| 摘要: |
| 以遥感影像数据、DEM数据、降雨数据、土壤类型数据为基础，通过GIS和RS技术，结合美国通用水土流失方程（USLE）估算宁乡市的土壤侵蚀模数，模型指标包括降雨侵蚀力因子（R）、土壤可侵蚀性因子（K）、坡度坡长因子（LS）、植被覆盖度因子（C）、水土保持措施因子（P）。评价结果表明，2015年宁乡市土壤平均侵蚀模数为1 410.64 t/（km2·年），属于中度侵蚀等级状情况，土壤侵蚀类型主要为微度侵蚀、剧烈侵蚀和轻度侵蚀，侵蚀面积分别为1 548.87、434.16和397.91 km2，占侵蚀总面积的53.84%、15.09%和13.88%。土壤侵蚀模数较高的地区主要集中在宁乡市的沩山、长冲等山地、丘陵地区。系统分析出宁乡市土壤侵蚀与USLE模型的相关影响因子的关系，海拔高程与土壤侵蚀强度成正相关关系，与侵蚀面积成负相关关系，在<200 m海拔高程地区微度侵蚀面积范围最大。县内土壤侵蚀面积最大地区是在25°以下的坡度带，土壤侵蚀面积总体随着坡度的增加而减小。土地利用类型中耕地和林地的土壤侵蚀最为严重，其次是城镇用地 > 草地 > 水域 > 裸地。根据宁乡市土壤侵蚀现状，提出综合治理措施，以期为政府开展水土保持工作提供科学依据。 |
| 关键词: 土壤侵蚀 GIS RS USLE 措施 |
| DOI：10.11841/j.issn.1007-4333.2018.12.18 |
| 分类号: |
| 基金项目:国家自然科学基金项目（41571168） |
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| Quantitative evaluation of soil erosion in Ningxiang City based on GIS and USLE |
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CAO Sheng1, OUYANG Mengyun2, ZHOU Weijun1, TAN Xuelan1, LIU Pei1, TAN Jie1
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1.College of Resources and Environment, Hunan Agricultural University, Changsha 410128, China;2.College of Food Science and Technology, Hunan Agricultural University, Changsha 410128, China
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| Abstract: |
| Based on the remote sensing image data, DEM data, rainfall data and soil type data, the soil erosion modulus of Ningxiang City was calculated by using GIS and RS techniquescombined with the universal soil erosion equation (USLE). Model indexes include rainfall erosion factor, soil erosion factor, slope length factor, vegetation coverage factor, soil and water conservation measures factor. The results showed that:The average soil erosion modulus was 1 410.64 t/(km2·a) in Ningxiang City in 2015, which belonged to the moderate erosion grade. The main types of soil erosion were micro-erosion, severe erosion and slight erosion. The erosion area was 1 548.87, 434.16 and 397.91 km2, accounting for 53.84%, 15.09% and 13.88% of the total erosion area respectively. The areas with high soil erosion modulus are mainly concentrated in Weishan, Changchong and other hilly areas in Ningxiang City. In conclusion, the relationship between soil erosion and the related influencing factors of USLE model was systematically analyzed. The elevation was positively correlated with the soil erosion intensity, and negatively correlated with the erosion area. The area of micro erosion was the largest in<200 m elevation area. The largest area of soil erosion was in the slope zone below 25°, and the soil erosion area generally decreases with the decrease of slope. The soil erosion of cultivated land and forest land was the most serious in the land use types, followed by urban land, grassland, water area and bare land. According to the present situation of soil erosion in Ningxiang City, comprehensive control measures were put forward to provide a scientific basis for the government to carry out soil and water conservation. |
| Key words: soil erosion GIS RS USLE measures |
