Characterizing flood events and their impacts on rice production in the Mekong Delta of Vietnam

Abstract

A significant percentage of rice areas in the Mekong Delta are vulnerable to various degrees of flooding. Flash floods that occur with short duration at early rice stages could increase farm inputs, but can be avoided to reduce production losses. Farmers have developed their own coping strategies to avoid/reduce the risks. Viet Nam government also provides mitigating and relief programs to cushion the impacts of submergence. This study used secondary and household-level data to characterize flood events and estimate its impacts on rice farming households. Significant findings indicated that there are two to three flood events in the Mekong River. Stagnantfloods in July to November, with >1.0m depth can cause serious inundation. Flash floods (20-60 cm depth) of 7 to 20 days duration at the early rice stage in November/December can be avoided by re-sowing and adjusting the cropping calendar. Floods decrease yield and production by 20-100% if there is no adjustment adopted. From 2000 to 2001, heavy rains and tidal movement in the Mekong Delta inundated 422,032 ha rice and destroyed 87,106 ha of agricultural land. Submergence-tolerant rice varieties are criticalto addressing the poverty situation in the rice areas. Breeders should develop more rice varieties that withstandthe excess water and are adaptable under varying flooding conditions. Aswomen become increasingly involved in farming, they should have equal opportunities as men in acquiring knowledge, making decisions on which varieties to use and appropriate management practices should be adapted under the complexity of conditions in flood-prone areas.