Sustainable Water Management Solutions for Large Cities (Proceedings of symposium S2 held during the Seventh IAHS Scientific Assembly at Foz do Iguaçu, Brazil, April 2005). IAHS Publ. 293, 2005, 294-298

1 Water Technology Centre, Indian Agricultural Research Institute, New Delhi – 110 012, India

2 Central Research Institute for Dryland Agriculture, Hyderabad, India

Abstract During the 20th century, urbanization in India has resulted in population increase and other infrastructure developments leading to a large demand for water. For Delhi, the population growth is exponential similar to that of the country, whereas the water availability has decreased resulting in the over-exploitation of groundwater due to industrial, domestic and irrigation expansion. The increased demand and related supply caused the water table to decline and groundwater quality to deteriorate. In order to understand the long-term effects of urbanization on groundwater resources, composite groundwater samples from more than 200 cased wells adjoining Delhi were collected during 1998 and 2004, and the hydrochemical data generated thereby were compared to the earlier published data pertaining to 1964 and 1976. Results are presented through GIS themes to provide a comprehensive understanding of the urbanization effects on the quality of groundwater during the past four decades. It has been observed that the spatial variations in anions, cations and micronutrients indicate that water quality has deteriorated more in the west and northwestern parts than in other areas of the city. Using the limited data available, the quantities of over-exploited groundwater have been estimated for specific areas of the city. Integrating the quantity and quality aspects of groundwater with the other factors governing the status of groundwater, an attempt has been made to develop a simple Decision Support System for the effects of urbanization on groundwater; it is named UGWSTATUS. Results are presented and discussed.

Key words DSS; EC; GIS; groundwater quality; urbanization; water demand