粤西坡地土壤侵蚀特征及退化分析——以广东省郁南县大湾镇为例

Analysis on the Soil Erosion Characteristics and Degradation at the Slope Lands of West Guangdong Province——in Dawan Township,Yunan County of Guangdong Province

坡地是广东省重要的土地资源,也是水土流失的策源地。研究坡地的土壤侵蚀及退化问题,对于坡地的可持续利用具有重要的意义。本文以广东省郁南县大湾镇为例,探讨了粤西典型坡地不同侵蚀区的侵蚀形态特征,以及土壤侵蚀所导致的坡地退化,分析了影响土壤退化的原因,并提出了退化坡地的整治措施。研究区以花岗岩发育的弱侵蚀强度为主,占总侵蚀面积的86.2%。土壤侵蚀导致坡地退化,主要表现为植被退化、土壤贫瘠化、沙质化等,影响坡地退化的主要原因是区域生态系统的脆弱性、坡地土壤的易蚀性以及不合理的人类活动,对退化坡地的整治应从坡面植被恢复、沟蚀与崩岗植被工程和水土保持耕作法等方面入手。

Slope land is the important land resource and the source of soil erosion in Guangdong Province.The research on the soil erosion and degradation has the important meaning to the sustainable use of the slope land.Taking the Dawan Township,Yunan County of Guangdong Province as example,the essay initially discussed the erosion morphological characters in the different typical slope erosion areas and the degradation of slope land caused by the soil erosion in the west of Guangdong Province.It was analyzed the reasons of the soil degradation and provided the management measures for the degraded slope land.In the research areas,most slope lands are slightly eroded granite distribution,accounting for 86.2% of the total eroded land area.The soil erosion resulted in the degradation of slope lands,mainly appearing as the vegetation degradation,soil nutrition depletion and sandification,etc.The main reasons of slope land degradation include the fragility of the regional eco-system,the erodibility of the slope soil and unreasonable human activities.The management to the degraded slope land should be focus on the recovery of the slope vegetation,vegetation development for gully erosion and collapse and soil conservation expedient of tillage,etc.