论文部分内容阅读
湖沼地区,主要指长江中下游的洞庭湖、波阳湖、太湖等地区。湖沼地区按地形可分为湖汊、洲滩、垸(读音同“院”,湖南、湖北省在湖泊地带挡水用的堤圩)内三个类型。湖汊与洲滩型的钉螺,主要分布在冬季枯水位线及夏季洪水位线之间的一定高程的芦、草滩范围内。在一年中被水淹2～4个月的滩地,钉螺密度较高,与有螺滩地相连的河沟、塘、废田也常有螺。水淹在8个月以上以及洪水淹不到的地带,一般无螺。垸内型的钉螺主要分布在其内湖边、荒地、沟渠和田边。湖沼地区有螺面积宽广,约占全国有螺面积90％,包括湖南、湖北、江西、江苏、安
Lake area, mainly refers to the middle and lower reaches of Yangtze River Dongting Lake, Bo Yang Lake, Taihu Lake and other regions. Lakes and terrain can be divided into three types according to the terrain: lakeshore, beach, embankment (pronounced the same as “hospital”, Hunan, Hubei in the lake with the water retaining dike). The snail on the lake and the island beach are mainly distributed in the range of grasslands and grasslands at a certain elevation between the winter dry water level line and the summer flood water level line. During the year flooded 2 to 4 months of the beach, snail density is higher, with the conch beach connected river ditch, ponds, waste fields often snail. Water flooded in more than eight months and flooding can not reach the area, generally non-Lo. Embankment-type snails are mainly distributed in the lake, wasteland, ditch and Tanabe. Lakes and lakes area has a broad spiral area, accounting for about 90% of the national spiral area, including Hunan, Hubei, Jiangxi, Jiangsu, Ann