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Assessment of impacts to the sequence of the tropical cyclone Nisarga and monsoon events in shoreline changes and vegetation damage in the coastal zone of Maharashtra, India
2022
Mishra, Manoranjan | Kar, Dipika | Santos, Celso Augusto Guimarães | Silva, Richarde Marques da | Das, Prabhu Prasad
The tropical cyclones impact both the eastern and western coasts of India, causing severe socio-environmental problems. This study analyzed shoreline changes and vegetation degradation caused by cyclone Nisarga and monsoon events in Maharashtra coastal zone and Mumbai region, India. In this study, the shoreline change was studied using the Net Shoreline Movement (NSM) statistical technique embedded in the digital shoreline analysis system (DSAS) tool. The effects of the cyclone on the vegetation were mapped using the Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), and the rainfall distribution from Global Precipitation Measurement (GPM) data. The correlation between rainfall data and vegetation loss was analyzed using geographically weighted regression. The results also show that 90% of the events were concentrated in the 80–300 mm classes, being classified as sudden increases. This cyclone caused erosion in 56.32% of the shoreline; the highest erosion level was observed along the coastal zone of Maharashtra (near Mumbai city). Cyclone Nisarga has also impacted the vegetation loss most prominently in the region, with mean EVI in pre-cyclone equal to 0.4 and post-cyclone equal to 0.2. These eco-physical studies using geospatial technology are needed to understand the behavior of changes in shoreline and vegetation and can also help coastal managers plan for resilient coastal systems after the passage of tropical cyclones.
Afficher plus [+] Moins [-]Analysis of Shoreline Change of North Central Timor Regency, Indonesia
2023
L. Ledheng and E. M. Y. Hano’e
Shoreline change is a process that occurs due to the impact of natural factors and human activities. Geographically, the coastal area of North Central Timor Regency (NCT) is in the northern part of the island of Timor, East Nusa Tenggara Province (ENT). Physically, the area is affected by the oceanographic dynamics of the Sawu Sea waters and aquaculture activities, which impact the damage to coastal ecosystems. This study aims to analyze shoreline change in the northern coastal area of NCT Regency. The data used are Landsat 8 images from 2015-20221 to describe current conditions. Meanwhile, Landsat 5 imagery data from 1990 - 2000 was used to describe the initial conditions. The satellite imagery is analyzed to map shoreline changes that experience accretion or abrasion. The results show that the shoreline of the study area has experienced changes in accretion and abrasion. Based on the area of change in the northern coastal area of NCT Regency, the dominant accretion area was 1108.07 m2 with a rate of change of 20.19 m.year-1, as long as 1021 meters, while the abrasion was 845.43 m2 at a rate of 12.65 m.year-1 as long as 36520 meters. The average shoreline change distance in accretion conditions was 11.3 meters, while the abrasion was 7.93 meters. The shoreline shift due to the highest abrasion in Ponu was -16.08, while accretion in North Oepuah was 35.63 meters. The results of this research will contribute to planning the management of the coastal area of NCT Regency.
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