The critical importance of multi-decadal groundwater level observations for informing robust climate change impact assessments: lessons from sub-Saharan Africa

2020 ◽  
Author(s):  
Mark Cuthbert ◽  
Richard Taylor
Keyword(s):  
Climate Change ◽  
Groundwater Recharge ◽  
Preferential Flow ◽  
Sub Saharan Africa ◽  
Critical Importance ◽  
Tropical Africa ◽  
Apparent Lack ◽  
Climate Controls ◽  
Strong Control

<p>Groundwater is of fundamental importance to strategies for poverty reduction in tropical Africa and understanding the sustainability of more widespread groundwater abstraction for improving water and food provision is a key challenge. However, the hydraulic processes governing groundwater recharge that sustain this resource, and their sensitivity to climatic variability and change, are poorly constrained. Here we present results from The Chronicles Consortium initiative, which has collated multi-decadal groundwater hydrographs and co-located rainfall records across tropical Africa to better understand climate controls, among others, on groundwater recharge.</p><p>We find that recharge in more arid environments is generally highly dependent on infrequent large rainfall events causing focused recharge through losses during ephemeral overland flows. This process is not included in any large scale hydrological or land surface models, and these events are often driven by synoptic climate controls, which are themselves poorly constrained in existing climate models. In more humid locations, we find surprisingly linear relationships between rainfall and recharge indicating an apparent lack of threshold behaviour that is embodied in most hydrological models and hypothesise this is due to prevalence of preferential flow processes in the soil zone. While aridity exerts a strong control on the predominant recharge process, geological variations can dominate the observed sensitivity of recharge to climate variability.</p><p>Our results reveal the critical importance of long-term observational records for understanding the sensitivity of recharge to climate processes with implications well beyond Africa. This especially true in dryland environments where interpretations of short records would miss fundamental, episodic climate-controls on recharge expressed in longer records. We conclude that without a sound long-term observational basis for groundwater-climate sensitivity, climate change forecasts cannot be confidently constrained.</p>

scholarly journals OBSERVED SHIFT AND MERGE OF HYDROLOGICAL REGIMES IN THE SOTA CATCHMENT, BENIN; AN EVIDENCE OF CLIMATE CHANGE

2018 ◽  
Vol 6 (6) ◽  
pp. 205-211
Author(s):  
Oyerinde G. T. ◽  
Olowookere B.T.
Keyword(s):  
Climate Change ◽  
Sub Saharan Africa ◽  
Climate Trends ◽  
Adaptation Measures ◽  
Policy Makers ◽  
Discharge Data ◽  
Vegetation Zones ◽  
Shift Analysis ◽  
Sub Saharan

Sub-Saharan Africa have low resilience capacities to the challenges of climate change. This study is aimed at assessing climate trends and regime shifts at the Sota Catchment, Benin. Long term rainfall and river discharge were analyzed from 1950-2010 in order to generate patterns of changes in the basin. Analysis of the hydro-meteorological were based on the two prominent vegetation zones (Sudan and Guinea Savannah) in the catchment. The rainfall and discharge data were subjected to regime shift analysis and Standardized Precipitation Indices (SPI) were computed. Downward trend of precipitation was observed in the Guinea and Sudan vegetation zones of the catchments from 1970. Rainfall and runoff amount at the two assessed vegetation zones was different in the Guinea and Sudan zone up till 1970. Clear merge of rainfall and runoff amount and patterns was witnessed between the two vegetation zones at 2007. This calls for attention of scientists and policy makers in the region to deploy necessary adaptation measures based on such clear evidence of climate change.

scholarly journals Climate Change Impacts on Groundwater Recharge in Cold and Humid Climates: Controlling Processes and Thresholds

Climate ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 6
Author(s):  
Emmanuel Dubois ◽  
Marie Larocque ◽  
Sylvain Gagné ◽  
Marco Braun
Keyword(s):  
Climate Change ◽  
Groundwater Recharge ◽  
Water Resource Management ◽  
Global Climate Models ◽  
Future Climate Change ◽  
Temperature Changes ◽  
Wide Range ◽  
Long Term Changes ◽  
Precipitation And Temperature

Long-term changes in precipitation and temperature indirectly impact aquifers through groundwater recharge (GWR). Although estimates of future GWR are needed for water resource management, they are uncertain in cold and humid climates due to the wide range in possible future climatic conditions. This work aims to (1) simulate the impacts of climate change on regional GWR for a cold and humid climate and (2) identify precipitation and temperature changes leading to significant long-term changes in GWR. Spatially distributed GWR is simulated in a case study for the southern Province of Quebec (Canada, 36,000 km2) using a water budget model. Climate scenarios from global climate models indicate warming temperatures and wetter conditions (RCP4.5 and RCP8.5; 1951–2100). The results show that annual precipitation increases of >+150 mm/yr or winter precipitation increases of >+25 mm will lead to significantly higher GWR. GWR is expected to decrease if the precipitation changes are lower than these thresholds. Significant GWR changes are produced only when the temperature change exceeds +2 °C. Temperature changes of >+4.5 °C limit the GWR increase to +30 mm/yr. This work provides useful insights into the regional assessment of future GWR in cold and humid climates, thus helping in planning decisions as climate change unfolds. The results are expected to be comparable to those in other regions with similar climates in post-glacial geological environments and future climate change conditions.

