Topographical maps not only show planimetric position but also indicate relief by some method.

地形图不仅表示位置，而且还通过某种方法显示地貌。

We propose that As anomalism in groundwater possibly resulted from the combined effects of organic matter-enriched lacustrine sediments, geological setting and topographical characteristics.

通过究，可以看以还原环境为主富含有机沼相沉积环境、特定地、地形条件为地下水砷异常原因。