1980—2015 年清水河流域水系连通变化研究

为揭示城市化发展情景下区域水系连通的变化规律, 以永定河支流清水河流域为对象, 集成遥感影像、统计资料及土地利用等数据, 运用河流连通性综合评价体系, 将基于障碍物累积影响的河流纵向连通性及基于土地破碎度的河流横向连通性相结合, 系统性地研究1980—2015年清水河流域的水系连通性变化。根据专家知识并结合清水河实际情况, 可将清水河河道阻碍物分为水库、水闸、漫水桥和河道堆积物4种类型。1980—2015年阻碍物的数量持续增长, 2000年比1980年增加10.4%, 2015年增加23.9%。1980—2015年,清水河流域纵向连通性整体上呈升高趋势, 纵向连通性差的汇水区比例由1980年的40%逐渐降低 2015年的14%。纵向连通性升高的区域集中在流域东部及中部, 西南部部分汇水区连通性加剧恶化。河流横向连通性整体上变化不明显, 其中流域西部有所下降, 东部有所好转。1980—2015年清水河流域综合连通性整体上呈升高趋势, 综合连通性差的汇水区占比在1980, 2000和 2015年分别为26%, 17%和11%。综合连通性升高的区域集中在流域东部, 而流域西南部部分区域连通性始终较差。研究结果揭示了京津冀城市化进程中流域连通性的变化规律, 可为区域防洪减灾和河流生态修复提供参考。

Study on the Change of River Connectivity in QingshuiRiver Basin from 1980 to 2015

In order to reveal the changing rules of regional water system connectivity under the development ofurbanization, this paper takes Qingshui River, a tributary of the Yongding River, as an object, integrates remotesensing imagery, statistical data, and land use data, uses the comprehensive evaluation system for river connectivity, combining the longitudinal connectivity of rivers based on the cumulative effects of barriers and thelateral connectivity of rivers based on the effects of catchment fragmentation, and systematically studies the connectivity changes of water systems in the Qingshui River Basin from 1980 to 2015. The results of the studyindicate that based on expert knowledge and combined with the actual situation of the Qingshui River, the barriersof the Qingshui River can be divided into four types: reservoirs, sluice gates, diffuse bridges, and riveraccumulations. During the study period, the number of barriers continues to increase. In 2000, the number ofbarriers increases by 10.4% in comparison with 1980 and increases by 23.9% in 2015. From 1980 to 2015, thelongitudinal connectivity of the Qingshui River Basin as a whole shows an upward trend. The proportion of thewatershed with poor vertical connectivity gradually decreases from 40% in 1980 to 14% in 2015. The areas withincreased vertical connectivity are mainly concentrated in the eastern and central parts of the basin, and theconnectivity in the southwestern part of the catchment area deteriorates. The overall change in river lateralconnectivity is not significant, with the western part of the basin decreasing and the eastern part having improved.From 1980 to 2015, the comprehensive connectivity of the Qingshui River Basin shows an overall upward trend.The proportion of catchments with poor comprehensive connectivity is from 26% in 1980, 17% in 2000 and 17% in2015, respectively. The areas with increased connectivity are mainly concentrated in the east of the basin, while theconnectivity in some areas in the southwest of the basin is always poor. The study reveals the law of connectivitychanges in the basin during the urbanization process in Beijing, Tianjin and Hebei, and can provide a scientificreference for regional flood prevention and disaster reduction and river ecological rehabilitation.