Spatial characteristics of vegetation habitat suitability and mountainous settlements and their quantitative relationships in upstream of Min River, southwestern of China

Abstract

Vegetation habitat suitability (HS) and mountainous settlements are continuously varying, and display spatial heterogeneity in their spatial arrangement at multiple scales substantially. This paper focuses on spatial characteristics of vegetation HS and mountainous settlement and their quantitative relationships in the upstream of Min River, southwest of China. Based on the spatially distributed maps of vegetation HS types and different nationality mountainous settlements, we first described spatial differentiation and cluster of vegetation HS from global and local standpoints through lacunarity analysis and Multilevel Bayesian model. Then, we depicted the effects of nationality attribute on the spatially distributed characteristics of mountainous settlements. Finally, we revealed the relationships between the geometrical features of mountainous settlements and vegetation HS. The detailed results were as following: 1) The vegetation habitats are classified into four types based on the vegetation HS indexes, the largest spatially heterogeneities of comprehensive, unsuitable and worst unsuitable vegetation HS types occurred in Wenchuan county, but the largest spatially heterogeneities of suitable and sub-suitable vegetation HS categories appeared in Songpan county. The largest spatially clusters of comprehensive, suitable and sub-suitable vegetation HS categories were in Wenchuan, Songpan and Lixian counties, respectively. This suggested that their spatial clusters were low and spatial heterogeneity were high. However, the largest spatially clusters of unsuitable and worst unsuitable vegetation HS types were in Maoxian county. 2) The largest spatially cluster occurred in the Han nationality mountainous settlements revealed their closure characteristics in mountainous regions. Meanwhile, the spatial cluster of all mountainous settlements across watershed approximated to Tibetan nationality mountainous settlement, indicating that the spatial heterogeneity and layout characteristics of Tibetan nationality mountainous settlement could reflect the spatial differentiation of all settlements across watershed. 3) The average values of vegetation HS indexes for Tibetan-Qiang-Hui-Han nationality mountainous settlements were 2.8157, 2.6217, 2.5291 and 2.6441. It meant that the spatial distribution of mountainous settlements perfectly match with spatial pattern of vegetation habitat. Moreover, the sensitivities of geometrical feature characteristics for all mountainous settlements to vegetation HS were similar to Qiang nationality mountainous settlement. The quantitative results obtained from analysis on spatial characteristics of vegetation HS and mountainous settlements, and their interactive relationships could provide effective data supports for ecological construction of vegetation habitat and spatial reconstruction of mountainous settlements.