山东省自然科学基金ZR2012DQ003;国家自然科学基金项目41301544;中国科学院南京地理与湖泊研究所"一三五"规划项目NIGLAS2012135002;the Natural Science Foundation of Shandong ProvinceZR2012DQ003;the National Natural Science Foundation of China41301544;the "1-3-5" Planning Program of Nanjing Institute of Geography and Limnology,Chinese Academy of SciencesNIGLAS2012135002