基于自然地理分区的1990-2010年中国粮食生产格局变化

Spatial change of China's grain production based on geographical division of natural factors during 1990-2010

1978年以来，在全球变化与工业化、城市化背景下，中国粮食生产格局发生了明显变化，这一变化不仅影响到国家尺度上的粮食供销格局，也影响农业资源的利用效率、农业生产的受灾风险，甚至区域生态安全。以往的研究大多在南北地区、三大地带、八大粮食产区等分区基础上考察这一变化，难以充分反映这一变化的自然地理特点。利用1990-2010年县域粮食产量数据和粮食生产集中度指标，通过考察不同雨量带、温度带和地貌类型区集中度指数的变化来揭示格局变化的自然地理特点。研究发现：1990-2010年间，中国各区粮食产量均有不同程度的增长，但由于增长幅度不同，中国粮食生产中心由800mm以上雨量带向400～800mm雨量带偏移，由亚热带向中温带和暖温带转移，并逐渐向平原地区集中。结果表明，中国粮食生产格局变化不利于水热资源的高效利用，但却有利于发展机械耕作，从而提高劳动生产率。应对格局变化，中国粮食生产应进一步提高水资源保障能力和防灾减灾能力。

The spatial pattem of grain production in China has changed remarkably under the background of global change, industrialization and urbanization over the past 20 years. This change has great impacts on grain supply and grain market, efficiency of agricultural resources, disaster risk of agricultural production on national scale, and ecological security on regional scale as well. Current research focused on the spatial change of China＇s grain production based on three schemes of geographical division including North and South China division, three economic regions, and eight grain-producing bases. These schemes reflected geographical features of grain production in China. In this paper, location quotients of grain production and yield data of 2344 counties were used to analyze variations of grain production in geographical regions defined by disparity of annual precipitation, effective temperature, and landforms. The results indicated that the grain production in all the geographical regions presented an increasing trend during the period 1990-2010. Due to the spatial disparity of regional growth rate, the centre of grain production in China moved northward： from the regions with precipitation over 800 mm to those with precipitation between 400 mm and 800 mm; from subtropical zone to mid-temperate zone and warm-temperate zone; and gradually concentrated in fiat plains. The results implied that the change of spatial patterns of China＇s grain production went against the efficient use of water and heat resources, but it was beneficial to the application of agricultural machines and the improvement of labor productivity. Given the change trends of spatial pattern of grain production, background of climate change, and the national aim of grain security, China should enhance its ability to improve efficiency of water resources and reduce the risk of natural disasters.