Analysis of land cover change and rainfall on the global land surface water coverage database for 1987-2015

摘要

In this paper, taking into account population density of the world, major river basin was delineated continent wise all over the world using HYDRO1k data. Then, monthly rainfall change from the year 1981 to 2014 and daily LSWC (Land surface water coverage) change from 1987 to 2015 based on each major river basin was computed and compared with each other. A good agreement was found between LSWC pattern and rainfall pattern, showing a seasonal variation characteristic in each year. However, it could be seen that rainfall is not the only factor that bring about change in LSWC. Also, it was found that the change of urban area is very strong. Especially in Yangtze basin, from 2000 to 2012, the urban changed from 0.07% to 0.83%. Moreover, the proportion of cropland increased significantly, especially in Ganges basin increased by 57.64%, grew to nearly 70% from 1992 to 2012. Besides, the trend of consistent growth was showed both in cropland and LSWC. It is indicated that the widespread expansion of cropland may bring about LSWC increasing.