基于地形梯度的典型退耕区土壤侵蚀时空分异特征研究OA北大核心CSTPCD
Study on Spatial and Temporal Variations of Soil Erosion in Typical Farmland Conversion Area Based on Topographic Gradient
[目的]研究典型退耕区退耕前后地形分异条件下的土壤侵蚀时空动态变化特征,为巩固退耕还林(草)成果提供科学支撑.[方法]采用RUSLE模型定量分析了延安市1989-2019年土壤侵蚀强度时空演变特征,结合地形因子探究了土壤侵蚀在各高程、坡度上的分异规律,通过LMDI模型了解影响土壤侵蚀模数变化的降雨因子、植被因子与水土保持因子,并分析了其贡献值,利用CA-Markov模型预测了延安市2029年土壤侵蚀状况.[结果]1989年、1999年、2009 年、2019 年延安市平均土壤侵蚀模数分别为 12 554.80 t/(km2·a),8 237.17 t/(km2·a),5 936.57 t/(km2·a),4 473.02 t/(km2·a),侵蚀类型整体以微度侵蚀为主,在空间上呈现北高南低的分异特征;侵蚀强度总体随高程的升高而降低,但在五级高程上侵蚀加剧;侵蚀强度与坡度存在一致性,坡度增加,侵蚀加剧;近年来,植被因子和水土保持因子对土壤侵蚀的抑制作用增加;2029年延安市土壤侵蚀状况总体好转.[结论]延安市土壤侵蚀状况总体明显改善,但局部依然存在侵蚀加剧的情况,未来延安市应重点治理北部高海拔、东部黄河沿岸地区,加强对高坡度区域的监测.
[Objective]The aims of this study are to explore the characteristics of spatial and temporal dynamics of soil erosion in typical farmland conversion area under different topographic conditions before and after the'Grain for Green'project,and to provide scientific support for consolidating project results.[Methods]The RUSLE model was used to quantitatively analyze the spatial and temporal evolution characteristics of soil erosion intensity in Yan'an City from 1989 to 2019,and the distribution patterns of soil erosion on various elevations and slopes were explored in combination with topographic factors.The precipitation,vegetation and soil and water conservation factor affecting the change of soil erosion modulus were decomposed by the LMDI model and their contribution values were analyzed.The CA-Markov model was used to predict the soil erosion status of Yan'an City in 2029.[Results]The average soil erosion modulus in Yan'an City in 1989,1999,2009 and 2019 were 12 554.80 t/(km2·a),8 237.17 t/(km2·a),5 936.57 t/(km2·a)and 4 473.02 t/(km2·a),respectively.The erosion type was dominated by slight erosion,showing the spatial differentiation characteristics of low level in the south and high level in the north.The soil erosion intensity generally decreased with the increase of elevation,but the erosion increased at the fifth elevation.The soil erosion intensity was consistent with the slope gradient,and the erosion intensity increased with the increase of slope gradient.The inhibitory effect of vegetation factor and soil and water conservation factor on soil erosion had increased in recent years.The soil erosion situation in Yan'an City will be generally improved in 2029.[Conclusion]The soil erosion status in Yan'an City has improved significantly,but there is still the increased erosion in some areas.In the future,the high-altitude areas in the north and the bank areas of the Yellow River in the east of Yan'an City should be given more attention,meanwhile,the monitoring of high-slope areas should be strengthened.
高毅丰;韩磊;火红;赵子林;常钰卿;刘钊;曹鑫鑫;杨梅丽;李亚北
长安大学地球科学与资源学院,西安 710054长安大学土地工程学院,西安 710054||陕西省土地整治重点实验室,西安 710054||中国科学院地球环境研究所黄土与第四纪地质国家重点实验室,西安 710061中国气象局乌鲁木齐沙漠气象研究所,乌鲁木齐 830002长安大学地球科学与资源学院,西安 710054长安大学地球科学与资源学院,西安 710054长安大学土地工程学院,西安 710054长安大学地球科学与资源学院,西安 710054长安大学地球科学与资源学院,西安 710054长安大学地球科学与资源学院,西安 710054
农业科学
土壤侵蚀RUSLELMDICA-Markov延安市
soil erosionRUSLELMDICA-MarkovYan'an City
《水土保持研究》 2024 (3)
30-41,48,13
国家自然科学基金项目(41871190)陕西省重点研发计划(2021SF-440)长安大学中央高校基本科研业务费专项资金(300102353201)黄土与第四纪地质国家重点实验室开放基金(SKLLQG2002)
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