ABSTRACT
An aerial study was conducted on a major proposed port site (Dugarajapatnam port, Tupilipalem, Nellore District of Andhra Pradesh, India). It showed the phenomenal mouth dynamics periodically. Landsat 8 OLI/TIRS multitemporal satellite images dated October 27, 2014 (monsoon) and August 27, 2015 (pre-monsoon) were chosen to demonstrate the closing and opening of the lagoon mouth during monsoon and pre-monsoon, respectively. Twelve water samples from each season (monsoon and pre-monsoon) were collected by using a shallow water sampler from both lagoon and open sea for comparison. The physico-chemical parameters viz., pH, air temperature, water temperature, electrical conductivity (EC), salinity, dissolved oxygen (DO), organic matter (OM), and silica were estimated. The results revealed 234that the pH ranged between 7.1 and 7.4 during both the seasons (monsoon and pre-monsoon). Variation in air temperature and water temperature across all the stations was observed. However, these variations were not significantly different across the stations. In addition, around the stations, these differences were not significant. Both the lower and higher values of DO were recorded from the brackish environment and it may be absorbed from the waste products of plant photosynthesis. The study area is covered with full of mangrove swamps and Avicennia marina is the dominant among all the mangroves. A higher value of salinity was observed at the lagoon side of the Tupilipalem coast during lagoon mouth closing period. From monsoon to pre-monsoon, the concentration of silica increased. Multivariate statistics, the most general multivariate statistical techniques, was used to minimize data and derive a limited number of latent factors to evaluate the relationship among coastal morphodynamics and the distribution of physico-chemical parameters. The significant seasonal variation among the studied physico-chemical parameters is the proxy for the influence of seasonal lagoon mouth closure. The relevant satellite datasets revealed the change detection of lagoon mouth dynamics periodically. The details are discussed in this paper.
