A thesis submitted in partial fulfillment of the requirements for the Degree of Master of Science in Urban Envirortmental Management, School of Environment Resources and Development

Thesis (M.Sc.) - Asian Institute of Technology, 2011

Pollution is a major problem of urban irrigation everywhere. Since 1995, Thailand has been affected by climate change and this also applies to Klang Rangsit Canal (KRC) in Phathumthani, the study area. Unpredictable climate change in relation to canal water resources has led to polluted water and high canal water variability. The present research is an attempt to investigate the combined impacts of three main factors: (1) Water flow the canal water management system (CWMS), (2) Pollution issues, and (3) Local habitat along the canal. This combined study is based on the perception of people's adaptation and government responses. One of the major factors in canal water variability is the unpredictability of the canal water level (CWL) based on Northern precipitation, which makes canal water control difficult. The study shows that the CWL influences canal water ventilation and consumption which are the major factors in canal water degradation. It also identifies changing urban social characteristics that influence changes in canal water consumption, and thereby affect canal water quality. Inadequate CWMS conditions also have a destructive effect on communities because people are unaware of the impo11ance of KRC in various areas. Furthermore, the current approach to inadequate CWMS focuses only on an overview of the problems of flood protection and drought in isolation from canal water quality and local people's needs. Based on to these findings, the researcher reconm1ends (1) improving local and national co-operation between people in order to understand their conditions, facilitate their adaptation and prevent further environmental degradation through community involvement by instituting laws and other appropriate measures to raise people's awareness of the conditions. (2) Preparing for low CWL conditions with seasonal variability of canal water consumption and providing conditions appropriate for canal water ventilation and consumption. (3) Wastewater monitoring and evaluation and ( 4) implementing more effective measures to control and assess the situation over time.