ALBERT

Description: To feed the growing population, achieve the Sustainable Development Goals, and fulfil the commitments of the Paris Agreement, West African countries need to invest in agricultural development and renewable energy, among other sectors. Irrigated agriculture, feeding millions of people, and hydropower, generating clean electricity, depend on water availability and compete for the resource. In the Volta basin, the planned 105 000 ha of irrigated land in Burkina Faso and Ghana could feed hundreds of thousands of people. However, irrigation in the dry season depends on upstream dams that change the river’s flow regime from intermittent to permanent, and at the same time irrigation water is no longer available for hydropower generation. Using an integrated eco-hydrological and water management model, we investigated the water demand and supply of three planned irrigation projects and the impacts of the planned Pwalugu multi-purpose dam on the hydropower potentials and water availability in the entire Volta basin. We found that future irrigation withdrawals would reduce the hydropower potential in the Volta basin by 79 GWh a−1 and the operation of Pwalugu by another 86 GWh a−1. Hence, Pwalugu contributes only about 101 GWh a−1 of its potential of 187 GWh a−1. Under climate change simulations, using an ensemble of eight bias-adjusted and downscaled GCMs, irrigation demand surprisingly did not increase. The higher evaporation losses due to higher temperatures were compensated by increasing precipitation while favouring hydropower generation. However, water availability at the irrigation site in Burkina Faso is clearly at its limit, while capacity in Ghana is not yet exhausted. Due to hydro-climatic differences in the Volta basin, the cost of irrigating one hectare of land in terms of lost hydropower potential follows a north-south gradient from the hot and dry north to the humid south. Nevertheless, food production should have priority over hydropower, which can be compensated by other renewables energies.

Description: Hydropower is the world’s largest and most widely used renewable energy source. It is expected that climate and land use changes, as well as hydraulic engineering measures, will have profound impacts on future hydropower potential. In this study, the hydropower potential of the Bafing watershed was estimated for the near future (P1: 2035–2065) and the far future (P2: 2065–2095). For this purpose, the moderate scenario ssp 126 and the medium–high scenario ssp 370 were used to explore possible climate impacts. In three management scenarios, we tested the interaction of the existing Manantali Dam with two planned dams (Koukoutamba and Boureya) using an ecohydrological water management model. The results show that, under ssp 126, a 6% increase in annual river flow would result in a 3% increase in hydropower potential in the near future compared with the historical period of 1984–2014. In the far future, the annual river flow would decrease by 6%, resulting in an 8% decrease in hydropower potential. Under ssp 370, the hydropower potential would decrease by 0.7% and 14% in the near and far future, respectively. The investment in the planned dams has benefits, such as an increase in hydropower potential and improved flood protection. However, the dams will be negatively affected by climate change in the future (except in the near future (P1) under ssp 126), and their operation will result in hydropower potential losses of about 11% at the Manantali Dam. Therefore, to mitigate the effects of climate change and adjust the operation of the three dams, it is essential to develop new adaptation measures through an optimization program or an energy mix combining hydro, solar, and wind power.

Description: Land use and Land cover change (LULCC) is a major global problem, and projecting change is critical for policy decision-making. Understanding LULCCs at the watershed level is essential for transboundary river basin management. The present study aims to analyse the past and future LULCCs in two significant watersheds of the Senegal River basin (SRB) in West Africa: Bafing and Faleme. This study used Landsat images from 1986, 2006 and 2020 and the Random Forest classification method to analyze past LULCCs in these two watersheds. The results revealed: In Bafing, vegetation, settlement, agricultural areas and water increased, while the bareground decreased significantly between 1986-2020. In Faleme, two periods have different trends. Between 1986-2006, vegetation, settlement, agricultural areas and water increased, while bareground decreased. Between 2006-2020, settlement increased, while vegetation, agricul-tural areas, water and bareground decreased. To predict LULCCs in 2050 under business-as- usual assumptions, the Multilayer Perceptron and Marcov Chain model (MLP-MC) was used. The MLP-MC shows better results on Bafing than on Faleme but without questioning its application on the two watersheds. Bafing has seen a trend towards ”more people, more trees”, while Faleme has seen a trend towards ”more people, more deforestation”. These results contribute to develop appropriate land management policies and strategies to achieve or to maintain sustainable development in the SRB.

