1990-2015年红碱淖地区土地利用/土地覆盖与景观格局的时空演变

目的]研究近25 a红碱淖地区的土地利用景观格局演变,为西北矿区生态环境保护、煤炭的绿色开采以及沙漠湖泊的环境管理和决策提供基础数据和科学依据.方法]选取1990,2000,2005,2010和2015年5期Landsat TM/ETM+/OLI影像,利用遥感、地理信息系统技术和地理数学统计方法定量分析红碱淖地区土地利用/土地覆盖的动态变化和景观格局的演变特征.结果] 1990-2015年,红碱淖地区的耕地和沙地面积分别增加了3.56％和21.87％,林草地和水体的面积分别减少了23.85％和2.25％,区域内水体和林草地退化严重,林草地主要转化为沙地和耕地;景观指数中,平均斑块面积减少,斑块总数、形状指数和多样性指数增加,景观破碎化程度加大,景观类型增加.结论]上游修建水库和开采地表水使湖泊面积减少,退耕还林工程使得林草地面积增加等人为因素是影响红碱地区域景观格局变化的主要驱动因素.

Dynamic Change of Land Use/Cover and Spatio-temporal Evolution of Landscape Pattern in Hongjiannao Region During 1990-2015

Objective] To analyze the land use and landscape pattern evolution of Hongjiannao region in the past 25 years and to provide basic data and scientific basis for the protection of ecological environment, green mining of Northwest China and environmental management of desert lake.Methods] Remote sensing images, i. e., TM in 1990, ETM⁺ in 2000, TM in 2005, TM in 2010 and OLI in 2015 were used as data source. Quantitative method of remote sensing and geographic information system technology and mathematical statistical analysis were used to illustrate the land use/land cover dynamic change and landscape pattern evolution characteristics.Results] From 1990 to 2015, the cultivated land and sandy land area of Hongjiannao region increased by 3.56% and 21.87%; Grassland and water area were reduced by 23.85% and 2.25%, respectively. The water and vegetation shrank greatly, forest and grassland were mainly converted to sandy land and cultivated land. The landscape indexes like average patch area, total number of patch, patch shape index and diversity index all increased; Landscape fragmentation enlarged and landscape types increased.Conclusion] In the upper reaches of lake, the construction of reservoirs and the exploitation of surface water, the application of returning farmland to forest and grassland, are the main driving influences of landscape pattern changes in Hongjiannao region.