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杨家沟位于秦安城东北3华里,是葫芦河的支流,属黄土邱陵第三副区。沟全长6.5公里,总流域面积11.85平方公里。海拔高程沟口为1,150公尺,分水岭最高为1,490公尺。共有大小支毛沟90多条,其中300～1,000公尺较大支沟42条,平均每平方公里有支毛沟13条。沟的中下游岩石裸露,沟多成V字形。支毛沟纵比降一般10°左右。洪水期含沙量达60％,年降雨量450公厘左右;60％多集中于7、8、9三个月。无霜期140天,早霜在9月上旬,晚霜在5月上旬,气候干燥,春旱较多,造成播种时的困难。最近几年气候变化,每当晚秋作物扬花结籽期,往往发生旱灾,减产。自然被复不良,村庄道路及沟凹处散生
Yangjiagou is located in the northeast of Qin’an City, 3 Wuli, is the tributary of the gourd, is a loess Qiu Ling third sub-district. Gully 6.5 km in length, the total drainage area of 11.85 square kilometers. Mizoguchi elevation of 1,150 meters, the highest watershed 1,490 meters. A total of more than 90 furrows in size, of which 300 to 1,000 meters larger than the tributary 42, with an average of 13 per furrow furrows. The rock in the middle and lower reaches of the trench is bare and the ditch is mostly V-shaped. Vertical furrow drop about 10 °. During the flood season, the sediment concentration reached 60% and annual rainfall was about 450 mm. More than 60% were concentrated in 7, 8 and 9 months. Frost-free period of 140 days, early frost in early September, late frost in early May, the climate is dry, spring drought, resulting in planting difficulties. In recent years, climate change, every late autumn flowering seedling stage, often drought, cut. Nature is bad complex, village roads and furrows scattered