Ecology, Environment and Conservation Paper

ESTIMATION OF DISSOLVED OXYGEN USING SPATIAL ANALYSIS BASED ON ORDINARY KRIGING METHOD AS EFFORT TO IMPROVE THE QUALITY OF SURABAYA’S RIVER WATER, INDONESIA

Karina Bias Rachmawati, Istiqlal Abadiyah Sukma, Alfika Triamartha, Khabibah Puspa Dela and Nur Chamidah

Abstract

River water quality level measurements can be identified through the levels of Dissolved Oxygen (DO) in river. If DO level in the river is high, the river water quality will be better. Based on data from the Ministry of Environment and Forestry (KLHK) in 2017, as many as 73.24% of rivers were in heavy pollution due to factory waste, household waste, and other hazardous substances. According to Perum Jasa Tirta II, 62% of river pollution in Surabaya was caused by domestic household waste. In this paper, we estimate DO level at five locations in Surabaya¡¯s rivers by using spatial analysis based on ordinary kriging method. The ordinary kriging is an important tool in geostatistics for prediction DO level at each unobserved site based on observed site around it. One of the estimated DO level rivers is Ngagel/Jagir River, which is one of the water sources in Surabaya’s Water Utility Company (PDAM). The results of the analysis show that the estimated value of drinking water PDAM from Ngagel/Jagir River is 3.078 mg/L and can be classified below the drinking water standard. The obtained results of this study are expected to describe the condition of rivers in Surabaya and to be used as a reference for evaluation of DO levels to improve the quality of Surabaya¡¯s rivers water by environmental service of Surabaya.