Johannesson G.A.,National Energy Authority |
Xuezhong Y.,China Institute of Water Resources and Hydropower Research |
Phiri I.,Ministry of Energy and Water Development |
Hartmann J.,WWF |
And 8 more authors.
Water Alternatives | Year: 2010
The World Commission on Dams (WCD) has called for developers, governments, civil society, etc. to use its Strategic Priorities as a starting point for dialogue and initiatives to address issues regarding the development of dams. One very notable follow-up initiative has been led by the hydropower industry. The International Hydropower Association developed Sustainability Guidelines (IHA, 2004) and a Sustainability Assessment Protocol (IHA, 2006), and most recently has been involved in a two-year process with governments, NGOs and the finance sector to develop a broadly endorsed sustainability assessment tool based on review and update of the IHA Sustainability Assessment Protocol. This cross-sectoral process, known as the Hydropower Sustainability Assessment Forum (HSAF), has drawn on the knowledge base and many of the findings and recommendations of the World Commission on Dams, as well as a number of other developments in the last ten years. A fundamental premise of the work of the Forum is that an industry-driven and -owned initiative has far-reaching potential to influence performance in the hydropower sector. At the same time, the potential for the use of a broadly endorsed sustainability assessment tool for hydropower by those in other sectors is well recognised and aspired to by the Forum. This paper describes the work of the Forum up to August 2009 and the contents of the Draft Protocol released publicly in August 2009, and considers some of the commonalities and points of departure between this process and the WCD. The Forum's work on the Hydropower Sustainability Assessment Protocol is a work in progress, so this paper can describe but not give a full analysis of the work while it is in train.
Van de Giesen N.,Technical University of Delft |
Stomph T.-J.,Wageningen University |
Ajayi A.E.,Federal University of Technology Akurre |
Ajayi A.E.,Federal University of Lavras |
Agriculture, Ecosystems and Environment | Year: 2011
This article provides an overview of both experimental and modeling research carried out over the past 15 years by the authors addressing scaling effects in Hortonian surface runoff. Hortonian surface runoff occurs when rainfall intensity exceeds infiltration capacity of the soil. At three sites in West Africa (Côte d'Ivoire, Ghana, and Burkina Faso) runoff was measured from plots of different lengths to assess scale effects. Consistently, longer plots showed much lower runoff percentages than shorter plots. There were large variations in runoff percentages from one rainstorm to the next but there were very good correlations between plots of equal length for each single event. This strongly suggests that temporal dynamics are the cause behind the observed scale effects. In the literature, spatial variability is often proffered as explanation for such scale effects without providing a mechanism that would cause consistent reduction in runoff percentages with increasing slope length. To further examine whether temporal dynamics can indeed provide the explanation, Hortonian runoff was simulated using models with increasing levels of complexity. The simplest model was already able to reproduce the observed scale effects. Also more complex models were used that accounted explicitly for spatial variability. The conclusions remained the same regarding the role of temporal dynamics. Finally, a dimensional analysis was developed that helps predict under which circumstances one can expect scale effects similar to the ones observed in West Africa. © 2010 Elsevier B.V.
Bartlein P.J.,University of Oregon |
Harrison S.P.,University of Bristol |
Harrison S.P.,Macquarie University |
Brewer S.,University of Wyoming |
And 17 more authors.
Climate Dynamics | Year: 2011
Subfossil pollen and plant macrofossil data derived from 14C-dated sediment profiles can provide quantitative information on glacial and interglacial climates. The data allow climate variables related to growing-season warmth, winter cold, and plant-available moisture to be reconstructed. Continental-scale reconstructions have been made for the mid-Holocene (MH, around 6 ka) and Last Glacial Maximum (LGM, around 21 ka), allowing comparison with palaeoclimate simulations currently being carried out as part of the fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change. The synthesis of the available MH and LGM climate reconstructions and their uncertainties, obtained using modern-analogue, regression and model-inversion techniques, is presented for four temperature variables and two moisture variables. Reconstructions of the same variables based on surface-pollen assemblages are shown to be accurate and unbiased. Reconstructed LGM and MH climate anomaly patterns are coherent, consistent between variables, and robust with respect to the choice of technique. They support a conceptual model of the controls of Late Quaternary climate change whereby the first-order effects of orbital variations and greenhouse forcing on the seasonal cycle of temperature are predictably modified by responses of the atmospheric circulation and surface energy balance. © 2010 The Author(s).
Joffre O.M.,GTZ |
Aquaculture Research | Year: 2010
This case study looks at changing livelihood strategies of the coastal population in Soc Trang Province in the Mekong Delta, Vietnam, and their impacts on natural resources. It provides an opportunity not only to document the impact of shrimp farming on coastal livelihood but also to better understand the link between brackish water aquaculture development and natural resource use. The approach includes a socio-economic survey in six villages of the province focusing on risk strategies and livelihood diversification. Shrimp farming was found to be less risky and more profitable for households and private companies with a higher investment capacity than for poorer households. Households facing a high risk in shrimp farming diversified their aquaculture production, with other high-value species like mud crab and elongated goby as a coping mechanism. The use of natural resources' collection is shifting from home consumption towards market-oriented sales of juvenile mud crabs, clams or fish (elongated goby) to supply seed for brackish water aquaculture developments. © 2010 The Authors. Aquaculture Research © 2010 Blackwell Publishing Ltd.