Search

Your search keyword '"Seddon, David"' showing total 458 results
Start Over Author "Seddon, David"
458 results on '"Seddon, David"'

4. The climate controls and process of groundwater recharge in a semi-arid tropical environment : evidence from the Makutapora Basin, Tanzania

Author

Seddon, David

Subjects
550
Abstract

Groundwater is a vital source of freshwater in semi-arid sub-Saharan Africa. Climate change, to which this region is particularly vulnerable, and increasing water demand are expected to increase the strategic importance of groundwater. The responses of groundwater systems to these forcings remain unclear. Here, in the intensively monitored and pumped groundwater system in the Makutapora Basin of central Tanzania, an analogue for semi-arid tropical areas underlain by weathered and fractured crystalline rock aquifers, I: (1) assess the relationship between precipitation intensity and groundwater recharge, (2) delineate the predominant recharge processes, and (3) project the impacts of climate change and increasing groundwater abstraction on future groundwater resources. Analysis of one of the longest known groundwater-level records in tropical Africa using a modified water-table fluctuation method, incorporating a numerical flow model to account for transience in response to pumping, shows more intensive precipitation disproportionately generates groundwater recharge. This bias is corroborated by a comparison of the stable-isotope composition of groundwater and precipitation as a function of intensity. Recharge is shown to occur via leakage from ephemeral streambeds through the formation and decay of groundwater 'mounds'. Stable-isotope tracers and hydrometric evidence of streambed inundation confirm the predominance of focused recharge pathways. Projections of groundwater resources, using a fully integrated MIKE SHE/MIKE 11 model, indicate that changes to recharge due to climate change will be small in the context of likely increases in groundwater abstraction. However, the bias of disproportionate groundwater recharge production from intensive precipitation, together with new insight regarding the processes and controls of recharge in this semi-arid environment, suggest that climate change may not only enhance groundwater recharge but also enable strategies (e.g. Managed Aquifer Recharge) to artificially enhance the sustainability of groundwater withdrawals since these events and processes are predictable.

Published
2019

14. The Berbers

Author

Montagne, Robert, primary, Seddon, David, additional, and Gellner, Ernest, additional

Published
2020
Full Text
View/download PDF

15. Observed controls on resilience of groundwater to climate variability in sub-Saharan Africa

Author

Cuthbert, Mark O., Taylor, Richard G., Favreau, Guillaume, Todd, Martin C., Shamsudduha, Mohammad, Villholth, Karen G., MacDonald, Alan M., Scanlon, Bridget R., Kotchoni, D. O. Valerie, Vouillamoz, Jean-Michel, Lawson, Fabrice M. A., Adjomayi, Philippe Armand, Kashaigili, Japhet, Seddon, David, Sorensen, James P. R., Ebrahim, Girma Yimer, Owor, Michael, Nyenje, Philip M., Nazoumou, Yahaya, Goni, Ibrahim, Ousmane, Boukari Issoufou, Sibanda, Tenant, Ascott, Matthew J., Macdonald, David M. J., Agyekum, William, Koussoubé, Youssouf, Wanke, Heike, Kim, Hyungjun, Wada, Yoshihide, Lo, Min-Hui, Oki, Taikan, and Kukuric, Neno

Published
2019
Full Text
View/download PDF

23. Conclusion

Author

Montagne, Robert, primary, Seddon, David, additional, and Gellner, Ernest, additional

Published
2019
Full Text
View/download PDF

24. Methodological Considerations in Evaluating Long-Term Systems Change: A Case Study From Eastern Nepal

Author

Koleros, Andrew, Jupp, Dee, Kirwan, Sean, Pradhan, Meeta S., Pradhan, Pushkar K., Seddon, David, and Tumbahangfe, Ansu

Abstract

This article presents discussion and recommendations on approaches to retrospectively evaluating development interventions in the long term through a systems lens. It is based on experiences from the implementation of an 18-month study to investigate the impact of development interventions on economic and social change over a 40-year period in the Koshi Hills region of Nepal. A multi-disciplinary team used a mixed-methods approach to data collection and analysis. A theory-based analytical approach was utilized to produce narratives of plausible cause and effect and identify key drivers of change within the context of cumulative and interconnected impacts of multiple programs and factors. This article responds to increasing interest in development evaluation to look beyond intervention-specific impact to broader determinants of change to assist with intervention planning. It is the authors' hope that this will stimulate debate and progress in the use of high quality research to inform future development work.

Published
2016
Full Text
View/download PDF

32. Author Correction: Observed controls on resilience of groundwater to climate variability in sub-Saharan Africa

Author

Cuthbert, Mark O., Taylor, Richard G., Favreau, Guillaume, Todd, Martin C., Shamsudduha, Mohammad, Villholth, Karen G., MacDonald, Alan M., Scanlon, Bridget R., Kotchoni, D. O. Valerie, Vouillamoz, Jean-Michel, Lawson, Fabrice M. A., Adjomayi, Philippe Armand, Kashaigili, Japhet, Seddon, David, Sorensen, James P. R., Ebrahim, Girma Yimer, Owor, Michael, Nyenje, Philip M., Nazoumou, Yahaya, Goni, Ibrahim, Ousmane, Boukari Issoufou, Sibanda, Tenant, Ascott, Matthew J., Macdonald, David M. J., Agyekum, William, Koussoubé, Youssouf, Wanke, Heike, Kim, Hyungjun, Wada, Yoshihide, Lo, Min-Hui, Oki, Taikan, and Kukuric, Neno

Published
2020
Full Text
View/download PDF

41. Why Are Doctors So Unhappy?

Author

West, P. A., Parsons, Keith, Evans, Susan, Laurence, Mike, McKenzie, Kwame, Jakeman, Nicola, Gregson, P. N., Stewart, Andy, Seddon, David, Smith, Simon, Hart, Julian Tudor, Newman, Marion, Wilke, Gerhard, Davies, Peter, Brennan, Frank, Zeckhausen, William, Culliford, Larry, Workman, Stephen, Hunter, David, and Davies, Sharon

Published
2001

Catalog

Books, media, physical & digital resources
See catalog results