My spatial problem is about land use/land cover (LULC) change associated with the establishment of artisanal, small-scale gold mines (ASGM) in rural Senegal. Put in the vernacular we’ve learned in the course, I’d phrase my question this way:

How is the spatial pattern of LULC change related to the spatial pattern of ASGM establishment via the mechanism of deforestation?

As part of their establishment, ASGM requires clearing the land where the mines will be, as well as additional timber harvesting to build the homes where the miners will live while working and additionally to bolster the mines shafts themselves. As such, I’m curious as to what the exact change is that accompanies ASGM establishment, as this is a sub-set of my graduate thesis which seeks to understand more broadly how ASGM impacts the environment and the lives of the miners themselves, to understand better if a household diversifying into ASGM is better suited towards adapting to future climate change than if they hadn’t.

The dataset I have is very high resolution (VHR) satellite imagery (panchromatic and multispectral) courtesy of the Digital Globe Foundation. The panchromatic imagery has a resolution of .3m while the MS imagery is around 1.24m — as part of the preprocessing I’ve pansharpened the images so the overall imagery is stills sub-meter, which is necessary to investigate ASGM as its footprint is too small for detection with Landsat or other sensors. The imagery covers about 16 gold mines I’ve identified, and has imagery from 2018 and 2009/2010.

My present hypothesis is that, while obviously there will be a decrease in LULC at the mine in general, the area around the mine will also be indicative of some change — in my literature review, I’ve found some information that the environment up to 20km around a gold mine can be impacted. I think in this case the impact won’t be as drastic, but it’s what I’m expecting.

Currently I’m not sure how to approach the problem. The first step will be to just map out the mining locations first in ArcPro and from there try to see how the forest cover has changed between present and past. Beyond that I’m not sure how to answer the question.

Ultimately I’d like to produce maps, to demonstrate the environmental impact that ASGM has (or not, potentially!). I’ve also considered producing similar maps showing the relative impact subsistence agriculture has had in non-mining villages as a comparison.

I feel somewhat prepared for this task. I’m comfortable working with ArcGIS and have some knowledge of ArcPy (though I’m a bit rusty). I can use ModelBuilder pretty competently and feel that I have a good grasp of what to do in that arena. My major hurdle right now is not knowing what I don’t know — I need some more exposure to the tools available to me for addressing this problem. However, I feel confident that with enough time and work, this problem is not intractable!

One problem is that, given the rural area and part of the world I’m looking at, Digital Globe does not frequently sample the area and so the imagery I have is not necessarily on the anniversary date. Given the drastic climate differences (rainy season and dry season), the vegetation may look drastically different.

As an example, bellow is Kharakhena in November 2008, with the original village highlighted in red.

Here is the village of Kharakhena in March 2017. The village is highlighted in yellow and the mine in blue.

The difference is very dramatic, but I’m not sure how to approach this analytically.

This is my spatial problem! I believe that this is significant as a part of my thesis work exploring livelihood diversification in rural Kedougou. As 70% of the population in the region lives below the poverty line, and most people engage in subsistence farming as their primary livelihood, I am interested in how ASGM operates as a livelihood diversification option. Specifically, I’m interested in assessing whether it is an “erosive” coping strategy: one which households undertake out of lack of other options and one which may diminish the household’s overall capacity to react to future stresses and shocks. I’m assessing this through an evaluation of the “Three Capitals” (sometimes five) which constitute a household’s assets. The three capitals are Economic, Environmental, and Social. I’m assessing the impact of ASGM on miners’ Social and Economic capital through interviews which I’ve already conducted, and I’m assessing the impact of ASGM on miners’ Environmental capital through remote sensing. Together, I hope to paint a holistic picture of ASGM’s impact on miners’ livelihood capitals in the region in order to better understand if it is indeed an “erosive” coping strategy, which, if it is, needs to be known in order to help miners and farmers find different ways to adapt to future climate change.