海河流域河流空间分布特征及演变趋势

海河流域涵盖我国"京津冀"经济圈,河流对流域内人类生存和经济发展具有重要支撑作用,研究河流空间分布及演变趋势对于合理利用河流水资源、保护河流生态和实现经济可持续发展具有重要意义.本文运用遥感资料的GIS分析方法,对海河流域的河流地貌、水系结构、河流曲率和河网密度、闸坝等指标进行分析,发现:1海河流域河流地貌划分为上游山区段、中部平原段和下游滨海段,3个区段水系形状依次为树枝状(受人为干扰小),编织状(中度人为干扰),稀疏编织状(人为干扰强烈);2流域水库和水闸修建阻断河流纵向连续性,五大水系(滦河、北三河、永定河、大清河、子牙河)连续性指标值低于5;320世纪60年代—80年代—2000年,流域河流平均曲率不断减小,河网密度呈现不定向波动,反映出人为控制对河道形态改变程度大.今后应减少人类活动对河流自然属性的改变,河流治理和修复过程中应充分考虑保护和改造河流地貌、水系结构、河流曲率和河网密度.

The spatial distribution and evolution trend of rivers in Hai River Basin

River systems provide necessary resources supporting economic development of the Hai River Basin which covers the "Jing-Jin-Ji" economic region. It has important implications for rational utilization of water resources, maintenance of a good ecological condition, and sustainable economic development to study distribution and evolutionary tendency of river systems. Based on the remote sensing image, we analyzed fluvial landform, form of river networks, reservoir and sluice, channel curvature and density using Arcgis, and the results show that:1 The Hai River System was classified into the upper reaches of the mountain zone, the middle reaches of the plain and the lower reaches of coastal areas terrain according to its land forms. The shapes of river networks were divided into "arborization" (least human disturbance), "braiding" (moderate human disturbance) and "sparse braiding" (intense human disturbance). 2 Connectivity along river channel was blocked by a large amount of reservoirs and sluices. There were five river systems (Luanhe, Beisanhe, Daqinghe,Yongdinghe, Ziyahe) with continuity index below 5. 3 From the 1960s, the 1980s to the year 2000, mean channel curvature decreased, and drainage density showed a non-directional fluctuation, which indicated a strong human disturbance. It is significant to reduce negative effects on natural attributes of river systems. During the process of river improvement and restoration, it needs to give adequate consideration in the protection and modification of landform, structure of river system, channel curvature and density.