长江中下游地区耕地复种指数时空特征及驱动机制研究

Spatial and Temporal Characteristics and Driving Mechanism of Multiple Cropping Index of Cultivated Land in the Middle and Lower Reaches of the Yangtze River

长江中下游地区是重要的粮食主产区,其耕地复种指数变化对我国粮食生产具有重要的影响。利用HANTS算法构建2001—2018年研究区耕地复种指数数据库;通过MK检验方法、最小二乘法分析该区域复种指数的时空变化特征,并利用地理空间探测器对影响不同区域复种指数变化的驱动机制进行研究。结果表明:(1)从时间序列上分析,该区域以一年两熟复种模式为主;整体复种指数呈现下降趋势,一年两熟模式的耕地面积显著下降。(2)从空间格局上分析,安徽、江苏、江西、湖北的中部等地区以一年两熟模式为主;湖北、湖南等地区一年两熟模式下降显著。(3)从复种指数时空转移分析,2001—2015年安徽北部、江苏北部、湖南中部等地区种植模式主要从一年一熟转为一年两熟;2015—2018年安徽中部、上海北部、湖南中部等地区种植模式从一年两熟转为一年一熟。(4)粮食单产水平、地均化肥使用量是该区域复种指数变化的关键因子;人均耕地面积对江西省复种指数变化影响较大,而对其他地区复种影响较小。

The middle and lower reaches of the Yangtze River is an important major grain producing area,and its change of multiple cropping indexes has an important impact on China's grain production.In this study,firstly,the multiple cropping indexes database of cultivated land in the study area from 2001 to 2018 was constructed by using Hants algorithm.Secondly,the temporal and spatial variation characteristics of multiple cropping indexes were analyzed by MK test and least square method.Finally,the driving mechanism of multiple cropping index change in different regions is analyzed by using geospatial detector.The results show that:(1)from the time series analysis,the pattern of double cropping in a year is the main pattern in this region;The overall multiple cropping index showed a downward trend,and the area of double cropping pattern decreased significantly.(2)From the spatial pattern analysis,Anhui,Suzhou,Jiangxi,central Hubei and other regions are mainly in the pattern of two crops a year.In Hubei,Hunan and other areas,the pattern of two crops per year decreased significantly.(3)From 2001 to 2015,the planting pattern of Northern Anhui,northern Suzhou and central Hunan changed from one crop a year to two crops a year.From 2015 to 2018,the planting pattern of central Anhui,northern Shanghai and central Hunan changed from two crops a year to one crop a year.(4)Grain yield per unit area and average fertilizer use are the key factors of multiple cropping index change in the region.The area of arable land per capita has a greater impact on changes in the replanting index in Jiangxi Province,while other regions have a smaller impact on replanting.