scholarly journals Infectious disease, development, and climate change: a scenario analysis

2007 ◽  
Vol 12 (5) ◽  
pp. 687-706 ◽  
Author(s):  
RICHARD S.J. TOL ◽  
KRISTIE L. EBI ◽  
GARY W. YOHE
Keyword(s):  
Climate Change ◽  
Infectious Disease ◽  
Infant Mortality ◽  
Infectious Diseases ◽  
Sub Saharan Africa ◽  
Absolute Poverty ◽  
Control Programs ◽  
Short Run ◽  
Sub Saharan

We study the effects of development and climate change on infectious diseases in Sub-Saharan Africa. Infant mortality and infectious disease are closely related, but there are better data for the former. In an international cross-section, per capita income, literacy, and absolute poverty significantly affect infant mortality. We use scenarios of these three determinants and of climate change to project the future incidence of malaria, assuming it to change proportionally to infant mortality. Malaria deaths will first increase, because of population growth and climate change, but then fall, because of development. This pattern is robust to the choice of scenario, parameters, and starting conditions; and it holds for diarrhoea, schistosomiasis, and dengue fever as well. However, the timing and level of the mortality peak is very sensitive to assumptions. Climate change is important in the medium term, but dominated in the long term by development. As climate can only be changed with a substantial delay, development is the preferred strategy to reduce infectious diseases even if they are exacerbated by climate change. Development can, in particular, support the needed strengthening of disease control programs in the short run and thereby increase the capacity to cope with projected increases in infectious diseases over the medium to long term. This conclusion must, however, be viewed with caution, because development, even of the sort envisioned in the underlying socio-economic scenarios, is by no means certain.

Effort to curb illicit logging in Africa to fall short

2015 ◽  
Keyword(s):  
Climate Change Mitigation ◽  
Large Scale ◽  
Sub Saharan Africa ◽  
Tropical Africa ◽  
Content Type ◽  
Food And Agriculture ◽  
The World ◽  
Sub Saharan ◽  
Change Mitigation

Subject Outlook for deforestation in sub-Saharan Africa. Significance The UN Food and Agriculture Organisation's World Forestry Congress last week said that the world has lost 129 million hectares (ha) of forested area since 1990, mainly in tropical Africa and South America. Three of the ten states with the fastest declines since 2010 are in sub-Saharan Africa (SSA), due to demand for wood-fuel and timber for export. Much of the timber is traded illicitly, depriving states of revenue. Impacts Large-scale deforestation could undermine long-term climate change mitigation; forests are critical for absorbing carbon dioxide. The depletion of reserves of rare trees such as Madagascan rosewood will raise its value over time, boosting demand. Gabon's afforestation push -- it has gained 200,000 ha since 2010 due to state programmes -- will support eco-tourism.

scholarly journals Climate change and mycotoxins

2019 ◽  
Vol 11 (2) ◽  
pp. 283-290
Author(s):  
Stephen O. Fapohunda ◽  
Annabella A. Adewunmi
Keyword(s):  
Climate Change ◽  
Sub Saharan Africa ◽  
Aspergillus Species ◽  
Subtropical Climate ◽  
Tropical Africa ◽  
Surveillance Studies ◽  
Food And Feed ◽  
Sub Saharan

The role of climate change on mycotoxin profile and activity was reviewed. The unprecedented spread and relocation experienced by some regulated mycotoxins on food and feed items were investigated. Aspergillus species and aflatoxin, originally associated with tropical and subtropical climate characteristics of Sub-Saharan Africa are now comfortable guests in temperate zones. The same applies to Fusarium and Penicilium species, earlier thought to be strictly specific to temperate regions of Europe, now encountered in tropical Africa, with their toxins like zearalenone and trichothecenes, particularly in recent surveillance studies. This review is an update on the unstable trend on a global mycotoxin map with reference to the obvious climatic dynamics, having Africa in view

scholarly journals Climate Signals in River Flood Damages Emerge under Sound Regional Disaggregation

2020 ◽  
Author(s):  
Inga Sauer ◽  
Ronja Reese ◽  
Christian Otto ◽  
Tobias Geiger ◽  
Sven N. Willner ◽  
...  
Keyword(s):  
Climate Change ◽  
Sub Saharan Africa ◽  
Climate Signal ◽  
Hazard Exposure ◽  
River Flood ◽  
Individual Contributions ◽  
Climate Signals ◽  
Sub Saharan ◽  
Induced Changes

Abstract Climate change highly affects precipitation patterns. Here, we address the question whether the signal of climate change is already detectable in time series of reported damages caused by fluvial floods. Building on hazard indicators from process-based hydrological simulations, we develop an empirical model to reconstruct reported damages and quantify individual contributions of climate-induced changes in hazard, exposure, and vulnerability to observed trends. Across nine world regions, trends in damages are generally dominated by increasing exposure and decreasing vulnerability, with the latter being most pronounced in less developed regions. However, accounting for heterogeneity in changes of hazard frequency and magnitude within a region, a climate signal is detectable, especially in South and Sub-Saharan Africa as well as in Latin America. Damages in most regions are subject to a monotonous trend even after accounting for natural variability where an effect of long-term global warming can not yet be distinguished from a potential influence from multidecadal oscillations.

