USING GIS AND REMOTE SENSING TO MONITOR ARSENIC DISPERSAL FROM A GATSUURT MINING AREA, MONGOLIA

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1 USING GIS AND REMOTE SENSING TO MONITOR ARSENIC DISPERSAL FROM A GATSUURT MINING AREA, MONGOLIA GANDOLJIN.N 1, BATBILEG.B 2, ENKHDUL.T 3, DARJAA.TS 4 1, 2 NUM-ITC-UNESCO Laboratory for Remote Sensing and GIS National University of Mongolia Building 1, Street of university, Ulaanbaatar, Mongolia Tel , Fax Ganaa_7911@yahoo.com, Saihanaa_b2000@yahoo.com 3, 4 Faculty of Chemistry, National University of Mongolia Building 1, Street of university, Ulaanbaatar, Mongolia t.enkhdul@yahoo.com KEYWORDS: Landsat, arsenic, arsenic removal, GIS ABSTRACT: This study aims to use remote sensing and Geographic Information System (GIS) to monitor the concentrations of arsenic in Gatsuurt Gold Mining Area, Selenge Province. Land cover classification for soil, vegetation and land use types was developed and changes in land use and land cover have been identified. Chemical analyses of water samples in the area were analyzed by atomic absorption spectrometry. The arsenic content in artificial lakes (sediment s and algae s arsenic content) of Gatsuurt gold mining area were determined. Arsenic contents in the water samples taken from artificial lakes of Gatsuurt were 2-12 times higher than the standard for drinking water which was 0.01 mg/l. The samples taken from Gatsuurt River and well water were contained lower amount arsenic than the standard. The arsenic content in the sediments were not more than 500 mg/kg. These data used with Landsat derived data to monitor and map the change of concentrations between 2007 and This data was incorporated into the GIS to analyze the dispersal of arsenic over time. 1. INTRODUCTION Since Mongolian Government started Gold program from 1993 the intensity of gold mining was increased drastically and it s influenced the economics growth. Toxic heavy metals such as arsenic emission were increased. The discharge of mining drainage water containing arsenic contributes to its dispersion in the environment. Arsenic is a common trace-level constituent of gold-quartz vein deposits in mining regions. This toxic metalloid is often present in waste material, water and soil near gold mining areas. The resulting contamination of surface waters, groundwater and sediments is a matter of great public concern due to the deleterious effects of arsenic on human health (Guezennec, 2009). In water, arsenic exists mostly as trivalent arsenite. Thus, this paper s objective is to generate land cover classification Mandal soum of Selenge aimag and investigate the arsenic pollution in Gatsuurt gold mining area of the study area.

2 2. STUDY AREA The study area is located approximately 90 km north of Ulaanbaatar, central northern Mongolia, at approximately latitude N 48º and longitude E 106º (figure1). 3. METHODOLOGY AND DATA Figure 1. Mandal Soum of Selenge Aimag. We used Landsat satellite data to generate land cover classification. The Landsat data (Path/Row: 132/026) acquired on July 22, 2007, Septemer 10, 2008 and August 20, We applied supervised classification named as minimum distance to determine changes of land cover from 2007 to GIS tools were used to show arsenic affected area in this study area. To investigate arsenic pollution in this area, 13 water samples were taken from artificial lakes, Gatsuurt River which passes by mining site and deep-well. Total 6 samples of sediment were collected from artificial lakes. Two algae samples collected from two of 8 artificial lakes, where algae growth was observed. The samples were collected middle of October, Arsenic and other chemical analysis were determined by atomic absorption spectrometry (Shimadzu, Japan), and ICP-MS (Canada, Actlabs). Temperature and ph was measured by portable ph meter (Eutech, Korea) on-site. 4. RESULTS AND DISCUSSION The figure 2 and figure 3 show land cover classification from 2007 to This classification performs that bare soil increased in 2009 more than (figure 2, 3).

3 Figure 2. Land cover classification maps for 2007 (left) and 2008 (right). Figure 3. Land cover classification for We showed with arsenic affected area using Arc GIS 9.3 software (figure 4). Figure 4. Arsenic affected area in Gatsuurt mining. Table 1 and table 2 show arsenic concentration and other analysis. Arsenic concentrations are between 1 and 121 ppb. In Narst River from the study area, Lake #1, drinking water and deep well water arsenic concentration did not exceed the recommended maximum concentration limit (MCL) of 10ppb for drinking water. Dissolved arsenic concentration in artificial lakes is variable, but nonetheless the concentration is 2 to 12.1 and two times higher than that the recommended MCL Gatsuurt River is passes by the Gatsuurt gold mining site, which is part of the drinking water supply for nomads, this is a public health concern.

4 Table 1. The physical, chemical properties of water samples Elemental analysis (ppm) Samples ph Temp. 0 C As * 1 Upstream of Narst River (ppb ) Lake # Lake # Lake # Lake # Lake # Lake # Lake # Lake # Mid-Gatsuurt River 11 Downstream of Gatsuurt River 12 Drinking water Deep well Note: * - concentration is in ppb. Table 2. Elemental analysis of sediment and algae. Samples Color, odor Elemental analysis (ppm) As 1 Algae, Narst river Green, odorous 54 2 Sediment Lake #1 Brown, no odor 44 3 Sediment Lake #2-1 Brown, no odor Sediment, Lake #3 Brown, no odor Sediment Lake #4 Brown, no odor Algae, Lake #4 Green, odorous 48 6 Sediment Lake #5 Brown, no odor Sediment, Mid- Gatsuurt River Brown, odorous 136

5 5. CONCLUSION We generated land cover classification using remote sensing and showed areas with arsenic pollution using GIS. The arsenic pollution in Gatsuurt gold mining area was investigated. The high samples showed possible absorption of arsenic. Thus, we concluded that it is useful to determine arsenic pollution using GIS analysis. In the future, we need to have additional materials and investigation References Scott Groser, Bob Booth, Andy Mitchell (1999), ArcGis pp. Borch T, Kretzchmar R, Kappler A, Cappellen P.V, Ginder-Vogel M, Voegelin A, Campbell K. (2010), Environment. Sci. Technol. 44, 15-23pp. Erdenetsetseg,D. (1986), Standard method for arsenic determination, Ulaanbaatar, Central Geological Laboratory Guezennec A.G, Touze S, Battaglia-Brunet F, Morin D. (2009) Abstracts of the Internation Mine Water Conference, Pretoria, South Africa, pp. Scott Groser, Bob Booth, Andy Mitchell (1999), ArcGis pp.