Possible climate change/variability and human impacts, vulnerability of drought-prone regions, water resources and capacity building for Africa

Abstract

This review article discusses the climate, water resources and historical droughts of Africa, drought indices, vulnerability, impact of global warming and landuse to drought-prone regions in West, Southern, and Greater Horn of Africa, which have suffered recurrent severe droughts in the past. Recent studies detected warming and drying trends in Africa since the mid-20 th century. Based on the 4 th Assessment Report of the Intergovernmental Panel of Climate Change, and that of the 5 th Coupled Model Intercomparison Project (CMIP5), both northern and southern Africa are projected to experience drying such as decreasing precipitation, runoff and soil moisture in the 21 st Century and could become more vulnerable to impact of droughts. The daily maximum temperature is projected to increase up to 8 o C (RCP8.5 of CMIP5), precipitation indices such as total wet day precipitation (PRCPTOT) and heavy precipitation days (R10mm) could decrease, while warm spell duration (WSDI) and consecutive dry days (CDD) could increase. Uncertainties of the above long-term projections, teleconnections to climate anomalies such as ENSO and Madden Julian Oscillation which could also affect water resources of Africa, and capacity building in terms of physical infrastructure and non-structural solutions, are also discussed. Given traditional climate and hydrologic data observed in Africa are generally limited, satellite data should also be exploited to fill in the data gap for Africa in future.

Terrestrial Water Storage in African Hydrological Regimes Derived from GRACE Mission Data: Intercomparison of Spherical Harmonics, Mass Concentration, and Scalar Slepian Methods

“…In the Volta basin, the precipitation is bound for TWS that changes at an annual scale with a phase lag of −0.42 ± 0.1 months [67]. The spatiotemporal variability of TWS and the declining or replenishing water level in lakes and water bodies have undergone climate change extremes (e.g., the Indian Ocean Dipole (IOD) and El Niño-Southern Oscillation) [68,69,70]. For example, half of the lost water in the Victoria Lake in last 80 years is attributed to climate conditions [71], and the 2006 to 2007 IOD fluctuations have replenished aquifer resources in Tanzania and East Africa [72].…”

Patterns in woody vegetation structure across African savannas

“…Abiotic environmental factors, such as the rainfall regime, soil type, and topography, impact ecohydrological processes by controlling infiltration rates, runoff generation, and available water capacity, which in turn impact the growth and survival of woody plants in the landscape . Climate, both rainfall patterns and temperatures, could change in many parts of Africa (Gan et al, 2016), and the effect on vegetation will depend on how those pressures interact with other abiotic and biotic factors. In addition to ecohydrological factors, savannas are heavily influenced by the frequency and intensity of fires (Bond, 2008), as well as herbivore regimes (Sankaran et al, 2008), which often combine to suppress woody cover to levels well below its climatic potential (Sankaran et al, 2005).…”

Repercussions of institutional governance changes on communication practices in the Afar National Regional State, Ethiopia

“…This would highlight the relevant communication practices needed to reach both groups and the weaknesses described by each group. Additionally, as the Horn of Africa is recognized as having an increased vulnerability to drought (Gan et al, ), the need for timely and informed aid work is likely to increase.…”