基于景观生态指标的农用地连片阈值调整方法

【目的】集中连片是当前农用地整治的推进手段,集中连片阈值的不同对农用地整治工程成本有直接影响。本文基于景观生态指标,研究农用地整治中连片阈值的优化方法。【方法】通过引入景观生态指标,应用GIS平台的空间数据处理功能获取指标数据,实现连片性评价的定量化;基于GIS平台的缓冲功能,模拟设定不同阈值(dx)时连片性的变化;观察dx在一定范围内变化时连片性的变化曲线图,识别农用地连片的最优阈值(d0)。【结果】以广东省罗定市2010年优质农用地空间数据为例,当农用地整治连片间距范围在0~50 m时,阈值d0为12 m,因此建议将全区间距≤12 m的相邻地块进行连接。对佛山市高明区农用地数据重复试验,得到了该地区最优连片阈值,表明该方法可用。【结论】基于景观生态指标确定农用地连片阈值,具有直观、可靠和普适的优点,可以为全国范围内的农用地整治工作提供参考。

Farmland connectivity threshold adjustment based on landscape ecological indexes

[Objective] Concentrated connectivity is the propulsion in current farmland consolidation , and concentrated connectivity threshold has a direct effect on engineering cost .This research focuses on stud-ying the adjustment method of concentrated connectivity threshold based on landscape ecological indexes .[Method]Five landscape ecological indexes , which were obtained based on special processing functions in GIS platform,were used to achieve the quantitative evaluation of farmland connectivity .Based on the buffer function in GIS platform ,the changes of farmland connectivity were simulated by setting different threshold dx.The curve of farmland connectivity was observed when the threshold dx was changing, and the optimal connectivity threshold d0 was identified .[Result]Taking farmland in Luoding City , Guang-dong Province as an example , when the consolidation threshold ranged from 0 to 50 m, the optimal con-nectivity threshold d0 was 12 m.The farmlands, which separated less than or equal to 12 m, should be connected .As the experiment was repeated in Gaoming District of Foshan City , the optimal connectivity threshold was also found , which testified the feasibility of this method .[Conclusion]The method, which finds the optimal connectivity threshold based on landscape ecological indexes , is straightforward , reliable and pervasive , and can provide the technical reference for national farmland consolidation .