Application of GIS in Mine Contamination and Associated Environmental Impacts

Chade Salame and Arsalan SyedEAS 351: Environmental Application of GISDecember 6, 2016

Introduction to mining and acid mine drainage

GIS and Remote Sensing methods to measure mining impacts

Two case studies and limitations of GIS applications

Concluding remarks

Outline

Contamination Through Mining and AMD Mining has been a huge part of how we function day to day. It provides us with

minerals and elements and eventually, products that we use daily.

However, it comes at an expense when considering the environmental impacts and contamination that results from its activity. Degradation of the land, destruction of forestry, and contamination of surround soil

and groundwater.

One of the largest sites of contamination is a result of Acid Mine Drainage (AMD). It is the accumulation of acidic products in the environment from the process of mining. During exploitation, mines release metal sulphides (i.e. FeS2) that will oxidize by

reacting with water/atmosphere, then formation of sulfuric acid (H2SO4; Mounia et al., 2013).

4FeS2 + 15O2 + 14H2O => 4Fe(OH)3 ¯+ 8H2SO4

Figure 1: From the Tulsequah Chief Mine in northwestern British Columbia. Acid-leaching site into the Taku River that flows into Alaska (Tucker, 2016). Photo retrieved from https://goo.gl/gfFWpA.

Figure 2: Contaminated Colorado River. Accidental waste water seepage from the Gold King Mine. Highly acidic with heavy metals like iron, zinc, aluminum, copper, and cadmium. Retrieved from

https://goo.gl/1KGMfG.

General Methods The goal is to determine the spatial extent and level of pollution at

mining sites in order to develop or implement the best approach and technique in prevention and reclamation.

Must identify contaminant transport pathways and their locations (whether it be dump sites, excavation areas, etc).

Conventional methods of achieving this is by ground sampling and setting up systemic grids to cover large portions of land which can be time consuming and costly.

To address this issue, GIS and Remote Sensing can be used to develop flow pathway maps as a result of surface runoff.

Methods of Data CollectionLow Resolution Data:

MODIS AVHRR MERIS

Higher resolution data: Landsat Aster Ikonos Quickbird

These high resolution satellites can be used for geological mapping, subsidence related features, detailed pollution studies, and mining related infrastructure.

Radar data: Envisat ASAR TerraSar-X and TandDEM-X

Düzgün et al., 2011

Case Studies

Figure 3: Location of study area. Retrieved from Yenilmez et al. (2011).

Methods for Generating a Raster DEM and Flow Accumulation Map

Obtain topographic map

and an ASTER satellite image

ArcGIS 9.3 to generate DEM with 3D and

Spatial Analyst tools

Elevation contour map in Vector

format

DEM using TIN then to Raster DEM (Fig. 4)

Flow directions generated

Flow accumulation map

(Fig. 5)

36 soil samples collected

Elemental characterization of nearby coal to

determine contents

Analysis of results

Figure 4: Digital Elevation Model generated. High elevations are seen in white. Retrieved from

Yenilmez et al. (2011).

Figure 5: Flow accumulation map. High accumulation is represented by deeper colors.

Retrieved from Yenilmez et al. (2011).

Figure 6: Soil pH distribution with high elevation in grey. From Yenilmez et al. (2011).

Results

Figure 7: Distribution of Cr soil concentration. From Yenilmez et al. (2011).

Limit of Cr concentration is 100 mg/kg by the SPCR.

Results indicated a range of 195 to 650 mg/kg.

Significant amount of Cr contamination observed in the area and on flow pathways.

Trend was observed in almost all of the trace element studies.

Implications and Limitations of this Study Concentrations were higher (especially Cr, Ni, and Cu) closer to

contamination sources. Lower concentrations at higher elevations but higher concentrations downslope and along flow pathways.

Therefore, with the aid of GIS, we can locate areas that have a higher potential of being impacted by contamination via transport routes. Also, this would help determine sample locations, taking both less time and cost to do so.

However, more data is needed to supply background concentrations and what these values were beforehand to grasp a greater understanding of the area.

Study limited due to budget concerns.

They used the elemental characteristics of a coal seam from the Ilgaz-Ilisilik mining site so its not a true representation of the mining site of focus in this study.

Figure 8: Map of study area. Modified from Brugge et al. (2009).

Methods to Develop Risk Communication Strategy

Water Hauling Map

Collection of Survey and Participant

Demographics

Creation of Demographic

Tables

Water Sample Collection from

Wells

Relate Collected Water Sample

Data with Survey Data

ArcMap 9.2 Used to Create Base

Map Layers1m Resolution

RGB Orthophotos

Compilation of Chapter

Boundaries, Locations, Roads,

Mines, Hydrography

Water Hauling Map

Methods to Develop Risk Communication Strategy

Soil Restriction Map

Collection of Survey and Participant

Demographics

Creation of Demographic

TablesCollection of Soil

SamplesRelate Collected Soil Sample Data with Survey Data

Extrapolation of Soil Uranium

Concentration in Missing Data

Coverage Areas

Kriging Analysis to Create Sediment

Uranium Estimation

Apply Geostatistical Analyst Tool

Log Transformation of Data

Data Fit using Gaussian Semi-

Variogram

Manual Classification of

Uranium Concentration

Areas

Soil Restriction Map

Results

Figure 9: Percent of participants hauling water from unregulated source, regulated source and groceries. Modified from Brugge et al. (2009).

Figure 10: Recommended Water Hauling Map. Modified from Brugge et al. (2009).

Figure 11: Recommended Soil Restriction Map. Modified from Brugge et al. (2009).

Implications and Limitations of Study The presented water recommendation map was understood by the

Navajo tribe and they were able to identify regulated water wells in their area.

The soil restriction map was understood by the majority of the tribe with the exception of the elders.

The limitations include language barriers, available data to create additional features, and knowledge gap within the Navajo tribe.

Overall, the use of GIS based thematic mapping for risk communication was effective because it provides a new approach to risk based mapping which involves the community in the decision making process.

Conclusion

Application of remote sensing and GIS have a wide range of capabilities and can assist in developing maps that determine areas of contamination and can provide a low-cost alternative to remediation.

As explained in the two case studies, using GIS can give us an idea of the level of contamination in surrounding areas and allows us to focus on areas of immediate concern to address human impacts as well as, ecological and socio-cultural problems.

References Cited

Brugge, D., Cajero, M., Downs, M., Durant, J. L., George, C. M., Henio-Adeky, S., ... & Shuey, C. (2009). Development of risk maps to minimize uranium exposures in the Navajo Churchrock mining district. Environmental Health, 8(1), 1.

Düzgün, Ş., Künzer, C., & Karacan, C. Ö. (2011). Applications of remote sensing and GIS for monitoring of coal fires, mine subsidence, environmental impacts of coal-mine closure and reclamation. International Journal of Coal Geology, 86(1), 1-2.

Mounia, B., Mostapha, B., Rachid, H., Hassan, B., Abdelhakim, J., & Mohamed, S. (2013). Impact of mining wastes on groundwater quality in the province Jerada (eastern Morocco). International Journal of Engineering Science and Technology, 5(8), 1601.

Tukker, P. (2016). Owners of B.C.'s Tulsequah Chief mine site pushed into receivership. Retrieved December 05, 2016, from http://www.cbc.ca/news/canada/north/tulsequah-chief-mine-bankrupt-receivership-1.3758668

Yenilmez, F., Kuter, N., Emil, M. K., & Aksoy, A. (2011). Evaluation of pollution levels at an abandoned coal mine site in Turkey with the aid of GIS. International journal of coal geology, 86(1), 12-19.