Risk assessment of drought disaster in the maize-growing region of Songliao Plain, China

This study presents a methodology for risk analysis and assessment of drought disaster to agricultural production in the maize-growing area of Songliao Plain of China based on Geographical Information Systems (GIS) from the viewpoints of climatology, geography, disaster science, and environmental science and so on. Crop yield-climate analysis and regression analysis were employed to analyze and quantify relationships between the fluctuation of maize yield and agro-meteorological disasters, and to evaluate the consequences of drought disaster based on historical climate, crop yield, crop sown area, crop damaged area and crop loss data from 41 maize-producing districts of Songliao Plain (1949-1990). The model of risk assessment of drought disaster combined the occurrence frequency, duration and intensity of drought, spatial extent of damage caused by drought and regional production level of maize were developed using a method of quantitative risk analysis. It is shown that drought was the greatest agro-meteorological disaster. Among all agro-meteorological disasters, drought occurs with the highest frequency, covers the largest area, and causes the greatest loss to agricultural production and economy in the region. From 1949 to 1990, the negative value years of the fluctuation of maize yield due to agro-meteorological disasters accounted for 55%, of which 60% was caused by drought. A significant positive relationship between the negative values of fluctuation of maize yield and drought affected area was found, which indicates that the adverse impacts of drought on maize production are similar to the damage extent of drought disaster. According to the risk extent of drought disaster to maize, the Songliao Plain was divided into four sub-regions: high risk zone, medium risk zone, low risk area and slight risk zone by using fuzzy cluster analysis. It showed the risk degree of drought disaster in the Songliao Plain increases gradually from south to north and from east to West. The information obtained from interviewing the district official committees in relation to result compiled was statistically evaluated. The results obtained in this study can provide the basis for developing strategies to mitigate drought and reducing the losses, and to ensure agricultural sustainable development. (C) 2003 Elsevier B.V. All rights reserved.