Description: Ethiopia, Sudan and Egypt are currently embroiled in a politically charged conflict that surrounds the soon-to-be-completed Grand Ethiopian Renaissance Dam (GERD), with Ethiopia’s energy objectives purportedly conflicting with the water needs in Sudan and Egypt. Here we show that the multiple political and environmental challenges that surround GERD could be mitigated by explicitly coupling its operation to variable solar and wind power, which would create an incentive for Ethiopia to retain a seasonality in the Blue Nile flow. We found that this could deliver fivefold benefits across the three countries: decarbonizing power generation in the Eastern Africa Power Pool; allowing compliance with Sudan’s environmental flow needs; optimizing GERD’s infrastructure use; harmonizing the yearly refilling schedules of GERD and Egypt’s High Aswan Dam; and supporting a strong diversification of Ethiopian power generation for domestic use and for Eastern Africa Power Pool exports. These results argue for an explicit integration of complementary hydro, solar and wind power strategies in GERD operation and Eastern Africa Power Pool expansion planning.

Description: Burkina Faso has a high socio-economic dependency on agriculture, a sector which is strongly influenced by weather-related factors and increasingly challenged by the impacts of climate change. Currently, only limited information on climate risks and its impacts is available for the agricultural sector in the country. Therefore, this study aims to provide a comprehensive climate risk analysis including a thorough evaluation of four potential adaptation strategies that can guide local decision makers on adaptation planning and implementation in Burkina Faso. The impact assessment consists of several steps including climate projections based on two emissions scenarios (SSP3-RCP7.0 and SSP1-RCP2.6), hydro-logical modelling on water availability changes, modelling and comparison of future yields of four widely used crops (maize, sorghum, millet and cowpeas) and an assessment of livestock production under future climate conditions. Based on the projected climate change impacts on agricultural production, four different adapta-tion strategies ((1) Integrated soil fertility ma-nagement (ISFM), (2) irrigation, (3) improved seeds and (4) climate information services (CIS)) suggested and selected by different national stakeholders were analysed regarding their potential to risk mitigation, (cost-)effectiveness and suitability for local conditions. The analyses have been further complemented by expert- and literature-based assessments, semi-structured key informant interviews and two stakeholder work-shops. The results show that the mean daily temperature is on the rise and projected to increase further by 0.6°C (2030) up to 1.1°C (2090) under SSP1-RCP2.6 and by 0.5°C (2030) up to 3.6°C (2090) under SSP3-RCP7.0 in reference to 2004, dependent on future greenhouse gas emissions. Some un-certainty exists for annual precipitation projections, with slight increases until 2050 followed by a slight decrease under SSP1-RCP2.6 and continuous increase under SSP3-RCP7.0 with high year-to-year variability. Projected impacts of cli-mate change on yields vary between regions and show partly opposing trends. Some regions in the north show increasing yields (up to +30% in SSP1-RCP2.6 and up to +20% in SSP3-RCP7.0), while few regions in the south present decreasing yields (down to -30% in SSP1-RCP2.6 and down to -20% in SSP3-RCP7.0). Crop models show that the areas suitable for cowpeas will decrease in Burkina Faso under future climate change conditions while the suitability for maize, millet and sorghum will remain stable. Moreover, the potential to produce multiple crops will become more and more difficult, which limits farmers’ diversification options. Regarding the livestock sector, it seems very likely that the grazing potential will decrease under both climate change scenarios with higher decreases under SSP1-RCP2.6 than under SSP3-RCP7.0. All four adaptation strategies were found to be economically beneficial, can have a high potential for risk mitigation and entail different co-benefits. Particularly, ISFM can be highly recommended for smallholder farmers, resulting in very positive effects for societies and environment. Irrigation and improved seeds have a high potential to improve livelihoods especially in Northern Burkina Faso, but are also complex, costly and support-intensive adaptation strategies. Lastly, CIS can support farmers to make informed decisions and thereby reduce the impact of climate risks. Generally, a combination of different adaptation strategies can entail additional benefits and active stakeholder engagement as well as participatory approaches are needed to ensure the feasibility and long-term sustainability of adaptation strategies. The findings of this study can help to inform national and local adaptation and agricultural development planning and investments in order to strengthen the resilience of the agricultural sector and especially of smallholder farmers against a changing climate.

