W WATER QUALITY ASSESMENT BASED ON THE WATER QUALITY INDEX (WQI) APPROACH USING GEOSPATIAL ANALYSIS

Abstrak

Water quality refers to the chemical, physical, or biological characteristics of water, in which
assessing the condition of water relative to the requirements of biotic species or to any human purposes. The
aim of this study was to analyze the water quality of the Way Kuripan River based on the Water Quality
Index (WQI) calculation method. Water samples were taken from five different areas (WK01, WK02, WK03,
WK04 and WK05). WQI was calculated on the basis of six parameters; dissolved oxygen (DO), biochemical
oxygen demand (BOD), chemical oxygen demand (COD), pH, total suspended solid (TSS) and ammoniac-
nitrogen (NH3-N). The calculation started by identifying the equation of the Sub-Index (SI) based on the
parameter value, calculating the Sub-Index (SI) of each parameter, and calculating the Water Quality Index.
The results show that WK01 and WK04 have WQI values of 70.3 and 70.11. Those values show that water
quality of the Way Kuripan River was in class III or slightly polluted. WK02 (WQI = 55.8) and WK03
(WQI=53.8) were highly polluted. The lowest WQI of the Way Kuripan River was in WK05 = 38.3, and
classified as Class V (highly polluted). Moreover, Geospatial analysis was done to identify the distribution of
water quality geographically. It shows that home industry and human activities, were spread along the river
flow, and it caused the fluctuation of water quality. The results of this study can be used as a reference by the
local government for water resources management.