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Spatio-Temporal Pattern Change of Winter Wheat Production and Its Implications in the North China Plain

The North China Plain (NCP) is the most important winter wheat production region and an area of water shortage in China. The stability of winter wheat (T. aestivum L.) production in spatial pattern and the sustainability of water resources have been a major policy concern in China. This study explored the barycenter shift and change trends of wheat total production during 1998–2015, using methods of barycenter model, Sen’s slope, and Mann Kendall test, and analyzed the influence of external factors and the response of water resources. Results indicated that the barycenter of wheat production moved southwards by 115.16 km during 1998–2015, with an average speed of 6.77 km/year. For the entire NCP, the total production showed phased changes during the study period: It decreased during 1998–2003, and then continuously increased during 2004–2015. Of the wheat production increase in the NCP, yield increase and sown area expansion averagely contributed 64.5% and 35.5%, respectively, and the contribution proportion of yield increase continuously increased since 2003. At county level, total wheat production showed a significant increase and decrease trend in 87 and 29 counties, mainly distributed in the southern and northern NCP, respectively. The increase of total production at county level was mainly contributed by yield growth in the southern NCP, while the decrease in the north was due to the reduction of sown area to great extent. The southward shift was jointly resulted by the spatial variation of input factors, benefit, and water prices. These spatial pattern changes alleviated the water pressure in the north region to some extent, in the case of ensuring the production increase of winter wheat. Therefore, the current spatial shift should be continuously promoted in the future.