Abstract

Abstract
This year’s retreating monsoon has really saved the southern states of India, particularly TN and Karnataka in the nick of time, suppressing the much talked about Cauvery issue. In a single day, Meenambakkam airport in Chennai recorded 14 cm of rainfall with incessant rain recorded across the city and major parts of Tamil Nadu. Even the best claimed roads in Chennai were inundated and flooded with water and to a knee-deep level in some low lying areas like Velacherry, Nanganallur, Madipakkam and Palikkaranai. This water stagnation owing to its short lived nature is simply neglected even by GIS analyst. But the problems associated with it in terms of traffic congestion, break down of vehicles, and the worsening of road conditions immediately after rain can estimate to run in lakhs even in a single day in any city. This situation worsens year after year, particularly in metros like Chennai where water stagnation attains notoriety in combination with road digging for cables, metro water pipes laying and others. Recently, a person lost his lives after falling into the water filled ditch dug up by cable layers. After seeing the hardships faced by the common man, this attempt has been made to explore the practicality of using RS, GIS and GPS to the rescue of Chennaites from water stagnation to improve the flow of rain water to reach drainage and effective utilization of rainwater by various harvesting mechanisms to augment the ground water level. Also, this stagnant water will greatly improve the water holding capacity of Chennai reservoirs which would otherwise emptied into the Bay of Bengal.

This study is more of practical usefulness at various levels at this critical moment and this attempt highlights the utility of Remote Sensing in delineating the low lying areas in Chennai for input into GIS. Here, particularly the IKONOS data and input from GPS will be of immense use in mapping the street level water stagnation to know the real situation of the streets. Once the data is brought into GIS environment and upon mapping, this approach clarifies the hidden non-cooperation among various road users – Road development authority, Municipality, Chennai Metropolitan Authority, Builders and all the road diggers. This study helps to strike a balancing act among various agencies in maintaining the slope aspect while making various infrastructure development in Chennai. In Indian cities, GIS, RS and GPS technologies are used individually for various infrastructure developmental works. But this water stagnation during monsoon and its after effect has not been studied so far and remain neglected till date. Initiation of such studies at this period will be critical importance now for analysis.

This study also help in identifying the areas to be avoided from construction activities not to worsen the situation. Areas requiring proper integrated developmental tactics to be incorporated using RS, GIS and GPS, particularly in maintaining the slope aspect of the roads. Such studies also help in demarcating the historic lake areas so to improve the ground water potential by adopting water harvesting mechanisms to the already water starved Chennai. Furthermore, this integrated approach goes one step further in restricting the density of apartment type houses by carefully identifying areas to suggest for more parks to improve the ground water potential of Chennai.