摘要
提高耕地产能对于满足中国日益增长的粮食安全需求有重要意义。该研究基于MODIS-EVI数据,通过构建作物EVI生长曲线,利用二次差分法及阈值法提取耕地复种指数并计算最优生长时长(Most Active Day, MAD)表征耕地产能变化,分析了2001-2017年四川省复种指数不变区内单季作物种植区,双季作物的第一、二季种植区内耕地产能变化及潜力特征。结果表明:1)研究期内四川省93.5%的耕地复种指数未发生变化,复种指数不变区内熟制以一年一季(占总耕地面积的88.3%)和一年两季(占总耕地面积的2.7%)为主;2)研究期内四川省单季作物产能显著下降与显著提升区分别占总面积的24.0%和33.2%,产能稳定区占比最大;双季中第一、二季作物产能分别呈先降后升和波动下降趋势,产能变化耕地面积分别占总面积的62.1%和49.4%;3)双季作物产能提升潜力大。研究期内四川省单季作物产能提升区和产能下降区产能提升潜力小于40%的耕地占比分别为83.8%和71.4%;双季作物第一、二季作物产能提升区内产能提升潜力大于40%的耕地分别占89.5%和67.6%。双季作物产能提升潜力大于80%的耕地面积超过一半,表明四川省双季作物的耕地产能仍有较大的提升空间。该研究所提出的耕地产能量化方法,可以应用于大尺度、长时间序列的耕地产能变化监测、耕地产能提升潜力空间识别等,可为优化耕地产能监测方法、促进耕地保护政策与规划制定提供借鉴。
Productivity of cultivated land needs to be greatly improved for the ever-growing demand for food security in China.Monitoring the productivity of cultivated land can contribute to figuring out the background of food security for the decision-making on protection policies of targeted farmland.In this study,a Savitzky-Golay filter was selected to rebuild the smoothing Enhanced Vegetation Index(EVI)curve of crop growth using the moderate resolution imaging spectroradiometer(MODIS)-EVI data.The moving window method was utilized to eliminate the possible impact of climate factors on crop yield and extract the Multiple Crop Index(MCI)of cultivated land from the EVI growth curve by the quadratic difference method.The threshold method was used to calculate the optimal growth time(Most Active Day,MAD)and characterize the change of farmland productivity.Taking Sichuan Province of China from 2001 to 2017 as a research object,an attempt was made to analyze the spatial distribution and potential characteristics of cultivated land productivity.The results were obtained:1)The Multiple Cropping Index(MCI)of 93.5%of cultivated land in Sichuan Province remained unchanged from 2001 to 2017.The areas with changed MCI were mainly concentrated in Chengdu city and all around,such as Meishan and Deyang.The cropping system in the MCI constant zone was dominated by a single-cropping system(accounting for 88.3%of the total arable land)and a double-cropping system(2.7%of that);2)There was a great variation in the productivity of cultivated land in Sichuan Province from 2001 to 2017.The area that single-season crop productivity significantly reduced and increased accounted for 24.0%and 33.2%of the total cultivated land.The decreased areas were distributed mainly in the northeastern(Nanchong,Guangyuan)and southern(Neijiang,Zigong,Yibin)Sichuan.In the double-season crop,the areas with the changing productivity of the first and second crops were 62.1%and 49.4%of cultivated land,respectively,indicating a trend of first decreasing and then risin
作者
吴心怡
金晓斌
韩博
徐伟义
任婕
孙瑞
周寅康
Wu Xinyi;Jin Xiaobin;Han Bo;Xu Weiyi;Ren Jie;Sun Rui;Zhou Yinkang(School of Geographic and Oceanographic Sciences,Nanjing University,Nanjing 210023,China;Key Laboratory of Coastal Zone Exploitation and Protection,Ministry of Land and Resources,Nanjing 210023,China;Jiangsu Land Development and Consolidation Technology Engineering Center,Nanjing 210023,China)
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2021年第3期238-249,共12页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家自然科学基金项目(41971234、41971235)。
关键词
产能
潜力
耕地
EVI
最优生长时长
四川省
productivity
potential
cultivated land
EVI
optimal growth time
Sichuan Province
