基于县域单元的我国水稻生产时空动态变化

水稻是我国最重要的粮食作物之一, 阐明近几十年来水稻的时空动态变化特征, 对于优化水稻布局、促进水稻生产的可持续发展具有重要意义。本研究基于1985年以来的县域水稻生产数据, 分析了我国水稻产量、面积和单产的时空动态变化特征和水稻生产重心迁移轨迹, 在此基础上量化了水稻面积和单产对总产的贡献度。结果发现, 我国水稻产量变化以49年周期为主, 21年为辅, 面积变化周期为26年, 单产变化周期为60年; 1985—2015年间, 在水稻种植区域内, 近50%地区产量上升, 约70%播种面积减少, 80%以上区域单产增加; 我国水稻产量、面积重心分别向东北方向迁移229 km和225 km, 而东北稻作区产量、面积重心分别向北偏东方向迁移238 km和242 km; 我国水稻生产主导因素中单产占比由56.3%下降至28.3%, 面积由34.7%上升至63.1%。结果表明, 全国各稻作区单产提升、东北早熟单季稻区面积增加、华中双单季稻区和华南双季稻区面积减少是我国水稻种植面积变化的主要特征。因此, 合理布局我国水稻的种植面积和持续提高的水稻单产是稳定和提升我国水稻产量的主要措施, 充分利用光热资源、提高机械化程度和比较效益是促进我国水稻生产发展的关键途径。

Spatio-temporal Changes of Rice Production in China Based on County Unit

Rice is one of the most important grain crops in China. To clear spatio-temporal change characteristics of rice in recent decades is of great significance in optimizing the layout of rice and promoting the sustainable development of rice production. This study was conducted to figure out spatio-temporal dynamic changes of national rice production, planting area and yield; to map gravity center migration path of rice production and area based on county data particularly since 1985; and to quantitatively analyze rice production contribution merely caused by area and yield. Variation period was calculated by wavelet analysis using deviations from average of national rice-producing data from 1949 to 2017. Rice-producing gravity centers were computed by ArcGIS using county-level data of rice production and planting area, and then connected them in order of year. Production contribution was firstly divided into three components separately resulted from area, yield and mutual interaction, in that case production changes caused by them could be reckoned to get production contribution rate. ArcGIS was applied to display spatial distribution on the background of two maps including Chinese rice cropping regionalization and provincial administrative division. To come out, the variation periods were respectively 49 years and 21 years, 26 and 60 years of production, area and yield. From 1985 to 2015, nearly 50% of planting region increased in rice production, about 70% decreased in rice planting area, and more than 80% increased their yields. The gravity center of national rice production and planting area migrated northeastwards about 229 km and 225 km. What’s more, the gravity center of the northeast migrated more northeastwards at about 238 km and 242 km. In China, the proportion of yield, as a dominant factor of rice production contribution, fell from 56.3% to 28.3%, and area increased from 34.7% to 63.1%. In conclusion, increasing yield in every rice cropping region, increasing planting area in single cropping region of northeastern and decreasing planting area in double cropping region of South China and single and double cropping region of Central China are main rice distribution characteristics in China. Rational layout of rice planting area and increasing yield are more and more important in stabilizing and enhancing rice production. Rationally using resources, increasing the degree of mechanization and comparative effectiveness are critical pathways to promote Chinese rice production.