A Case Study on the Correlation between Land Use Types and Water Quality of the Bang Pakong River in Chachoengsao Province, Thailand

Abstract

Multiple human activities, like as urbanization, industrialization, and agricultural endeavors, are modifying the land use in Bang Pakong River, Chachoengsao Province, as a result of the rapid population rise. These land use changes in the province of Chachoengsao have led to the discharge of pollutants into the river. This study intends to evaluate the connection between land use changes and water quality in the Bang Pakong River's upstream (US), middle stream (MS), and downstream (DS) regions. GIS and statistical analysis were utilized to assess the relationship between land use change and the quality of the Bang Pakong River, including dissolved oxygen, total phosphorus, biological demand oxygen, and turbidity. The classification of land use types into five groups included urban land, agriculture, forest, water body, and miscellaneous land. The Spearman correlation was utilized to determine the relationship between land use changes and river water quality. Monitoring of water quality revealed a decline in the quality of the BPKR, which flows through the Chachoengsao Province, from 2008 to 2018. Changes in the land use of water bodies and forests have a positive effect on the water quality of middle and downstream streams. The land uses identified as important sources of total phosphorus and turbidity contamination in water were reduced in the forest and miscellaneous regions of the BPKR's upstream and middle streams. The transformation of agricultural land has an adverse effect on the water quality of middle stream. The results revealed that the conversion of forested land improved water quality, particularly the concentration of dissolved oxygen upstream. Furthermore, the findings provide a mechanism for evaluating river water quality, mitigating water pollution, and optimizing land use by utilizing landscape patterns.