多因素影响下的喀斯特山区坡耕地分布特征——以贵阳市花溪区为例

Study on the Distribution Characteristics of Sloping Farmland in Karst Mountain Area Under the Influence of Multiple Factors-A Case Study of Huaxi District of Guiyang

为研究喀斯特山区坡耕地在岩性、土壤类型、坡位和居民点影响下的分布特征,为区域水土流失治理提供参考,以贵州省贵阳市花溪区为研究对象,结合花溪区高清影像图、高程图(DEM)、地质图和土壤类型图为主要数据源,利用ArcGIS 10.2平台,基于其空间叠加分析、数理统计等功能,对多因子影响下的喀斯特山区坡耕地分布特征进行了分析。结果表明:花溪区坡耕地面积占全区总面积的21.07%,占全区耕地面积的63.85%,是花溪区主要耕地类型;在各岩组上,坡耕地的分布面积从大到小依次为:石灰岩组>白云岩组>普通砂页岩组>紫色砂页岩组,其中在普通砂页岩组和石灰岩组上分布较为集中连片,在白云岩组和紫色砂页岩组上分布较为零散;坡耕地的各土壤类型面积依次表现为:水稻土>黄壤>石灰土>紫色土>潮土,其中黄壤最为集中连片,水稻土则较为分散;不同坡位区域中,坡耕地面积依次表现为;下坡位>中坡位>上坡位,其中在下坡位区域分布最为集中连片,上坡位区域分布最为零散;同时坡耕地和居民点在空间分布上具有显著相关性,距离居民点越远,坡耕地分布越稀疏。综上所述,在多种因素共同作用下,花溪区坡耕地呈现出“西部多东部少”的空间格局,其中普通砂页岩组和石灰岩组上的坡耕地连片区可优先考虑进行治理。

In order to study the distribution characteristics of sloping cultivated land in karst mountainous areas under the influence of lithology,soil type,slope position and residential area,and to provide reference for regional soil erosion control,we took Huaxi District,Guiyang City,Guizhou Province as the research objects.High-definition image maps,elevation maps(DEM),geological maps and soil type maps in Huaxi District were used as the main data sources.Based on its spatial superposition analysis,mathematical statistics and other functions,we analyzed the distribution characteristics of sloping cultivated land in karst mountainous areas under the influence of multiple factors by using ArcGIS 10.2 platform.The results showed that the sloping farmland area accounted for 21.07%of the total area of Huaxi District,accounting for 63.85%of the total area of cultivated land,the farmland was the main type of cultivated land in Huaxi District;In each lithology category,the distribution area of sloping farmland decrased in the order:limestone>dolomite>common sandy shale>purple stone area,in which the distribution of common sandy shale area and limestone area concentrated and connected,the distribution of dolomite area and purple stone area scattered;the area of each soil type in the sloping farmland decreased in the order:paddy soil>yellow soil>limestone soil>purple soil>alluvial soil,in which the yellow soil was the most concentrated contigous,paddy soil was more dispersed;the area of sloping cultivated land in different slope positions decreased in the order:downslope>middle breaking>uphill,the sloping cultivated land most concentrated and connected in downslope region,and most scattered in the uphill region;at the same time,there was the significant correlation between the spatial distribution of sloping farmland and residential land;the farther the distance from residential land was,the sparser the distribution of slope farmland was.In conclusion,under the joint action of multiple factors,the sloping cultivated land in Huaxi district presented a spatial pattern of‘more in the west and less in the east’,and the contiguous sloping cultivated land on the common sandy shale formation and limestone formation should be given priority to governance.