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1 流域概况城山小流域位于东港市西北部,总面积20.5km~2。流域内两个村,1055户。农业人口3975人。该流域属北温带湿润地区,年降雨量889mm。多降于6~8月份,多年年均蒸发量1200mm。无霜期145天。多年来,由于管理不善,山林被乱砍滥伐,蚕场长期过度放养,多处开矿采石、烧窑,使这里的水土流失逐年加剧,每逢汛期,流域内常发生洪水灾害。仅1985年的两次洪水就冲毁耕地13.3多hm~2,水冲沙压20hm~2。80%的山区小河堤被冲毁,经济损失达10多万元。
1 Basin Overview Chengshan small watershed is located in the northwest of Donggang City, with a total area of 20.5km ~ 2. Two villages in the basin, 1055 households. Agricultural population of 3975 people. The basin is humid north temperate, annual rainfall of 889mm. More down in 6 to August, many years the average annual evaporation 1200mm. Frost-free period of 145 days. Over the years, due to poor management, deforestation has been deforested, long-term over-stocking silkworm farm, many mining quarrying, kiln, so that the soil erosion year by year intensified every flood season, frequent floods within the basin. Only two floods in 1985 washed away more than 13.3 hm2 of cultivated land and the flood embankment in the mountainous area with a flood pressure of 20hm ~ 2.80% was destroyed with an economic loss of more than 100,000 yuan.