多属性约束空间最邻近连接农用地分等省级汇总方法

Multiple Attribute Constraint and Nearest-neighbour Provincial Summary Method for Farmland Quality Database

针对农用地分等省级汇总工作中汇总底图更新滞后的问题,提出了快速汇总底图更新方法。在遵循汇总原则基础上,研究以空间真实性损失最小为目标,多属性约束空间最邻近连接省级汇总方法,并利用该方法开发软件实现省级汇总的自动化。以北京市大兴区为研究区进行实例验证,利用区域耕地质量的空间标准距离、平均中心和标准差椭圆指标分析汇总底图的处理合理性和对比汇总前后耕地质量的分布情况。结果表明,除16等外,汇总后各等别的空间标准距离均减少,说明汇总成果较县级成果等别分布更加聚集,汇总底图处理较为合理;比较汇总前、后耕地质量平均中心和分布方向可知,汇总前、后大兴区耕地质量的高低比重分布和方位分布几乎未发生变化,说明省、县耕地质量的空间分布高度一致。

An important part in farmland quality evaluation is summarizing the county-level results into provincial result.As the foundation of the national summary,the summary accuracy directly affects the distribution of the national farmland land quality.Because of the summary base map lags behind,a method was proposed for quickly updating summary base map.Meanwhile,the multiple attribute constraint and nearest-neighbour provincial summary method for farmland quality database was proposed,then the summary software was developed for automating provincial summary.Daxing district of Beijing was taken as an example,then the rationality of summary base map process was analyzed and the distribution of farmland land quality before and after summarizing was compared by the standard distance,mean center and standard deviation ellipse indexes.Results showed that except grade 16,the standard distance reduced after summarizing,which meant that the summary result was more gathered than the county level and the process of summary base map was reasonable.Furthermore,by comparing the mean centre and the directional distribution before and after summarizing,the distribution of farmland quality almost had no change,which indicated that the spatial distributions of the province and county farmland quality were in highly consistent.