Geo-Dynamics, Salinity Gradient, and Vegetation Interdependence in Chilika Lagoon, a Tropical Wetland in Eastern India

Abstract

<p>Chilika a shallow brackish lagoon, India, is shrinking for sediment surplus budget. South Mahanadi deltaic branches <em>i.e.</em> Daya and Bhargavi terminate at the southwest swamps of the Lagoon. The annual average salinity of the lake was depleted from 22.31ppt (1957-58) to 8.5 ppt. (1999-2000) as the mixing process of saline and fresh water was influenced from 1995. Trepidation of conversion of Chilika to a atrophied fresh water lake due to blooming population and their hydrologic interventions like Kolleru lake in (India), Aral Lake (Uzbekistan) was apprehended by 1950’s and was alarming by 1999 when the shallow inlet(s) shifted extreme north. The shallow mud flats of lean salinity were reclaimed further for agriculture. The ecology and biodiversity degraded with substantial pecuniary loss to the lagoon dependents. Anthropogenic interventions like, Hirakud dam (1956), dredging of Sipakuda Inlet (2000), Naraj barrage at delta head (2004), Gobardhanpur barrages (1998) and Gabkund cut with weir (2014) were made to the hydraulic system. The deteriorating health, perturbed biodiversity and declined ecosystem of the lagoon has forced to have a comparative study of the various morphologic changes passed over the Chilika with time. The meteorological, hydrologic and the salinity study of the lagoon area for the period 1990 to 2016 have shown changes. Topographic study using GIS is developed by collecting data from Glovis Classic (Google) and the interpretation is done using ERDAS 9.2 software for various geomorphic features (1984 and 2017) before and after the current anthropogenic interventions and compared with previous studies.</p>

Sustainable Harvests under Different Bio-economic Scenarios of Chilika Wetland’s Fisheries

“…The timeframe shown in Table 1 also demonstrates how the rapid expansion of aquaculture in the region led to the socioeconomic decline of the traditional fishing population that depended on the lake. Kadekodi and Gulati (1999), Kadekodi and Nayampalli (2003), Mohapatra et al (2007), and Mishra et al (2019) indicate that the growth of shrimp farming intensified lake degradation by altering its hydrological balance. It hinders the free water and tidal migration of species-including juveniles, • Strict norms based on caste-defined fishing rights and entitlements.…”

Appraising the Impact of Naraj Barrage on Sedimentation of Chilika Lagoon; the Soft Computing Model for Prediction

“…The lagoon was subjected to rapid sedimentation since 1990s. It was downsized with incessant decrease in salinity due to shifting of mouth to remote north and depleted inlet Mishra S. P. et al [4]. Consequently, conversion of the brackish water lagoon to a sweet water one similar to the Kolleru Lake in Andhra Pradesh was apprehended.…”