Quantifying Focused Groundwater Recharge Induced by Irrigation Surface Water Reservoirs in Crystalline Basement Areas for Complementary Irrigation

Through the practice of irrigation, surface water reservoirs (SWRs) contribute to the socio-economic development and food production activities of populations in Sub-Saharan Africa (SSA). However, they tend to dry up prematurely. One solution to circumvent these irrigation water shortages is to ensure their conjunctive use with groundwater. The objective of this study is to better understand the contribution of SWRs to groundwater recharge and to determine if groundwater may be considered as a complementary local resource for irrigation. The study was carried out on two watersheds in Burkina Faso, Kierma and Mogtedo. The spatiotemporal analysis of piezometric and SWRs level records coupled with physico-chemical analyses of water was used to characterize exchanges between SWRs and groundwater. The regional groundwater recharge at the scale of the watersheds was assessed. At the SWRs scale, a water balance methodology was developed and used to estimate focused recharge. The results show that SWRs interact almost continuously with groundwater and contribute focused recharge. The magnitude of this recharge is a function of the geological context and the sediment texture of the SWRs. It is estimated at 5 mm/day in Kierma and 4 mm/day in Mogtédo. These values are higher than the natural recharge estimated at 0.2 mm/day in Kierma and 0.1 mm/day in Mogtédo. Additionally, the values of hydraulic conductivity are between 0.01 and 2 m/day in Kierma and between 1 × 10−4 and 0.2 m/day in Mogtédo. These conductivities could allow pumping in large-diameter hand-dug wells with a significant yield between 0.5 and 120 m3/day in Kierma and between 0 and 10 m3/day in Mogtédo to palliate the early drying up of the SWRs.

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Effect of dynamically varying zone-based hedging policies on the operational performance of surface water reservoirs during climate change

Geological Society London Special Publications ◽

10.1144/sp488.1 ◽

2018 ◽

Vol 488 (1) ◽

pp. 277-289 ◽

Cited By ~ 3

Author(s):

Adebayo J. Adeloye ◽

Bankaru-Swamy Soundharajan

Keyword(s):

Climate Change ◽

Surface Water ◽

Operational Performance ◽

Dynamic Hedging ◽

Water Reservoirs ◽

Complex Dynamic ◽

Water Shortages ◽

Operational Conditions ◽

Static Hedging ◽

The Impact

AbstractHedging is universally recognized as a useful operational practice in surface water reservoirs to temporally redistribute water supplies and thereby avoid large, crippling water shortages. When based on the zones of available water in storage, hedging has traditionally involved a static rationing (i.e. supply to demand) ratio. However, given the usual seasonality of reservoir inflows, it is also possible that hedging could be dynamic with seasonally varying rationing ratios. This study examined the effect of static and dynamic hedging policies on the performance of the Pong reservoir in India during a period of climate change. The results show that the reservoir vulnerability was unacceptably high (≥60%) without hedging and that this vulnerability further deteriorated as the catchment became drier due to projected climate change. The time- and volume-based reliabilities were acceptable. The introduction of static hedging drastically reduced the vulnerability to <25%, although the hedging reduction in the water supplied during normal operational conditions was only 17%. Further analyses with dynamic hedging provided only modest improvements in vulnerability. The significance of this study is its demonstration of the effectiveness of hedging in offsetting the impact of water shortages caused by climate change and the fact that static hedging can match more complex dynamic hedging policies.

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Focused groundwater recharge in a dryland environment: hydrometric and isotopic evidence from central Tanzania

10.5194/egusphere-egu2020-12214 ◽

2020 ◽

Author(s):

David Seddon ◽

Japhet J. Kashaigili ◽

Richard G. Taylor ◽

Mark O. Cuthbert ◽

Lucas Mihale ◽

...

Keyword(s):

Groundwater Recharge ◽

Surface Waters ◽

Poverty Alleviation ◽

Managed Aquifer Recharge ◽

Sub Saharan Africa ◽

Aquifer Recharge ◽

Ephemeral Stream ◽

Groundwater Levels ◽

Sub Saharan ◽

Semi Arid

Groundwater, and its replenishment via recharge, is critical to livelihoods and poverty alleviation in drylands of sub-Saharan Africa and beyond, yet the processes by which groundwater is replenished remain inadequately observed and resolved. Here, we present three lines of evidence, from an extensively-monitored wellfield in central semi-arid Tanzania, indicating focused groundwater recharge occurring via leakage from episodic, ephemeral stream discharges. First, the duration of ephemeral streamflow observed from daily records from 2007 to 2016 correlates strongly (R2 = 0.85) with the magnitude of groundwater recharge events observed and estimated from piezometric observations. Second, high-resolution (hourly) monitoring of groundwater levels and stream stage, established in advance of the 2015-16 El Ni&#241;o, shows the formation and decay of groundwater mounds beneath episodically inundated adjacent streambeds. Third, stable-isotope ratios of O and H of groundwater and precipitation as well as perennial and ephemeral surface waters trace the origin of groundwater to ephemeral stream discharges. The identification and characterisation of focused groundwater recharge have important implications not only, locally, for protecting and potentially augmenting replenishment of a wellfield supplying the capital of Tanzania through Managed Aquifer Recharge but also, more widely, in understanding and modelling groundwater recharge in dryland environments.

