1. Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences,State Key Laboratory of Resources and Environment Information System,Beijing,China,100101
2. Chinese Academy of Agricultural Sciences,State Key Laboratory of Efficient Utilization of Arid and Semi-Arid Arable Land in Northern China, Institute of Agricultural Resources and Regional Planning,Beijing,China,100081
3. Beijing Water Science and Technology Research Institute,Beijing,China,100048