摘要
土壤侵蚀受土地利用、气候变化等多种因素的综合影响。王茂沟流域作为黄土高原丘陵沟壑区的典型治理小区,从20世纪开始实行了退耕还林等一系列水土保持措施。本文基于CSLE模型评估流域内2010年、2015年和2020年土壤侵蚀强度及时空演变特征,并结合土地利用/覆被变化(LUCC)探究不同时段其土地利用空间分布格局与土壤侵蚀的响应规律,以此验证水土保持成效。结果表明:2010—2020年王茂沟流域年均土壤侵蚀模数下降0.11 t hm^(-2)a^(-1),整体土壤侵蚀状况略有改善,但微度侵蚀占比减少5.56%,极强烈侵蚀增加4.02%,侵蚀严重区域主要分布在流域北部、中部及西北部;由于降雨减少以及植被恢复,2015年流域土壤侵蚀状况较2010年得到极大缓解,而极端降雨的发生和植被覆盖质量下降又使得2020年土壤侵蚀模数出现回弹;2010—2020年间流域北部及东北部草地与耕地间转化极为明显,草地质量下降致使其土壤侵蚀模数均值较耕地更大,分别为13.69 t hm^(-2)a^(-1)与12.99 t hm^(-2)a^(-1)。研究成果有助于厘清黄土高原典型小流域土壤侵蚀与极端气候和土地利用变化间的响应关系,为未来提高水土保持效益与降低水土流失风险提供科学的数据支持。
Soil erosion is influenced by various factors,such as land use and climate change.The Wangmaogou watershed,as a typical area for soil and water conservation in the hilly and gully regions of the Loess Plateau,has implemented a series of measures since the 20th century,including the Grain for Green Project.This study evaluated the spatial and temporal evolution characteristics of soil erosion intensity in the watershed in the years of 2010,2015,and 2020 using the CSLE model.It also studied the situation of land use/cover change(LUCC)to analyze the spatial distribution patterns of land use and the responses of soil erosion in different time periods,thereby verifying the effectiveness of the soil and water conservation measures.The results revealed that from 2010 to 2020,the annual average soil erosion modulus in the study area decreased by 0.11 t hm^(-2)a^(-1),indicating a slight improvement in overall soil erosion conditions.However,the proportion of slight erosion decreased by 5.56%,while severe erosion increased by 4.02%,with the higher erosion zone mainly distributed in the northern,central,and northwestern parts of the watershed.Compared to the year 2010,soil erosion conditions in the watershed were greatly relieved in 2015 due to the decrease of rainfall and restoration of vegetation,but rebounded in 2020 resulting from the extreme rainfall events and declining vegetation cover quality.From 2010 to 2020,there were significant conversions between grassland and farmland in the northern and northeastern parts of the watershed.The decline in grassland quality resulted in a higher average soil erosion modulus compared to farmland,at 13.69 t hm^(-2)a^(-1)and 12.99 t hm^(-2)a^(-1),respectively.This study would contribute to figuring out the relationship between soil erosion in typical small watersheds of the Loess Plateau,extreme climatic events,and land use changes,providing scientific data support for future efforts to improve soil and water conservation benefits and mitigate soil erosion risks.
作者
石学瑾
张彪
郭家龙
冯浩
吴淑芳
SHI Xuejin;ZHANG Biao;GUO Jialong;FENG Hao;WU Shufang(Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas,Ministry of Education,Northwest A&F University,Yangling 712100,Shaanxi,China;Institute of Soil and Water Conservation,CAS and Ministry of Water Resources,Yangling 712100,Shaanxi,China)
出处
《地理学报》
EI
CSSCI
CSCD
北大核心
2024年第7期1787-1803,共17页
Acta Geographica Sinica
基金
国家自然科学基金项目(41671276)。
