基于GIS的青藏高原人口统计数据空间化

GIS Based Spatialization of Population Census Data in Qinghai-Tibet Plateau

根据2000年第5次全国人口普查数据分析,西藏、青海2省区各市县平均人口密度与海拔高度、土地利用、主要道路有较强的相关关系,河流水系对居民点分布的影响较为明显,而居民点是人口分布的重要指示因子。以GIS软件为工具,通过较为客观的方式赋予各影响因子人口分布影响权重,运用多源数据融合技术进行了人口统计数据的空间化。结果显示,通过数据融合产生的人口密度与各市县实际人口密度的相关系数大于0.80,与试验区各乡镇的实际人口密度的相关系数大于0.75。最终生成的栅格人口密度数据既与各市县统计型人口数据保持一致,又反映了各市县内部人口分布的空间变化。

In the Qinghai-Tibet Plateau, correlation ratios between p opulation density and percentages of arable land and city and town us ed land at county level reach 0.90 and 0.85 respectively. In Qinghai p rovince, there exists a logarithmic correlation of ratio =-0.86 between population density and average territorial elevation at county level. There is a correlation of ratio = 0.82 between population density and main highway density at county level. Correlation ratios between populatio n density and densities of city and town residential areas, township reside ntial areas and village residential areas reach 0.82, 0.87 and 0.92 resp ectively. Density of residential areas drops along with increasing of distance to rivers. Therefore, territorial elevation, land use, road and r iver system are the main factors affecting distribution of population in the Qinghai-Tibet Plateau. Residential areas are an important indica tor to distribution of population. Weight values of affecting factors are assigned objectively and multiple sources data fusion technology is applied to spatialize population census data. There is a correlation of ratio > 0.80 between the population density generated by data fusion and actual population at county level, and ratio > 0.75 at township level. The finally generated grid population density not only keeps consistence with statis tical population data at county level but also reflects changes of population d istribution inside each county.