国家重点基础研究发展计划项目No.2012CB417004;国家自然科学基金No.41173118;易灾地区生态环境功能评估项目No.2110199;Supported by the National Basic Research Program of China No.2012CB417004,the National Natural Science Foundation of ChinaNo.41173118 and the Program of Ecological Environment Function Evaluation of Easy to Disaster Area of China No.2110199