On the impact of the climate change on the agricultural disaster loss caused by drought in China and the regional differences between the North and the South
The impact of drought on agricultural production is getting worse and worse in China under the climate change,but due to the complexity and its significant regional differences of disaster loss caused by drought,the understanding of the law and the mechanism for the agricultural loss caused by drought are very limited.In this paper,using the data of Chinese agricultural drought disaster and the conventional meteorological data since 1961,a more systematic analysis of the disaster loss index trends is made,such as the different intensity disaster ratios and the comprehensive agricultural loss rate caused by the agricultural drought,and the regional differences in the North and the South of the past 50 years.We researched the characteristics that the temperature mutation have the effects on the agricultural loss caused by drought since 1990s,we discussed also the dependence between the comprehensive agricultural loss rate and the climatic factors of temperature and precipitation,as well as the distribution characteristic of the agricultural loss rate in the climatic space.The results showed that the comprehensive agricultural loss rate increased by an average of 0.5%per decade in the past 50 years,and the risk increased significantly under the climate change.Moreover,the comprehensive loss rate is increased by about 0.6% per decade in the North,higher one time than the South,with the increasing of risk faster significantly than the South.The North agricultural drought disaster can occur in a loose temperatures condition,and it occurred in the years with the higher temperatures in the South.And,the warming trend is increasing clearly after the temperature mutation,with the national comprehensive loss rate is increased by about 0.9%,and higher significantly risk;and the increment is 1.8%in the North,about four times higher than the South,suggesdoi ting that the North climatic mutation has more prominent impact on the agricultural drought disaster risk than the South.The response of the North comprehensive loss rate to precipitation is more sensitive than the South,but the South is more sensitive in terms of temperature.Meanwhile,the impact of the key periods temperature and precipitation for the comprehensive loss rate is more significant than the annual;in the key periods the North is more prominent in terms of precipitation than the South.These new scientific understanding has important implications for agricultural drought disaster prevention in China.