Spatio-temporal pattern of cold and frost damage in China

Cold and frost damage is a natural disaster of significant impact on crop yield in China. Extensive analysis of the spatial and temporal patterns of cold and frost damage has been done in this paper. Most of Chinese cropland areas are affected by cold damage, especially in the northeast and Huanghuaihai regions. The intensity of cold damage in North and Central China has been increasing in the last two decades. South China and Southwest China including Yunnan and Guangdong Provinces lie in relatively low latitude zones also suffered from severe cold damage in some years.In the last two decades, the trend of cold damage can be described as a sequence of weak-strong-weak. The most serious cold damage occurred in China during 1992 to 1999. In 1998, 8.67 million hectares of cropland was damaged in the whole China, Jiangsu and An'hui Provinces accounting for more than 5 million hectares. Cold damage impact dropped after 1999 with annual cold damage area above 37 million hectares. Variation analysis on the development of cold damage for three time periods (1986～1991, 1992～1999 and 2000～2005) indicates that cold damage is becoming stronger in most of Chinese provinces. Annual damaged cropland area in eight provinces increases by more than 100 thousand hectares. Spatial and temporal analysis of cold damage in China can be vital in regional planning of crops and can provide strong scientific basis for forecasting and effective defenses.