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Impact of physico-chemical parameters on zooplankton diversity of freshwater reservoirs around Amravati District, Maharashtra

Environment Conservation Journal ◽

10.36953/ecj.2013.14322 ◽

2013 ◽

Vol 14 (3) ◽

pp. 131-135

Author(s):

K. B. Sangve

Keyword(s):

Surface Water ◽

Impact Assessment ◽

Indicator Species ◽

Chemical Characteristics ◽

Chemical Parameters ◽

Water Reservoirs ◽

Tolerant Species ◽

Physico Chemical ◽

Pollution Indicator ◽

Course Of Study

Impact assessment was carried out on the zooplankton diversity of Pohra, Wadali and Chhatri surface water reservoirs around Amravati with respect to their physico-chemical characteristics. During course of study zooplankton were represented by five major groups i.e. Ostracoda, Rotifera, Cladocera, Protozoa and Copepoda. High value of physico-chemical parameters and low zooplankton diversity were recorded in Chhatri reservoir, moderate in Wadali lake and low value of physico-chemical parameters and high zooplankton diversity were recorded in Pohara lake. The Chhatri reservoir was found to contain most of the pollution indicator species. Wadali reservoir also exhibited few pollution tolerant species. Prominent among them were Ceratodaphnia, Lepadella, Monostyla, Rotarria, Cyclops, Diaptomus and Ectocyclops. The water in all the reservoirs was found to be eutrophic in the order of Pohra > Wadali > Chhatri.

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Successful small-scale irrigation or environmental destruction? The political ecology of competing claims on water in the Uluguru Mountains,Tanzania

Journal of Political Ecology ◽

10.2458/v24i1.20881 ◽

2017 ◽

Vol 24 (1) ◽

pp. 406 ◽

Cited By ~ 6

Author(s):

Elizabeth Harrison ◽

Anna Mdee

Keyword(s):

Political Ecology ◽

Sub Saharan Africa ◽

External Support ◽

Small Scale ◽

The Political ◽

Water Shortages ◽

Uluguru Mountains ◽

Sub Saharan ◽

Small Scale Farmers ◽

Nearby City

Abstract In the Uluguru Mountains of Tanzania, an expansion in informal hosepipe irrigation by small-scale farmers has enabled the development of horticulture, and resulted in improvements in farmers' livelihoods. This has largely taken place independently of external support, and can be seen as an example of the 'private' irrigation that is increasingly viewed as important for sub-Saharan Africa. However, these activities are seen by representatives of government and some donors as the cause of environmental degradation and water shortages downstream, especially in the nearby city of Morogoro. As a result, there have been attempts to evict the farmers from the mountain. Negative narratives persist and the farmers on the mountainside are portrayed as a problem to be 'solved.' This article explores these tensions, contributing to debates about the formalization of water management arrangements and the place of the state in regulating and adjudicating rights to access water. We argue that a focus on legality and formalization serves to obscure the political nature of competing claims on resources that the case illustrates. Keywords: irrigation; Tanzania; ethnography; political ecology; water

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The Rock Art of Sub-Saharan Africa

The Oxford Handbook of the Archaeology and Anthropology of Rock Art ◽

10.1093/oxfordhb/9780190607357.013.25 ◽

2018 ◽

Author(s):

Jean-Loïc Le Quellec

Keyword(s):

Rock Art ◽

Sub Saharan Africa ◽

Chemical Analyses ◽

New Techniques ◽

History Of Research ◽

Physico Chemical ◽

History Of ◽

Sub Saharan ◽

Key Dimensions ◽

Art Research

This chapter presents key dimensions of sub-Saharan African rock art (pictograms and petroglyphs). Particular attention is paid to recent approaches, the application of physico-chemical analyses, and stylistic determinations used to establish reliable chronologies. Stylistic approaches have been particularly influential in the interpretation of rock imagery, as has the identification of specific motifs (such as loincloths and aprons) that serve to indicate ritual and initiatory roles, particularly for women. The preservation of rock art and access to sites are topics of renewed concern that tend to increasingly involve local communities. In sub-Saharan Africa as in other parts of the world, rock art research is well poised to build on a long history of research, and to benefit from new techniques such as digital enhancement that are likely to considerably improve knowledge and increase the known corpus of art.

