Brigadier L.,Nanjing University of Information Science and Technology |
Ogwang B.A.,Nanjing University of Information Science and Technology |
Ongoma V.,Nanjing University of Information Science and Technology |
Ongoma V.,South Eastern Kenya University |
And 2 more authors.
Natural Hazards | Year: 2016
This study diagnoses the circulation anomalies associated with the 2010 December–February (DJF) flood in comparison with the 1992 DJF drought over Zambia. Monthly precipitation data for 39 meteorological stations were sourced from Zambia Meteorological Department, the Climate Research Unit precipitation data, and reanalysis datasets are used. Composite analysis was employed to understand the circulation anomalies during the period under review. Results show that the average precipitation over Zambia was above normal; however, some parts of the country received normal rainfall. The climatology of zonal wind is characterized by easterly flow except at low level. During the flood year, this flow was enhanced as observed in the anomalous vertical cross section of the zonal wind; a reversed flow was observed during the drought year. The region was characterized by rising motion during the flood year, which is associated with convergence at low level and divergence at upper level, as opposed to the drought year which exhibited sinking motion. Convergence at low level leads to vertical stretching, whereas divergence at low level leads to vertical shrinking, which suppresses convection due to subsidence. The observed atmospheric circulations can be monitored in the update of seasonal weather forecast to avert the losses associated with floods in future. © 2015, Springer Science+Business Media Dordrecht. Source
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. Source