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
为了明确延河流域2003—2014年土壤保持量的时空动态变化特征及其约束条件,基于合成孔径雷达(Interferometric Synthetic Aperture Radar,INSAR)获取的高分辨率数字高程模型(Digital Elevation Model,DEM),结合SWAT(Soil and Water Asse...为了明确延河流域2003—2014年土壤保持量的时空动态变化特征及其约束条件,基于合成孔径雷达(Interferometric Synthetic Aperture Radar,INSAR)获取的高分辨率数字高程模型(Digital Elevation Model,DEM),结合SWAT(Soil and Water Assessment Tool)水文模型模拟流域逐月土壤保持量,从时空变化的角度展开分析,并引入流域水土保持措施及植被覆盖措施数据,以此揭示水土保持治理对流域土壤保持服务的影响。并在此基础上通过叠加分析揭示了地形因子对土壤保持的影响。结果表明:(1)SWAT模型在进行径流、泥沙模拟时,率定期和验证期的模拟结果均达到模型要求。(2)2003—2014期间,延河流域年均土壤保持量为1002.02万t,以土壤低保持量为主。土壤保持量的时空动态特征表现为时间变化主要受降水量影响,总体上呈增加趋势;空间变化主要受地形影响,具体表现为下游最大,上游次之,中游最低。其中2003年和2014年的空间分布特征表明,多年来实施的水土保持措施以及植被覆盖措施产生了明显的生态效益。(3)土壤保持量受坡度、高程、坡向的影响规律明显,具体表现为:随坡度、高程的增大土壤保持量呈先增大后减小的趋势;对坡向而言,土壤保持量表现为半阳坡>阴坡>阳坡>半阴坡>平地。该研究可为延河流域水土治理提供一定的科学依据。展开更多
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.
文摘为了明确延河流域2003—2014年土壤保持量的时空动态变化特征及其约束条件,基于合成孔径雷达(Interferometric Synthetic Aperture Radar,INSAR)获取的高分辨率数字高程模型(Digital Elevation Model,DEM),结合SWAT(Soil and Water Assessment Tool)水文模型模拟流域逐月土壤保持量,从时空变化的角度展开分析,并引入流域水土保持措施及植被覆盖措施数据,以此揭示水土保持治理对流域土壤保持服务的影响。并在此基础上通过叠加分析揭示了地形因子对土壤保持的影响。结果表明:(1)SWAT模型在进行径流、泥沙模拟时,率定期和验证期的模拟结果均达到模型要求。(2)2003—2014期间,延河流域年均土壤保持量为1002.02万t,以土壤低保持量为主。土壤保持量的时空动态特征表现为时间变化主要受降水量影响,总体上呈增加趋势;空间变化主要受地形影响,具体表现为下游最大,上游次之,中游最低。其中2003年和2014年的空间分布特征表明,多年来实施的水土保持措施以及植被覆盖措施产生了明显的生态效益。(3)土壤保持量受坡度、高程、坡向的影响规律明显,具体表现为:随坡度、高程的增大土壤保持量呈先增大后减小的趋势;对坡向而言,土壤保持量表现为半阳坡>阴坡>阳坡>半阴坡>平地。该研究可为延河流域水土治理提供一定的科学依据。
