Sisira Saddhamangala Withanachchi

Water Quality in Surface Water: A Preliminary Assessment of Heavy Metal Contamination of the Mashavera River, Georgia

Water quality contamination by heavy metal pollution has severe effects on public health. In the Mashavera River Basin, an important agricultural area for the national food system in Georgia (e.g., vegetable, dairy and wine production), water contamination has multiple influences on the regional and country-wide health. With new industrial activities in the region, sediment extraction, and discharge of untreated wastewater into the river, its tributaries and irrigation canals, a comprehensive study of water quality was greatly needed. This study examined sediment and water samples from 17 sampling sites in the Mashavera River Basin during the high and low precipitation seasons. The results were characterized utilizing the Geo-accumulation Index (Igeo), Enrichment Factor (EF), Pollution Load index (PLI), Contamination Factor (CF) and Metal Index (MI). According to the CFs, Cu > Cd > Zn > Pb > Fe > Mn > Ni > Cr > Hg is the descending order for the content of all observed heavy metals in sediments collected in both seasons. Fe and As were additionally examined in water samples. Overall, As, Cd and Pb, all highly toxic elements, were found in high concentrations in downstream sample sites. According to these results, comprehensive monitoring with narrow intervals between sampling dates, more sample sites along all waterways, and proximate observation of multiple trace metal elements are highly recommended. Moreover, as the part of the water quality governance system, an immediate and sustainable collective action by all stakeholders to control the pollution level is highly recommended, as this issue is linked to the security of the national food system and poses a local public health risk.

Social–ecological dynamics in irrigated agriculture in dry zone Sri Lanka: a political ecology

The study deals with social–ecological dynamics in irrigated agriculture in Sri Lanka’s dry zone. Paddy cultivation on small-scale farms, the prevalent livelihood strategy in the region, is highly dependent on irrigation. Small village tanks and large-scale irrigation schemes shape agricultural life, together with modernized agrarian technologies in accordance with “Green Revolution” approaches. Based on field research conducted in North Central and Eastern Province in 2013/2014, this paper evaluates the current state of rural development in the dry zone through the perspective of political ecology, emphasizing the central role of sustainable water management issues. We find that hardships of the local populations are mainly comprised by the occurrence of a quasi-epidemic kidney disease (CKDu), socio-economic tensions, and post-conflict challenges. Through the lense of the political ecology approach, the study suggests that agricultural modernization in the Sri Lankan dry zone has created severe dilemmas to the social and environmental sustainability of irrigated agriculture.