基于DEM-GRA的岩溶区火龙果等土宜的研究

根据因地制宜的规划种植之理念,以GIS为技术平台,建立了数字高程模型(DEM),并运用灰色关联分析(GRA),对天等县峰丛洼地区仍屯基地的六个样地火龙果的土宜条件进行了综合分析。结果表明,坡度较缓、山影量小、坡麓土层较厚的后山2(样地2)、边界山4(样地4)和狭岭6(样地6)为火龙果种植的极度适宜土地,而土层较薄、山影量大的边界山(样地3)适宜性最差,坡度偏大、其它条件均适宜的后山1(样地1)和山影量偏大、其它条件均适宜的狭岭5(样地5)介于中间,为高度适宜土地。在样地2、样地4和样地6中,由于样地2与火龙果种植环境条件的关联度大于样地4、样地6,所以其土宜条件更好,最适宜火龙果种植。在此基础上,把土宜评价的方法拓宽于石漠化治理的布局设计,在团乐、独山、小山等小流域的封山育林区选择出最适宜的地段进行了人工补植,补植树苗成活率均在85%以上,且长势较好。

Study on land suitability for Hyloccreus undatus and some other plants in karst area based on DEM-GRA

In light of adjust measures to local conditions, DEM is established based on GIS platform and land suitability for Hyloccreus undatus at 6 sample plots in Rengtun karst depression, Tiandeng County is analyzed comprehensively by means of GRA in the paper. The results prove that plot 2, 4 and 6 being gentler in gradient an d smaller in hill shadow as well as thicker in soil layer are quite suitable for Hyloccreus undatus; but plot 3 being thinner in soil layer and larger in hill shadow is not suitable for Hyloccreus undatus; plot 1 with higher gradient and other suitable conditions and plot 5 being laugher in hill shadow but suitable in other conditions are both suitable for Hylocereus undatus, which situated between the former two types. Among plot 2, 4 and 6, plot 2 is better correlated to the suitable conditions for Hyloccreus undatus and most suitable for Hyloccreus undatus growth. According to the above evaluations, the land suitability evaluation method is used in harnessing karst rock desert, and artificial replanting at suitable patches in Tuanle and Dushan as well as Xiaoshan karst basins is done with the survival rate of the replanted plants higher than 85% and grows well meanwhile.