Remote sensing and GIS in the recent Chennai flood study

Flood in Chennai is still indelible in the minds of the people. The most anguish and torment nature of affected people is colossal despair to the society and panic worldwide. This paper focuses on prediction of runoff in Chennai Adyar watershed, Tamil Nadu in India during the storm events in 2005 and 2015 floods. The runoff water available for artificial recharge in the basin is estimated through Soil Conservation Service (SCS) Curve number method. The land use/land cover and hydrologic soil classification are processed in ArcGIS for each of the 19 micro-watersheds and the volume of runoff is estimated. This paper represents the rainfall–runoff in that particular micro-watershed level, and curve fitting relationship of rainfall–runoff is shown. The remote sensing and GIS play a vital role in the study, and the results were obtained. The total volumes of rainfall drained as runoff are 326.67 million m 3 , 280.99 million m 3 and 207.69 million m 3 in October, November and December 2005 flood, respectively, and 71.33 million m 3 , 681.88 million m 3 and 312.92 million m 3 in October, November and December 2015 flood, respectively. This runoff results will create awareness to save the excess water flow during flood season and be helpful for planning the artificial groundwater recharge. Thus, some useful management measures have to be implemented at the earliest to avoid the impacts of Chennai floods.