S. Venkateswaran

Drainage morphometric analysis of the Nagavathi watershed, Cauvery river basin in Dharmapuri district, Tamil Nadu, India using SRTM data and GIS

A drainage morphometric analysis of Nagavathi watershed in Dharmapuri district has been chosen for the present study. Geospatial tools, such as remote sensing and GIS, are utilized for the extraction of watershed and its drainage networks. The Shuttle Radar Topographic Mission (SRTM) data have been used for drainage morphometric analysis and evaluating various morphometric parameters Linear aspect, Aerial aspect Relief aspect. The morphometric parameters of Nagavathi watershed have been analyzed and evaluated by pioneer methods, such as Horton and Strahler. The bifurcation ratio varies from 0.8 to 43.1. The elongation ratio of Microwatersheds varies from 0.13 to 0.43, indicates Microwatersheds fall under elongated pattern. This study would help the local people to utilize the resources for planning rainwater harvesting and watershed management.

Temporary fluoride concentration changes in groundwater in the context of impact assessment in the Vaniyar sub-basin, South India

India’s surface water and groundwater distribution is temporally variable due to the monsoon. Agriculture is one of the dominant economic sectors in India. Groundwater quality is regularly assessed to determine usability for drinking and irrigation. In this study, World Health Organization and Bureau of Indian Standards guidelines were used to determine suitability of groundwater near artificial recharge structures (ARS) with a focus on the structures´ impact on groundwater quality. Groundwater resources were evaluated for irrigation suitability using electrical conductivity (EC), sodium adsorption ratio, the US Salinity Laboratory diagram, sodium concentration, Wilcox’s diagram, Kelly’s index, and Doneen’s permeability index. EC and major ions were tested in recharge areas at different distances from the ARS. The construction of ARS at optimal distances along major streams has improved groundwater quantity and quality in the sub-basin. Before construction of ARS, fluoride concentrations were higher; after construction, fluoride was reduced in most locations. Water stored in the check dam and groundwater in the wells closer to the structure were suitable for both drinking and irrigation purposes. Impact of ARS on nearby groundwater quality was observed at Pallipatti, Mulayanur, Venkadasamuthram, Pudupatti, Poyyappatti, Harur1, and Sekkampatti. More distant sites included Pappiredipatti, Nambiyappati, Menasi, Harur, Todampatti, and Adikarapatti. Data demonstrated improved groundwater quality in the area of the ARS. Through recharge, the non-potable fluoride in the region is reduced to the permissible limit for human consumption.

Delineation of fresh and seawaters interface using geospatial techniques in the Ramanathapuram coastal aquifer system Tamil Nadu south India

Mangrove waste comprises of naturally decomposed dead mangrove leaves, twigs, and branches. This research aims to determine the types of bacterial symbionts in mangrove waste with potency as anti-bacterial agents. These anti-bacterial agents will subsequently be used in the production of compost with bio-activators. The research process involves isolation of symbiont bacteria, identification for symbiont bacteria with potency as anti-bacterial agent, DNA extraction using High Pure PCR Temperature Preparation Kit (Roche), DNA amplification by PCR 16s rDNA, and DNA Sequencing. Resulting amplified 16S rDNA are analyzed and then sequenced using Genetix program. Symbionts with identified anti-bacterial properties are used in bio-activator production. Samples of Sargassum seaweed are treated separately with resulting bio-activator product from the research and other bio-activator products for nutritional content comparison. Four types of symbiont bacteria are identified as potential anti-bacterial agents, namely Pseudomonas sp., Flavobacterium sp., Acinetobacter sp., Bacillus subtilis. It is further found that bio-activator products from mangrove waste have better quality compared to those found in the market and non-bio activator added liquid organic fertilizers. Therefore, bio-activators from mangrove waste is a potential alternative as natural bio-activator productsT coastal ocean connects terrestrial (e.g., rivers and estuaries) with oceanic ecosystems and is considered as a major component of global carbon cycles and budgets. The coastal waters are featured with a high biodiversity and high primary production. Because of the excessive primary production, a large fraction of primary organic matter becomes available to consumers as detritus in the coastal waters. Bacterioplankton have long been known to play a key role in the degradation of this detritus, and export and storage of organic matter in the coastal ecosystems. However, the primary and secondary production and the carbon biogeochemical processes in the ecosystems are largely regulated by nutrient inputs from riverine and other anthropogenic activities through heterotrophic microbial communities.A major gap exists in integrating climate projections and social–ecological vulnerability analyses at scales that matter, which has affected local-scale adaptation planning and actions to date. We address this gap by providing a novel methodology that integrates information on: (i) the expected future climate, including climate-related extreme events, at the village level; (ii) an ecological assessment of the impacts of these climate forecasts on coral reefs; and (iii) the social adaptive capacity of the artisanal fishers, to create an integrated vulnerability assessment on coastal communities in five villages in Papua New Guinea. We show that, despite relatively proximate geographies, there are substantial differences in both the predicted extreme rainfall and temperature events and the social adaptive capacity among the five fishingdependent communities, meaning that they have likely different vulnerabilities to future climate change. Our methodology shows that it is possible to capture social information and integrate this with climate and ecological modeling in ways that are best suited to address the impacts of climate-mediated environmental changes currently underway across different scales.T coastal zone (CZ) is a social-ecological system (SES) that is both dynamic and complex. Coastal SES are some of the most valuable in the Earth System (ES). The high ecologic, social and economic value of the coastal zone is influenced by global and climate changes, as well as pressures from anthropogenic activities. The rapid development of the economy and society in China has led to a concentration of the human population along the coast. This puts these coastal SES under increasing and multiple pressures, but also increases the risk to the population from dramatic accidents (e.g. oil spills, Tianjin explosion) and natural hazards (e.g. storm surges). Such accidents have resulted in the deterioration of the coastal environment, damage to natural resources, and loss of ecosystem functions and services. A comprehensive understanding of the coastal natural status, changes and resilience is fundamental for sustainable development. Such knowledge is the basis for the adaptive management of coastal SES and is crucial to their sustainability. Several analytical frameworks exist to support the adaptive management of the coastal SES. They can contribute valuable insights and be used together to develop a locally adapted integrative framework. Research on coastal environmental damage assessment (CEDA) as well as coastal social-ecological systems in China aims to setup a technical framework for CEDA and to contribute to co-designed, locally-adapted integrative management frameworks. This paper presents our preliminary results to provide scientific support for the policymaking with respect to the sustainable coastal zone management in China.