Environmental Degradation Due to Unplanned Quarries for Engineering Purpose in the North-Western Part of Bangladesh

Abstract

The study area is in different parts of Pangram Upazila, Lalmonirhat district, in the northwestern part of Bangladesh, where many quarries were identified for engineering purposes. The studied areas encompass about 55 km along the banks of the Dharla and Saniazan rivers near the India-Bangladesh border. The main objective of the study was to delineate the environmental degradation due to unplanned gravel extraction in the study area. By collecting field data with the help of augers, field observation, digging, and GPS, I also collected information from the local statistical office. A major portion of the mapped area is occupied by the Tista Fan and covered by the floodplain deposits of the Holocene age. Tista alluvial fan deposits are generally composed of sand and stone (gravel) at various percentages, which are working as the main raw materials of construction throughout the country. The source of the gravel is exposed in the various overthrust sheets of the Darjeeling Himalaya of Nepal, Tibet, India, and Bhutan. Large amounts of stones (gravel) and sand were extracted unconditionally from the riverbed, riverbank, and surroundings by using the mechanical dredgers and excavators. The unplanned way of extraction is increasing the riverbank erosion and destroying the surrounding agricultural lands, landscapes, river navigation, and biodiversity. Sound and dust are created in the quarry areas due to unplanned use of dredgers and stone crushers, which is aggravating the environmental pollution. Many kinds of environmental pollution might be faced in the surveyed as well as surrounding areas of Lalmonirhat district due to this unplanned extraction/quarry. Environmental degradation might be enhancing the negative impact of the climatic conditions of the country. Stones (gravel) and sand are part of mineral resources and are needed for construction or engineering purposes around the country. Sand and stone should be extracted for engineering purposes in an environmentally planned way so that agricultural lands, biodiversity, landscapes, and other negative environmental issues are protected, which must be reduced to prevent future environmental degradation of the country.