1980—2016年黄土高原地区人口和可达性异速标度分析

Allometric scaling analysis of population and accessibility on the Loess Plateau from 1980 to 2016

论文基于黄土高原地区乡镇1980、1990、2000、2010、2016年5期截面数据,利用位序—规模法则和异速标度律,分析了乡镇尺度人口和可达性规模结构、等级体系及异速标度演化关系。结果表明:①人口规模以中小等级乡镇为主,60%的乡镇人口规模正增长,总体呈“南北高、中间低”分布格局;可达性水平总体呈明显上升趋势,空间上自东南向西北逐渐降低;河谷平原区人口规模和可达性均最大。②人口和可达性均呈位次型分布,人口位序—规模具有明显双分形结构,由均衡向极化转变;可达性位序—规模以2000年为转折点由双分形演变为单分形,由低水平均衡转向更高水平均衡。③3006个乡镇整体以正异速生长为主,负异速生长为辅,黄土高塬沟壑区、河谷平原区内乡镇异速生长类型以人口增长正异速生长为主,黄土丘陵沟壑区、土石山区、沙地和沙漠区内乡镇以人口下降正异速生长为主,农灌区内乡镇异速生长以人口增长正异速一级和人口下降负异速一级为主。最后根据人口和可达性异速类型和空间分布特征,提出各分区发展的建议。

Based on the 1980,1990,2000,2010,and 2016 panel data at the town and township level on the Loess Plateau,this study analyzed the population and accessibility scale structure,hierarchical system,and allometric scaling by using rank-size distribution and allometric growth model of the fractal theory.The results show that:1)Population size was mainly small and medium,and population of 60%of the towns and townships was growing at a positive rate.The distribution of population presented a pattern of"high in the north and south,and low in the middle".Potential accessibility on the Loess Plateau tended to increase over time and the spatial distribution of potential accessibility gradually decreases from southeast to northwest.Population and potential accessibility of valley plains both are the highest.2)The rank-size distributions of population and accessibility comply with the power-law relation,and both present a log-normal distribution.The distribution of population size changed from equilibrium to polarization,and the distribution of potential accessibility tended to be further balanced.The population rank-size distribution was characterized by dual fractals from 1980 to 2016,while the accessibility rank-size distribution had evolved from dual fractals to single fractals with 2000 as a turning point.Accessibility scale distribution tended to be stable.3)The characteristics of population-accessibility allometric growth were clear.The 3006 towns and township mainly showed positive allometry,supplemented by negative allometry.The allometric growth types of towns and townships in the gully areas of the Loess Plateau and the valley plains were dominated by positive allometric growth with population growth.The allometric growth types of towns and townships in the hilly-gully areas of the Loess Plateau,sandy and desert areas,and earth-rock mountain areas were dominated by negative allometric growth with population decline.The irrigated regions were dominated by positive allometric growth with population growth and negative allometric growth with population decline.Finally,according to the population and accessibility allotypes and spatial distribution characteristics,some policy recommendations for the development of each region are put forward.