Demography and the Future of Democracy

2020 ◽  
Vol 18 (3) ◽  
pp. 867-880
Author(s):  
Jack A. Goldstone ◽  
Larry Diamond
Keyword(s):  
Climate Change ◽  
Negative Impact ◽  
The United States ◽  
Sub Saharan Africa ◽  
Global Democracy ◽  
Liberal Democratic ◽  
The World ◽  
Sub Saharan ◽  
Long Term Trend

The world is in the midst of a demographic recession. This counters what should be a long-term trend toward greater democracy. Recent research has shown that progress toward stable democracy is strongly associated with progress in the demographic transition. Since most of the world is rapidly dropping in fertility as more countries complete this transition, democracy should be spreading. However, a resurgence of anxiety, nationalism, and support for strong-man governance is associated with sudden waves of immigration from unfamiliar sources. Because certain parts of the world—mainly Central America, sub-Saharan Africa, and the Middle East—still have very young and rapidly growing populations who suffer from poor economic prospects, adverse climate change, and bad governance, those regions are sending waves of migrants seeking asylum to Europe and the United States, raising anxieties that undermine liberal democratic governance. Global democracy is thus being tugged in opposing directions by current demographic trends. Improving governance in poorer countries to cope with the negative impact of climate change and to create better economic prospects, as well as efforts to reduce fertility, are essential to diminish the surges of migrants and restore the impetus toward democracy that should prevail in mature societies.

scholarly journals Predicting the impacts of climate change on groundwater recharge in an arid environment using modeling approach

2019 ◽  
Vol 11 (1) ◽  
pp. 88-99 ◽  
Author(s):  
Reza Ghazavi ◽  
Haidar Ebrahimi
Keyword(s):  
Climate Change ◽  
Groundwater Recharge ◽  
Flow Model ◽  
Moving Average ◽  
Arid Environment ◽  
Weather Data ◽  
Climate Scenarios ◽  
Content Type ◽  
Average Rainfall

Purpose Groundwater is an important source of water supply in arid and semi-arid areas. The purpose of this study is to predict the impact of climate change on groundwater recharge in an arid environment in Ilam Province, west of Iran. Design/methodology/approach A three-dimensional transient groundwater flow model (modular finite difference groundwater FLOW model: MODFLOW) was used to simulate the impacts of three climate scenarios (i.e. an average of a long-term rainfall, predicted rainfall in 2015-2030 and three years moving average rainfall) on groundwater recharge and groundwater levels. Various climate scenarios in Long Ashton Research Station Weather Generator were applied to predict weather data. Findings HadCM3 climatic model and A2 emission scenario were selected as the best methods for weather data generation. Based on the results of these models, annual precipitation will decrease by 3 per cent during 2015-2030. For three emission scenarios, i.e. an average of a long-term rainfall, predicted rainfall in 2015-2030 and three years moving average rainfall, precipitation in 2030 is estimated to be 265, 257 and 247 mm, respectively. For the studied aquifer, predicted recharge will decrease compared to recharge calculated based on the average of long-term rainfall. Originality/value The decline of groundwater level in the study area was 11.45 m during the past 24 years or 0.48 m/year. Annual groundwater depletion should increase to 0.75 m in the coming 16 years via climate change. Climate change adaptation policies in the basin should include changing the crop type, as well as water productivity and irrigation efficiency enhancement at the farm and regional scales.

Rangeland ecology.

2020 ◽  
pp. 395-422
Author(s):  
Polly Ericksen ◽  
Pierre Hiernaux ◽  
Augustine Ayantunde ◽  
Philip K. Thornton ◽  
Jason Sircely ◽  
...  
Keyword(s):  
Climate Change ◽  
Research Agenda ◽  
Rangeland Management ◽  
Sub Saharan Africa ◽  
Rangeland Ecology ◽  
Development Interventions ◽  
Sub Saharan ◽  
Donor Interest ◽  
Semi Arid

Abstract Rangelands research in arid and semi-arid sub-Saharan Africa has been reinvigorated by renewed government and donor interest in pastoral livelihoods. The challenges facing productive rangelands remain competition over resources, which has been exacerbated by armed conflict; overuse of some rangelands as fragmentation continues; and the failure of many technical and governance interventions. The unresolved development challenges of pastoralism in East and West Africa make it essential to renew long-term empirical research to understand rangeland dynamics and to develop appropriate public policies. The rangelands research agenda at the International Livestock Research Institue focuses on: (i) governance for better rangeland management; (ii) monitoring rangeland conditions to improve development interventions; (iii) understanding the interactions between climate change and the rangelands; and (iv) improving rangelands productivity for pastoral resilience.

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