民勤土地利用格局时空变化研究

应用1987年和2010年两期TM遥感数据,在GIS技术的支撑下,解译提取民勤县土地利用类型空间分布信息,用FRAGSTATS3.3软件计算斑块类型和景观两个层次的7个景观格局指数,分析民勤县土地利用类型空间转化特点和质心转移趋势。结果表明：（1）23年间,民勤县土地利用类型转换明显,戈壁、耕地面积增加,草地面积减少,林地部分退化。（2）土地类型多样性和均匀度减小、聚集度增加,表明人类活动对民勤县土地利用影响大,土地利用结构受个别土地类型影响程度加深、稳定性下降。（3）民勤县土地利用质心整体向西南方向偏移,沙漠、耕地质心向西南方向偏移明显,沙进人退的趋势显著。

The Change of Land-use Pattern during 1987-2010 in Minqin, Gansu, China

Supported by the remote sensing data and GIS technology, using the multi-temporal TM images in 1987 and 2010 in Minqin, this paper analyzed the land-use pattern characteristics through seven selected landscape indices and spatial change of centroids of different land-use types. The results show: (1) The land-use types area changed frequently, especially for gobi, farmland, water area and woodland. (2) The landscape indices changed significantly from 1987 to 2010, with the landscape diversity index and evenness index decreasing and aggregation index increasing, it demonstrates that the whole landscape pattern was affected by specific patch types and the stability of landscape decreased. (3) From 1987 to 2010, the centroids of the main land-use types moved to the southwest, the centroid of farmland moved by 25.25 km to the southwest, while the centroid of sandy desert moved by 1.11 km to the southwest.