Integrating Land Use Planning and Surface Water Quality Management for Sustainable Development of River Basin, a case study of U-tapao River Basin, Thailand

Abstract

U-tapao River Basin is a sub-basin of large Songkhla Lake Basin which is located at the southern part of Thailand. U-tapao river is an important river of the basin and very much influenced from point sources and non-point sources of pollution from two major cities Hatyai and Songkhla. The purpose of this study was threefold; to evaluate the water quality of U-tapao river thereby study the impact of land uses on water quality of river; to prepare suitable land use planning map of the basin; and to evaluate the land use planning map on the basis of water quality framework. Most of studies in the current literature are concentrated on evaluation the impact of land use on water quality and preparing the suitability maps of agriculture, forest and urban on sustainable issues. But, there have been no studies evaluating land use planning map on the basis of water quality framework. This is a unique study and will contribute to establish a link between land use planning and water quality issues. Water quality data were collected the existing monitoring framework of Environmental Office-16, Songkhla and land use data were managed from the land use maps, provided from the Land Department, Thailand by using Geographic Information Systems(GIS). Descriptive statistics was used to describe the basic characteristics of water quality and land use indicators. Then, correlation and regression analyses were performed to determine relationships among the water quality parameters and land uses. Analysis of variance (ANOVA) was used to determine statistically significant variations in water quality and land uses. Multi criteria decision making method and analytical hierarchy process were used in GIS environment to prepare the suitability maps of agriculture, forest and urban area of U-tapao river basin. The study noted significant relationship between water quality and land use meaning that land use could be used as an indicator of the river water quality. The results identified clear relationship between land use and the water quality indicators which can be used in environmental protection and land use planning. Overall, preliminary results show that urbanization could become a serious problem in the future. The results emphasize the need to protect agricultural area in rapidly changing watersheds. Another objective is to develop suitable land use planning map for sustainable development of river basin. For this, land use suitability analyses were done. Land suitability analysis is the process of evaluation and grouping of specific areas of land in terms of their suitability for a defined use; and this is an important step for sustainable land use planning. By using GIS technique, this study intended to analyze and map suitable land areas for agriculture, forest and urban lands of U-tapao river basin.