以沣河流域内秦渡镇水文站1956-2016年实测径流数据为基础,分析年内变化特征;用M-K方法对沣河年际、丰水期、枯水期3个时期的径流量进行了突变分析,再用滑动t检验突变点的可信度。结果表明:沣河年径流量在1956-2016年中整体呈减少趋势,...以沣河流域内秦渡镇水文站1956-2016年实测径流数据为基础,分析年内变化特征;用M-K方法对沣河年际、丰水期、枯水期3个时期的径流量进行了突变分析,再用滑动t检验突变点的可信度。结果表明:沣河年径流量在1956-2016年中整体呈减少趋势,减少率为175.71×10^(4) m ^(3)/a;径流年内分配在20世纪70、80年代较为集中,主要在7-9月,全年占比达43.87%,2006年以后年内分配较为均匀;沣河年径流量在1982年发生突变;丰水期在1977和1985年各发生1次突变,其中1977年的丰水期径流量全年占比从15.2%增加至64.4%;枯水期在2001年发生1次突变。研究结果可以为沣东、沣西新城的防洪和海绵城市建设以及陕西省斗门水库的正常运行提供参考。展开更多
为评估海绵化改造对城市内河洪水特性的影响,基于模型GAST(GPU accelerated surface water flow and transport model),定量研究了理想流域和沣河流域西咸新区沣西新城段海绵城市建设前后在3种入流条件(2.75、7.69、17.06 m^(3)/s)和3...为评估海绵化改造对城市内河洪水特性的影响,基于模型GAST(GPU accelerated surface water flow and transport model),定量研究了理想流域和沣河流域西咸新区沣西新城段海绵城市建设前后在3种入流条件(2.75、7.69、17.06 m^(3)/s)和3种降雨重现期(2、10、50 a)组合工况条件下的洪水流量过程。结果表明:设计降雨重现期为2、10、50 a时,理想流域的峰值流量削减率在6.64%~67.34%之间,实际流域的峰值流量削减率在2.66%~43.57%之间,两者差别不大。海绵化改造在一定程度上削减了内河的峰值流量,峰值削减率与上游来流量呈反比,与区间汇流量成正比。但峰现时间有延迟有提前,无明显规律。展开更多
Six outcrop sections in Fenghe River,Northwestern China,were sampled and analyzed.This study aims to determine provenance,tectonic setting,and source-area paleoweathering of the sediments of Fenghe River in combinatio...Six outcrop sections in Fenghe River,Northwestern China,were sampled and analyzed.This study aims to determine provenance,tectonic setting,and source-area paleoweathering of the sediments of Fenghe River in combination of lithofacies analysis and bulk-rock geochemical data.The lithofacies in the studied area were classified as gravel,sand,and fine-grained clastic lithofacies,reflecting generally channel fill deposits,channel bar deposits,and over-bank deposits,respectively.The Chemical Index of Alteration(CIA),Plagioclase Index of Alteration(PIA),and Chemical Index of Weathering(CIW)values ranged 50.10–62.29,50.13–66.35,56.52–71.12,respectively,together with element ratios such as Rb/Sr,K/Na,Rb/K,Th/K,Rb/Ti,and Cs/Ti indicate that the source area was under a low to moderate chemical weathering condition probably in cold and semi-arid climates.Moreover,plot of SiO_(2)vs.(Al_(2)O_(3)+K_(2)O+Na_(2)O)suggests that the sediments were deposited in a semi-arid climate.Plots of Cr/Th vs.Th/Sc,TiO_(2)vs.Zr,La/Yb vs.rare earth element(REE),and La-Th-Sc ternary diagrams,along with the lithology,indicate that the sediments in Fenghe River were mainly originated from felsic igneous rocks.Major elements-based discrimination diagrams and Th-Sc-Zr/10 and La-Th-Sc ternary diagram of the samples indicates that the source rocks of Fenghe River developed in a composite active continental margin and continental island arc field.展开更多
文摘以沣河流域内秦渡镇水文站1956-2016年实测径流数据为基础,分析年内变化特征;用M-K方法对沣河年际、丰水期、枯水期3个时期的径流量进行了突变分析,再用滑动t检验突变点的可信度。结果表明:沣河年径流量在1956-2016年中整体呈减少趋势,减少率为175.71×10^(4) m ^(3)/a;径流年内分配在20世纪70、80年代较为集中,主要在7-9月,全年占比达43.87%,2006年以后年内分配较为均匀;沣河年径流量在1982年发生突变;丰水期在1977和1985年各发生1次突变,其中1977年的丰水期径流量全年占比从15.2%增加至64.4%;枯水期在2001年发生1次突变。研究结果可以为沣东、沣西新城的防洪和海绵城市建设以及陕西省斗门水库的正常运行提供参考。
文摘为评估海绵化改造对城市内河洪水特性的影响,基于模型GAST(GPU accelerated surface water flow and transport model),定量研究了理想流域和沣河流域西咸新区沣西新城段海绵城市建设前后在3种入流条件(2.75、7.69、17.06 m^(3)/s)和3种降雨重现期(2、10、50 a)组合工况条件下的洪水流量过程。结果表明:设计降雨重现期为2、10、50 a时,理想流域的峰值流量削减率在6.64%~67.34%之间,实际流域的峰值流量削减率在2.66%~43.57%之间,两者差别不大。海绵化改造在一定程度上削减了内河的峰值流量,峰值削减率与上游来流量呈反比,与区间汇流量成正比。但峰现时间有延迟有提前,无明显规律。
基金Supported by the National Natural Science Foundation of China (Nos.42130206,41302076)the MOST Special Fund awarded by the State Key Laboratory of Continental Dynamics,Northwest University (No.201210128)the Shandong Provincial Key Laboratory of Depositional Mineralization&Sedimentary Mineral,Shandong University of Science and Technology (No.DMSM2017033)。
文摘Six outcrop sections in Fenghe River,Northwestern China,were sampled and analyzed.This study aims to determine provenance,tectonic setting,and source-area paleoweathering of the sediments of Fenghe River in combination of lithofacies analysis and bulk-rock geochemical data.The lithofacies in the studied area were classified as gravel,sand,and fine-grained clastic lithofacies,reflecting generally channel fill deposits,channel bar deposits,and over-bank deposits,respectively.The Chemical Index of Alteration(CIA),Plagioclase Index of Alteration(PIA),and Chemical Index of Weathering(CIW)values ranged 50.10–62.29,50.13–66.35,56.52–71.12,respectively,together with element ratios such as Rb/Sr,K/Na,Rb/K,Th/K,Rb/Ti,and Cs/Ti indicate that the source area was under a low to moderate chemical weathering condition probably in cold and semi-arid climates.Moreover,plot of SiO_(2)vs.(Al_(2)O_(3)+K_(2)O+Na_(2)O)suggests that the sediments were deposited in a semi-arid climate.Plots of Cr/Th vs.Th/Sc,TiO_(2)vs.Zr,La/Yb vs.rare earth element(REE),and La-Th-Sc ternary diagrams,along with the lithology,indicate that the sediments in Fenghe River were mainly originated from felsic igneous rocks.Major elements-based discrimination diagrams and Th-Sc-Zr/10 and La-Th-Sc ternary diagram of the samples indicates that the source rocks of Fenghe River developed in a composite active continental margin and continental island arc field.
