High-resolution monitoring of inland water bodies across China in long time series and water resource changes

The accurate examination of inland water body distributions, types, areas and sizes is critical for global water cycling, while water resources and the diagnosis of utilization problem are essential to sustainable water management. Therefore, there remain less well-studied in China, especially for the accurate examination of long time series. Based on high-resolution satellite imagery from the late 1970s, statistical water resource data and precipitation data, this study identifies inland rivers, lakes, reservoirs and ponds larger than 0.001 km2, examines the regularity of different water distributions; analyzes area, perimeter and water resource changes for ten basins from long time series, quantitatively and qualitatively analyzes determinants, and illustrates main characteristics and water use problems affecting each basin and presents a number of suggestions. The results show that inland water body areas increased from 1980 to 2015 and that reservoir and pond areas increased considerably, while lake and river areas changed little. Land surface water resources and precipitation declined slightly from 1997 to 2015. Climatic conditions determine basic water body and resource distributions and volumes at the macroscopic scale, and human activities have greatly altered spatial patterns. Basin with rivers in the southwest includes highly exploitable water resources. Basin with rivers in the northwest faces considerable water shortages and fragile environmental conditions. The Yellow River, the Haihe River and the Songhua and Liaohe River Basins suffer from water shortages and pollution. The other four basins are experiencing eutrophication and frequent meteorological and geological hazards. Sustainable water management must be based on basin characteristics and major problems.