Early warnings of hazardous thunderstorms over Lake Victoria

Thiery, Wim; Gudmundsson, Lukas; Bedka, Kristopher M.; Semazzi, Fredrick H. M.; Lhermitte, Stef; Willems, Patrick; Lipzig, Nicole Van

doi:10.1088/1748-9326/aa7521

Cited by 44 publications

(31 citation statements)

References 32 publications

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“…To reduce the number of casualties from weather related events, the Lake Victoria Intense storm Early Warning System (VIEWS) has been developed to forecast hazardous thunderstorms over the lake at night (Thiery et al 2017). For the information emerging from these systems to be successfully used at community level, it is critical to ensure that they meet the needs of the users.…”

Section: Disaster Managementmentioning

confidence: 99%

Identifying user needs for weather and climate services to enhance resilience to climate shocks in sub-Saharan Africa

Nkiaka

Taylor

Dougill

et al. 2019

Environ. Res. Lett.

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The vulnerability of social-ecological systems in sub-Saharan Africa (SSA) to climate variability and change means that there is an urgent need to better integrate weather and climate information into societal decision-making processes. Long-term climate adaptation in these regions has received increasing attention, with recent initiatives aiming to increase resilience to climate change at timescales of years to decades. Less focus has been given to weather and short-term climate information. However, users are principally interested in shorter timescales (hours to seasons) where actions can immediately reduce the impacts of severe weather events. Focusing on the priority sectors of agriculture and food security, water and disaster management, this paper uses a systematic literature review approach to analyse 61 empirical case studies drawn from academic literature and projects across SSA. We identify the main users of climate services and outline current practices and reported benefits. Barriers that impede the delivery and uptake of climate services are identified and potential strategies for overcoming them outlined based on the reporting of successful practices. Our findings show that greater capacity building of personnel working for National Meteorological and Hydrological Services and Agricultural Extension staff and reinforcing and sustaining collaboration between different stakeholders (climate scientists, hydrologists, extension workers, farmers and other user groups), are essential factors for improving the uptake and utility of weather and climate services to enhance resilience to climate shocks in SSA.

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Section: Disaster Managementmentioning

confidence: 99%

Identifying user needs for weather and climate services to enhance resilience to climate shocks in sub-Saharan Africa

Nkiaka

Taylor

Dougill

et al. 2019

Environ. Res. Lett.

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“…Global evaporation observation datasets like LandFlux-EVAL and the Global Land Evaporation Amsterdam Model (GLEAM) do not resolve evaporation above large water surfaces like Lake Victoria (Mueller et al, 2013;Martens et al, 2017). Therefore, evaporation is assessed by using the latent heat flux (LHF) output of the regional climate model COSMO-CLM 2 (Davin and Seneviratne, 2012), of which the highresolution downscaling (∼ 7 km) with the ERA-Interim reanalysis provides an adequate representation of the climate over and around the African Great Lakes (Thiery et al, 2015(Thiery et al, , 2016(Thiery et al, , 2017Docquier et al, 2016;Jacobs et al, 2016Jacobs et al, , 2017Jacobs et al, , 2018Delandmeter et al, 2018). Here, the annual evaporation climatology is estimated from daily LHF of the COSMO-CLM 2 model output for 1996-2008 and applied to each year of the observational WB analysis period.…”

Section: Evaporation Datamentioning

confidence: 99%

Modelling the water balance of Lake Victoria (East Africa) – Part 1: Observational analysis

Vanderkelen

Lipzig

Thiery

2018

Hydrol. Earth Syst. Sci.

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Abstract. Lake Victoria is the largest lake in Africa and one of the two major sources of the Nile river. The water level of Lake Victoria is determined by its water balance, consisting of precipitation on the lake, evaporation from the lake, inflow from tributary rivers and lake outflow, controlled by two hydropower dams. Due to a scarcity of in situ observations, previous estimates of individual water balance terms are characterized by substantial uncertainties, which means that the water balance is often not closed independently. In this first part of a two-paper series, we present a water balance model for Lake Victoria, using state-of-the-art remote sensing observations, high-resolution reanalysis downscaling and outflow values recorded at the dam. The uncalibrated computation of the individual water balance terms yields lake level fluctuations that closely match the levels retrieved from satellite altimetry. Precipitation is the main cause of seasonal and interannual lake level fluctuations, and on average causes the lake level to rise from May to July and to fall from August to December. Finally, our results indicate that the 2004–2005 drop in lake level can be about half attributed to a drought in the Lake Victoria Basin and about half to an enhanced outflow, highlighting the sensitivity of the lake level to human operations at the outflow dam.

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“…Over the whole CORDEX-Africa domain, all RCMs capture the main elements of the seasonal mean precipitation distribution and its cycle, but also significant biases are present in individual models depending on season and region (Nikulin et al, 2012;Kim et al, 2014). Here, a specific region is investigated wherein lakes act as main driving features of the regional climate (Thiery et al, 2015(Thiery et al, , 2016(Thiery et al, , 2017Docquier et al, 2016). Therefore, model performance is primarily determined by how lakes are resolved in the models.…”

Section: Model Quality and Projected Changesmentioning

confidence: 99%

Modelling the water balance of Lake Victoria (East Africa) – Part 2: Future projections

Vanderkelen

Lipzig

Thiery

2018

Hydrol. Earth Syst. Sci.

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Abstract. Lake Victoria, the second largest freshwater lake in the world, is one of the major sources of the Nile river. The outlet to the Nile is controlled by two hydropower dams of which the allowed discharge is dictated by the Agreed Curve, an equation relating outflow to lake level. Some regional climate models project a decrease in precipitation and an increase in evaporation over Lake Victoria, with potential important implications for its water balance and resulting level. Yet, little is known about the potential consequences of climate change for the water balance of Lake Victoria. In this second part of a two-paper series, we feed a new water balance model for Lake Victoria presented in the first part with climate simulations available through the COordinated Regional Climate Downscaling Experiment (CORDEX) Africa framework. Our results reveal that most regional climate models are not capable of giving a realistic representation of the water balance of Lake Victoria and therefore require bias correction. For two emission scenarios (RCPs 4.5 and 8.5), the decrease in precipitation over the lake and an increase in evaporation are compensated by an increase in basin precipitation leading to more inflow. The future lake level projections show that the dam management scenario and not the emission scenario is the main controlling factor of the future water level evolution. Moreover, inter-model uncertainties are larger than emission scenario uncertainties. The comparison of four idealized future management scenarios pursuing certain policy objectives (electricity generation, navigation reliability and environmental conservation) uncovers that the only sustainable management scenario is mimicking natural lake level fluctuations by regulating outflow according to the Agreed Curve. The associated outflow encompasses, however, ranges from 14 m3 day−1 (−85 %) to 200 m3 day−1 (+100 %) within this ensemble, highlighting that future hydropower generation and downstream water availability may strongly change in the next decades even if dam management adheres to he Agreed Curve. Our results overall underline that managing the dam according to the Agreed Curve is a key prerequisite for sustainable future lake levels, but that under this management scenario, climate change might potentially induce profound changes in lake level and outflow volume.

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Early warnings of hazardous thunderstorms over Lake Victoria

Cited by 44 publications

References 32 publications

Identifying user needs for weather and climate services to enhance resilience to climate shocks in sub-Saharan Africa

Identifying user needs for weather and climate services to enhance resilience to climate shocks in sub-Saharan Africa

Modelling the water balance of Lake Victoria (East Africa) – Part 1: Observational analysis

Modelling the water balance of Lake Victoria (East Africa) – Part 2: Future projections

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