最近15年来中国气候变化、农业自然灾害与粮食生产的初步研究

本文分析了最近１５ａ来中国气候变化在最近５０ａ来的比较特征,并着重分析与讨论了这一期间气候变化、农业自然灾害与粮食生产的关系。结果表明：降水变化是影响中国粮食生产变化的主要原因,温度变化对粮食生产的影响主要表现在高纬度地区和高海拔地区；因气候变化影响粮食产量的变化幅度一般为３％～５％,个别年份可达１０％左右；因农业自然灾害造成的粮食减产幅度一般在５％～１０％,个别可达１０％左右。

A PRELIMINARY STUDY OF THE CLIMATIC CHANGE, NATURAL DISASTERS OF AGRICULTURE AND GRAIN YIELD IN CHINADURING THE PAST 15 YEARS

his paper analyses the main features of the climatic change, natural disasters of agriculture and grain yield in China during the past 15 years in comparison with the situation of the last 50 years. The conclusions are as follows: (a) During the last 15 years, the average temperature increased by 0.1～0.9℃ in China. The temperature increase was higher in the north than in the south. The average increase in the north was 0.5～o.9℃ .The precipitation increased or decreased by 3%～10%. The regions with precipitation increase were the northern part of Northeast China, Xinjiang, East China, the northern part of Central China and Sichuan and Guangxi Provinces. In general, the increase was between 1% and 5%. (b) During the last 15 years, flood, water 　logging and drought were the main natural hazards of agriculture in China. The drought stricken areas and flooded areas covered 17.6% and 8.1% of the sowing area in the corresponding periods respectively. The proportion of the drought stricken areas of each province was about 5%～19%. The proportion of flooded areas of each province was about 2%～10%. (c) The grain yield change due to the climatic change has obvious regional laws. The law shows that in the whole country the rich harvest year and the poor harvest year occur alternately and that the east and the west or the south and the north supplement each other in grain yield. In the past, we pointed out the law that “the south will have flood when the north has drought ”or “the south will have drought when the north has flood”. Actually it is not very exact. (d) During the last 15 years, the range of the grain yield decrease due to natural hazards occupied about 15% of the grain yield in the same period.The loss induced by meteorological disasters occupied about 40%. That was 6% of the grain yield in the same period. The continuous uptrend of the grain yield decrease proportion in the main grain production regions is one of the major reasons for the slow increase in grain yield in China since 1984.