As a component of streamflow, baseflow is critical for regulating seasonal distribution of river fows and stabilizing water supplies. Water resources in the arid area of Northwest China are mainly from multiple catchm...As a component of streamflow, baseflow is critical for regulating seasonal distribution of river fows and stabilizing water supplies. Water resources in the arid area of Northwest China are mainly from multiple catchments in the alpine that could be influenced by varieties of climatic, land cover, soil and geological factors. While numerous studies have been done on streamflow, systematic analysis of baseflow in the alpine river systems is scare. Based on historical daily streamflow data and the automated digital filter method of baseflow separation, this study investigated characteristics of hydrographs of overland flow, streamflow and baseflowof river systems fed by rainfall, snowmelt, glacier melt or mixtures of these. This study also calculated the recession constants and baseflow indices of 65 river systems. While the recession constant was o.oo34- o.o728 with a mean of o.o18, the baseflow index was 0.27-0.79 with a mean of 0.57. Further, Spearman＇s correlation analysis showed that the baseflow index was significantly correlated with catchment climatic factors （e.g., precipitation and temperature）, topographic factors （e.g., elevation and slope） and aquifer properties represented by the recession constant. Multiple regression analysis indicated that the factors explained 65% of the variability of baseflow index in the studv area.展开更多
Baseflow is an essential component of streamflow and plays a crucial role in maintaining the stability of streamflow.However,few quantitative studies have identified the effects of leading factors on baseflow variatio...Baseflow is an essential component of streamflow and plays a crucial role in maintaining the stability of streamflow.However,few quantitative studies have identified the effects of leading factors on baseflow variation at the small watershed scale,especially in subtropical China.In this study,the small watershed(Pengchongjian watershed,2.90 km2),located in Southern China,was considered to explore the quantitative impact of precipitation,evapotranspiration,temperature,and vegetation restoration on baseflow.The digital filter method was used to separate baseflow by daily streamflow records from 1983 to 2014.The stepwise regression models were developed for selecting significant influencing factors of baseflow at seasonal and annual scales.The direct and indirect effects,as well as their quantitative relationships between baseflow and multiple factors,were clarified by the path analysis.The results showed that filtered average annual baseflow significantly decreased(p<0.05),ranging from 72.82 to 305.85 mm,and the average yearly baseflow index was 0.22.In addition,various significant influencing factors of baseflow had different direct and indirect effects on baseflow at seasonal and annual scales.The precipitation was the dominant factor with respect to the direct impact,which directs path coefficient was 0.891 in spring,0.823 in summer,1.599 in autumn,1.332 in winter,and 0.917 in an annual scale,respectively.In terms of the indirect effects,evapotranspiration played a leading role during the spring,autumn,winter,and annual scale,whereas the average temperature was the dominant factor during the summer.Overall,results demonstrated that the baseflow variation was mainly attributed to climate change.The present works are beneficial for revealing the internal mechanism of the baseflow variations in the study area,and it can provide a scientific basis for managing water resources in the watershed.展开更多
基流是径流中相对稳定的组成部分,是枯水期径流的主要来源。为探究伊洛河流域径流和基流的时空变化特征,本文通过比较SWAT(Soil and Water Assessment Tool)模型及Chapman法在伊洛河流域基流分割的适用性,选择最优基流分割方法,确定流...基流是径流中相对稳定的组成部分,是枯水期径流的主要来源。为探究伊洛河流域径流和基流的时空变化特征,本文通过比较SWAT(Soil and Water Assessment Tool)模型及Chapman法在伊洛河流域基流分割的适用性,选择最优基流分割方法,确定流域的基流过程,并采用Mann-Kendall检验法、年内分配指标和反距离加权插值法,分析径流、基流和基流指数(Baseflow index,BFI)的年际、年内变化和空间分布特征。结果表明:(1)通过黑石关站实测径流数据验证,SWAT模型在伊洛河流域的适用性较好,模拟基流比Chapman法更精确;(2)1964—2017年伊洛河流域径流、基流和BFI均呈显著下降趋势,但三者突变情况有所差异;径流和基流年内呈现“单峰型”分布,且具有明显的季节性和不均匀性的特点,基流迟滞效应显著;(3)径流、基流和BFI值在流域西部和中部相对较高,东部相对较低,整个地区90%以上的子流域年均BFI小于0.5。本文结果可为伊洛河流域水资源合理开发利用及生态环境保护提供参考。展开更多
