喀斯特地区县域土壤侵蚀估算及其对土地利用变化的响应

发布时间：2018-04-02 21:25

本文选题：土壤侵蚀　切入点：RMMF模型　出处：《中国水土保持科学》2017年05期

【摘要】：喀斯特地区土层浅薄,不合理的土地利用导致严重的水土流失,加剧石漠化程度。为定量分析生态工程实施前后土壤侵蚀状况及其对土地利用变化的响应,基于GIS技术和RMMF模型,对环江县1991、2000和2010年土壤侵蚀进行模拟,并采用邻近水文站和径流小区泥沙监测数据进行验证。结果表明:1991、2000和2010年研究区土壤侵蚀模数分别为76.36、76.46和49.60 t/(km~2·a),与相关监测数据比较一致;土壤侵蚀总量分别为34.76万、34.80万和22.58万t,主要来源于非喀斯特区(均约占全县侵蚀总量的94%)。研究区微度侵蚀面积占90%以上,轻度及以上等级所占比例较小。对比不同土地利用类型的土壤侵蚀模数,旱地远大于其他类型,其次是中覆盖度草地和其他林地。相同降雨条件下,由于旱地面积减少,2010年土壤侵蚀量较1991年减少4.21万t;2010年喀斯特区、非喀斯特区土壤侵蚀量较2000年分别减少了4.21%和8.76%。这预示生态工程实施后,环江县耕地减少、林地增加,土壤侵蚀减少。本研究为评估喀斯特地区土壤侵蚀现状以及退耕还林的水土保持效应提供参考依据。
[Abstract]:The shallow and unreasonable land use in karst area results in serious soil erosion and exacerbates the degree of rocky desertification.In order to quantitatively analyze soil erosion and its response to land use change before and after implementation of ecological engineering, soil erosion was simulated in Huanjiang County in 1991 ~ 2000 and 2010 based on GIS technology and RMMF model.The sediment monitoring data of adjacent hydrological stations and runoff plots were used to verify the results.The results showed that the soil erosion modulus of the study area in 1991 and 2010 was 76.36 ~ 76.46 and 49.60 t/(km~2 / a respectively, which was consistent with the relevant monitoring data, and the total soil erosion was 347600 ~ 34.8 million and 225800 t respectively, which mainly came from non-karst area (about 94% of the total erosion in the whole county).The area of micro-erosion is more than 90%, and the proportion of mild and above grade is small.Comparing the soil erosion modulus of different land use types, dryland is much larger than other types, followed by middle coverage grassland and other woodland.Under the same rainfall conditions, the amount of soil erosion decreased by 42100 t in 2010 compared with 1991, and decreased by 4.21% and 8.76% respectively in 2010 compared with 2000 in karst and non-karst areas.This indicates that after the implementation of the ecological project, the cultivated land in Huanjiang county decreases, the forest land increases and the soil erosion decreases.This study provides a reference for evaluating the current situation of soil erosion and soil and water conservation effect of returning farmland to forest in karst area.
【作者单位】：中国科学院亚热带农业生态研究所亚热带农业生态过程重点实验室;中国科学院环江喀斯特生态系统观测研究站;中国科学院大学;
【基金】：国家重点基础研究发展计划(973计划)“黔桂喀斯特山地水土要素时空变化过程及其生态效应”(2015CB452703) 国家重点研发计划“水土流失/漏失关键过程与阻控技术”(2016YFC0502403)
【分类号】：S157.1

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