| 摘要: |
| 研究东江源区土壤侵蚀对于加强东江流域的生态环境保护和建设，提高粤港地区的用水安全，保证粤港地区的繁荣、稳定发展意义重大。基于1995—2020年的降雨数据、土壤数据、DEM数据和Landsat影像数据，采用RS、GIS技术以及RUSLE模型定量分析东江源区土壤侵蚀时空特征。结果表明：（1）东江源区土壤侵蚀以微度和轻度侵蚀为主，严重侵蚀区域主要分布在源区东南部，果园和矿区等的开发使得局部区域侵蚀加剧。（2）1995—2020年，土壤侵蚀程度总体有所下降，微度以上侵蚀面积共减少了10.19%，土壤侵蚀模数下降了57.75%。其中2008年土壤侵蚀模数最大，达到2397.13 t· (km2·a) −1，2020年土壤侵蚀模数最小，为669.47 t (km2·a) −1。（3）近26 a以来，东江源区土壤侵蚀改善区域的面积达到16.52%，侵蚀加剧区为4.28%，以矿区侵蚀加剧情况最为明显。（4）源区内土壤侵蚀较严重区域主要发生在矿区、裸地、耕地和果园区，矿产资源的过度开采、不合理的农业耕作方式以及大面积的果树种植等引发更为严重的土壤侵蚀。 |
| 关键词: 东江源区 土壤侵蚀 RUSLE模型 时空特征 |
| DOI：10.7515/JEE222008 |
| CSTR： |
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| 基金项目:江西省高校人文社会科学研究项目（JC20119） |
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| Spatial-temporal variation of soil erosion in Dongjiang source area based on RUSLE model |
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SONG Shuihong, LI Hengkai, ZHANG Zhiwei1
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1. School of Civil and Surveying Engineering & Mapping Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China
2. Jiangxi College of Applied Technology, Ganzhou 341000, China
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| Abstract: |
| Background, aim, and scope Soil erosion is a major ecological and environmental problem worldwide, and increasingly serious soil erosion has hindered ecologically sustainable construction and development. Here, we studied the Dongjiang source area, an important drinking water source in Guangdong and Hong Kong, systematically analyzing the spatial and temporal variation in soil erosion in this region. Our aim was to improve the current status of soil erosion in the area, enhance the water security of Guangdong and Hong Kong, and ensure their prosperous and stable development. Materials and methods We used RS and GIS technology, together with the RUSLE model, to calculate the soil erosion modulus in the Dongjiang source area based on rainfall data, soil data, DEM data, and Landsat image data from 1995 to 2020. We then classified the soil erosion intensity with the help of “SL190—2007, standards for classification and gradation of soil erosion” issued by the Ministry of Water Resources of the People’s Republic of China. Finally, we analyzed the spatial and temporal characteristics of soil erosion in the Dongjiang source area using a combination of quantitative and qualitative methods. Results The results showed that: (1) the degree of soil erosion in the Dongjiang source area was mainly very low or low, and areas of serious erosion were found primarily in the southeast. (2) From 1995 to 2020, the overall degree of soil erosion decreased: areas with a degree of erosion greater than “very low” declined by 10.19%, and the soil erosion modulus decreased by 57.75%. The maximum soil erosion modulus was 2397.13 t·(km2·a) −1 in 2008, and the minimum was 669.47 t· (km2·a) −1 in 2020. (3) Over the past 26 years, the area of improved soil erosion in the Dongjiang source area was 16.52%, and the area of erosion intensification was 4.28%. Erosion intensification was most obvious in mining areas. (4) Serious soil erosion occurred in mining areas, bare land, cultivated land, and orchard areas. Discussion Our results showed a high correlation between land use status and the spatial and temporal distribution of soil erosion in the study area, and the influence of different land use types on the degree of soil erosion varied greatly. The degree of soil erosion was relatively serious in mining areas, bare land, cultivated land, and orchard areas. Therefore, to improve soil erosion in the source area, the government can promote rational land use by formulating ecological protection policies such as “control of mining”, “reclamation of bare land and mining areas”, “return of cultivated land and orchards to woodland and grassland”, etc. In addition, the spatial and temporal distribution of soil erosion in the Dongjiang source area are also influenced by climatic factors to some extent, and their mechanisms of influence require further study. Conclusions (1) By 2020, soil erosion in the study area was light, although the development of orchards and mining areas had led to severe erosion in some areas. (2) The degree of soil erosion in the Dongjiang source area has been alleviated over the past 26 years, and this is inseparable from a series of prevention and control measures carried out by the government. (3) Mineral resource mining, farming, and fruit tree planting are the main factors that cause soil erosion in the Dongjiang source area. Recommendations and perspectives This research has theoretical implications for our understanding of the changing characteristics and driving forces of soil erosion in the Dongjiang source area; it can provide evidential support for strengthening ecological and environmental protection and sustainable construction in the Dongjiang River Basin. |
| Key words: Dongjiang source area soil erosion RUSLE model spatial-temporal characteristics |
