挠力河流域农垦开发中居民地景观生态特征的变化

运用G IS、景观格局分析与聚落分析方法定量分析了挠力河流域在快速农垦开发中居民地分布格局的时空变化,探讨了景观格局形成的机制。景观指数分析表明近50 a来居民地面积和数目激增,居民地斑块面积、聚集度增大,表明人类对挠力河流域景观扰动持续增强。在所有背景地类中,居民地与耕地的邻接比例最高。伴随居民地和耕地迅速扩张,两者邻接比例呈上升趋势,两者相互影响越来越大。不同时期居民地扩张强度高值区分布有所不同,主要分布在早期的耕地新增区,1954—2000年挠力河流域居民地扩张高值区最终主要分布于该流域的西部与中部。虽然居民地数目和面积均激增,各居民地之间的距离亦呈缩短趋势,但居民地最近邻点指数表明,近50 a来挠力河流域居民地分布类型一直为随机分布,农垦经济仍占主导地位,人为规划比城镇发达地区薄弱。

Dynamic change in landscape of residential land in agricultural reclamation of the Sanjiang Plain:a case study of the Naoli River Valley

With the aid of GIS,together with the theory of landscape ecology and settlement geography,spatial pattern of the residential land in the Naoli River Valley was analyzed.All the landscape indices,including patch mean area,patch cohesion index,sum-area and number of residential lands,have been increasing during the last 50 years,which shows that the agricultural settlement in the Naoli River Valley has been intensified,and its agricultural economy gradually turning into an urban economy.There are seven land use types,including residential land,wetland,farmland,water surface area,woodland,grassland and bottomland in the study area.Residential land is closely related to the other types of land use,but particularly to farmland,and the relationship between the two is turning closer and closer.Distribution of areas high in extension strength of the residential land varies somewhat with the time period.But they are mainly distributed at the early frontier of the reclamation.It eventually turned out that in the period from 1954 to 2000,the areas of high value of extension strength of residential land were mainly located in the western and central parts of the Naoli River Valley.Although both the area and number of residential lands have been increased greatly,the distribution of residential lands always shows a stochastic pattern,so it can be concluded that agricultural economy is still the prominent type of economy in the Naoli River Valley.