Description: Niger has a high socio-economic dependency on agriculture which is strongly influenced by weather-related factors and highly vulnerable to climate change. Currently, only limited information on climate risks and its impacts is available for the agricultural sector in the country. Therefore, this study aims to provide a comprehensive climate risk analysis including a thorough evaluation of four potential adaptation strategies that can guide local decision makers on adaptation planning and implementation in Niger: (1) agroforestry and farmer managed natural regeneration (FMNR) of trees, (2) integrated soil fertility management (ISFM), (3) irrigation and (4) improved fodder management for livestock. The impact assessment includes climate projections based on two future emissions scenarios (SSP3-RCP7.0 and SSP1-RCP2.6), hydrological modelling on water availability, modelling and comparison of future yields of four dominant crops (sorghum, millet, maize and cowpeas) and an as-sessment of livestock production under future climate conditions. Based on the projected climate change impacts on agricultural production, the four adaptation strategies suggested by different national stakeholders were analysed regarding their potential to risk mitigation, cost-effectiveness and suitability for local conditions. The analyses have been complemented by expert- and literature-based assessments, semi-structured interviews and two stakeholder workshops. The results show that the mean daily temperature is projected to increase further in Niger, up to +1.3 °C (SSP1-RCP2.6) and +4.2 °C (SSP3-RCP7.0) by 2090, in reference to 2004. The mean annual precipitation sum is also projected to increase until 2050 under both emissions scenarios, with a slight decrease in the interannual variability. In the second half of the century, this trend in precipitation is likely to continue (SSP3-RCP7.0) or decrease slightly (SSP1-RCP2.6), while the year-to-year variability would increase. Greater annual rates of groundwater recharge due to increasing precipitation amounts and higher annual mean river discharge are expected until mid-century. Sorghum yields would decline in general, by 20-50% (SSP1-RCP2.6) or 40-75% (SSP3-RCP7.0) by 2090, compared to 2005. Crop models hinted at an increase in the suitability of sorghum and millet, and no significant change for maize and cowpeas in Niger under both emissions scenarios. In addition, the potential for multiple cropping would de-crease from mid-century, limiting farmers’ diversification options. Regarding the livestock sector, the grazing potential is likely to decrease in the south and increase in the central regions of Niger, under SSP1-RCP2.6, while it is expected to increase in the whole country under SSP3-RCP7.0. All four adaptation strategies were found to be economically beneficial, risk-independent, with a medium to high risk mitigation potential, and can bring about various co-benefits. FMNR practice can be highly recommended, as the upscaling potential is high and the climate resilience of local livelihoods will be strengthened. ISFM can help to improve water use efficiency and benefit from positive environmental and social outcomes. Irrigation has a medium potential to improve livelihoods of smallholder farmers but is also a support-intensive adaptation strategy that needs to be carefully implemented in order to avoid overexploitation of local water resources. Lastly, improved fodder management, especially al-falfa production, contributes to building up resilience of livestock farming systems and affects women and youth employment positively. Gener-ally, a combination of different adaptation strategies can yield additional benefits and active stake-holder engagement as well as participatory ap-proaches are needed to ensure the feasibility and sustainability of adaptation strategies. The findings of this study can help to inform national and local adaptation as well as development planning and investments in order to strengthen the climate resilience of the Nigerien agricultural sector and especially of smallholder farmers.

Description: Understanding land use and cover (LULC) dynamic is of great importance to sustainable development in Africa where deforestation is a common problem. This study aimed to assess the historical and future dynamics of LULC in the Nakambé River Basin. Landsat images were used to determine LULC dynamics for the years 1990, 2005 and 2020 using Random Forest classification system in Google Earth Engine while the predicted LULC of 2050 was simulated using the Markov Chain and Multi-Layer-Perceptron neural network in Land Change Modeler. The findings showed significant changes in LULC patterns. From 1990 to 2020, woodland and shrubland decreased by − 45% and − 68%, respectively, while water body, cropland and bare land/built-up increased by 233%, 51%, and 75%, correspondingly. From 2020 to 2050, the results revealed that under the Business-as-usual scenario, bare land/built-up and water bodies could continue to increase by 99% and 1%, respectively. However, cropland, shrubland, and woodland could decrease by − 32.61%, − 33.91%, and − 46.86%, respectively. Under the afforestation scenario, the contrary of Business-as-usual could occur. While woodland, shrubland, and cropland would increase by 22.24%, 51.57%, and 18.13%, correspondingly, between 2020 and 2050, the area covered by water bodies and bare land/built-up will decrease by − 6.16% and − 39.04%, respectively. The results of this research give an insight into past and future LULC dynamics in the Nakambé River Basin and suggest the need to strengthen the policies and actions for better land management in the region.