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Impacts of Climate Variability and Drought on Surface Water Resources in Sub-Saharan Africa Using Remote Sensing: A Review

Remote Sensing ◽

10.3390/rs12244184 ◽

2020 ◽

Vol 12 (24) ◽

pp. 4184

Author(s):

Trisha Deevia Bhaga ◽

Timothy Dube ◽

Munyaradzi Davis Shekede ◽

Cletah Shoko

Keyword(s):

Remote Sensing ◽

Surface Water ◽

Water Resources ◽

Climate Variability ◽

Hydrological Drought ◽

Sub Saharan Africa ◽

Water Index ◽

Surface Water Resources ◽

Normalized Difference Water Index ◽

Sub Saharan

Climate variability and recurrent droughts have caused remarkable strain on water resources in most regions across the globe, with the arid and semi-arid areas being the hardest hit. The impacts have been notable on surface water resources, which are already under threat from massive abstractions due to increased demand, as well as poor conservation and unsustainable land management practices. Drought and climate variability, as well as their associated impacts on water resources, have gained increased attention in recent decades as nations seek to enhance mitigation and adaptation mechanisms. Although the use of satellite technologies has, of late, gained prominence in generating timely and spatially explicit information on drought and climate variability impacts across different regions, they are somewhat hampered by difficulties in detecting drought evolution due to its complex nature, varying scales, the magnitude of its occurrence, and inherent data gaps. Currently, a number of studies have been conducted to monitor and assess the impacts of climate variability and droughts on water resources in sub-Saharan Africa using different remotely sensed and in-situ datasets. This study therefore provides a detailed overview of the progress made in tracking droughts using remote sensing, including its relevance in monitoring climate variability and hydrological drought impacts on surface water resources in sub-Saharan Africa. The paper further discusses traditional and remote sensing methods of monitoring climate variability, hydrological drought, and water resources, tracking their application and key challenges, with a particular emphasis on sub-Saharan Africa. Additionally, characteristics and limitations of various remote sensors, as well as drought and surface water indices, namely, the Standardized Precipitation Index (SPI), Palmer Drought Severity Index (PDSI), Normalized Difference Vegetation (NDVI), Vegetation Condition Index (VCI), and Water Requirement Satisfaction Index (WRSI), Normalized Difference Water Index (NDWI), Modified Normalized Difference Water Index (MNDWI), Land Surface Water Index (LSWI+5), Modified Normalized Difference Water Index (MNDWI+5), Automated Water Extraction Index (shadow) (AWEIsh), and Automated Water Extraction Index (non-shadow) (AWEInsh), and their relevance in climate variability and drought monitoring are discussed. Additionally, key scientific research strides and knowledge gaps for further investigations are highlighted. While progress has been made in advancing the application of remote sensing in water resources, this review indicates the need for further studies on assessing drought and climate variability impacts on water resources, especially in the context of climate change and increased water demand. The results from this study suggests that Landsat-8 and Sentinel-2 satellite data are likely to be best suited to monitor climate variability, hydrological drought, and surface water bodies, due to their availability at relatively low cost, impressive spectral, spatial, and temporal characteristics. The most effective drought and water indices are SPI, PDSI, NDVI, VCI, NDWI, MNDWI, MNDWI+5, AWEIsh, and AWEInsh. Overall, the findings of this study emphasize the increasing role and potential of remote sensing in generating spatially explicit information on drought and climate variability impacts on surface water resources. However, there is a need for future studies to consider spatial data integration techniques, radar data, precipitation, cloud computing, and machine learning or artificial intelligence (AI) techniques to improve on understanding climate and drought impacts on water resources across various scales.

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Urbanization and Floods in Sub-Saharan Africa: Spatiotemporal Study and Analysis of Vulnerability Factors—Case of Antananarivo Agglomeration (Madagascar)

Water ◽

10.3390/w13020149 ◽

2021 ◽

Vol 13 (2) ◽

pp. 149

Author(s):

Fenosoa Nantenaina Ramiaramanana ◽

Jacques Teller

Keyword(s):

