绵阳市土地利用变化对水土流失的影响研究
2018-11-02羊秀娟唐庆陈伟华
羊秀娟 唐庆 陈伟华
摘 要:研究绵阳市土地利用变化状况与水土流失的关系,对于解决水土流失问题有着十分重要的意义。该研究发现,绵阳市近20年来土地利用变化情况如下:林地、居住及工矿用地、交通运输用地不断增加;草地、水域及水利设施用地不断减少;耕地则是先减少后增加;园地先增加后减少;其他的备用土地不断减少。由于各土地利用类型所造成的水土流失是不同的,而水土流失情况则有所好转,说明两者之间有明显的相关性。
关键词:绵阳市;土地利用;水土流失;变化趋势
中图分类号 F301.24 文献标识码 A 文章编号 1007-7731(2018)14-0112-03
Study on Land Use Change and Soil and Water Conservation in Mianyang City
Yang Xiujuan et al.
(School of Land and Resources,China West Normal University,Nanchong 637000,China)
Abstract:The study of the relationship between land use change and soil erosion in Mianyang is of great significance for solving the problem of soil erosion. The change of land use in Mianyang in recent 20 years has been found to be as follows:woodland,residential and industrial and mining land,traffic and transportation land are increasing continuously;grassland,water and water conservancy facilities are decreasing continuously;the cultivated land is reduced first and then increases;the garden land increases first and then decreases;other spare land is continuously reduced.Because of the different soil and water losses caused by land use types,soil erosion is improved,indicating a clear correlation between them.
Key words:Mianyang City;Land use;Water loss and soil erosion;Variation trend
水土流失是指自然因素或人為活动对土地资源不合理的开发利用,致使土壤表层物质遭受破坏,土壤被侵蚀剥夺、搬运,且侵蚀速度大于土壤形成速度,终使岩层暴露,再次被侵蚀[1-3]。水土流失可分为水力侵蚀、重力侵蚀和风力侵蚀3种,其中水力侵蚀在我国水土流失所占比重极大。目前水土流失现象较为普遍,我国水蚀总面积为161.22万km2,占国土总面积的17.0%,是我国分布最广、危害最严重的水土流失类型[4]。根据水利部公报显示,2004年全国土壤侵蚀量达16.22亿t,其中尤以长江、黄河的土壤侵蚀量最多,分别达到9.32亿t和4.91亿t[5]。根据第1次水利普查,四川省水蚀面积高达114420km2,占幅员的23.54%,其中绵阳地区水土流失10845km2,占幅员面积的53.5%,多数地区属于强度侵蚀[6]。“5.12”汶川地震之后,表层物质疏松,水土流失情况加剧,但经过一系列治理后有所改善。
土地是人类进行各种活动的载体,是人类赖以生存和发展的物质基础。……
