Impacts of climate change on hydro-meteorological drought over the Volta Basin, West Africa, by P. G. Oguntunde, B. J. Abiodun & G. Lischeid; https://doi.org/10.1016/j.gloplacha.2017.07.003

Global and Planetary Change, (online July 12, 2017), https://doi.org/10.1016/j.gloplacha.2017.07.003

Impacts of climate change on hydro-meteorological drought over the Volta Basin, West Africa

Philip G. Oguntunde, Batatunde J. Abiodun, and Gunnar Lischeid

Highlights

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We examined the past and future characteristics of drought over Volta River Basin.

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We investigated the coupling between drought and streamflow with wavelets analysis.

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A 2–3 month lead time was found between drought indices and stream flow.

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Drought area extent is projected to increase by 24% to 34% in the future.

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This study may guide policy on strategic and adaptive capacity building in the basin.

Abstract

This study examines the characteristics of drought in the Volta River Basin (VRB), investigates the influence of drought on the streamflow, and projects the impacts of future climate change on the drought. A combination of observation data and regional climate simulations of past and future climates (1970–2013, 2046–2065, and 2081–2100) were analyzed for the study. The Standardized Precipitation Index (SPI) and Standardized Precipitation and Evapotranspiration (SPEI) were used to characterize drought while the Standardized Runoff Index (SRI) were used to quantify runoff. Results of the study show that the historical pattern of drought is generally consistent with previous studies over the Basin and most part of West Africa. RCA ensemble medians (RMED) give realistic simulations of drought characteristics and area extent over the Basin and the sub-catchments in the past climate. Generally, an increase in drought intensity and spatial extent are projected over VRB for SPEI and SPI, but the magnitude of increase is higher with SPEI than with SPI. Drought frequency (events per decade) may be magnified by a factor of 1.2 (2046–2065) to 1.6 (2081–2100) compared to the present day episodes in the basin. The coupling between streamflow and drought episodes was very strong (P < 0.05) for the 1–16-year band before the 1970 but showed strong correlation all through the time series period for the 4–8-years band. Runoff was highly sensitive to precipitation in the VRB and a 2–3 month time lag was found between drought indices and streamflow in the Volta River Basin. Results of this study may guide policymakers in planning how to minimize the negative impacts of future climate change that could have consequences on agriculture, water resources and energy supply.

http://www.sciencedirect.com/science/article/pii/S0921818116305215

Impact of climate change on staple food crop production in Nigeria, Climatic Change, September 2015; doi: 10.1007/s10584-015-1428-9

Climatic Change, 132(2) (September 2015) 321-336; doi: 10.1007/s10584-015-1428-9

Impact of climate change on staple food crop production in Nigeria

• Valentina Mereu
• , Gianluca Carboni
• , Andrea Gallo
• , Raffaello Cervigni
•  and Donatella Spano

Abstract

Climate change impact on the agricultural sector is expected to be significant and extensive in Sub-Saharan Africa, where projected increase in temperature and changes in precipitation patterns could determine sensible reductions in crop yields and concerns for food security achievement. This study presents a multi-model approach to analysing climate change impacts and associated risks for staple food crops in Nigeria. Previous attempts to evaluate climate change impacts in Nigeria had mainly focused on a reduced number of crops, with analysis limited to single experimental fields or specific areas, and in many cases considering only a limited number of climate models. In this work, crop simulation models implemented in the DSSAT-CSM software were used to evaluate climate change impacts on crop production in different Agro-Ecological Zones, considering multiple combinations of soils and climate conditions, varieties and crop management. The climate impact assessment was made using an ensemble of future climate projections, to include uncertainty related to climate projections. Even if precipitations could increase in most parts of Nigeria, this is not likely to offset the crop yield reduction due to the increase in temperatures, particularly over the medium-term period (2050), with yield decreases projected especially for cereals. The short-term effects are more uncertain and yields for cassava and millet might actually increase by 2020. Moreover, yield reductions are only partially mitigated by the direct effect of increased CO₂ atmospheric concentrations enhancing crop yields. In both periods and for all crops, there is a higher risk that crop yields may fall below the actual risk threshold.

http://link.springer.com/article/10.1007/s10584-015-1428-9