基于RUSLE模型的三江源高寒草地土壤侵蚀评价

发布时间：2018-12-11 06:10

【摘要】：探讨三江源区高寒草地生态系统土壤侵蚀问题在保障青藏高原乃至全球生态和生产功能方面具有重要意义。以~(137)Cs示踪法为基础,结合RUSLE(Revised Universal Soil Loss Equation)模型,以GIS反演为手段,综合分析三江源区2001-2012年土壤侵蚀影响因子的特征和土壤侵蚀空间分布规律。结果表明,1)土壤侵蚀影响因子呈现空间异质性特征,降雨侵蚀力因子年际浮动变化较大,但总体呈上升态势;土壤可蚀性因子呈斑块化分布特征,较高可蚀性类占到总面积的95.66%;坡度坡长因子的空间分布规律受海拔显著影响;植被覆盖与管理因子在研究区自西北向东南呈现空间异质性特点,过度放牧是引起下垫面侵蚀现象严重的主要原因。2)对RUSLE模型的验证显示相关系数和平均均方根偏差分别为0.49和75.29%,RUSLE模型估算存在一定的高估,在没有形成三江源区高寒草地土壤侵蚀机理模型前,应用RUSLE模型仍然是较好的现实选择之一。3)利用RUSLE模型估算的三江源2001-2012年平均侵蚀量为3.1×109 t/年,侵蚀强度分级重心转移分析表明中度侵蚀、强度和极强度侵蚀重心相对集中,侵蚀程度最高的3个地区为格尔木市唐古拉乡、治多县和兴海县。4)由土壤流失量结合市场价值法,估算出研究区2001-2012年平均有机质经济损失价值为114354元/km2,总年均经济损失达399亿元,整个研究区受土壤侵蚀现象所产生的经济损失数额巨大。因此,创新发展三江源区高寒草地"分类、分级、分段、分区"的土壤侵蚀防治措施已迫在眉睫。
[Abstract]:It is of great significance to discuss the problem of soil erosion in alpine grassland ecosystem in the source region of the three Rivers in order to protect the ecological and productive functions of the Qinghai-Tibet Plateau and even the whole world. Based on ~ (137) Cs tracer method, combined with RUSLE (Revised Universal Soil Loss Equation) model and GIS inversion, the characteristics of soil erosion influencing factors and the spatial distribution of soil erosion in the source region of the three Rivers from 2001 to 2012 were analyzed. The results showed that: 1) soil erosion factors showed spatial heterogeneity, rainfall erosivity factors fluctuated greatly among different years, but the overall trend was rising; The characteristics of soil erodibility factor were patch distribution, the higher erodibility class accounted for 95.66% of the total area, the spatial distribution law of slope length factor was significantly affected by altitude. Vegetation cover and management factors showed spatial heterogeneity from northwest to southeast in the study area. Overgrazing is the main reason for the serious erosion of the underlying surface. 2) the correlation coefficient and the mean root mean square deviation of the RUSLE model are 0.49 and 75.29 respectively, and the estimation of the RUSLE model is overestimated to some extent. Before the formation of the soil erosion mechanism model of alpine grassland in the source region of the three rivers, the application of RUSLE model is still one of the better practical choices. 3) the average erosion amount of the three rivers in 2001-2012 estimated by RUSLE model is 3.1 脳 10 ~ 9 t / year. The analysis of gradation gravity center transfer of erosion intensity shows that the center of gravity of moderate erosion, intensity and extreme intensity erosion is relatively concentrated, and the three areas with the highest erosion degree are Tanggula Township of Golmud City. According to the method of soil loss and market value, the average economic loss of organic matter in the study area from 2001 to 2012 was estimated to be 114354 yuan / km2, and 39.9 billion yuan per year. The economic loss caused by soil erosion in the whole study area is huge. Therefore, it is urgent to develop the soil erosion control measures of classification, division and division of alpine grassland in the source area of the three rivers.
【作者单位】：草地农业生态系统国家重点实验室农业部草牧业创新重点实验室兰州大学草地农业科技学院;华能新能源股份有限公司;
【基金】：国家重点研发计划(2016YFC0501906) 国家自然科学基金面上项目(31172250)资助
【分类号】：S812.2

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