Impact of Coastal Salinity Ingression and Assessment of Htl Ingression and Regression over a Decade in the Bhavnagar Taluka: a Gis Based Vulnerability Assessment
IMPACT OF COASTAL SALINITY INGRESSION AND ASSESSMENT OF HTL INGRESSION AND REGRESSION OVER A DECADE IN THE BHAVNAGAR TALUKA : A GIS BASED VULNERABILITY ASSESSMENT
ABSTRACT
Climate change can have many impacts upon human societies. The impacts will vary from region to region. These impacts include sea-level rise, melting of mountain glaciers, floods, droughts, changes in storm intensities, changes in biological variables that have impacts upon human societies. This paper is however concerned with the ‘impact of sea level rise’ causing ‘salinity ingression’ in Bhavnagar Taluka; a part of Gulf of Cambay, Gujarat. Over last two and a half decades, a process of rapid sea water ingress (at some places as deep as 10–15 km. from the seacoast) is observed along the coastal belt of Gujarat. The major objective was to study the decadal changes in salt affected lands as well as agricultural lands. The change in High Tide Line along the study area was also studied using the same datasets of two periods. The resulted salinity ingress in the study area is mainly due to the large scale ground water extraction for agriculture as well as industrial purposes combined with intensive mining activity. Remote sensing data can be used in the objectives concerned with the monitoring changes in surface phenomena over time. In this study IRS LISS III data representing two different tidal conditions of the period 2000-2010 were used to compute and analyze the salinity ingression over a decade. The results indicate that there has been an increase in the ingress of sea water into the agricultural fields. This is one of the strong reasons of increasing soil salinity of coastal areas along the Bhavnagar Taluka. At some places in the study area it was also found that salinity is increasing not only because of natural causes but there is a big human intervention in it, the prohibition of which is necessary for long term coastal resource management. This sort of study could help in the
ABSTRACT
Climate change can have many impacts upon human societies. The impacts will vary from region to region. These impacts include sea-level rise, melting of mountain glaciers, floods, droughts, changes in storm intensities, changes in biological variables that have impacts upon human societies. This paper is however concerned with the ‘impact of sea level rise’ causing ‘salinity ingression’ in Bhavnagar Taluka; a part of Gulf of Cambay, Gujarat. Over last two and a half decades, a process of rapid sea water ingress (at some places as deep as 10–15 km. from the seacoast) is observed along the coastal belt of Gujarat. The major objective was to study the decadal changes in salt affected lands as well as agricultural lands. The change in High Tide Line along the study area was also studied using the same datasets of two periods. The resulted salinity ingress in the study area is mainly due to the large scale ground water extraction for agriculture as well as industrial purposes combined with intensive mining activity. Remote sensing data can be used in the objectives concerned with the monitoring changes in surface phenomena over time. In this study IRS LISS III data representing two different tidal conditions of the period 2000-2010 were used to compute and analyze the salinity ingression over a decade. The results indicate that there has been an increase in the ingress of sea water into the agricultural fields. This is one of the strong reasons of increasing soil salinity of coastal areas along the Bhavnagar Taluka. At some places in the study area it was also found that salinity is increasing not only because of natural causes but there is a big human intervention in it, the prohibition of which is necessary for long term coastal resource management. This sort of study could help in the