Improved maps of surface water bodies, large dams, reservoirs, and lakes in China

Abstract

Abstract. Data and knowledge of surface water bodies (SWB), including large lakes and reservoirs (surface water areas > 1 km2), are critical for the management and sustainability of water resources. However, the existing global or national dam datasets have large georeferenced coordinate offsets for many reservoirs, and some datasets have not reported reservoirs and lakes separately. In this study, we generated China's surface water bodies, Large Dams, Reservoirs, and Lakes (China-LDRL) dataset by analyzing all available Landsat imagery in 2019 (19 338 images) in Google Earth Engine and very-high spatial resolution imagery in Google Earth Pro. There were ∼ 3.52 × 106 yearlong SWB polygons in China for 2019, only 0.01 × 106 of them (0.43 %) were of large size (> 1 km2). The areas of these large SWB polygons accounted for 83.54 % of the total 214.92 × 103 km2 yearlong surface water area (SWA) in China. We identified 2418 large dams, including 624 off-stream dams and 1794 on-stream dams, 2194 large reservoirs (16.35 × 103 km2), and 3051 large lakes (73.38 × 103 km2). In general, most of the dams and reservoirs in China were distributed in South China, East China, and Northeast China, whereas most of lakes were located in West China, the lower Yangtze River basin, and Northeast China. The provision of the reliable, accurate China-LDRL dataset on large reservoirs/dams and lakes will enhance our understanding of water resources management and water security in China. The China-LDRL dataset is publicly available at https://doi.org/10.6084/m9.figshare.16964656.v3 (Wang et al., 2021b).

Analysing spatio‐temporal patterns of non‐native fish in a biodiversity hotspot across decades

“…Yunnan is estimated to have over 600 freshwater fish species (accounting for around 40% of the total number of freshwater fish species in China), and most of them are endemic (Chen, 2013; Chu & Chen, 1989, 1990; Tao et al, 2023). The region is dotted with over 23 isolated highland lakes and 125 reservoirs (>1 km 2 ), covered by the watersheds of six large rivers, namely the Jinsha‐Yangtze (watershed area in Yunnan: 109,382 km 2 ), Nanpan‐Pearl (59,191 km 2 ), Yuan‐Red (74,349 km 2 ), Lancang‐Mekong (88,287 km 2 ), Nu‐Salween (33,529 km 2 ) and Dulong‐Irrawaddy (19,097 km 2 ; Figure 1; Wang et al, 2022). These watersheds encompass all main types of waterbodies, including rivers, lakes and reservoirs (Figure 1).…”

“…According to the dominant waterbody type present, the subdrainage basins were allocated into four groups, including river type (subdrainage basins containing neither lakes nor reservoirs, N = 107), lake type (subdrainage basins containing lakes but no reservoirs, N = 11), reservoir type (subdrainage basins containing reservoirs but no lakes, N = 73) and lake‐reservoir coexistence type (subdrainage basins containing both lakes and reservoirs, N = 11). As fish occurrence data for small lakes and reservoirs were largely unavailable, only those with an area over 1 km 2 were counted (Wang et al, 2022). For subdrainage basin clipping, we assigned the entire subdrainage basin where the occurrence point presented is the distribution range of the species.…”

Can Water-Detection Indices Be Reliable Proxies for Water Discharges in Mid-Sized Braided Rivers Using Coarse-Resolution Landsat Archives?

“…Although NDVI, which is based on the NIR and red bands, is often used to detect vegetation coverage [45], it is extracted here to help understand the nature of the three selected indices. In general, image pixels with positive values of these indices represent water area and/or extent [46,47], though a negative threshold value of some indices has also been chosen for detecting water features [47,48].…”

A high-resolution dataset of water bodies distribution over the Tibetan Plateau

“…Besides surface water bodies, dataset of large dams and reservoirs was also generated by Wang et al . 25 .…”