IMPAK GUNA TANAH TERHADAP KUALITI AIR SUNGAI LIWAGU, SABAH

Abstract

This article aimed to identify the water quality of the Liwagu River, Sabah, due to the impact of land use activities in the sub-basin area. The Liwagu river provides the main water source for the local population for domestic purposes. Observations on the water quality of the Liwagu river and identification of the types of land use activities along the river were investigated. Assessment of the Liwagu river water quality engaging six parameters, namely biochemical oxygen demand (BOD), chemical oxygen demand (COD), dissolved oxygen (DO), alkaline index (pH), ammonia nitrogen (NH3N) and suspended solids (SS) in five stations that were selected. All of the parameters were analyzed against the Water Quality Index (WQI) standards by the Department of Environment (DOE) Malaysia. Water quality sampling was carried out three times, which were in February, March, and April 2019. The results showed that the average value of WQI in February 2019 was at a good level (Class I), and in March and April, 2019 was at a clean level (Class II). The COD parameter showed values that exceeded the standards set by DOE Malaysia. The decline in water quality parameters was also contributed by tourism, agriculture, settlements, and loging upstream and along the river. In conclusion, the impact of land use activities on the quality of the Liwagu river was still under control and planned in terms of its development. However, monitoring for river pollution should be conducted regularly by various parties as an early step in preventing the degradation of the Liwagu river's water quality since the water source is also used by the nearby villagers as a source for water supply.