Penilaian indeks kualiti air Alur Ilmu UKM, Sub Lembangan Sungai Langat (Assessment of water quality index at Alur Ilmu, UKM Sub-Cathment of Langat River)

Abstract

Artikel ini membincangkan tentang kajian penilaian kualiti air Alur Ilmu, Universiti Kebangsaan Malaysia (UKM) dengan melibatkan 10 stesen persampelan. Keseluruhan panjang sungai ini adalah sekitar 1.79km bermula dengan stesen persampelan pertama iaitu di Tasik Ghazali dan berakhir di Masjid UKM. Masalah kualiti air yang kian meruncing dari semasa ke semasa telah menyebabkan keadaan fizikal Alur Ilmu dilihat semakin tercemar dan tidak menyenangkan. Justeru, satu kajian kualiti air yang terkini telah dilakukan bermula pada Jun 2019 sehingga Ogos 2019 dengan menggunakan kaedah ex-situ dan in-situ di kawasan kajian. Parameter kajian yang terlibat adalah seperti Oksigen Terlarut (DO), Permintaan Oksigen Kimia (COD), Jumlah Pepejal Terampai (TSS), Pemintaan Oksigen Biokimia (BOD), pH dan Ammonia Nitrogen (NH₃-N). Sebanyak empat kali data diambil untuk mewakili kajian semasa cuaca kering dan sebanyak lima kali semasa cuaca basah atau selepas hujan. Indeks Kualiti Air (IKA) oleh Jabatan Alam Sekitar (JAS) Malaysia telah digunakan untuk mengukur tahap pencemaran dan kesesuaian jenis guna air seperti yang disarankan oleh Piawaian Kualiti Air Kebangsaan (NWQS). Seterusnya, keseluruhan hasil kajian dibandingkan untuk membezakan keadaan kualiti air semasa cuaca kering dan cuaca basah. Penggunaan aplikasi ArcGIS turut digunakan dalam konteks spatial khususnya untuk mewakili hasil data IKA di setiap stesen persampelan yang telah ditetapkan. Dapatan kajian mendapati, keadaan stesen persampelan di bahagian hulu dan tengah Alur Ilmu mencatatkan kelas IKA yang tercemar berbanding di kawasaan hilir. Kemerosotan kualiti air di stesen persampelan hulu dan tengah Alur Ilmu adalah disebabkan oleh keterdedahan kawasan stesen persampelan dengan kafeteria dan fakulti. Kerjasama daripada pelbagai pihak khususnya segenap lapisan warga UKM amat diperlukan bagi menjamin kelestarian kualiti air di Alur Ilmu ini dapat dijaga dan dipelihara.

Kata kunci: cuaca kering, cuaca basah, ex-situ, ArcGIS, in-situ, kualiti air

This article discusses the study of water quality assessment of the Alur Ilmu, Universiti Kebangsaan Malaysia by involving 10 sampling stations. The entire length of the river is about 1.79km starting with the first garbage station at Lake Ghazali and ending at Masjid UKM. Increasing water quality issues from time to time have caused the physical state of the science flow to become increasingly polluted and unpleasant. Therefore, a recent water quality study was conducted from June 2019 to August 2019 using ex-situ and in-situ methods in the study area. The study parameters involved are Dissolved Oxygen (DO), Chemical Oxygen Demand (COD), Total Suspended Solids (TSS), Biochemical Oxygen Demand (BOD), pH and Nitrogen Ammonia (NH₃-N). The data has been collected four times to represent the study during dry weather and five times during wet or after rain. The Water Quality Index (WQI) by the Department of the Environment (DOE) of Malaysia has been used to measure the level of pollution and suitability of water used as suggested by the National Water Quality Standards (NWQS). Furthermore, the overall results of the study were compared to distinguish between water quality during dry and wet weather. The used ArcGIS applications have been used in spatial contexts in particular, for each WQI results data at each location. The study found that the sampling center at the upstream and middle of the science stream recorded an impaired WQI class compared to downstream controls. The deterioration of water quality at the upstream and central sampling stations was due to the exposure of the station sampling area to the cafeteria and faculty. Collaboration from various parties in UKM is essential to well-balanced and ensure the quality of water in this Alur Ilmu UKM is maintained.

Keywords: dry weather, wet weather, ex-situ, ArcGIS, in-situ, water quality