Integrated planning of water quality management system in the Tha Chin River Basin

The Tha Chin River Basin is located in central Thailand with an area of approximately 11,942 km2. The local economic development in the basin is based on a number of resources used by various human activities such as water supply, agricultural irrigation, fishery, industrial processing and navigation. However, increasing environmental concerns are associated with the social and economic development in the basin. Water quality in the Tha Chin River is deteriorating due to the increasing discharge of human-made contaminants. This research focuses on providing a plan for water quality management in the Tha Chin River Basin, with a special emphasis on pollution-related economic activities.;Since the study basin could contain a large-scale regional water quality management system with various interactive relationships between human activities, optimization modeling is considered suitable for integrated planning of various activities in the entire basin. The decision variables represent human activities in different spatial locations (twenty-seven subareas) over the planning time horizon (four periods). The constraints consist of relationships among economic and environmental concerns. The objective is to accomplish the desired compromise among environmental, resources and economic considerations.;This planning study provides a basis for the formulation of policies/strategies with respect to the regional socio-economic development and environmental protection. The developed optimization model allows various data and their interactions to be effectively incorporated into the planning processes. In general, the results indicate that most of the agricultural activities should be maintained at the existing levels. However, vegetable and prawn farming could be considered as alternative activities in order to promote agricultural production. Motor and food processing industries should be promoted. Conversely, textile/leather and special material industries should be reduced or terminated, due to their low economic efficiencies and high pollution potentials.