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针对京津水源区生态环境脆弱、水土流失空间分异大、突发性强等问题,以河北省平泉县东北沟典型小流域为例,采用GIS技术与CSLE模型对其土壤侵蚀进行二维空间模拟及侵蚀规律研究,并对模型模拟精度进行验证。结果表明:模型确定性系数>0.85,模拟结果可信度高;小流域侵蚀模数为2359.24t·km-2·a-1,属于轻度侵蚀,侵蚀主要源于15°以上坡面,占侵蚀总量的92.1%;土壤侵蚀模数随坡度先逐渐增加,当坡度>45°时,土壤侵蚀模数有减小的趋势;土壤侵蚀模数空间异质性显著,坡耕地侵蚀模数最大,为6112.90t·km-2·a-1;荒草地占总面积33.2%,侵蚀量却达总量的74.9%;59.3%的侵蚀来自阳坡和半阳坡,而阴坡半阴坡仅占流域侵蚀量的16.2%。研究为利用CSLE模型对小流域土壤侵蚀进行空间模拟提供技术范例,为京津水源区土壤侵蚀规律研究及水土保持生态建设提供科学参考。
In view of the fragile ecological environment in Jing-Jin water source area, the large spatial heterogeneity of soil and water loss, and sudden emergencies, taking the typical small watershed of Dongbeigou, Pingquan County, Hebei Province as an example, the two-dimensional space of soil erosion was studied using GIS and CSLE models Simulation and erosion research, and verify the model simulation accuracy. The results show that the model has a certainty coefficient of> 0.85, and the simulation result has high credibility. The erosion modulus of small watershed is 2359.24t · km-2 · a-1, which belongs to slight erosion. The erosion mainly comes from the slope above 15 °, accounting for The soil erosion modulus increased gradually with slope degree. When the slope degree was more than 45 °, the soil erosion modulus tended to decrease. The spatial heterogeneity of soil erosion modulus was significant, and the erosion modulus of sloping land was the largest , Which is 6112.90t · km-2 · a-1. The total area of wasteland is 33.2%, while the erosion amount is 74.9% of the total. 59.3% of the erosion comes from the sunny and semi-sunny slopes, while the shady and half-slope only Accounting for 16.2% of the basin erosion. The study provides a technical example for using CSLE model to simulate soil erosion in small watershed, and provides scientific reference for the research on soil erosion law and soil and water conservation and ecological construction in Beijing and Tianjin water source areas.