Environmental and socio-economiqc impacts of integrated rice shrimp. Farming: Companion modelling case study in Bac Lieu Province, Vietnam

Abstract

Conflict over water demand, potential extreme poverty coupled with economic differentiation, and potential soil salinization in drought occurrence are three impacts caused by rice-shrimp farming in Bac Lieu coastal province, Mekong Delta, Vietnam. This study uses creative approach namely Companion Modelling for quantifying those mentioned impacts. Two successive RPG sessions and a RiceShrimpMD ABM in Companion Modelling approach were co-constructed between researchers and involved local stakeholders over the period 2006-2009. Lessons learned from the RPGs and five-year simulation results of the RiceShrimpMD ABM show that conflict over water demand for rice and shrimp crop occurs when both rice and shrimp crops coexist in the same period after September, which is a right time proposed to start rice crops. In downstream locations of the province, more conflicts occurred in the scenario where earlier salinity over 5ppt was provided in December and without any application for serving appropriate environmental conditions on rice crop. Extrem poverty and economic differentiation occurred whenever people had less concern to practice rice in rice-shrimp farming system, especially in the downstream location; rice yield reduced a bit due to the effects of salinization, compared to normal yield in the drought-free year. However, this environmental impact can be avoided as rice crops are annually practiced. Income obtained from rice crop is an essential compensation to reduce household extreme poverty. This study is confident that the companion modeling approach is an appropriate methodology for opening opportunity to all relevant stakeholders to share their knowledge of and a dialogue on water demand, enhancing better understanding of and collaboration on water management issues for sustainable development. (Résumé d'auteur