基金funded by the International Co-operation Program of the Ministry of Science and Technology of China (Grant No. 2010DFA92720)the Project of the National Eleventh-Five Year Research Program of China (Grant No. 2012BAC19B07)
文摘As a component of streamflow, baseflow is critical for regulating seasonal distribution of river fows and stabilizing water supplies. Water resources in the arid area of Northwest China are mainly from multiple catchments in the alpine that could be influenced by varieties of climatic, land cover, soil and geological factors. While numerous studies have been done on streamflow, systematic analysis of baseflow in the alpine river systems is scare. Based on historical daily streamflow data and the automated digital filter method of baseflow separation, this study investigated characteristics of hydrographs of overland flow, streamflow and baseflowof river systems fed by rainfall, snowmelt, glacier melt or mixtures of these. This study also calculated the recession constants and baseflow indices of 65 river systems. While the recession constant was o.oo34- o.o728 with a mean of o.o18, the baseflow index was 0.27-0.79 with a mean of 0.57. Further, Spearman＇s correlation analysis showed that the baseflow index was significantly correlated with catchment climatic factors （e.g., precipitation and temperature）, topographic factors （e.g., elevation and slope） and aquifer properties represented by the recession constant. Multiple regression analysis indicated that the factors explained 65% of the variability of baseflow index in the studv area.
基金funded by the National Natural Science Foundation of China(grant number 31960331)the support from Jiangxi Hydrological Bureauthe local government in Duchang County,Jiujiang。
文摘Baseflow is an essential component of streamflow and plays a crucial role in maintaining the stability of streamflow.However,few quantitative studies have identified the effects of leading factors on baseflow variation at the small watershed scale,especially in subtropical China.In this study,the small watershed(Pengchongjian watershed,2.90 km2),located in Southern China,was considered to explore the quantitative impact of precipitation,evapotranspiration,temperature,and vegetation restoration on baseflow.The digital filter method was used to separate baseflow by daily streamflow records from 1983 to 2014.The stepwise regression models were developed for selecting significant influencing factors of baseflow at seasonal and annual scales.The direct and indirect effects,as well as their quantitative relationships between baseflow and multiple factors,were clarified by the path analysis.The results showed that filtered average annual baseflow significantly decreased(p<0.05),ranging from 72.82 to 305.85 mm,and the average yearly baseflow index was 0.22.In addition,various significant influencing factors of baseflow had different direct and indirect effects on baseflow at seasonal and annual scales.The precipitation was the dominant factor with respect to the direct impact,which directs path coefficient was 0.891 in spring,0.823 in summer,1.599 in autumn,1.332 in winter,and 0.917 in an annual scale,respectively.In terms of the indirect effects,evapotranspiration played a leading role during the spring,autumn,winter,and annual scale,whereas the average temperature was the dominant factor during the summer.Overall,results demonstrated that the baseflow variation was mainly attributed to climate change.The present works are beneficial for revealing the internal mechanism of the baseflow variations in the study area,and it can provide a scientific basis for managing water resources in the watershed.
文摘基流是径流中相对稳定的组成部分,是枯水期径流的主要来源。为探究伊洛河流域径流和基流的时空变化特征,本文通过比较SWAT(Soil and Water Assessment Tool)模型及Chapman法在伊洛河流域基流分割的适用性,选择最优基流分割方法,确定流域的基流过程,并采用Mann-Kendall检验法、年内分配指标和反距离加权插值法,分析径流、基流和基流指数(Baseflow index,BFI)的年际、年内变化和空间分布特征。结果表明:(1)通过黑石关站实测径流数据验证,SWAT模型在伊洛河流域的适用性较好,模拟基流比Chapman法更精确;(2)1964—2017年伊洛河流域径流、基流和BFI均呈显著下降趋势,但三者突变情况有所差异;径流和基流年内呈现“单峰型”分布,且具有明显的季节性和不均匀性的特点,基流迟滞效应显著;(3)径流、基流和BFI值在流域西部和中部相对较高,东部相对较低,整个地区90%以上的子流域年均BFI小于0.5。本文结果可为伊洛河流域水资源合理开发利用及生态环境保护提供参考。