Urban Areas ◽

Urban Expansion ◽

Spatiotemporal Analysis ◽

Natural Increase ◽

Economic Resources ◽

Sub Saharan Africa ◽

High Rate ◽

Vulnerable Groups ◽

Drainage Networks ◽

Sub Saharan

Flooding is currently one of the major threats to cities in Sub-Saharan Africa (SSA). The demographic change caused by the high rate of natural increase, combined with the migration toward cities, leads to a strong demand for housing and promotes urbanization. Given the insufficiency or absence of adequate planning, many constructions are installed in flood-prone zones, often without adequate infrastructure, especially drainage systems. This makes them very vulnerable. Our research consists of carrying out a spatiotemporal analysis of the agglomeration of Antananarivo (Madagascar). It shows that urbanization leads to increased exposure of populations and constructions to floods. There is a pressure on land in flood-prone zones due to the exponential growth of the population at the agglomeration level. Some 32% of the population of the Antananarivo agglomeration lived in flood-prone zones in 2018. An analysis of the evolution of built spaces from 1953 to 2017 highlights that urban expansion was intense over those years (6.1% yearly increase of built areas). This expansion triggered the construction of built areas in flood-prone zones, which evolved from 399 ha in 1953 to 3675 ha in 2017. In 2017, 23% of the buildings in the agglomeration, i.e., almost one out of every four buildings, were in flood-prone zones. A share of the urban expansion in flood-prone zones is related to informal developments that gather highly vulnerable groups with very little in terms of economic resources. Better integration of flood risk management in spatial planning policies thus appears to be an essential step to guide decisions so as to coordinate the development of urban areas and drainage networks in a sustainable way, considering the vulnerability of the population living in the most exposed areas.

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Coping with Erratic Water Supply in Small Towns

Population Growth and Rapid Urbanization in the Developing World - Advances in Electronic Government, Digital Divide, and Regional Development ◽

10.4018/978-1-5225-0187-9.ch010 ◽

2016 ◽

pp. 192-208

Author(s):

Never Mujere ◽

Trust Saidi

Keyword(s):

Water Supply ◽

Small Towns ◽

Economic Effects ◽

Sub Saharan Africa ◽

Collaborative Approach ◽

Technical Expertise ◽

Water Shortages ◽

Urban Settlements ◽

Sub Saharan ◽

Artificial Water

In Sub-Saharan Africa, artificial water shortages are common due to financial constraints impeding the procurement of adequate equipment to harness water. Most previous studies on variability of water supply in sub-Saharan Africa have largely focused on large urban settlements such as cities and towns. Thus, this chapter therefore presents findings from a study conducted to assess the causes and effects of erratic water supply in Kamwaza Township in Zimbabwe as well as to establish and evaluate coping strategies to the problem of erratic water supply. From the study, it was also observed that erratic water supply has socio-economic effects and these include high incidences of diseases, disruption of service delivery at institutions such as the hospital, clinic and schools and retarded infrastructural development. The study recommends a collaborative approach from all stakeholders in solving the problem of erratic water supply by upgrading the pumping station, repairing leaking pipes, employing people with technical expertise and sinking boreholes.

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Managing ground and surface water resources using innovative methods in rural and urban areas of Sub-Saharan Africa

Physics and Chemistry of the Earth Parts A/B/C ◽

10.1016/j.pce.2016.05.004 ◽

2016 ◽

Vol 93 ◽

pp. 1

Author(s):

Benjamin Mapani ◽

Lapologang Magole ◽

Hodson Makurira ◽

Dominic Mazvimavi ◽

Maideyi Meck ◽

...

Keyword(s):

Surface Water ◽

Water Resources ◽

Urban Areas ◽

Sub Saharan Africa ◽

Rural And Urban Areas ◽

Surface Water Resources ◽

Innovative Methods ◽

Rural And Urban ◽

Sub Saharan

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The Use of Desalination Technologies to Alleviate Water Shortages in Sub-Saharan Africa (SSA): Challenges and Recommendations

Urban Studies and Public Administration ◽

10.22158/uspa.v1n1p101 ◽

2018 ◽

Vol 1 (1) ◽

pp. 101

Author(s):

Obeta Michael Chukwuma

Keyword(s):

Management Strategies ◽

Sub Saharan Africa ◽

Water Supply Systems ◽

Water Shortages ◽

Critical Issues ◽

Sub Saharan ◽

Using Data ◽

Desalination Plants ◽

Supply Systems ◽

Ssa Countries

Water scarcity is a major and growing problem in SSA. A SSA country (South Africa) has adopted desalination as a strategy for dealing with water shortages; while the construction of new desalination plants have been proposed in some others (Ghana, Namibia and Cape Verde). This review paper examines the use of desalination technologies for augmenting supplies in sixteen SSA countries, using data derived mainly from published literature. Results reveal that the usage of desalinated freshwater to augment supplies in the region is relatively recent; however the usage is on the increase, especially in countries with arid climate. Several factors including massive failures of public water supply systems, increases in the demand for freshwater, rapid and high rates of urbanization, population growth and the reoccurring droughts account for increases in the demand for desalination technologies in SSA. Many critical issues and constraints make the desalination option neither the most feasible nor a priority for water supplies within the humid parts of SSA. The paper recommends that for quality and sustainable service delivery to be attained in the region, governments should develop alternative freshwater sources, address infrastructural decay, employ new management strategies in the water sector and distribute water infrastructure equitably.

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