Assessment and Distribution of Waterlogging Damage Risks for Melons and Vegetables in Hainan Province from October to November

Hainan, as an important agricultural zone for winter melons and vegetables in China, suffers from waterlogging, chilling and drought risks that threat production during its growth period. In order to offer guidance to reduce waterlogging damage and assure production, the theoretical framework of natural disaster risk system is implemented based on meteorological station observations from 1998 to 2011, the yield and planted area data, as well as waterlogging disaster data for melons and vegetables. A waterlogging level index system is constructed through comparing the hazard index with disaster based on the principal component analysis of four factors, i.e., precipitation, rain days, continuous rain days and maximum continuous rain days. A comprehensive waterlogging risk index model for melons and vegetables is built integrating with hazard index, damage sensitivity index, damage loss index and damage prevention capability index.Results show that the waterlogging hazard index increases from southwest to northeast, the risk probability of different level hazard index are different in regions, and the distribution of high and low risk probability are of the opposite. Due to results of disaster hazard spatial pattern, it implicates that more attention should be paid to those high hazard regions. Considering waterlogging sensitivity is partly influenced by slope gradient, the damage index increases from the central mountain to the periphery. Among three disasters, waterlogging causes most yield reduction for paprika, watermelon and cowpea which are in conformity with their biological characteristic. Taking yield loss and production status as factors to represent damage vulnerability and prevention capability, waterlogging damage loss index and prevention capability index differ in different regions. The distribution of comprehensive waterlogging risk index for melons and vegetables is similar for four kinds of melons and vegetables, which increases from southwest to northeast induced by factors such as precipitation, terrain and soil. The distribution characteristic is conformed to the real waterlogging situation in Hainan Province. Results can provide useful information which contribute to a better understanding of disaster damage risk for melons and vegetables and help for the policy formation of agro-meteorological disaster risk management.