京津地区近50年来水稻播种面积变化及其对降水变化的响应研究

基于滑动－ｔ突变检验结果，对京津两地近５０年来水稻种植面积的变化进行了阶段划分，并分别讨论了各阶段的变化特点。两地水稻种植面积的阶段性均受自然、技术和政策等多方面因素的综合影响。事件相关分析发现，作为人类对隆水变化响应的裟种植面积的变化较降水变化滞后一年，使得年雨量变化与当年水稻种植面积变化之间存在在明显的负相关。

Changes of the Rice-Seeded Area in Beijing and Tianjin Region during the Past 50 Years and Its Responses to the Changes of precipitation

According to the result of Moving-t test analysis, The changes of rice-seeded area during the past 50 years are divided into three stages, 1949-1968, 1969-1985 and 1986-1996, in Beijing, and two stages, 1949-1971 and 1972-1995, in Tianjin, respectively. In both regions, the rice-seeded areas show the fluctuation from rise first and then fall down. And before 1970, the changes in the two regions were, on the whole, similar. But after 1970, the changes in the two regions tended to difference. The changes of rice-seeded area in both regions were all resulted from the comprehensive influence of the natural, the technological and the political factors. It is the faultiness of the policies that has made the rice- seeded area being extended over the capability of water resource supply. In order to serve the need of the rice planting, the exploitations of water resources in both regions all have been extended from rain to surface water and then to groundwater. But when the water resources still could not meet the need, the rice-seeded area was reduced. As a response of farmers to the annual rain variation, the variation of rice-seeded area is lagged behind that of the rain by one year, which resulted in the remarkable negative correlation features between the precipitation of a year and the rice-seeded area of the same year. Such important phenomena makes the water resources can not be used sufficiently in the years with more precipitation, but the shortage of water resources be strengthened in the drought years.