1. School of Water Conservancy and Civil Engineering, Northeast Agricultural University, Harbin 150030, China
2. Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun, China
3. Key Laboratory of Groundwater Resources and Environment Ministry of Education, Jilin University, Changchun 130021, P. R. China