TEMPORAL AND SPATIAL CHANGES IN WATER QUALITY OF THE INDUS BASIN

Abstract

Total useable water supply for agriculture is essentially fixed and is a limiting factor for increasing agriculture production. The objectives of this paper are to evaluate water quality of rivers, drains and groundwater. Suggestions are made for controlling pollution and for sustainable use of water. The scope of the paper is limited to the Indus Basin. The criteria based on TDS, SAR and RSC was used to categorize water as useable, marginal and hazardous quality for agricultural use. Data of different water quality surveys from 1959 to 2003 were used for the study. Spatial changes of groundwater quality indicate saline water intrusion towards fresh groundwater pockets. Temporal changes of groundwater quality also show deterioration of water, quality over long periods. Canal supplies need to be increased to reduce reliance on groundwater which indirectly help sustainable use of groundwater. River water quality at Kotri, the lowest point in the Indus River system, is suitable for irrigation throughout the year. However, pollution is a serious issue particularly during low flow periods. During the year 2004 about 40 persons died in Hyderabad due to pollution in drinking water the source of which was the River Indus. Municipal and Industrial effluents are being disposed into rivers, drains and canals without treatment which is not only detrimental to crops, human beings, livestock and marine life but also a potential threat to environment. Out of 143 outfall drains of the Indus Basin, the effluent quality of 53 drains is useable. 46 marginal and 44 hazardous. A large number of farmers are using drainage effluent for agriculture. There is no monitoring of land and water for such use. Provincial irrigation department and environment protection agencies should provide technical guidance and support to the farmers, using the drainage effluent. The Environment Act should be strictly implemented. Provincial Irrigation and Drainage Authorities (PIDA‘s) must work with Provincial Environmental Protection Departments to achieve the compliance of NEQS and protecting the quality of rivers, canals and agricultural drainage effluent. it is recommended that integrated water resource management approach should be adopted by consulting and involving all the stakeholders to protect the water quality in the Indus Basin. A regulator programme for water quality monitoring in irrigated areas and water bodies of the country should be Initiated.