1. School of Electronics and Information Engineering, Sias University, Xinzheng, China
2. School of Environment, Nanjing Normal University, Nanjing, China
3. Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing, China
4. Department of Geological Sciences, University of Alabama, Tuscaloosa, AL, USA
5. Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, Shenzhen, China