Artisanal and small-scale miners are facing unprecedented challenges due to the novel coronavirus (Covid-19) pandemic. The paper adopts a practice-based approach to examine the impact of Covid-19 on gold and gemstone artisanal and smallscale mining (ASM) practices in sub-Saharan Africa. It highlights the informality of ASM and discusses how the Ghana and Kenya governments' measures have significantly increased the vulnerabilities of the miners and mining communities. Based on a document analysis of the governments' responses to Covid-19, mining industry reports, and interviews with 29 mining stakeholders in Ghana and Kenya, the paper identifies the economic and social impacts of the Covid-19 pandemic on gold and gemstone ASM in both countries. We highlight the key policy challenges and suggest actions that can help mitigate the negative impacts the pandemic has had on ASM, which include the need to address informality in the ASM sub-sector.

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Man has contributed to land cover alteration since time-immemorial through clearing of land for residential, agriculture, recreational and industrial purposes. The emergence of adapting wild plants and animals for human use as well as industrialisation have also contributed to the alteration of land cover. Over the years, anthropogenic activities have had great impact on the Weija catchment. This study seeks to map the catchment and determine the impact of anthropogenic activities using Remote Sensing techniques. Observations and measurements were made on the field as well as classification of land cover using Landsat images of years 1991, 2003 and 2017. Results showed an increase in built-up areas by 18% from 1991 to 2017. Other classes such as shrubs increased due to decrease in dense vegetation. This study confirms the use of Remote Sensing as a valuable tool for detecting change in land cover and determining the impact of anthropogenic activities in the Weija Catchment. Keywords: Land Cover, GIS, Remote Sensing, Weija Catchment, Anthropogenic Activities

High cost of metric photogrammetric cameras has given rise to the utilisation of non-metric digital cameras to generate photogrammetric products in traditional close range or terrestrial photogrammetric applications. For precision photogrammetric applications, the internal metric characteristics of the camera, customarily known as the Interior Orientation Parameters, need to be determined and analysed. The derivation of these parameters is usually achieved by implementing a bundle adjustment with self-calibration procedure. The stability of the Interior Orientation Parameters is an issue in terms of accuracy in digital cameras since they are not built with photogrammetric applications in mind. This study utilised two photogrammetric software (i.e. Photo Modeler and Australis) to calibrate a non-metric digital camera to determine its Interior Orientation Parameters. The camera parameters were obtained using the two software and the Root Mean Square Errors (RMSE) calculated. It was observed that Australis gave a RMSE of 0.2435 and Photo Modeler gave 0.2335, implying that, the calibrated non-metric digital camera is suitable for high precision terrestrial photogrammetric projects. Keywords: Camera Calibration, Interior Orientation Parameters, Non-Metric Digital Camera

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