Estimating Scenario-based Impacts of Climate and Land use Changes on Potential River Ecology of a Rainforest Catchment in Ghana, West Africa
Abstract
This study analysed impacts of climate and land use changes on potential ecological alterations of the Bonsa River in Ghana, West Africa, using the ACRU hydrological model. Five RCP8.5 climate change scenarios (wet, 25th percentile, 75th percentile, dry and a multi-model median of nine GCMs) from the CMIP5 AR5 models for near (2020 – 2039) and far (2060 – 2079) future time slices as well as five land use scenarios were used. The GCM climate change scenarios were obtained by using change factors to downscale pre-processed GCM climate data, using observed climate data for the control period of 1990 to 2009, while the land use scenario data were obtained from previous studies. The land use of 1991 was used as the baseline land use, while the Richter’s range of variability approach (RVA) was used to assess the potential river ecological impacts. The results indicate that between 1990 and 2011, the hydrology has been altered substantially and there is a potential for higher hydrological alterations under the predicted future LU scenarios. The study shows that under extreme flow conditions, the recent and the potential future hydrological regimes may increase stress for some wildlife as the magnitudes and durations of streamflows are above the pre-impact streamflows. However, the life cycle of wildlife has not been affected significantly under the recent or potential future land use scenarios because the seasonal pattern of streamflows has not changed in both scenarios. For the scenarios of potential future LU changes, the BAU shows the highest potential alterations, while the EGR shows the least and river ecological alterations resulting from combined climate change and land use changes were higher than those resulting from separate climate change impacts.
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Aduah, M. S, Jewitt, G. P. W and Toucher, M. L. W. (2017). “Assessing suitability of the ACRU hydrological model in a rainforest catchment in Ghana, West Africa”, Water Science, Vol. 31, No. 2, pp. 198-214.
Aduah, M. S, Toucher, M. L and Jewitt, G. P. W. (2018). “Estimating potential future land use in the Bonsa catchment, Ghana, West Africa”, South African Journal of Geomatics, Vol. 7, No. 3, pp. 279-291.
Aduah, M. S, Warburton, M. L and Jewitt, G. (2015). “Analysis of land cover changes in the Bonsa catchment, Ankobra Basin, Ghana”, Applied Ecology and Environmental Research, Vol. 13, No. 4. pp. 935-955.
Akabzaa, T. M, Jamieson, H. E, Jorgenson, N and Nyame, K. (2009). “The Combined Impact of Mine Drainage in the Ankobra River Basin, SW Ghana”, Mine Water and the Environment, Vol. 28, No. 1, pp. 50-64.
Anon., (2009). “Indicators of Hydrologic Alteration software Version 7.1, User's Manual”, The Nature Conservancy.
Anon., (2013). “Summary for Policymakers. In: Stocker, T. F, Qin, D, Plattner, G. K, Tignor, M, Allen, S. K, Boschung, J, Nauels, A, Xia, Y, Bex, V and Midgley, P. M (eds.), Climate Change 2013: The Physical Science Basis”, Contribution of Working Group I to the Fifth Assessment Report, Intergovernmental Panel on Climate Change. Cambridge, United Kingdom and New York, NY, USA.
Anon., (2015). “Future climate projections, Climate System Analysis Group, University of Cape Town. Cape Town, South Africa”, http://cip.csag.uct.ac.za/webclient2/datasets/africa-merged-cmip5/#nodes/cmip5-anomalies?folder_id=33&extent=99799, Accessed: 24th August, 2015.
Buytaert, W, Vuille, M, Dewulf, A, Urrutia, R, Karmalkar, A and Celleri, R. (2010). “Uncertainties in climate change projections and regional downscaling in the tropical Andes: implications for water resources management”, Hydrology and Earth System Sciences, Vol. 14, No. 7, pp. 1247-1258.
Chen, J, Brissette, F. P and Leconte, R. (2011). “Uncertainty of downscaling method in quantifying the impact of climate change on hydrology”, Journal of Hydrology, Vol. 401, No. 3-4, pp. 190-202.
Forbes, K. A, Kienzle, S. W, Coburn, C. A, Byrne, J. M and Rasmussen, J. (2011). “Simulating the hydrological response to predicted climate change on a watershed in southern Alberta, Canada”, Climatic Change, Vol. 105, No. 3-4, pp. 555-576.
Fowler, H. J, Blenkinsop, S and Tebaldi, C. (2007). “Linking climate change modelling to impacts studies: recent advances in downscaling techniques for hydrological modelling”, International Journal of Climatology, Vol. 27, No. 12, pp. 1547-1578.
Ghile, Y. B. (2004). “An adaptation of the SCS-ACRU hydrograph generating technique for application in Eritrea,. Unpublished MSc Thesis”, School of Bioresources Engineering and Environmental Hydrology, University of Natal, South Africa.
Hillman, B, Douglas, E. M and Terkla, D. (2012). “An analysis of the allocation of Yakima River water in terms of sustainability and economic efficiency”, Journal of Environmental Management, Vol. 103, No. 2012, pp. 102-112.
