内蒙古河套灌区作物种植结构变化及其驱动因素

Changes and driving factors of crops planting structure in Hetao Irrigation Region in Inner Mongolia

农业种植结构是区域农业生产的重要部分,是决定区域水、土资源分配的核心。以2000-2018年MODIS NDVI多时相遥感数据为基础,结合不同物候期玉米、小麦、向日葵和番瓜的野外光谱测定和种植区GPS标定,构建了基于阈值分割的作物识别方法,分析了河套灌区主要农作物种植结构变化及驱动因素。结果表明:玉米等4类作物种植面积变化趋势存在差异,其中玉米种植面积71.1×10^(3)-199.3×10^(3)hm^(2),呈波动上升趋势(P<0.001);小麦49.3×10^(3)-249.2×10^(3)hm^(2),呈波动下降趋势(P<0.001);向日葵140.2×10^(3)-337.4×10^(3)hm^(2),呈波动上升趋势(P<0.001);番瓜6.4×10^(3)-68.3×10^(3)hm^(2),呈波动上升趋势(P<0.001)。研究时段内向日葵发生转换的面积最大,向日葵种植用地向玉米、小麦和番瓜转移面积为107.9×10^(3)hm^(2)。作物种植面积变化驱动因素是引黄水量、地下水埋深、气温、人口活动、社会经济发展(GDP)和城市建设因素共同作用的结果。

Agricultural planting structure is an important part of regional agricultural production and the core of regional water and soil resources allocation.In this paper,based on the MODIS NDVI multi-temporal remote sensing data from 2000 to 2018,combined with the field spectrometry of maize,wheat,sunflower and zucchini in different phenological phases and the GPS calibration of the planting area,a crop identification method based on threshold segmentation was constructed,and analyzed the changes of planting structure and driving factors of main crops in Hetao irrigation region.The results showed that:there were differences in the trends of acreage of maize and other crops,including maize acreage varied from 71.1×10^(3)-199.3×10^(3)hm^(2)with a fluctuating upward trend(P<0.001);Wheat varied from 49.3×10^(3)-249.2×10^(3)hm^(2),with a fluctuating downward trend(P<0.001);sunflower acreage varied from 140.2×10^(3)-337.4×10^(3)hm^(2)with a fluctuating upward trend(P<0.001);zucchini acreage varied from 6.4-68.3×10^(3)hm^(2),with a fluctuating upward trend(P<0.001).During the study period,the area of sunflower conversion was the largest,and the area of sunflower planting land transferred to maize,wheat and zucchini was 107.9×10^(3)hm^(2).The driving factors for the change in crop planting structure was the result of the combined effects of water diversion from the Yellow River,groundwater depth,temperature,population activity,social and economic development(GDP)and urban construction factors.