Spatio-temporal changes in rice area at the northern limits of the rice cropping system in China from 1984 to 2013

• Published in: Journal of Integrative Agriculture Vol. 16; no. 2; pp. 360 - 367
• Main Authors: LI, Zhi-peng, LONG, Yu-qiao, TANG, Peng-qin, TAN, Jie-yang, LI, Zheng-guo, WU, Wen-bin, HU, Ya-nan, YANG, Peng
• Format: Journal Article
• Language: English
• Published: Key Laboratory of Agri-informatics, Ministry of Agriculture/Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, P.R.China%Institute of Agricultural Economics and Regional Planning, Hunan Academy of Agricultural Sciences, Changsha 410125, P.R.China 01.02.2017; Elsevier
• Subjects: artificial neural network; Heilongjiang Province; Landsat; Landsat images; paddy rice; 中国; 人工神经网络; 时空动态变化; 时空变化; 水稻种植; 种植制度; 面积; Landsat images; Heilongjiang Province; artiifcial neural network; paddy rice
• ISSN: 2095-3119; 2352-3425
• DOI: 10.1016/S2095-3119(16)61365-5

Rice area has been expanding rapidly during the past 30 years under the influence of global change in northeastern China, which is the northernmost region of rice cultivation in China. However, the spatio-temporal dynamic changes in rice area are still unclear, although they may have important policy implications for environmental protection and adaptation to climate change. In this study, we aimed to identify the dynamic changes of the rice area in Heilongjiang Province of northeastern China by extracting data from multiple Landsat images. The study used ground quadrats selected from Google Earth and the extraction of a confusion matrix to verify the accuracy of extraction. The overall accuracy of the extracted rice area was higher than 95% as a result of using the artificial neural network （ANN） classification method. The results showed that the rice area increased by approximately 2.4×10^6 ha during the past 30 years at an annual rate of 8.0×10^4 ha, and most of the increase occurred after 2000. The central latitude of the rice area shifted northwards from 46 to 47°N during the study period, and moved eastwards from 130 to 133°E. The rice expansion area accounted for 98% of the total change in rice area, and rice loss was notably rare. The rice expansion was primarily from dryland. In addition, rice cultivation in marshland and grassland played a minor role in the rice expansion in this region.