我区位于浙北杭嘉湖平原,境内河网密布。全区中部和东北部地势特别低平,水田的高程多在3—4米之间(距吴淞零点),河流年平均水位在3—3.2米,在多雨季节,不少地方水位高于田面。土壤以河湖相沉积物发育的青紫泥和黄斑土为主,土层深厚肥沃。但因质地粘细,透水性差,15—20厘米的土层形成滞水层(常称“潜水层”),使大麦、小麦、油菜、紫云英等越 My area is located in northern Zhejiang Hangjiahu plain, the territory of the river network. The terrain is particularly low in the central and northeastern part of the region. The paddy fields have an elevation of 3-4 meters mostly (from the Wusong zero point). The average annual river water level is 3-3.2 meters. In the rainy season, many places have higher water levels than the fields. The soil is mainly composed of brucite and macrophyllite, which are rich in sediments of rivers and lakes, with deep and fertile soil. However, due to fine texture sticky, poor water permeability, 15-20 cm of soil formation of water layer (often called “diving layer”), so that barley, wheat, rape,