随着全球气候变化的加剧,其对流域水文过程的影响日益显著。湘江流域作为中国南方重要的水资源区域,其径流变化不仅直接影响区域水资源的可持续利用,还对生态安全和社会经济发展具有深远意义。本研究基于VIC (Variable Infiltration Cap...随着全球气候变化的加剧,其对流域水文过程的影响日益显著。湘江流域作为中国南方重要的水资源区域,其径流变化不仅直接影响区域水资源的可持续利用,还对生态安全和社会经济发展具有深远意义。本研究基于VIC (Variable Infiltration Capacity)水文模型,结合第六次国际耦合模式比较计划(CMIP6)气候模式数据,系统预测未来变化情况。研究结果显示,湘江流域未来时期(2020~2099年)的气候及径流变化在时间和空间尺度上均表现出显著特征。年际尺度上,在SSP2-4.5 (中等排放情景)和SSP5-8.5 (高排放情景)下,未来时期降水量和平均温度均呈现增加趋势,且高排放情景下增幅更为显著;径流量在两个情景下均显著增加,中等排放情景下增幅更大。年代尺度上,2020s、2030s和2060s为降水与径流枯水期,2040s、2050s、2070s、2080s和2090s则为丰水期。SSP2-4.5情景下极端降水和径流事件可能集中在2040s、2080s和2090s,而SSP5-8.5情景下则可能出现在2040s和2070s;径流量时间分布与降水变化高度一致,进一步验证了降水是径流变化的主导驱动因子,湘江流域未来径流变化主要是由降水引起。这些研究为未来流域水资源管理和自然灾害预防提供了重要参考。With the intensification of global climate change, its impacts on hydrological processes in river basins are becoming more and more significant. As an important water resource region in southern China, the runoff changes in the Xiangjiang River Basin not only directly affect the sustainable utilization of regional water resources, but also have far-reaching significance on ecological security and socio-economic development. This study is based on the VIC (Variable Infiltration Capacity) hydrological model, combined with the climate model data from the Sixth International Coupled Model Intercomparison Program (CMIP6), to systematically predict future changes. The results show that the climate and runoff changes in the Xiangjiang River Basin in the future period (2020~2099) exhibit significant features at both temporal and spatial scales. At the interannual scale, both precipitation and mean temperature show increasing trends in the future period under SSP2-4.5 (medium emission scenario) and SSP5-8.5 (high emission scenario), and the increase is more significant under the high emission scenario;runoff increases significantly under both scenarios, and the increase is greater under the medium emission scenario. On the chronological scale, the 2020s, 2030s, and 2060s are dry periods for precipitation and runoff, and the 2040s, 2050s, 2070s, 2080s, and 2090s are abundant periods. Extreme precipitation and runoff events are likely to be concentrated in the 2040s, 2080s, and 2090s under the SSP2-4.5 scenario, and the 2040s, 2080s, and 2090s under the SSP5-8.5 scenario 2040s and 2070s. The temporal distribution of runoff is highly consistent with precipitation changes, which further verifies that precipitation is the dominant driving factor of runoff changes, and future runoff changes in the Xiangjiang River Basin are mainly caused by precipitation. These studies provide important references for future water resource management and natural disaster prevention in the basin.展开更多
Severe soil erosion and drought are the two main factors affecting the ecological security of the Loess Plateau,China.Investigating the influence of drought on soil conservation service is of great importance to regio...Severe soil erosion and drought are the two main factors affecting the ecological security of the Loess Plateau,China.Investigating the influence of drought on soil conservation service is of great importance to regional environmental protection and sustainable development.However,there is little research on the coupling relationship between them.In this study,focusing on the Jinghe River Basin,China as a case study,we conducted a quantitative evaluation on meteorological,hydrological,and agricultural droughts(represented by the Standardized Precipitation Index(SPI),Standardized Runoff Index(SRI),and Standardized Soil Moisture Index(SSMI),respectively)using the Variable Infiltration Capacity(VIC)model,and quantified the soil conservation service using the Revised Universal Soil Loss Equation(RUSLE)in the historical period(2000-2019)and future period(2026-2060)under two Representative Concentration Pathways(RCPs)(RCP4.5 and RCP8.5).We further examined the influence of the three types of drought on soil conservation service at annual and seasonal scales.The NASA Earth Exchange Global Daily Downscaled Projections(NEX-GDDP)dataset was used to predict and model the hydrometeorological elements in the future period under the RCP4.5 and RCP8.5 scenarios.The results showed that in the historical period,annual-scale meteorological drought exhibited the highest intensity,while seasonal-scale drought was generally weakest in autumn and most severe in summer.Drought intensity of all three types of drought will increase over the next 40 years,with a greater increase under the RCP4.5 scenario than under the RCP8.5 scenario.Furthermore,the intra-annual variation in the drought intensity of the three types of drought becomes smaller under the two future scenarios relative to the historical period(2000-2019).Soil conservation service exhibits a distribution pattern characterized by high levels in the southwest and southeast and lower levels in the north,and this pattern has remained consistent both in the historical and future periods.Over the past 20 years,the intra-annual variation indicated peak soil conservation service in summer and lowest level in winter;the total soil conservation of the Jinghe River Basin displayed an upward trend,with the total soil conservation in 2019 being 1.14 times higher than that in 2000.The most substantial impact on soil conservation service arises from annual-scale