humic-like components in the river water.Besides,the groundwater DOM characteristics were predominantly influenced by the mobilization of sedimentary organic matter and the introduction of allochthonous DOM resulting from surface-water recharge.Interestingly,humic-like components facilitated As enrichment through complexation and competitive adsorption effects in both surface water and groundwater under oxidizing conditions,whichwas supported by the significant positive correlations between As and humiclike component(R^(2)=0.31/0.65,P<0.05/0.01)and the concurrent mobilization of As and humic-like components from sediment incubation experiments.Moreover,the Structural Equation Modeling analysis revealed a stronger contribution of humic-like components to the As enrichment in the groundwater compared with surface water,possibly due to the relatively strongermicrobial activity and enhanced mobilization of humic-like components in alluvial aquifers.The present study thus provided new insights into the transformation of DOM and its important role in facilitating As enrichment in the aquatic environment from alpine river basins.
基金funded by the Second Tibetan Plateau Scientific Expedition and Research,Ministry of Science and Technology(Project No.2019QZKK0902)the West Light Foundation of the Chinese Academy of Sciences(Project No.E3R2120)the Research Programme of Institute of Mountain Hazards and Environment,Chinese Academy of Sciences(Project No.IMHE-ZDRW-01).
文摘Machine learning-based Debris Flow Susceptibility Mapping(DFSM)has emerged as an effective approach for assessing debris flow likelihood,yet its application faces three critical challenges:insufficient reliability of training samples caused by biased negative sampling,opaque decision-making mechanisms in models,and subjective susceptibility mapping methods that lack quantitative evaluation criteria.This study focuses on the Yalong River basin.By integrating high-resolution remote sensing interpretation and field surveys,we established a refined sample database that includes 1,736 debris flow gullies.To address spatial bias in traditional random negative sampling,we developed a semi-supervised optimization strategy based on iterative confidence screening.Comparative experiments with four treebased models(XGBoost,CatBoost,LGBM,and Random Forest)reveal that the optimized sampling strategy improved overall model performance by 8%-12%,with XGBoost achieving the highest accuracy(AUC=0.882)and RF performing the lowest(AUC=0.820).SHAP-based global-local interpretability analysis(applicable to all tree models)identifies elevation and short-duration rainfall as dominant controlling factors.Furthermore,among the tested tree-based models,XGBoost optimized with semisupervised sampling demonstrates the highest reliability in debris flow susceptibility mapping(DFSM),achieving a comprehensive accuracy of 83.64%due to its optimal generalization-stability equilibrium.
基金IWHR Basic Scientific Research Project,Grant/Award Number:JZ110145B0072024IWHR Internationally-Oriented Talent for International Academic Leader Program,Grant/Award Number:0203982012National Natural Science Foundation of China,Grant/Award Number:51609257。
文摘The Kulsi River basin,situated in the South Kamrup district of Assam,India,is noted for its rich fish diversity and significant deposits of Pre-Cambrian quality sand in its headstreams.These deposits gradually make their way downstream,acting as a catalyst for local livelihoods.However,the intricate ecosystem fos-tered by the Kulsi River is under significant ecological threat due to urbanization,population growth,and associated environmental stressors such as rampant sand mining,deforestation,and soil erosion.These changes pose a risk to the basin's ecological sustainability,increasing its vulnerability.This study employs the Analytical Hierarchical Process(AHP),a GIS-based multi-criteria decision analysis method,to assess and monitor the basin's ecological vulnerability.It seeks sustainable methods to rejuvenate ecological sustainability in the basin.Criteria such as slope,C factor,stream density,proximity to roads,soil erosion,literacy rate,soil erodibility factor,and rainfall were analyzed.The findings reveal varied vulnerability across the Kulsi River basin,with 6.24%of the area classified as extremely vulnerable,25.56%as highly vulnerable,24.56%as moderately vulnerable,32.67%as low vulnerable,and 10.94%as non-vulnerable.Highly vulnerable zones are notably in newly developed suburban areas adjacent to national highways.However,non-vulnerable zones are primarily in the upper river course and its surrounding regions in the southern direction.The findings highlight the urgent need for targeted mitigation strategies to address the adverse effects of human activities and natural processes on the basin's ecological integ-rity.This study maps the vulnerability of the Kulsi River basin.It provides valuable insights into sustainable management and hazard mitigation.The study highlights the link between human activity,ecological sustainability,and geomorphological hazards.