Homa, E. S, Brown, C, McGarigal, K, Compton, B. W and Jackson, S. D. (2013). “Estimating hydrologic alteration from basin characteristics in Massachusetts”. Journal of Hydrology, Vol. 503, No. 2013, pp. 196-208.
Hulme, M, Doherty, R, Ngara, T, New, M and Lister, D. (2001). “African climate change: 1900-2100”, Climate Research, Vol. 17, No. 2, pp. 145-168.
Jackson, B, Nicholson, S. E and Klotter, D. (2009). “Mesoscale Convective Systems over Western Equatorial Africa and Their Relationship to Large-Scale Circulation”, Monthly Weather Review, Vol. 137, No. 4, pp. 1272-1294.
Jalloh, A, Faye, M. D, Roy-Macauley, H, Sérémé, P, Zougmoré, R, Thomas, T. S and Nelson, G. C. (2013). “Overview. In: Jalloh, A, Nelson, G. C., Thomas,T. S., Zougmoré,R. And Roy-Macauley, H. (ed.) West African Agriculture and Climate Change: A Comprehensive Analysis”, International Food Policy Research Institute(IFPRI), Washington, DC, USA.
Kienzle, S. W, Nemeth, M. W, Byrne, J. M and MacDonald, R. J. (2012). “Simulating the hydrological impacts of climate change in the upper North Saskatchewan River basin, Alberta, Canada”, Journal of Hydrology, Vol. 412–413, No. 2012, pp. 76-89.
Kunstmann, H, Schneider, K, Forkel, R and Koche., R. (2004). “Impact analysis of climate change on an Alpine catchment using high resolution dynamic downscaling of ECHMAM4 time slices”, Hydrology and Earth System Sciences, Vol. 8, No. 6, pp. 1030 - 1044.
Maurer, E. P and Hidalgo, H. G. (2008). “Utility of daily vs. monthly large-scale climate data: an intercomparison of two statistical downscaling methods”, Hydrology and Earth System Sciences, Vol. 12, No. 2, pp. 551-563.
Mendlik, T and Gobiet, A. (2016). “Selecting climate simulations for impact studies based on multivariate patterns of climate change”, Climatic Change, Vol. 135, pp. 381-393.
Moradkhani, H, Baird, R. G and Wherry, S. A. (2010). “Assessment of climate change impact on floodplain and hydrologic ecotones”, Journal of Hydrology, Vol. 395, No. 3-4, pp. 264-278.
Moss, R. H, Edmonds, J. A, Hibbard, K. A, Manning, M. R, Rose, S. K, van Vuuren, D. P, Carter, T. R, Emori, S, Kainuma, M, Kram, T, Meehl, G. A, Mitchell, J. F. B, Nakicenovic, N, Riahi, K, Smith, S. J, Stouffer, R. J, Thomson, A. M, Weyant, J. P and Wilbanks, T. J. (2010). “The next generation of scenarios for climate change research and assessment”, Nature, Vol. 463, No. 7282, pp. 747-756.
Richter, B. D, Baumgartner, J. V, Braun, D. P and Powell, J. (1998). “A spatial assessment of hydrologic alteration within a river network”, Regulated Rivers: Research & Management, Vol. 14, No. 4, pp. 329-340.
Richter, B. D, Baumgartner, J. V, Powell, J and Braun, D. P. (1996). “A method for assessing hydrologic alteration within ecosystems”, Conservation Biology, Vol. 10, No. 4, pp. 1163-1174.
Richter, B. D, Baumgartner, J. V, Wigington, R and Braun, D. P. (1997). “How much water does a river need?”, Freshwater Biology, Vol. 37, No. 1997, pp. 231-249.
Ruelland, D, Ardoin-Bardin, S, Collet, L and Roucou, P. (2012). “Simulating future trends in hydrological regime of a large Sudano-Sahelian catchment under climate change”, Journal of Hydrology, Vol. 424-425, No. 2012, pp. 207-216.
Schulze, R. E. (1995). “Hydrology and Agrohydrology: A Text to Accompany the ACRU 3.00 Agrohydrological Modelling System”, Water Research Commission, Pretoria, South Africa.
Teng, J, Chiew, F. H. S, Timbal, B, Wang, Y, Vaze, J and Wang, B. (2012). “Assessment of an analogue downscaling method for modelling climate change impacts on runoff”, Journal of Hydrology, Vol. 472, No. 2012, pp. 111-125.
Warburton, M. L, Schulze, R. E and Jewitt, G. P. W. (2010). “Confirmation of ACRU model results for applications in land use and climate change studies”, Hydrology and Earth System Sciences, Vol. 14, No. 2010, pp. 2399-2414.
Yidana, S. M, Ophori, D and Banoeng-Yakubo, B. (2007). “Irrigation water resource management for sustainable agriculture - The Ankobra basin, Ghana”, Journal of Irrigation and Drainage Engineering-Asce, Vol. 133, No. 6, pp. 609-615.
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