Spatial pattern in residential area and influencing factors in oasis landscape
绿洲景观中居民地空间分布特征及其影响因子分析

In this paper, we studied the spatial patterns in the residential area and its i nfluencing factors in Zhangye oasis located in the middle reaches of Heihe River basin in northwest China. Five pattern indices (including the Area, the Mean Pa tch Area, the Patch Density,Average Nearest Distance and the Aggregation Index) were computed and analyzed using FRAGSTATS version 3\^0, and the shape index an d the spatial neighboring length and number between the residential area and oth er patches were calculated using Geographic Information System, and the Nearest Index that determines the type of residential area distribution were counted usi ng the method of settlement geography, and the radius of cultivation were comput ed using the method of buffer zone. The results indicated that the irrigated far mland which is the matrix of oasis landscape possesses the largest area in Zhang ye and its sub-oasis, and the residential patches are most broadly distributed and dominate the landscape patches. The mean area of residential area is small, and the shape is simple but its aggregation index is high. The irrigated farmlan d is the type that has the highest neighboring length with residential area, sug gesting a complex and close relationship between them. The distribution of resid ential area is random in Shajing sub-oasis but aggregated in the scale of oasis and other two sub-oasis (including the core oasis and Ganjun sub-oasis). Farm land is the key factor influencing the pattern of residential area distribution. The radius of cultivation, that can be derived by the method of buffer zone the oretically, showed a high correlation with the type of residential area distribu tion, suggesting that the former has a link of the latter. The average distance between residential patches and the nearest canals and rivers is 215m, and more than 75\^6% villages have canals passing through. The administrative center, Zha ngye city, has significant impacts on the distribution of residential area, the nearer the distance from Zhangye city, the greater the impacts on the residentia l area. We concluded that the combination of landscape pattern analysis, the set tlement geography and GIS can benefit the research on the pattern of residential area distribution and its influencing factors, and the Nearest Index, that have explicit ecological meanings, can be used to replace the Aggregation Index in F RAGSTATS.