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苏联科学院通讯院士A·A·莫尔恰诺夫指出,由于采伐木材,森林覆盖率下降,径流层和径流系数便增加,而在皆伐迹地上则几乎增长9倍。伐区的分布位置甚为重要,集水区下部的伐区对径流影响最大。上部和中部的皆伐迹地上形成的地表径流被集水区下部未经采伐的森林所吸收。在头5—6年内采伐对径流和径流系数变化的影响最大。美国在科罗拉多州选了两个毗邻的、完全绿化的集水区,面积各约90公顷。经8年观测
A. Morcianov, a communication fellow at the Academy of Sciences of the Soviet Academy of Sciences, pointed out that because of the decrease in forest cover due to the harvesting of timber, the runoff and runoff coefficient have increased, while the declination has almost increased ninefold. The distribution of cutting areas is very important, and the cutting area at the lower part of the catchment area has the greatest impact on runoff. The surface runoff formed in the upper and middle deforestation is absorbed by the undisturbed forest in the lower part of the catchment. Logging had the greatest impact on runoff and runoff coefficient changes in the first 5-6 years. The United States has selected two adjacent, fully greenery catchments in Colorado, each covering about 90 hectares. After 8 years of observation