Illegal sand mining is running rampant in the world due to the need for river sand as a binder in making concrete. Desert sand isn’t suitable for this purpose due to its shape. This illegal activity had led to the deaths of journalists, farmers, miners, and more, as well as causing ecological devastation across multiple countries. A new study led by Dr. Christopher Hackney at Newcastle University used PlanetScope Monthly Basemaps to map, monitor, and estimate volumes of sand extraction on the Lower Mekong River in Cambodia from 2016–2020. Hackney and colleagues monitored landscape changes, as well as counted the number of active vessels on the river over time. They found that the amount of sand being mined in this region is rapidly increasing year over year, and far outpaces the natural production rate of sand by the river. “The use of satellite imagery to monitor sand mining activities provides a low-cost means to generate up-to-date, robust estimates of sand extraction in the world’s large rivers that are needed to underpin sustainable management plans of the global sand commons,” the authors note in their study, saying the methodology they developed gives “insight into the environmental and biophysical implications of the sand extraction industry.”
The full study is open access and can found in Earth Surface Dynamics.
Figure above caption: (a) Rate of elevation change between 2013 and 2019 of the Mekong River near Rokar Korng highlighting areas of erosion (blue) and deposition (yellow). (b) Overlain on the map depicted in (a) are the locations of all observed mining vessels during the period 2016 to 2020 demonstrating that the zones of greatest erosion observed in (a) correspond to areas of high mining activity. (c) Histogram of elevation changes for this reach between 2013 and 2019. The median rate of bed elevation change is −0.25 m/yr (mean elevation change is −0.16 m/yr). The dashed line demarks zero net change in elevation. Image background in panels (a) and (b) are PlanetScope monthly composite scenes from December 2020.