岩溶槽谷区撂荒耕地空间分异特征及其驱动因子

Spatial differentiation characteristics and driving factors of abandoned cultivated land in Karst trough valley

以地处岩溶槽谷区的贵州省铜仁市碧江区和万山区为研究区,以2017年土地利用变更调查数据库和2019年高分遥感影像为基础,经目视解译和野外实地调查获取撂荒耕地数据,运用热点分析揭示撂荒耕地的空间分异特征,并采用二分类Logistic回归模型分析撂荒耕地的驱动因子。结果表明:研究区耕地总体撂荒率为17.32%,旱地撂荒率比水田高,分别为23.54%和9.52%。撂荒水田的极热点区分布于西南部和东北部的城乡结合部乡镇,冷点区空间分布规律不明显;撂荒旱地的极热点区分布于西部和东北部的城乡结合部乡镇,极冷点区和冷点区主要分布于东部乡镇。水田和旱地撂荒的驱动因子大致相同,但主次有所差异。水田撂荒的驱动因子从高到低依次为地块面积>距聚落距离>坡度>灌溉距离>交通距离>高程>地块形状指数,旱地撂荒的驱动因子从高到低依次为距聚落距离>地块面积>坡度>灌溉距离>高程>交通距离>地块形状指数。总体而言,岩溶槽谷区耕地撂荒的主要驱动因子是距聚落距离,说明劳动力析出、农村空心化是影响耕地撂荒的主要原因。同时,地块面积、坡度、灌溉距离等也与耕地撂荒密切相关。

To understand the spatial differentiation characteristics of abandoned cultivated land and its driving factors,Bijiang District and Wanshan District,Tongren City,Guizhou Province,located in the Karst trough valley area,were selected as the study area in the present study.The data of abandoned cultivated land was obtained through visual interpretation based on the 2017 land use change survey database and 2019 high-scoring remote sensing imagery and field surveys.The hot spots were used to analyze the spatial differentiation characteristics of abandoned cultivated land,and a two-class Logistic regression model was used to analyze driving factors.The results showed that the overall abandonment rate of cultivated land in the study area was 17.32%,and the abandonment rate of dry land(23.54%)was higher than that of paddy fields(9.52%).The extremely hot spots of abandoned paddy fields were distributed in the southwest and the rural-urban junction towns in the northeast,yet the spatial distribution of cold spots was not obvious.The extreme hot spots of abandoned dry land were distributed in the west and northeast,while the extreme cold and cold spots were mainly distributed in the east.The driving factors of paddy field and dry land abandonment were roughly the same,but the priority was different.The driving factors of the abandonment of paddy fields decreased as plot area>distance from settlement>slope>distance from irrigation>transportation distance>elevation>plot shape index,and the driving factors of the dry land abandonment decreased as distance from settlement>plot area>slope>distance from irrigation>elevation>transportation distance>plot shape index.In general,the main driving factor for the abandonment of cultivated land in the Karst trough valley was the distance from settlement,which indicated that the labor separation and rural hollowing were the main reasons for the abandonment of cultivated land.In addition,the abandonment of cultivated land was also closely related to the plot area,slope,distance from irrigation,etc.