Delineation of sensitive coastal zone of northern Ramanathapuram coast,Tamilnadu,India,using a GIS approach

This research aims to assess the sensitive coastal zones by analyzing the shoreline changes such as accretion and erosion in the eastern coastal part of Ramanathapuram District,Tamil Nadu,India.The study focused on Mandapam,Pirappanvalsai,Enmanamcondam,Nagachi,Terbogi,Athyuthu,Chitrakkottai,Pathengal,Attangarai,Alagankulam,and Devipattinam villages.Some of these areas are distinguished as highly sensitive ecological zone.The erosion of an area leads to irreplaceable disturbances to nature.Hence,erosion and accretion studies are top priorities when studying the coastal area.In addition to GIS technology,which has been widely used in the past 20 years,the End Point Rate(EPR)and Linear Regression Rate(LRR)analyses were conducted to better understand the shoreline changes.The stability of the coastal region was analyzed by observing the slope variations of the beach during the profile survey.In the study,we analyzed that the Quaternary deposits of sand are the dominant geological feature of the study area.Coral reefs and salt pans are highly distributed along the coastal stretch.The coast of Mandapam village has been detected as a highly sensitive region,with an average erosion rate of-3.1 m/yr and an average accretion rate of 1.22 m/yr,resulting in high erosion and low accretion.The coast is a steep coast with an average slope angle of 0.24°.This study provides insight into sustainable coastal zone management.

Analysis of Shoreline Changes in Ikoli River in Niger Delta Region Yenagoa,Bayelsa State Using Digital Shoreline Analysis System(DSAS)

The use of Digital Shoreline Analysis System was used to determine shoreline changes in Ikoli River,Yenagoa,Bayelsa State.Shoreline data were extracted from satellite imagery over thirty years(1991-2021).The basis of this study is to use Digital Shoreline Analysis System to determine erosion and accretion areas.The result reveals that the average erosion rate in the study area is 1.16 m/year and the accretion rate is 1.62 m/year along the Ikoli River in Ogbogoro Community in Yenagoa,Bayelsa State.The mean shoreline length is 5.24 km with a baseline length of 5.2 km and the area is classified into four zones to delineate properly area of erosion and accretion based on the five class of Linear regression rate,endpoint rate and weighted linear rate of which zone Ⅰ contain very high erosion and high erosion with an area of landmass 255449.93 m^(2) of 38%,zone Ⅱ contain moderate accretion,very high accretion and high accretion with a land area of 1666816.46 m^(2) with 24%,zone Ⅲ has very high erosion and high erosion with an area of landmass 241610.85 m^(2) of 34% and zone Ⅳ contain moderate accretion and high accretion with land area 30888.08 m^(2) with 4%.Out of the four zones,zone Ⅰ and Ⅱ were found to be eroding with 72% and zone Ⅱ and Ⅳ contain accretion with 28%.The result shows that 44% of the area have been eroded.Therefore,coastal engineers,planners,and shoreline zone management authorities can use DSAS to create more appropriate management plans and regulations for coastal zones and other coastal parts of the state with similar geographic features.