Simulating impact of over-grazing on grassland degradation using GIS: a case study in the Heihe River Basin, China

This study outlines the development of annual maps of irrigated cropland in China from 2000 to 2020 (CIrrMap250) by integrating remote sensing data, irrigated area statistics and surveys, and irrigation suitability map. CIrrMap250 showed superior performance than the existing products. CIrrMap250 revealed that China’s irrigated area has increased by about 180,000 km2 from 2000 to 2020, with the majority being water-unsustainable and occurring in regions facing high to severe water stress.

Little knowledge exists about whether students can improve their understanding of disaster risk reduction (DRR) through web geographic information system (GIS) technology and which factors affect their learning. This study has provided materials and curricula for DRR education in Chinese and Japanese high schools. The daily use of online maps and attention to disaster prevention affect the learning of all the materials. Increasing the use of online hazard maps is key to realizing social DRR.