Morpho-tectonic study plays an important role in deciphering the effects of tectonic activity in the geomorphic evolution of the drainage basins.Romushi watershed forms one of the major watersheds of the intermontane ...Morpho-tectonic study plays an important role in deciphering the effects of tectonic activity in the geomorphic evolution of the drainage basins.Romushi watershed forms one of the major watersheds of the intermontane Karewa Basin of Kashmir Valley.The Karewa sediments are characterized by glacio-fluvio-lacustrine deposits capped by the aeolian loess.The geomorphic,morphometric and lithostratigraphic studies of these cap deposits have been carried out to elucidate the effect of tectonics on the geomorphic evolution of Romushi Watershed.Geomorphic mapping was carried out using GPS measurements,DEM at 30m resolution,Topographic Position Index(TPI) model,topographic maps,LANDSAT TM Imagery and field data.Morphometric and morphotectonic analyses in GIS environment were used to calculate various geomorphic indices(Mountain Front Sinuosity Index,Bifurcation Ratio,Asymmetry Factor,River Profile,etc).These indices reveal that the tectonic uplift observed in the region due to Himalayan orogeny coupled with mass movement and aeolian deposition have dominated the landscape evolution of intermontane Karewa Basin of Kashmir throughout the Late Quaternary Period.Additional data from lithostratigraphic measurements were analyzed to understand the geomorphic evolution of intermontane Karewa Basin.The data revealed that the basin has experienced differential uplift and erosion rates from time to time in the geological past.This was corroborated by the results from the morphometric and morphotectonic analysis.展开更多
Climate change and human activities make major influences on hydrology,which are known to have important impacts on streamflow variation.Therefore,it is critically important to identify how climate change and human ac...Climate change and human activities make major influences on hydrology,which are known to have important impacts on streamflow variation.Therefore,it is critically important to identify how climate change and human activities will impact streamflow variation.Thus,the goal of this study is to identify the impacts of climate change and direct human activities on annual streamflow at four hydrologic stations in the Weihe River basin of China,with the estimation of evaporation based on the Budyko hypothesis.The Mann-Kendall test was employed to detect the break points of the four stations.According to the occurrence time of break points,the data series were divided into two periods:pre-change period(1960-1984)and post-change(1985-2010)period.The parameter of one-parameter Budyko-type model was calibrated with observed data during the pre-change period,with the R^(2) values ranged from 0.95 to 0.97 and the NSE values ranged from 0.80 to 0.94,and the high R^(2) and Nash-Sutcliffe Efficiency coefficient shows the model has good performance.The contribution ratios of climate change impacts on decreasing streamflow were 37%,23%,57%and 43%,and those of the impacts of direct human activities were 63%,77%,43%and 57%for the Linjiacun,Xianyang,Lintong and Huaxian station,respectively.Both the climate change and direct human activities have positive impacts on streamflow decrease at all of the four stations,and the direct human activities are the main factor causing the decrease of annual streamflow.展开更多
文摘Morpho-tectonic study plays an important role in deciphering the effects of tectonic activity in the geomorphic evolution of the drainage basins.Romushi watershed forms one of the major watersheds of the intermontane Karewa Basin of Kashmir Valley.The Karewa sediments are characterized by glacio-fluvio-lacustrine deposits capped by the aeolian loess.The geomorphic,morphometric and lithostratigraphic studies of these cap deposits have been carried out to elucidate the effect of tectonics on the geomorphic evolution of Romushi Watershed.Geomorphic mapping was carried out using GPS measurements,DEM at 30m resolution,Topographic Position Index(TPI) model,topographic maps,LANDSAT TM Imagery and field data.Morphometric and morphotectonic analyses in GIS environment were used to calculate various geomorphic indices(Mountain Front Sinuosity Index,Bifurcation Ratio,Asymmetry Factor,River Profile,etc).These indices reveal that the tectonic uplift observed in the region due to Himalayan orogeny coupled with mass movement and aeolian deposition have dominated the landscape evolution of intermontane Karewa Basin of Kashmir throughout the Late Quaternary Period.Additional data from lithostratigraphic measurements were analyzed to understand the geomorphic evolution of intermontane Karewa Basin.The data revealed that the basin has experienced differential uplift and erosion rates from time to time in the geological past.This was corroborated by the results from the morphometric and morphotectonic analysis.
基金supported by the National Natural Science Foundation of China(Granted No:51190093,51179149,51179148)National Program on Key Basic Research Project(973 Program)in China(2011CB403306-3)+1 种基金Program for New Century Excellent Talents in University(NCET-10-0933)governmental public industry research special funds for projects(201501058)and China Scholarship Council.
文摘Climate change and human activities make major influences on hydrology,which are known to have important impacts on streamflow variation.Therefore,it is critically important to identify how climate change and human activities will impact streamflow variation.Thus,the goal of this study is to identify the impacts of climate change and direct human activities on annual streamflow at four hydrologic stations in the Weihe River basin of China,with the estimation of evaporation based on the Budyko hypothesis.The Mann-Kendall test was employed to detect the break points of the four stations.According to the occurrence time of break points,the data series were divided into two periods:pre-change period(1960-1984)and post-change(1985-2010)period.The parameter of one-parameter Budyko-type model was calibrated with observed data during the pre-change period,with the R^(2) values ranged from 0.95 to 0.97 and the NSE values ranged from 0.80 to 0.94,and the high R^(2) and Nash-Sutcliffe Efficiency coefficient shows the model has good performance.The contribution ratios of climate change impacts on decreasing streamflow were 37%,23%,57%and 43%,and those of the impacts of direct human activities were 63%,77%,43%and 57%for the Linjiacun,Xianyang,Lintong and Huaxian station,respectively.Both the climate change and direct human activities have positive impacts on streamflow decrease at all of the four stations,and the direct human activities are the main factor causing the decrease of annual streamflow.