meteorological drought,which remains consistent both in the historical and future periods.Additionally,at the seasonal scale,meteorological drought exerts the highest influence on soil conservation service in winter and autumn,particularly under the RCP4.5 and RCP8.5 scenarios.Compared to the historical period,the soil conservation service in the Jinghe River Basin will be significantly more affected by drought in the future period in terms of both the affected area and the magnitude of impact.This study conducted beneficial attempts to evaluate and predict the dynamic characteristics of watershed drought and soil conservation service,as well as the response of soil conservation service to different types of drought.Clarifying the interrelationship between the two is the foundation for achieving sustainable development in a relatively arid and severely eroded area such as the Jinghe River Basin.展开更多
Land surface evapotranspiration(ET)is a critical component in the hydrological cycle but has not well been understood in data-scarce areas especially in river basins,like Nujiang River(NRB)which is characterized by la...Land surface evapotranspiration(ET)is a critical component in the hydrological cycle but has not well been understood in data-scarce areas especially in river basins,like Nujiang River(NRB)which is characterized by large elevation gradient and different vegetation zones with complex processes of water and energy exchange.The quality of ET from optical remote sensing is constrained by cloud cover which is common in the NRB in the monsoon seasons.To understand factors controlling the spatial-temporal heterogeneity of ET in NRB,we employed the Variable Infiltration Capacity(VIC)hydrological model by parameter optimization with support of quality controlled remote sensing ET product and observed river runoff series in the river.The modeled ET has increased during 1984-2018,which might be one of the reasons for the runoff decrease but precipitation increase in the same period.ET increase and runoff decrease tended to be quicker within altitudinal band of 2000-4000 m than in other areas in NRB.We observed that ET variation in different climatic zones were controlled by different factors.ET is generally positively correlated with precipitation,temperature,and shortwave radiation but negatively with relative humidity.In the Tundra Climate(Et)zone in the upper reach of NRB,ET is controlled by precipitation,while it is controlled by shortwave radiation in the snow climate with dry winter(Dw)zone.ET increase is influenced by the increase of temperature,wind speed,and shortwave radiation in the middle and downstream of NRB with warm temperate climate,fully humid(Cf)and warm temperate climate with dry winter(Cw).展开更多
文摘随着全球气候变化的加剧,其对流域水文过程的影响日益显著。湘江流域作为中国南方重要的水资源区域,其径流变化不仅直接影响区域水资源的可持续利用,还对生态安全和社会经济发展具有深远意义。本研究基于VIC (Variable Infiltration Capacity)水文模型,结合第六次国际耦合模式比较计划(CMIP6)气候模式数据,系统预测未来变化情况。研究结果显示,湘江流域未来时期(2020~2099年)的气候及径流变化在时间和空间尺度上均表现出显著特征。年际尺度上,在SSP2-4.5 (中等排放情景)和SSP5-8.5 (高排放情景)下,未来时期降水量和平均温度均呈现增加趋势,且高排放情景下增幅更为显著;径流量在两个情景下均显著增加,中等排放情景下增幅更大。年代尺度上,2020s、2030s和2060s为降水与径流枯水期,2040s、2050s、2070s、2080s和2090s则为丰水期。SSP2-4.5情景下极端降水和径流事件可能集中在2040s、2080s和2090s,而SSP5-8.5情景下则可能出现在2040s和2070s;径流量时间分布与降水变化高度一致,进一步验证了降水是径流变化的主导驱动因子,湘江流域未来径流变化主要是由降水引起。这些研究为未来流域水资源管理和自然灾害预防提供了重要参考。With the intensification of global climate change, its impacts on hydrological processes in river basins are becoming more and more significant. As an important water resource region in southern China, the runoff changes in the Xiangjiang River Basin not only directly affect the sustainable utilization of regional water resources, but also have far-reaching significance on ecological security and socio-economic development. This study is based on the VIC (Variable Infiltration Capacity) hydrological model, combined with the climate model data from the Sixth International Coupled Model Intercomparison Program (CMIP6), to systematically predict future changes. The results show that the climate and runoff changes in the Xiangjiang River Basin in the future period (2020~2099) exhibit significant features at both temporal and spatial scales. At the interannual scale, both precipitation and mean temperature show increasing trends in the future period under SSP2-4.5 (medium emission scenario) and SSP5-8.5 (high emission scenario), and the increase is more significant under the high emission scenario;runoff increases significantly under both scenarios, and the increase is greater under the medium emission scenario. On the chronological scale, the 2020s, 2030s, and 2060s are dry periods for precipitation and runoff, and the 2040s, 2050s, 2070s, 2080s, and 2090s are abundant periods. Extreme precipitation and runoff events are likely to be concentrated in the 2040s, 2080s, and 2090s under the SSP2-4.5 scenario, and the 2040s, 2080s, and 2090s under the SSP5-8.5 scenario 2040s and 2070s. The temporal distribution of runoff is highly consistent with precipitation changes, which further verifies that precipitation is the dominant driving factor of runoff changes, and future runoff changes in the Xiangjiang River Basin are mainly caused by precipitation. These studies provide important references for future water resource management and natural disaster prevention in the basin.
