摘要
黄土高原生态恶劣,水土流失严重,土地不合理利用及覆被较差是根本症结所在。退耕还林是改善黄土高原生态环境建设的重要措施。以安塞县马家沟流域为例,通过遥感与实地调查相结合的方法,获取2008年土地利用数据,对退耕后的土地利用格局现状进行分析。结果表明:2008年农、林、草地面积占流域总面积的91.6%。以草地类用地面积最广,占流域总面积的56.77%,其次为林地、农耕地,分别为19.6%和15.25%。流域上、中游梁峁顶及坡地绝大多数退耕成为未成林造林地,但仍保留有一定数量坡耕地。农耕地中的梯田面积占44.8%,坡耕地占42.4%,川坝地、川台地等占12.9%。各土地利用/覆被类型在流域上中下游分布集中程度不同。上游的土地利用/覆被状况与全流域分布格局相似。流域中农业用地类和园地相对集中分布在中游,而流域中的林地相对地集中分布在下游。中游发育的平缓地形地貌有益于发展农业耕作和园地种植。而下游村庄的行政隶属关系,使土地利用方向受城镇生态服务功能区划影响,因而林地异常集中。
Environment is friable and soil erosion is serious on the Loess Plateau.The irrational land use and low forest coverage are the fundamental reasons responsible for these problems.The land use type turned from farmland to forest/grass with the implementation of the ＇Grain for green＇ policy in 1999 is an important measure to improve the ecological environment on the Loess Plateau.The percentage of forest/grass coverage and its pattern changed the processes of surface flow and sediment discharge,influenced the hydrological regime.What it like of the current land use/cover pattern in the region is poorly known.The paper took the catchment of Majiagou in Ansai county,the typical loess hilly-gully region as a research area to check the land use/cover situation after 10-year implementation of the policy.Land use data in 2008 were obtained from the combination work of 2007＇s remote sensing image interpretation and field survey in December,2008,based on the land use map in 1990 provided by the land use bureau of Ansai county.The results showed that the area of the main landuse types of farmland,forest and grassland accounted for 91.6% of the entire catchment.The grassland was most extensive with 56.77% of the total area of catchment,then followed by forest and farmland,the area percentage were 19.60% and 15.25%,respectively.During the field survey,while lots of the slope farmlands were converted to grassland,still a number of slope farmlands exist there.Among the current farmlands,terrace land,slope farmland and other flat land along the river bed occupies 44.8%,42.4% and 12.9%,respectively.The catchment was divided to upper,middle and lower reaches based on the hydrological system.The concentricity of each landuse types varies in each reaches of catchment.The situation of each landuse types in the upper reaches is similar with that of total catchment.The farmland including orchard,mainly concentrates in the middle reaches due to the gentle landform development.While the forest in the catchment singularly focuses in
出处
《水土保持研究》
CSCD
北大核心
2010年第6期81-85,共5页
Research of Soil and Water Conservation
基金
中国科学院西部行动计划(二期)项目"黄土高原退耕还林(草)环境效应与效益评价"(KZCX2-XB2-05-03)
关键词
土地利用/覆被
格局
退耕还林
安塞县
黄土高原
land use/cover
pattern
farmland conversion to forest
Ansai county
the Loess Plateau
