关键词: 连续无雨日, 农业干旱风险, 西南地区

Abstract: Agro-drought risk assessment is helpful for improving ability of regional disaster management and mitigating the drought-induced loss. We used historic precipitation, disaster loss and socio-economical data in China as the basic data. The assessment was performed for the three crops with the biggest sown areas in each of prefecture-level region. By using the consecutive rainless days to scale the drought severity, we developed different standards of indexes to judge drought severities. The standards were relying on seasons, crop types and crop growth stages. Moreover, we developed a model for each type of crops. This model could be used to calculate risk loss under different severities of drought. In the next step, we integrated risk loss of each type of crops to assess the regional drought-induced agricultural loss, by weighting average approach. Using the above method we took Southwest China as a case area to assess its spatial distribution of agro-drought risk. We found that (1) from the results tested by historical loss of agro-drought hazards in recent 10 years (1997-2006) in Southwest China, the risk loss calculated by the model can reveal the loss differences between assessment units; (2) different risk regions divided by the composite risk index can well reflect the differences of spatial distribution in Southwest China; (3) high and extreme risk areas of agro-drought were primarily in the plateaus and mountains in the western and northern parts of the region, and slight and moderate risk levels were observed in the eastern, central and southern parts of Southwest China.

Key words: agro-drought risk, consecutive rainless days, southwest China