贵州高原山区正负地形特征及其对人口分布的影响

Characteristic of positive and negative terrains and its effect on population distribution in the mountainous area,Guizhou Plateau

正负地形可通过源汇过程对水、土资源进行再分配,影响山区的人口分布。获取正负地形数据,运用6个指标和多元逐步回归法,分析贵州高原山区正负地形特征及其对人口分布的影响。研究表明:①贵州高原山区的正负地形结构异质性明显。蚕食度、深切度、平均粗糙度比、形状指标、匀度指数、破碎度的平均值分别为1.07、371m、1.01、3.40、325和3.34,表明正地形被负地形蚕食明显、切入深度大,正、负地形的粗糙度基本相当,正负地形景观斑块呈现形状不规则、面积不均匀的破碎状态。6个正负地形指标中,匀度指数的变异性最大,变异系数为90.43%;平均粗糙度比的变异性最小,变异系数为1.06%;②贵州高原山区的人口分布不均匀性突出。人口累积达到40%时,累积面积百分比为14%;人口累积达到80%时,累积面积百分比约为50%;③6个正负地形指标中,蚕食度和深切度是影响人口分布的主要因素。蚕食度与人口密度呈正相关关系,深切度与人口密度呈负相关关系。研究成果为研究地形条件的人口影响提供补充,并为贵州高原山区人-地关系协调和土地可持续管理提供参考。

Positive and negative terrains can redistribute water and soil resources through source-sink processes, which affect the population distribution in mountainous area, and need to be further studied.This study obtains positive and negative terrains data, applies six indicators and stepwise multiple regression method, analyzes characteristic of positive and negative terrains and their effect on population distribution in the mountainous area, Guizhou Plateau.Results indicate that: 1) Heterogeneity of positive and negative terrains is obvious.The average nibble degree(ND), cutting depth(CD), mean-roughness-ratio(MRR), shape index(SI), homogeneous index(HI) and fragmentation(F) are 1.07, 371 m, 1.01, 3.40, 325 and 3.34, respectively.The positive terrain is nibbled obviously and cut deeply by the negative terrain, positive terrain is basically the same roughness as negative terrain, and landscape patches in positive and negative terrains are fragmented and showed irregular shape and uneven area.HI has the highest variability with the variation coefficient of 90.43%, and MRR has the lowest variability with the variation coefficient of 1.06%.2) The population distribution shows obvious inhomogeneity.When the cumulative percentage of population reaches 40%, cumulative percentage of area is 14%;when cumulative percentage of population reaches 80%, cumulative percentage of area is nearly 50%;the remaining 50% of the area accumulates only about 20% of the population.3)ND and CD are major factors affecting the population distribution.ND determines the population agglomeration level by affecting the land carrying capacity, and has a positive correlation with population density.CD determines population’s agglomeration level by affecting the geological hazard risk of human settlement, and has a negatively correlated with population density.Findings can expand research on impact of terrain on population, and provide reference for coordinating man-land relationship and achieving sustainable land management in the mountainous area, Guizhou Plateau.