国家自然科学基金51478344,41772295;国土资源部地面沉降监测与防治重点实验室开放基金No.KLLSMP201501.This work was supported by the National Natural Science Foundation of China51478344,41772295;the Key Laboratory of Land Subsidence Monitoring and Prevention,Ministry of Land and Resources of the People's Republic of ChinaKLLSMP201501