Pulicat lagoon Research Papers - Academia.edu (original) (raw)

Land use/land cover (LU/LC) is an important component in understanding the interactions of the human activities with the environment. Pulicat Lagoon is the second largest brackish water body in India and it is a home for many migrant... more

Land use/land cover (LU/LC) is an important component in understanding the interactions of the human activities with the environment. Pulicat Lagoon is the second largest brackish water body in India and it is a home for many migrant water birds for various regions. It is a breeding ground for several species of water birds and marine living organisms. For the analysis of land use and land cover changes in Pulicat Lagoon, Landsat data is used with. The comparison of LULC which is derived from toposheet and satellite imagery interpretation indicates that there is a significant change occurred from the past to the present scenario. The LULC change detection analysis is essential for the identification of changes made in land use and land cover by comparing the old Toposheet with recent satellite data. The main objective of this paper is to quantify the land use and land cover changes of Pulicat Lagoon using multi-temporal satellite image and change detection analysis. The changes were carried out using ArcGIS software and ENVI software by doing supervised and unsupervised classification of image and mapping of those analyzed data. Unsupervised classification is done by the computer itself by using some technique to determine which pixels are related and groups them into classes. The Normalized Difference Vegetation Index (NDVI) is a parameter for identifying vegetation changes in an area and also it has an obvious correlation with vegetation cover. Temporal variation corresponds to the vegetation change and growth using ENVI software. The NDVI of an area can be calculated using mathematical expressions (NIR-RED/NIR+RED) in the data which have the band combination of RED and Near InfraRed (NIR). It is necessary to monitor and detect the changes to maintain a sustainable environment for a proper development. In this study, LULC changes are investigated using Remote Sensing and Geographical Information System (GIS).

The Pulicat Lake is the second largest brackish water lake after Chilika Lake in India. The average area of the water spread is 461 sq km. During the monsoon Pulicat Lake receives freshwater through three major rivers, namely, the... more

The Pulicat Lake is the second largest brackish water lake after Chilika Lake in India. The average area of the water spread is 461 sq km. During the monsoon Pulicat Lake receives freshwater through three major rivers, namely, the Swarnamukhi, the Kalangi and the Arani .The Pulicat lagoon system, which is a storehouse of rich biological resources, is under great threat because of the anthropogenic influences. The Pulicat Lake ecosystem is degraded by siltation, bar mouth dynamics, shell mining and processing and population pressure due to the resettlement of villagers from Sriharikota Island. It has been determined that the extent of the lake, including its water spread area, is decreasing. Therefore, it is essential to assess the land use / land cover changes taking place in and around Pulicat Lake using remote sensing and GIS. Studies on its sediment characteristics are also vital. The grain size content reveals that most of the sediments contain clay and silt in enormous amounts. This lake has been the prime source of a livelihood through fishing for a large section of the population living in the surrounding villages. It is the most important refuge for water birds in south India. The fishing community who lives in and around Pulicat Lake follows the Padu system for fishing in the lake. In this study, apart from studies on configuration changes and sediment analysis, a study of the flora and fauna of the lake and the socioeconomic conditions of the local community were also carried out. Finally, mitigation measures for the sustainable protection of the lake's ecosystem were identified.

Pulicat Lagoon is the second largest water body covering an area of 757 sq.km. Located to the North of Chennai, it is a testimony to living heritage integrating monsoon heritage and cultural values of South India. This several million... more

Pulicat Lagoon is the second largest water body covering an area of 757 sq.km. Located to the North of Chennai, it is a testimony to living heritage integrating monsoon heritage and cultural values of South India. This several million years old lagoon is one of the five wetlands which have been acting as a magnet to attract monsoon clouds to bring rain to South East Coast of India, scripted strong maritime history, and bridged transnational shared heritage links. This paper will bring forth the attention to these values of this wetland which brings to this region of India a strong cultural landscape, and ecological bio-diversity. The traditional fishing practice called paadu-system, and its character to absorb shock during a natural disaster with the support of Buckingham Canal stretching 796 km proves as a lifeline of Coromandel Coast. The sustainable living and development which was the way of life for several thousand years is endangered. The paper attempts to find reasons for the systematic loss of the lagoon values, and bring forth holistic strategies for a sustainable shared landscape revival.

