Brick and tile clay mining from the paddy lands of Central Kerala (southwest coast of India) and emerging environmental issues

摘要

The increasing demand for building materials has led to indiscriminate exploitation of clay-rich topsoil from wetlands including the paddy lands of Central Kerala in the southwestern coast of India. The problem is critical in areas adjoining the major developmental centers having low per capita land and natural resource availability. Loss of fertile topsoil, shrinkage of agricultural lands and consequent food security issues, erosion of naturally evolved nutrients, lowering of water table in wells adjacent to the mining sites, etc., are some of the major environmental issues arising from indiscriminate brick and tile clay mining. Although, brick and tile clay mining brings short-term economic benefits and employment opportunities to a section of people, the process in the long run creates severe damages to the environmental settings of the area. The present paper deals with a few aspects of brick and tile clay mining in the paddy lands of Central Kerala, especially around Kochi City, a fast developing urban-cum-industrial center in South India, which demands large quantities of building materials including bricks and tiles for construction of infrastructural facilities. It is estimated that 729,695 tons/year (ty~(-1)) of brick and tile clays are extracted from the coastal lowlands of Central Kerala, spreading to the Chalakudy (135,975 ty~(-1)), Periyar (483,820 ty(-1)) and Muvattupuzha (109,900 ty~(-1)) river basins. The N, P and K loss through extraction of brick and tile clays amounts to 210 ty~(-1), 96 ty~(-1) and 9,352 ty(-1), respectively. As nutrient loss is an irreversible process in human time scale, its implications on agricultural productivity is a matter of serious concern. The study warrants the need for a comprehensive policy with an aim to regulate the mining activities on an environment- friendly basis in the densely populated coasts of the world, in general, and the study area in particular.