Quantitative analysis was performed on the filling-scouring process for the river reach within Makou and Tianjiazhen, the middle Yangtze River with the help of GIS and DEM techniques. The research results indicate tha...Quantitative analysis was performed on the filling-scouring process for the river reach within Makou and Tianjiazhen, the middle Yangtze River with the help of GIS and DEM techniques. The research results indicate that the river reach between Makou and Tianjiaz- hen was dominated by the scouring process, and the magnitude of scouring is increasing over time. The intensity of scouring process is more in the deep and narrower river reach than shallower and wider ones. The river reach in the Makou and Tianjiazhen river knot is in frequent scouring and filling process, however the river reach upper to the Makou and lower to the Tianjiazhen river knot is in moderate scouring and filling process. The river reach just upstream or downstream to the river knot （e.g. Makou and Tianjiazhen river knot in this research） is dominated by filling process and the river reach in the river knot is dominated by the scouring process. Research results indicate no changes in the boundary of the river but the scouring and the filling magnitude in specific river channel is strong. The filling and the scouring process of the study river reach is greatly impacted by the sediments and water from the upstream of the study river reach. The construction of the Three Gorges Dam just up- stream to Yichang will cause further decrease of the release of the sediment load to the middle and the lower Yangtze River basin, which will further intensify the scouring process of the river channel in the study river reach.展开更多
据苕溪流域现有的地层学、考古学、地方志等资料考证,其河道变迁可追溯至晚更新世末,演化过程具有阶段性:1)18—15 ka BP,苕溪河道剧烈下切,东、西苕溪独流入海,西苕溪顺地势东北流入海,东苕溪东流入杭州湾;2)15.0—7.5 ka BP,苕溪河道...据苕溪流域现有的地层学、考古学、地方志等资料考证,其河道变迁可追溯至晚更新世末,演化过程具有阶段性:1)18—15 ka BP,苕溪河道剧烈下切,东、西苕溪独流入海,西苕溪顺地势东北流入海,东苕溪东流入杭州湾;2)15.0—7.5 ka BP,苕溪河道下切能力减弱,沉积作用加强,东、西苕溪独流入海.8.7 ka BP以前,西苕溪流进钱塘谷地后注入杭州湾,8.7 ka BP之后,西苕溪流进古太湖湾;3)7.5—4.0 ka BP,苕溪河道沉积作用明显,河口发生淤积,5.0 ka BP以前,东、西苕溪独流入海,5.0 ka BP之后,西苕溪流入古西太湖,东苕溪在余杭东改道北流,入一泻湖,并在5.0—4.0 ka BP期间3次大规模改道;4)4.0 ka BP以来,苕溪河道沉积作用明显,东、西苕溪合流入太湖,且中下游段改道频繁.苕溪河道变迁始终与本区地理环境演化密切相关,包括对海面升降变化的响应、与太湖发育及古地形演变等的互动.展开更多
基金The research was financially supported by the Laboratory for Climate Studies, National Climate Center, China Meteorological Administration, No.CCSF2007-35 Supported by the Research Grants Council of the Hong Kong Special Administrative Region, China, No.CUHK4627/05H
文摘Quantitative analysis was performed on the filling-scouring process for the river reach within Makou and Tianjiazhen, the middle Yangtze River with the help of GIS and DEM techniques. The research results indicate that the river reach between Makou and Tianjiaz- hen was dominated by the scouring process, and the magnitude of scouring is increasing over time. The intensity of scouring process is more in the deep and narrower river reach than shallower and wider ones. The river reach in the Makou and Tianjiazhen river knot is in frequent scouring and filling process, however the river reach upper to the Makou and lower to the Tianjiazhen river knot is in moderate scouring and filling process. The river reach just upstream or downstream to the river knot （e.g. Makou and Tianjiazhen river knot in this research） is dominated by filling process and the river reach in the river knot is dominated by the scouring process. Research results indicate no changes in the boundary of the river but the scouring and the filling magnitude in specific river channel is strong. The filling and the scouring process of the study river reach is greatly impacted by the sediments and water from the upstream of the study river reach. The construction of the Three Gorges Dam just up- stream to Yichang will cause further decrease of the release of the sediment load to the middle and the lower Yangtze River basin, which will further intensify the scouring process of the river channel in the study river reach.
文摘据苕溪流域现有的地层学、考古学、地方志等资料考证,其河道变迁可追溯至晚更新世末,演化过程具有阶段性:1)18—15 ka BP,苕溪河道剧烈下切,东、西苕溪独流入海,西苕溪顺地势东北流入海,东苕溪东流入杭州湾;2)15.0—7.5 ka BP,苕溪河道下切能力减弱,沉积作用加强,东、西苕溪独流入海.8.7 ka BP以前,西苕溪流进钱塘谷地后注入杭州湾,8.7 ka BP之后,西苕溪流进古太湖湾;3)7.5—4.0 ka BP,苕溪河道沉积作用明显,河口发生淤积,5.0 ka BP以前,东、西苕溪独流入海,5.0 ka BP之后,西苕溪流入古西太湖,东苕溪在余杭东改道北流,入一泻湖,并在5.0—4.0 ka BP期间3次大规模改道;4)4.0 ka BP以来,苕溪河道沉积作用明显,东、西苕溪合流入太湖,且中下游段改道频繁.苕溪河道变迁始终与本区地理环境演化密切相关,包括对海面升降变化的响应、与太湖发育及古地形演变等的互动.