Pulicat lake is the second largest brackish water ecosystem on the East coast of India, 60 km north of Chennai city, Tamil Nadu, India and is supposed to be one of the habitats for Amphioxus (Branchiostoma lanceolatum). The... more

Pulicat lake is the second largest brackish water ecosystem on the East coast of India, 60 km north of Chennai city, Tamil Nadu, India and is supposed to be one of the habitats for Amphioxus (Branchiostoma lanceolatum). The cephalochordate Amphioxus (lancelet) is considered to be the closest relative to invertebrates. It has key vertebrate characteristics viz., a notochord, a dorsal nerve cord, segmented muscles, pharyngeal gill slits and a post anal tail. This interesting organism which was once found in abundance along the shores of the Pulicat lake area up to the late 1970’s has disappeared from this habitat. Changes in the topography of the lake area and pollution from various sources may be the possible causes.

Pulicat lagoon in the south-east coast of India is recharged with the highest fresh water influx annually during north-east winter monsoon. An abrupt heavy rainfall in November–December 2015 was a flood calamity in the region that... more

Pulicat lagoon in the south-east coast of India is recharged with the highest fresh water influx annually during north-east winter monsoon. An abrupt heavy rainfall in November–December 2015 was a flood calamity in the region that inundated the lagoon. We investigated the physico-chemical characteristics and palynological profile of the surface sediments from the lagoon at water depth between 0.5 and 2 m to understand the impact of the 2015 event. On the basis of a ‘marine index’, three zones were demarcated, the ‘LC zone’ (Araniar river-lagoon confluence, south), the ‘LM zone’ and the ‘LL zone’ (Kalangi river confluence, north) showing values of 4.55, 1.25 and 0.25, respectively, indicating the extent of tidal influence. The dissolved oxygen, pH and salinity ranged between 6.4 and 9.6 mg/L, 7.96–9.23 and average ~ 12.3 ppt at different sites, respectively. The highest salinity (31 and 31.8 ppt) was in the LC zone along with the highest dissolved inorganic nitrogen (DIN) concentrations (275–288 mmol/m3) too. The dissolved inorganic phosphates (DIP) ranged between 8.5 and 29.5 mmol/m3, which was relatively high. Sandy sediment, high sodium (Na+) and chloride (Cl−) ions too indicate the landward extension of seawater influx. Forsterite (Mg2SiO4) and beta-uranophane (Ca[(UO2)SiO3(OH)]2.(H2O) minerals show higher values with the dominance of olivine (MgFe)2SiO4) and quartz (SiO2) in this zone indicating magnitude of fresh water influx too through Araniar river. The highest calcium, magnesium and potassium ions were also observed in LC zone. Fe-rich goethite, calcite and aragonite were recorded at all sites but with dominance of illite in LL zone. Halite, an evaporite recorded from all sites shows inundation of the entire lagoon during flooding event. Results show a bloom of Biddulphia pulchella, B. biddulphiana and B. laevis in association with Cladophora in LC zone which serves as potential indicators of physico-chemical characteristics of the lagoon showing intense response to catastrophic events of floods due to above normal monsoon variability.

Pulicat Lagoon is a productive coastal lagoon on the southeast coast of India. Several studies of its physico‐chemical and biological characteristics have been undertaken. This project was the first to attempt to represent the lagoon’s... more

Pulicat Lagoon is a productive coastal lagoon on the southeast coast of India. Several studies of its physico‐chemical and biological characteristics have been undertaken. This project was the first to attempt to represent the lagoon’s ecological status in the form of a trophic state index. The investigation applied Carlson’s Trophic State Index (TSI) to determine the trophic status of Pulicat