基金supported by the National Natural Science Foundation of China(Nos.42301029,42371354)the Scientific Research Start-up Fund for New Young Faculty,China University of Geosciences,Wuhan(No.CUGXQN2307)China Meteorological Administration Innovation and Development Project(No.CXFZ2023J051).
文摘Compound extreme climate events may profoundly affect human activity in the Yangtze River Basin.This study analyzed the long-term spatiotemporal distribution characteristics of compound heatwave-drought and heatwave-waterlogging events in the Yangtze River Basin using multi-period historical observation data and future scenario climate model data.It also examined the changes in population exposure to compound extreme climate events in the basin and their driving factors by combining population statistics and forecast data.The results show that the occurrence days of compound heatwave-drought and heatwave-waterlogging events in the Yangtze River Basin have shown a significant upward trend both in historical periods and future scenarios,accompanied by a marked expansion in the affected areas.Compared to historical periods,population exposure in the Yangtze River Basin under future scenarios is expected to increase by 1.5–2 times,primarily concentrated in the key urban areas of the basin.The main factors driving the changes in population exposure are the increased frequency of extreme climate events and population decline in future scenarios.These findings provide scientific evidence for early mitigation of meteorological disasters in the Yangtze River Basin.
基金Supported by Guizhou Provincial Key Technology R&D Program(No.2202023QKHZC).
文摘[Objectives]This study was conducted to investigate water pollution in the Huanghou Underground River Basin.[Methods]Five representative water quality indicators,ammonia nitrogen(NH+4-N),nitrate nitrogen(NO_(3)^(-)-N),permanganate index(COD Mn),total phosphorus(TP),and nitrite nitrogen(NO_(2)^(-)-N),were selected.The single-factor pollution index(P i),Nemerow pollution index(P N),and water quality index(WQI)were calculated to quantitatively assess pollution characteristics and evaluate water quality in the basin.[Results]The overall water quality in the Huanghou Underground River Basin fell within the"slightly polluted to good"range,with pollution primarily concentrated in the upstream areas.The downstream water quality was generally better,as most pollutants from the upstream were diluted or degraded during migration,resulting in little impact on the downstream areas.[Conclusions]This study provides a theoretical basis for understanding the pollution characteristics and evaluation of water quality in the Huanghou Underground River Basin.
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.
基金the National Key R&D Program of China(No.2023YFC3206504)National Natural Science Foundation of China(Nos.52121006,41961124006,51911540477)+1 种基金Young Top-Notch Talent Support Program of National High-level Talents Special Support PlanResearch Project of Ministry of Natural Resources(No.20210103)for providing financial support for this research。
文摘This study employs the Long Short-Term Memory(LSTM)rainfall-runoff model to simulate and predict runoff in typical basins of the Jiziwan Region of the Yellow River,aiming to overcome the shortcomings of traditional hydrological models in complex nonlinear environments.The Jiziwan Region of the Yellow River is affected by human activities such as urbanization,agricultural development,and water resource management,leading to increasingly complex hydrological processes.Traditional hydrological models struggle to effectively capture the relationship between rainfall and runoff.The LSTM rainfall-runoff model,using deep learning techniques,automatically extracts features from data,identifies complex patterns and long-term dependency in time series,and provides more accurate and reliable runoff predictions.The results demonstrate that the LSTM rainfall-runoff model adapts well to the complex hydrological characteristics of the Jiziwan Region,showing superior performance over traditional hydrological models,especially in addressing the changing trends under the influence of climate change and human activities.By analyzing the interannual and within-year variations of runoff under different climate change scenarios,the model can predict the evolution trends of runoff under future climate conditions,providing a scientific basis for water resource management and decision-making.The results indicate that under different climate change scenarios,the runoff in several typical basins of the Jiziwan Region exhibits different variation trends.Under SSP1-2.6 and SSP2-4.5,some basins,such as the Wuding River Basin,Tuwei River Basin,and Gushanchuan Basin,show a decreasing trend in annual runoff.For example,in the Wuding River Basin,the average runoff from 2025 to 2040 is 12.48 m^(3)/s(SSP1-2.6),with an annual decrease of 0.10 m^(3)/s;in the Tuwei River Basin,the runoff from 2025 to 2040 is 12.96 m^(3)/s(SSP1-2.6),with an annual decrease of 0.10 m^(3)/s.In contrast,under SSP3-7.0 and SSP5-8.5,with climate warming and changes in precipitation patterns,runoff in some basins shows an increasing trend,particularly during the snowmelt period and with increased summer precipitation,leading to a significant rise in runoff.
