Development of termites severity probability map of futa campus area using geographical information system (GIS) technology

Environment, Development and Sustainability - Siting of buildings in rural urban development requires that the prevalence of termite activities is considered. The severity of termite activities...     

In situ experiments for element species-specific environmental reactivity of tin and mercury compounds using isotopic tracers and multiple linear regression

The fate of mercury (Hg) and tin (Sn) compounds in ecosystems is strongly determined by their alkylation/dealkylation pathways. However, the experimental determination of those transformations is still not straightforward and methodologies need to be refined. The purpose of this work is the development of a comprehensive and adaptable tool for an accurate experimental assessment of specific formation/degradation yields and half-lives of elemental species in different aquatic environments. The methodology combines field incubations of coastal waters and surface sediments with the addition of species-specific isotopically enriched tracers and a mathematical approach based on the deconvolution of isotopic patterns. The method has been applied to the study of the environmental reactivity of Hg and Sn compounds in coastal water and surface sediment samples collected in two different coastal ecosystems of the South French Atlantic Coast (Arcachon Bay and Adour Estuary). Both the level of isotopically enriched species and the spiking solution composition were found to alter dibutyltin and monomethylmercury degradation yields, while no significant changes were measurable for tributyltin and Hg(II). For butyltin species, the presence of light was found to be the main source of degradation and removal of these contaminants from surface coastal environments. In contrast, photomediated processes do not significantly influence either the methylation of mercury or the demethylation of methylmercury. The proposed method constitutes an advancement from the previous element-specific isotopic tracers’ approaches, which allows for instance to discriminate the extent of net and oxidative Hg demethylation and to identify which debutylation step is controlling the environmental persistence of butyltin compounds.     

“We are free when water is available”: gendered livelihood implications of sporadic water supply in Northern Ghana

ABSTRACT

Water shortages may present different and diverse implications for gender subgroups particularly in low-income settings. Yet, little research has documented the gendered livelihood implications of water shortages in Ghana. Based on a cross-sectional mixed method research involving a survey of 250 household heads and complemented with a qualitative study of 86 participants, the paper examines the differential effects of sporadic water supply in Tatale-Sanguli District of Northern Ghana. Our findings suggest that the livelihood effects of sporadic water supply in Tatale-Sanguli area are gendered, with females being disproportionately affected as compared to males. These differential effects are often framed by both gender role differentiation and inequities in access to vital productive resources and critical assets such as bicycles, tricycles and motor bikes. These findings highlight not only the need for local government and non-governmental organisations to step up efforts in water provision, but also to recognise the gendered effects of water shortages in Tatale-Sanguli District. Key to policy is also to ensure that programmatic interventions during water shortages take account of the likely gendered effects and differentiated burdens.     

Human health and sustainable water resources development in Nigeria: Schistosomiasis inartificial lakes

In the last three decades, there has been an unprecedented upsurge in dam construction in Nigeria to store water for year-round water supply, irrigation and fisheries. Out of a total of 323 dams identified in the literature, 246 (76.2%) were constructed since 1970. Although only 47 of the reservoir lakes have been surveyed for snail intermediate hosts and 11 of the 47 for human infection, the results obtained by the various workers are very revealing. Snail hosts of schistosomiasis were found in 20 (42.6%) of the 47 lakes and human infection in 10 (90.9%) of the 11 lakes investigated for the respective purposes. These findings show that dam construction is contributing to schistosomiasis transmission in Nigeria and, unless urgent steps are taken to reverse the situation, the adverse health consequences of the dams will more than balance their socio-economic benefits. This paper discusses these problems in the context of existing institutional and legal frameworks in Nigeria and identifies appropriate measures, that could achieve sustainable water resources development in the future.     

Analysis of the transitions between flow patterns in open-channel lateral cavities with increasing aspect ratio

Environmental Fluid Mechanics - The flow pattern within a storage zone governs the efficiency of passive scalar accumulation, spreading and homogenization. The present paper aims at characterizing...