成都平原边缘洪雅县农村居民点时空演变与景观格局

Spatial Distribution and Landscape Pattern of Hongya County in Chengdu Plain Edge

农村居民点是农村居民为生产和生活便利修建的固定住所,社会表现为农村居民空间的聚集,其时空演变与景观格局变化受当地自然环境、传统文化、经济发展等多种因素影响。笔者通过成都平原边缘洪雅县1997、2006、2015年三期遥感影像,借助RS、GIS软件提取农村居民点数据,结合DEM高程及坡度数据,研究了洪雅县农村居民点的时空演变及景观格局,并分析了其影响因素。结果表明:(1)1997—2015年,18年间洪雅县农村居民点的空间分布总体表现为更加聚集,地理聚集方向没有变化,持续地逐渐集中于该县北部平缓区域;(2)坡度对洪雅县农村居民点的布局影响强烈,农村居民点中超过70%分布在0°~5°范围内。随坡度的升高,农村居民点的斑块数及斑块面积总体上均表现为先降低后回升再降低;(3)海拔对洪雅县农村居民点的布局影响显著,<500 m范围集中了超过55%的农村居民点。从1997—2015年洪雅县农村居民点变化结果及趋势来看,农村居民点空间分布呈现逐渐优化过程,农村居民点有从高海拔地域向低海拔城镇迁移趋势明显。

Rural settlement is the fixed residence for rural residents to facilitate the production and living, the social manifestation is the aggregation of the rural residents, its spatial and temporal evolution and landscape pattern change were affected by local natural environment, traditional culture and economic development. Based on the remote sensing images of 1997, 2006 and 2015 in Hongya County of Chengdu Plain, RS and GIS software were used to extract the data of rural settlements, based on DEM elevation and gradient data, the temporal and spatial evolution and landscape pattern of rural settlements were studied, and its influencing factors were analyzed. The results showed that： （1） the spatial distribution of rural settlements in Hongya County was more agglomerate and the geographical clustering direction did not change from 1997 to 2015, and gradually concentrated to the flat area in the northern part of the county; （2） the gradient had strong influence on the layout of rural settlements in Hongya County, and more than 70% of the rural settlements were distributed in the range of 0°- 5°, with the increase of gradient, the patch number and plaque area of rural settlement area showed a trend of ＂decrease- increase-decrease＂; （3） altitude had significant influence on the distribution of rural residential area in Hongya County, more than 55% of rural settlements distributed in the range of 0-500 m. The trend of rural settlements change from 1997 to 2015 showed that the spatial distribution of rural residential area in Hongya County was gradually optimized, and the migration of rural settlements from high altitude area to low altitude town was obvious.