Assessment of Causes and Impacts of Sand Mining on River Ecosystem

Abstract

Sand is a crucial and limited resource. It is available easily. It has multifarious properties catering to many industries like construction, glass, and electroplating, as their raw material. The sand mining activity has started and increased exponentially in the past few decades. Especially in developing countries like China and India, the impact of sand mining has become extremely visible. The purpose of this study is to review the causes and impacts of sand mining on the riverine ecosystem. Through review, it was found that sand mining processes destroy sediment flow and create an imbalance in the sediment deposition formed by years of erosion and sedimentation of the riverine system. Excessive sand mining led to riverbed alteration, affecting the course of the river and causing bank erosion. Deepening of the rivers and river mouths leads to saline water. It also leads to loss of river ecosystem and services. Sand mining activities were found prominent near river body closer to construction site. This practice was found more active in the developing countries. Furthermore, illegal mining activities are rooted deeply in many regions of the world. The excavated pit has been known to cause drowning effect in the river leading to death of natives, narrowing of river width, and bank erosion. Earlier, the monitoring and assessment of sand mining activities were difficult but the use of geographical information systems (GIS) and remote sensing techniques has given a unique advantage. The satellite data, obtained from MODIS, LANDSAT, Google Earth Engine, etc., are processed using GIS tools and various topographical features such as land, water, vegetation, can easily be studied. The use of unmanned automatic vehicles (UAV's), spectral indices (Normalized Difference Water Index, Normalized Difference Vegetation Index, etc.), LULC, etc. was found to be effective in assessing the sand mining activities in the 35 river bodies. To remediate the situation, use of other materials such as M-sand, quarry stone dust, and 36 crushing rocks were suggested. The study revealed that there is an immediate need for monitoring the sand mining activities and taking strict actions to conserve our environment.