基金supported by the National Natural Science Foundation of China(42071285,42371297)the Key R&D Program Projects in Shaanxi Province of China(2022SF-382)the Fundamental Research Funds for the Central Universities(GK202302002).
文摘Severe soil erosion and drought are the two main factors affecting the ecological security of the Loess Plateau,China.Investigating the influence of drought on soil conservation service is of great importance to regional environmental protection and sustainable development.However,there is little research on the coupling relationship between them.In this study,focusing on the Jinghe River Basin,China as a case study,we conducted a quantitative evaluation on meteorological,hydrological,and agricultural droughts(represented by the Standardized Precipitation Index(SPI),Standardized Runoff Index(SRI),and Standardized Soil Moisture Index(SSMI),respectively)using the Variable Infiltration Capacity(VIC)model,and quantified the soil conservation service using the Revised Universal Soil Loss Equation(RUSLE)in the historical period(2000-2019)and future period(2026-2060)under two Representative Concentration Pathways(RCPs)(RCP4.5 and RCP8.5).We further examined the influence of the three types of drought on soil conservation service at annual and seasonal scales.The NASA Earth Exchange Global Daily Downscaled Projections(NEX-GDDP)dataset was used to predict and model the hydrometeorological elements in the future period under the RCP4.5 and RCP8.5 scenarios.The results showed that in the historical period,annual-scale meteorological drought exhibited the highest intensity,while seasonal-scale drought was generally weakest in autumn and most severe in summer.Drought intensity of all three types of drought will increase over the next 40 years,with a greater increase under the RCP4.5 scenario than under the RCP8.5 scenario.Furthermore,the intra-annual variation in the drought intensity of the three types of drought becomes smaller under the two future scenarios relative to the historical period(2000-2019).Soil conservation service exhibits a distribution pattern characterized by high levels in the southwest and southeast and lower levels in the north,and this pattern has remained consistent both in the historical and future periods.Over the past 20 years,the intra-annual variation indicated peak soil conservation service in summer and lowest level in winter;the total soil conservation of the Jinghe River Basin displayed an upward trend,with the total soil conservation in 2019 being 1.14 times higher than that in 2000.The most substantial impact on soil conservation service arises from annual-scale meteorological drought,which remains consistent both in the historical and future periods.Additionally,at the seasonal scale,meteorological drought exerts the highest influence on soil conservation service in winter and autumn,particularly under the RCP4.5 and RCP8.5 scenarios.Compared to the historical period,the soil conservation service in the Jinghe River Basin will be significantly more affected by drought in the future period in terms of both the affected area and the magnitude of impact.This study conducted beneficial attempts to evaluate and predict the dynamic characteristics of watershed drought and soil conservation service,as well as the response of soil conservation service to different types of drought.Clarifying the interrelationship between the two is the foundation for achieving sustainable development in a relatively arid and severely eroded area such as the Jinghe River Basin.
基金supported by the National Natural Science Foundation of China(42171129)the second Tibetan Plateau Scientific Expedition and Research(2019QZKK0208)Yunnan University Talent Introduction Research Project(YJRC3201702)。
文摘Land surface evapotranspiration(ET)is a critical component in the hydrological cycle but has not well been understood in data-scarce areas especially in river basins,like Nujiang River(NRB)which is characterized by large elevation gradient and different vegetation zones with complex processes of water and energy exchange.The quality of ET from optical remote sensing is constrained by cloud cover which is common in the NRB in the monsoon seasons.To understand factors controlling the spatial-temporal heterogeneity of ET in NRB,we employed the Variable Infiltration Capacity(VIC)hydrological model by parameter optimization with support of quality controlled remote sensing ET product and observed river runoff series in the river.The modeled ET has increased during 1984-2018,which might be one of the reasons for the runoff decrease but precipitation increase in the same period.ET increase and runoff decrease tended to be quicker within altitudinal band of 2000-4000 m than in other areas in NRB.We observed that ET variation in different climatic zones were controlled by different factors.ET is generally positively correlated with precipitation,temperature,and shortwave radiation but negatively with relative humidity.In the Tundra Climate(Et)zone in the upper reach of NRB,ET is controlled by precipitation,while it is controlled by shortwave radiation in the snow climate with dry winter(Dw)zone.ET increase is influenced by the increase of temperature,wind speed,and shortwave radiation in the middle and downstream of NRB with warm temperate climate,fully humid(Cf)and warm temperate climate with dry winter(Cw).
