Sand storage dams are hydraulic retention structures that increase the volume of coarse sediments in seasonal sandy streams by exclusively blocking the bedload transport during runoff events. However, siltation of fine grain particles, which are transported as part of the suspended load, is a major factor causing sand storage dams to perform poorly. Therefore, this study aimed to evaluate the hydrological performance and cost-efficiency of 30 sand storage dams. This study also aimed to increase the understanding of critical factors which may affect the performance and lead to siltation of sand storage reservoirs. The analysis was based on a physical survey of 30 sand storage dams that were built in onestage in southeastern Kenya. Most of the study sites had the capacity to produce sand. However, the reservoirs suffered from severe siltation, which caused generalized low annual yields, reduced supply capacities, and low cost-efficiency. It is argued that the main factors for the poor performance were the high inter-and intra-annual variability of bedload transport, which coupled with the construction of onestage spillways, led to siltation of the reservoirs. Thus, large volumes of fine grain particles accumulated in the reservoirs during runoff events with bedload layer heights lower than the height of the one-stage spillways. To systematically maximize the robustness to the inherent variability of bedload transport, and ensure optimal performance levels by systematically minimizing siltation, spillways should be built in stages of reduced height. Thus, the lower the stage height, the higher the probability of maximizing the accumulation of coarse sediment. It is estimated that a multi-stage construction process with stage heights of 20 cm would have produced a performance 26 times higher. This implies that the 30 reservoirs would have had the capacity to supply 8516 people as compared to the current supply capacity of 330 people. Improvements in the performance of sand storage dams can greatly assist attempts to link this technology with income-generating activities for agropastoralists in arid and semi-arid areas.
Small Islands Developing States (SIDS) are isolated and surrounded by ocean. The generation and use of energy resources are two very important aspects for the development of SIDS. Unfortunately, most of SIDS do not use their potential in respect of energy resources, and they as a result have to depend on the import of fossil fuels in order to meet their energy needs. This increases the overall vulnerability of SIDS as they have to depend on the rising or fluctuating fossil fuels prices. Some SIDS, especially in the geographically dispersed Pacific region, do not have proper access to energy whereas other SIDS struggle more with energy security issue. At the same time, SIDS are most vulnerable to the impacts and effects of climate change, as they are among the ones to be most severely affected in case of natural calamities and sea-level rise.Drawing on experiences from Fiji and Mauritius, this paper explains core elements related to energy access and security in SIDS, contextualizes and discusses barriers and list some of the strategies that may be used to ensure access to and a continuous supply of energy in SIDS. A situational analysis of two SIDS outlines their current energy situation and compares their energy policies to globally accepted criteria for SIDS policies as well as with each other. It is claimed that the diverging energy performances of Fiji and Mauritius cannot be explained by policies differences. The reasons for the varying energy performances may therefore lie in the administrative and institutional mechanisms used by the two countries in implementing their energy policies. Finally, to enable SIDS to reduce their overall vulnerability and become truly sustainable islands, it is recommended to undertake careful assessments of the particular local contexts under which island energy regimes operate.
Energy-intensive industrialization and various anthropogenic actions by humans over centuries have resulted in a huge build up of Greenhouse gases triggering consequential ‘Greenhouse effects’ and ‘Global warming’. This, in turn, has caused global climate change with adverse impact on ecology, environment, economy and human health. Among other things, the economic impact of global warming and climate change/aberration has been widely acknowledged to be phenomenal. In past few years, climate change economics has focused on diagnosing the economic underpinnings of climate change and offering positive and normative analyses of policies to confront the problem. While overlapping with other areas of environmental economics, climate change economics has a unique focus because of distinctive features of the climate problem, including the long time scale, the extent and nature of uncertainties, the international scope of the issue, and the uneven distribution of policy benefits and costs across space and time. The ‘Kyoto Protocol’ (1997), ‘Bali Action Plan’ (2007), and of late Copenhagen Accord (2009), have effectively provided, among other things, the institutional mechanisms and broad operational framework for funding such of those initiatives at local, regional and global levels that can limit and progressively reduce greenhouse gas emissions through carefully designed mitigation and adaptation actions. In this paper, an attempt has been made to discuss the various economic and financial implications in climate change impact assessment and thereby help formulation of appropriate strategies, including the mode of transfer of resources and technologies from the developed to the developing economy to respond to the various adverse impacts of climate change, primarily through mitigation and adaptation actions. The emerging business opportunities, borne out of economic responses to climate change management and Emissions trading in the post-Copenhagen scenario, is also briefly discussed.
This article examines the implications of turning a voluntary management instrument such as Environmental Management Systems (EMSs) into a compulsory one. Environmental Management Systems are voluntary operational management tools that can help firms to both reduce their impact on the natural environment and gain financial benefits (win-win strategy). However, some countries have lately enacted environmental regulations to pressurise firms to adopt EMSs. To this end, the findings of the previous studies have been examined with the help of a case study in Greece in order to identify management awareness in EMS-certified Greek firms in terms of the mandatory character of EMS adoption. The article particularly aims to examine the similarities and differences in the voluntary versus mandatory implementation of EMS, arising both from the present study as also from previous studies. ISO 14001, EMAS, proactive environmental management strategy, sustainable development Lal (2003) identify that British oil and gas firms are Keywords
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