青海省高寒草地土壤侵蚀强度及其空间分布特点

Soil Degradation Intensity and Spatial Distribution Characteristics of Alpine Grassland in Qinghai Province

开展高寒草地土壤退化评价有助于掌握高寒草地退化的空间分布规律,对维持草地生态安全、保障区域可持续发展具有重要的意义。本研究基于改进的通用土壤侵蚀修订模型对青海省高寒草地土壤侵蚀退化强度和空间分布进行评价,并计算了2005—2014年青海省高寒草地土壤侵蚀评价指数,从而分析其变化趋势。结果表明:2014年度青海省高寒草地土壤侵蚀强度轻度、中度、重度和极度剧烈退化面积及占比分别为166925 km^(2)(39.5%),98729 km^(2)(23.4%),949401 km^(2)(22.5%)及61787 km^(2)(14.6%)。土壤侵蚀强度整体呈现以最剧烈区域为中心,向四周辐射的趋势,主要影响因素包括风蚀、水蚀及放牧强度等。此外,青海省高寒草地2005—2014年土壤侵蚀变化恢复面积为258495 km^(2)(61.2%),反映了近年来青海省草地保护工作成效显著,然而在青海省的中东部地区高寒草地土壤退化的形势仍比较严峻,应当引起相关部门的高度重视。

The evaluation of alpine grassland soil degradation is helpful to grasp the spatial distribution of alpine grassland degradation,and has great significance to maintain grassland ecological security and ensure regional sustainable development.This study evaluated the soil degradation intensity and spatial distribution of alpine grassland in Qinghai Province based on the Improved Revised Universal Soil Loss Equation,and calculated the evaluation index of soil erosion of Alpine Grassland in Qinghai Province from 2005 to 2014,to evaluate the changing trend of soil erosion of alpine grassland.The results showed that the mildly degraded area of alpine grassland in Qinghai Province was 166925 km2,accounting for 39.5%of the total grassland area;the moderately degraded area was 98729 km2,accounting for 23.4%of the total grassland area;the severely degraded area was 949401 km2,accounting for 22.5%of the total grassland area;the extremely severely degraded area was 61787 km2,accounting for 14.6%of the total grassland area in 2014.The overall intensity of soil erosion was centered on the most intense area and radiated to the surrounding area.The main influencing factors included wind erosion,water erosion,and grazing intensity.In addition,the restoration area of soil erosion of alpine grassland in Qinghai Province from 2005 to 2014 was 258495 km^(2),accounting for 61.2%,which reflects the remarkable achievements of grassland protection in Qinghai Province in recent years.However,the situation of soil degradation of alpine grassland in the middle east of Qinghai Province is still severe,which should be paid great attention by relevant departments.