Identifying Catchments and Their Hydrological Boundaries in the Four Basins within Henan Province

Abstract

【Objective】 Identifying catchments and their hydrological boundaries in a river basin is important for improving water resource management and protecting its eco-environmental development. Taking the four rivers flowing through Henan province as an example, this paper calculated the catchments and their associated areas in each basin across the province. 【Method】 The four rivers we considered were the Yangtze River, the Yellow River, the Huai River and the Hai River; their catchment identification was based on the digital elevation model (DEM) data, where each catchment and its hydrological boundaries, streams at different levels, as well as counties in each basin were identified and calculated using ArcHydro in ArcGIS extension module. 【Result】 In terms of covered area, the biggest basin in the province is the Huai River, covering 52.70% of the provincial area, followed by the Yellow River with 21.62%, the Yangtze River with 16.50%, and the Hai River with 9.18%. In terms of areas being affected, the Yellow River impacted more places including Xingyang, Huiji and Jinshui District in Zhengzhou, Longting District, Xiangfu and Lankao County in Kaifeng, although some of them are not within its hydrological catchments. In terms of river network, the Yangtze River basin is most dense with a river-length density of 0.36 km/km2, followed by the Yellow River basin with 0.30 km/km2, the Huai River basin with 0.27 km/km2, and the Hai River basin with 0.20 km/km2. Spatially, river network is least dense in the north of the Yellow River, with a density of 0.15 km/km2 only. 【Conclusion】 ArcHydro in ArcGIS is accurate to extract catchment boundaries and the river network system in a basin, and it can be used for regional analysis of land usage or water resource management.

Keywords

• archydro
• digital elevation model (dem)
• henan province
• basin boundary
• river network