东北黑土区土壤侵蚀模型中植被因子C值的研究

C-value in the Model of Soil Erosion in Black Earth Area in the Northeastern China

利用人工降雨径流模拟试验法,重点研究了美国通用土壤流失方程(USLE)中植被与土壤侵蚀关系因子C值的地方适用性。初步估算出东北黑土农业区不同土地利用类型土壤侵蚀和非点源污染流失量化计算中的C值取值范围,进一步与国内其他地区应用的C值进行比较,得出了较满意的结果。其规律为本次试验C值普遍小于原美国通用土壤流失方程(USLE)中给出的经验C值。在此基础上,将试验C值应用于吉林二龙湖流域土壤侵蚀量研究中,并通过试验C值计算的土壤侵蚀量与其他方法计算结果相比较,验证估算值在实际应用中的适用性和实用性,为黑土丘陵区土壤侵蚀和非点源污染的控制和治理提供了科学依据。

The local applicability of Vegetation Coverage （C） factor in the Universal Soll Loss Equation was focused by using man-made rainfall simulation to insure the veracity of soil erosion estimated in black soil area in the Northeastern China. The C value was calculated by the formula C=Aplant/Ano plant, after compared with other C values used in different domestic regions, the results were relatively satisfied. The experimental C values followed the order： Chigh-coverage meadow〈Cshrub〈Carbor〈Clow-coverage meadow〈Ccom, and increased with the increase of slope of the same plant coverage. The coverage degree affected the C factor value prominently, with the C high-coverage meadow much lower than C low-coverage meadow. In the same condition of the soil and the same amount of rainfall, the Cshrub was lower than Carbor because of thick deadwood in shrub. The C value in dry land （corn land）was estimated 0.148-0.341, similar to the datum got from other domestic regions. The experimental Carbor and C low-coverage meadow were similar to the values used in Hainan Island, while, Cshrub and C high-coverage meadow were lower than those in the other parts. The experimental C values were lower than the ones in experienced C values in Universal Soil Loss Equation （USLE） generally, based on which, soil erosion load in the Erlong Lake, Jilin province was calculated by using the experimental C values and compared with the data calculated in other ways to validate the reliability and practicability of experienced C value, which provided a scientific basis for controlling and managing agriculture non-point source pollution in black soil hilly region.