近17年来崇阳县土地利用变化的生态效应及空间差异

Ecological effect of land use change and spatial difference in the past 17 years in Chongyang County

根据崇阳县1989年和2006年土地利用变更调查数据库(Mapgis6.5平台)以及TM影像,在GIS软件技术支持下采用空间叠加分析,得到了近17年来崇阳县土地利用的时空变化特征,同时采用景观生态学空间格局指数分析方法,选取景观多样性指数、景观破碎度指数和景观蔓延度指数等作为景观生态结构稳定性评价指标,综合评价了崇阳县各景观生态功能区的生态稳定性及其变化趋势,并计算了土地利用变化对生态服务价值的影响.研究表明,全县景观总体构成表现为破碎度较高并呈上升趋势,反映景观演化过程中人为干扰强度的加大;林地占有较大比重,林地的增加和耕地的减少是研究时段内土地利用变化的主要特征;研究时段内土地利用变化对生态环境的影响总体上看是正向的,土地利用的生态效益有所提高,但区域内部存在较大的空间差异.

As studying region of Chongyang County in Hubei, based on Landsat 5 TM （ThematicMapper） images of bands 4, 3 and 2 in 2002,and land change Investigation data of Chongyang County in 1989 and 2006（Mapgis6.5） ,this paper research on land use change character through the method of spatial superposition with Supermapdesk- proS. 3. In this paper, we evaluate the ecological stability of the landscape functional sections through three kinds of indices for spatial patterns including diversity index, fragmentation index, contagion index. After that, we put ecosystem service values in use to weigh the ecological values of corresponding land use types, so as to evaluate the ecological effect of regional land use change. The results show that, due to human activity, the index for landscape fragmentation has showed a tendency of increasing; the forestland has increased constantly but the farmland has decreased. And land use change in Chongyang county from 1989 to 2006 has got a good ecological effect, where the ecological benefit of land use is always increasing, but shows a distinct spatial difference.