Description: This study presents the assessment of water scarcity associated with livestock production in a watershed in Southern Brazil where 115 farms (poultry, pig, and milk) are located. The methods, AWARE—available water remaining, and BWSI—blue water scarcity index, were applied monthly for the year 2018, and the characterization factors (CF) were regionalized into five scenarios evaluated by varying water availability and environmental water requirements. Livestock water consumption accounted for 94.1% of the total water consumed. Low water scarcity was observed in all scenarios (BWSI 〈 0). The highest CFAWARE was observed in scenario 3, ranging from 2.15 to 9.70 m3 world eq.m3, with higher water scarcity in summer. In the same scenario, pig production presented the highest annual average water scarcity footprint (WSF) of 90.3 m3 world eq./t carcass weight. Among milk production systems, pasture-based systems presented the highest annual average WSF of 52.7 m3 world eq./t fat protein corrected milk, surpassing semi-confined and confined systems by 12.4% and 3.5%, respectively. In scenario 3, poultry production presented an annual average WSF of 49.3 m3 world eq./t carcass weight. This study contributes knowledge to the livestock sector to perform the assessment of water scarcity.

Description: Das Einzugsgebiet der Spree ist hydrologisch und wasserwirtschaftlich stark von der Entwicklung von Braunkohleförderung und –verstromung, verbunden mit Grundwasserabsenkungen, Versickerungsverlusten, Sümpfungswassereinleitungen, Kühlwassernutzung in thermischen Kraftwerken sowie Flutung ehemaliger Tagebaue, einem komplexen wasserwirtschaftlichen System und einem kontinentalen Klima geprägt. Im Projekt GLOWA Elbe wurden für das Gebiet Szenarien des globalen Wandels für den Zeitraum 2003 bis 2052 analysiert. Im Jahre 2004 war es das Ergebnis, dass das gegenwärtige System der Wasserbewirtschaftung die Folgen des angenommenen Klimawandels nicht ausgleichen kann. Nach Ablauf der ersten 20 Jahre des Simulationszeitraumes 2003 bis 2022 werden in diesem Artikel die in GLOWA Elbe und weiteren Projekten erzeugten Ergebnisse sowie die genutzten Eingangsdaten, Szenarien und Modelle hinsichtlich ihrer Übereinstimmung mit beobachteten Abflüssen bzw. Witterungsverlauf analysiert. Es zeigt sich, dass die in den Projekten genutzten Bergbauszenarien der Entwicklung bis zum jetzigen Zeitpunkt entsprechen, während die Szenarien zur klimatischen Entwicklung zum Teil deutlich von den Beobachtungen abweichen. Letzteres hat erhebliche Konsequenzen für die simulierten Abflüsse. Weiterhin kann gezeigt werden, dass auch in stark anthropogen überprägten Flusseinzugsgebieten die Auswirkungen des Klimawandels unter Nutzung hydrologischer und wasserwirtschaftlicher Modelle zuverlässig abgeschätzt werden können, wobei insbesondere die genutzten Klimaszenarien/-modelle eine erhebliche Unsicherheit hervorrufen. Deswegen ist es unabdingbar, in entsprechenden Klimafolgenstudien Eingangsdaten diverser Klimaszenarien/-modelle zu nutzen und die gesamte Bandbreite der hydrologischen/wasserwirtschaftlichen Ergebnisse darzustellen.

Description: Freshwater - a fragile resource - is essential for life, development, and the environment. The Senegal River is a strategic region for the socio-economic development of these countries. The Senegal River's water management in time and space is possible thanks to the existing and future hydropower reservoirs. Hydropower is the world's largest and most widely used renewable energy source. In the future, hydropower is expected to be profoundly impacted due to the changes in river flow caused by climate change. This study examined the impact of climate change on the hydropower potential in the Senegal River basin for the periods P2 (2035-2065) and P3 (2065-2095) compared to P1 (1984-2014) under ssp 126 and ssp 370. We found that for P2, compared to P1, an increase of 6% in the annual flow would lead to an increase of 3% in annual hydropower generation for the ssp 126. A decrease of -1% in annual flow would reduce -0.7% in annual hydropower generation for the ssp 370. For P3 compared to P1, a reduction of annual flow by -6% and -13% would cause a decrease of -8% and -14% in annual hydropower, respectively, for ssp 126 and ssp 370. The planned reservoirs would increase the surface water storage, but it would cause a loss of -11% of the hydropower of the existing reservoir. Therefore, it is crucial to develop new adaptation techniques by combining hydro, solar and wind energy to mitigate the effects of climate change.