A Study of Water Quality for Consumption of Si-Chang Island with Geographic Information System

Abstract

Recently, small and medium islands were face a shortage of fresh water for consumption, especially, small island with tourist destination, because it was a limited in resources, topography and physical properties. In dry season, It severely affected the lives. Si-Chang Island was selected because it was affected by this event every year. It had natural wells for absorbing seepage and surface waters. The surface water and groundwater were considered to freshwater source. Then, the water quality needed to examine for improve to meet the water standards for consumption. It will help the good health and quality of life for people. Therefore, the objective of this study is to examine the water quality for consumption in Si-Chang Island followed by the Department of Health drinking water standard 2020 and analyzed the water quality mapping for indicating water treatment position and guidelines for assessing water quality. The data input consisted of the elevation, slope, water path line; and use and collected the random water sample from reservoirs and wells that people used for consumption 9 samples. The water quality was generate using Inverse distance weighting method (IDW) and presented through the Geographic Information System (GIS). The results showed that the water quality was in the water standard criteria. It can be used for consumption if no other water source. However, the water needed to be treatment by boiling because Coliform Bacteria and E. coli pathogens are found. They caused diarrhea. The south of Si-Chang Island was no houses, but it was a landfill area. Then, the water quality was contaminated with many harmful substances, such as, arsenic and Fluoride. Water in the south did not be used for consumption.