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一、拦海造田区概况辽宁兴城拦海造田地区,位于辽宁省兴城县南渤海沿岸,地处暖温带半湿润地区,无霜期约175天,年平均气温9℃左右,年雨量600毫米上下,夏季降雨约占年雨量的60%,年蒸发量大于降雨量2～3倍,以五月份最大,因而围垦后土壤中可溶性盐季节性变化很明显.拦海造田区,原为渤海沿岸的长山寺湾,其形势系三面环山,东面连海的海湾浅滩,地势低平,高程一般为1.3米至～0.36米,局部地区-1.0米以下.围垦后田面大部份低于高潮位2～3米,垦区中部有潮沟由西向东伸展,至防潮坝附近形成一平坦洼地,可集积全灌区的地表水和地下径流,在垦区的西部和边缘修筑了防洪堤,封闭灌区,形成外水与内水分隔的排水体系,在封闭区以外140多平方公里的洪水,可沿防洪堤外新开河道,通过防洪排水闸排出,封闭区内
I. Overview of Blocking Coastal Areas of Liaoning Province Xingcheng Blocking Coastal Areas in Liaoning Province is located in the coast of the southern Bohai Sea in Xingcheng County, Liaoning Province. It is located in warm temperate semi-humid areas with frost-free period of about 175 days and an average annual temperature of about 9 ℃. Annual rainfall of 600 mm , Summer rainfall accounts for about 60% of the annual rainfall, annual evaporation is greater than 2 to 3 times the rainfall, the largest in May, so reclamation of soluble salt seasonal changes in the soil is very obvious. Changshan Temple Bay, the situation is surrounded by mountains on three sides, east of the sea with the Gulf Shoal, flat low level, the elevation is generally 1.3 meters to ~ 0.36 meters, some areas -1.0 meters below the reclamation of most of the fields below the high tide bit 2 to 3 meters. In the central part of the reclamation area, tidal flats extend from west to east to form a flat depressions near the dam, which can accumulate surface water and underground runoff in the whole irrigation area. Flood dykes, closed irrigation areas, Formed a drainage system of external water and internal water separation, in the enclosed area of more than 140 square kilometers of flood, flood control embankment can be opened along the river, flood discharge, closed area