ENVIRONMENTAL IMPACT ASSESSMENT OF PIT LATRINES USING REMOTE SENSING AND MULTI-CRITERIA SPATIAL ANALYSIS IN ULAANBAATAR (GER AREA), MONGOLIA

Abstract. This study aimed to analyze the environmental impact of pit latrines of ger-sprawl district areas (low rise sprawl area with detached “ger”- nomad’s mobile tent surrounded by fences or with handmade dwellings) in Ulaanbaatar capital city of Mongolia using remotely sensed data and multi-criteria spatial analysis. Within the last two decades, the residential areas without infrastructure have been significantly expanded and changed due to the migration of people from rural areas. 50.1% of the total population of Ulaanbaatar city is lives in ger district areas. Due to the formation of unstructured residential areas, pollution from pit latrines poses a risk to the urban environment and human health by infiltrating shallow water, being carried by floodwaters, and being released into the air. Therefore, to reduce the number of pit latrines in ger areas, the total number and location of pit latrines in the city were determined using high-resolution satellite imagery. In addition, spatial multi-criteria analysis methods were used to assess the negative impact of pit latrines on the environment and human health and categorize them into four zones. A total of 144,992 pit latrines were counted in Ulaanbaatar, with 9,443 pit latrines in Zone IV, 43,377 pit latrines in Zone III, 71150 pit latrines in Zone II, and 21,022 pit latrines in Zone I. The results of this study are important for implementing management measures to reduce soil pollution, such as restricting and banning the use of pit latrines in ger areas, installing toilets that meet MNS 5924: 2015 standards, and carrying out disinfection.