南四湖流域位于山东省的西南部,包括济宁市、枣庄市和菏泽市。地形东、西高,中部南四湖最低。大致以津浦铁路为界,东部为鲁中南低山丘陵区的西侧边缘,岩类以泰山群变质岩和寒武系、奥陶系的灰岩夹页岩为主,花岗岩次之。石炭系、二迭系、侏罗系碎屑岩多被第四系覆盖,仅在泗水、枣庄南部有零星出露。岩体的地基强度一般良好。湖西地区为黄泛冲积平原,除嘉祥、梁山一带有残山出露寒武系、奥陶系岩层外,其余均被第四系松散物所覆盖。土体除特 Nansi Lake Basin is located in the southwest of Shandong Province, including Jining, Zaozhuang and Heze City. Topography of the East, West, Central South Lake lowest. It is roughly bounded by the Jinpu Railway and the eastern part of the western edge of the Luzhongnan hilly region. The rocks are mainly composed of Taishan Group metamorphic rocks and Cambrian and Ordovician limestone intercalated rocks, followed by granite. Carboniferous, Permian, Jurassic clastic mostly covered by the Quaternary, only in Surabaya, southern Zaozhuang sporadic. The strength of the rock mass is generally good. In the western Hubei region, the Yellow River flood alluvial plain, with the exception of Jiaxiang and Liangshan, there are residual Cambosian and Ordovician rock outcrops, while the rest are covered by quaternary loose material. In addition to special soil