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黄土丘陵区的地形特点,就是沟多、平地少而分散。凡沟长在5公里以上者,多已下切到岩石层。在岩层缝隙里,往往有泉水涌出,成为终年流水的山溪。这就给这个地区普遍兴修小型水利准备了有利条件。同时,由于川道里耕地块小而分散,人口稀、劳力少等特点,采取群众性的小型水利措施比较经济。事实也是这样。在这些地区,二、三千亩的灌区,就要算做大型工程。同时由于旁山开渠,沟道密,桥涵也多,因而造价就高。根据经验每亩造价均约在百元左右,以往都是由国家投资兴办。同时,即使造价
Loess hilly terrain features, that is, more ditch, flat and scattered. Where ditch longer than 5 km, many have been cut to the rock layer. In the crevices of the rock formations, there are often spring water pouring out and become the stream that flows year after year. This has provided favorable conditions for the widespread rebuilding of small-scale water resources in this area. At the same time, due to the small and scattered cultivated land in Chuan Road, the population is small and the labor force is low. Therefore, it is more economical to adopt mass water conservancy measures. The same is true. In these areas, two or three thousand acres of irrigated areas should be counted as large-scale projects. At the same time as the next mountain open channel, dense channel, bridges and culverts and more, so the cost is high. According to experience, the cost per acre is about 100 yuan, in the past, it was invested by the state. At the same time, even if the cost