Remote Sensing and GIS Support to Identify Potential Areas for Wetland Restoration from Cropland: A Case Study in the West Songnen Plain, Northeast China

Wetland restoration is important to responding to climate change and ensuring ecological security. In terms of the serious wetland loss and limited wetland restoration in China, there is a need to investigate approaches to identifying potential areas for wetland restoration from cropland, in order to support making spatial decisions at a regional scale. Here, we provide an example of integrating remote sensing (RS) and geographical information systems (GIS) effectively to identify where and how many croplands could be converted into wetlands in the West Songnen Plain (WSNP). The map of potential areas for wetland restoration from croplands generated in this study is expected to help decision makers to implement wetland restoration in the WSNP. Besides the widely highlighted hydrological, topographical, and landscape features, four indicators, namely, flooded area, time under cultivation, human disturbance, and wetland conservation level, were selected to identify the potential areas for wetland restoration—with different priorities—from croplands. Satellite observation revealed that a total of 2753.3 km2 of wetlands have been cultivated into croplands for grain production from 1990 to 2015 in the WSNP. It is estimated that 8882.1 km2 of croplands are suitable for conversion to wetlands, of which 3706 km2 (29.4%) are with high priority, and 44.5% are from dry farmlands. A total of 3284.7 km2 of paddy fields are identified to be potential areas for wetland restoration, of which 1119.6 km2 are high priority, and another 2165.1 km2 are medium priority.