A Spatio-Temporal Assessment of the Water Quality in Tuul River, Mongolia

Abstract

The study was carried out in the surrounding area of Ulaanbaatar, the capital city of Mongolia. The research indicates that the Tuul River is not polluted until the Ulaanbaatar city and the pollution starts when the river runs through the city. All high values of Water Quality Index are measured at a sampling point Tuul-lower Songino. The quality of the river strongly depends on how well water has been treated when discharged from Central Wastewater Treatment Plant. The distance between pollution point sources at downstream section of study area is not enough for the river self-puri fi cation process to take place. The water quality was decreased during the period of this study and the value of WQI increased. The WQI are calculated with greater values in cold period and with lower values in warm period of the year. The time series of water quality maps are produced.

Keywords

• water quality assessment
• spatial and temporal changes