经过对坡度为5°和15°,集水面分别是塑料、水泥、三合土、夯实土和自然土等5种表面的车道型雨水径流试验研究结果表明,径流系数与降雨强度和坡度均有一定的关系;塑料、水泥面的平均径流系数为72％～77％,三合土、夯实土、自然土的平均径流系数为5％～18％。根据计算和试验结果,进行了垄膜沟植雨水集蓄试验研究,表明增产效果比较明显。根据设计降雨量、平均径流系数和小麦生育期需水量,估算了西峰、环县和天水等代表站集水面与耕种面积之比,其值在0.5～0.8之间。

The result of the rainwater harvesting test on the ten runoff zones-with slopes of 5 degrees and 15 degrees and covered with three -in-one soil,compacted soil and natural soil respectively, shows that the runoff coefficient is determined by rainfall intensity,slope and so on. The runoff coefficient is 72%-77% on the plastic and cement runoff zones and 5%-18% on the other runoff zones.Moreover,based on the calculated and test result,the test scheme-called furrow-culture and ridge-covered was carried out and the amount of increase in production is very notable.Meanwhile,according to the dependable rainfall,mean runoff coefficient and wheat water requirement,the ratio of harvesting area to planting area is calculated for the four representative stations and the value is 0.5-0.8.