State-of-the-art hydrological impact studies are based on weather data from regional climate mode... more State-of-the-art hydrological impact studies are based on weather data from regional climate model ensembles and require a certain degree of accuracy. Despite regional downscaling to finer resolution, RCM simulations often show considerable biases when compared to observed data and bias-correction is an attempt to improve the quality and reliability. However, correction methods are based on the stationarity assumption which presumes that future physical processes in the atmosphere are comparable to the period used to correct the simulations. This dataset provides bias-corrected daily precipitation, min/mean/max air temperature of ten CORDEX RCM runs covering the country of Ethiopia for historical (1970-1999) and over the 21st century for RCP 4.5 and RCP 8.5.
Die Rolle der Wissenschaft im Rahmen des Umweltmanagements ist es, Methoden zu entwickeln, die au... more Die Rolle der Wissenschaft im Rahmen des Umweltmanagements ist es, Methoden zu entwickeln, die aus Rohdaten relevante Informationen erzeugen, um umweltrelevante Entscheidungen zu unterstützen. Diesbezüglich wurden zwei innovative Methoden entwickelt, deren Anwendbarkeit anhand zweier Fallstudien, im Kontext geringer Datenverfügbarkeit, demonstriert wird. Integration von qualitativen und quantitativen Informationen in ein technisch-basiertes Monitoringund Bewertungssystem zur Bodenversalzung. Die Methode verbindet technisches und lokales Wissen über Bodenversalzung und Nutzungspraktiken im unteren Amudarya-Einzugsgebiet in Usbekistan. Entwicklung einer synthetischen Niederschlags-Abfluss-Datenbank für das Hochwasserrisiko- Management. Es handelt sich um ein effektives Werkzeug zur Einschätzung des Abflussverhaltens unter gegebenen Niederschlagseinschätzungen. Um die Anwendbarkeit in Regionen mit geringer Datenverfügbarkeit zu gewährleisten, wurde ein minimalistischer Ansatz verfolgt.
<p>Burundi is one of the poorest countries in the world with about 65% of the popul... more <p>Burundi is one of the poorest countries in the world with about 65% of the population living below the poverty line and suffering from alarming food insecurity. Its population is highly dependent on rain-fed agriculture, which makes them extremely sensitive to climate variability and extremes for their subsistence. During the last decades, heavy rains, floods, and landslides suffered by Burundi’s population have led to severe famines, death, conflicts, and internal displacement among other fatalities, indicating the high vulnerability of this region to extreme events. Therefore, it is of vital importance to provide detailed information about the potential impacts of climate change in order to enhance adaptation options and preparedness in a country for which little information about climate projections and hydro-climatic impacts is available.</p><p>In this work, we investigated the changes in future climate over Burundi projected by a set of 13 regional climate models, for two future periods, under RCP4.5 and RCP8.5. The projections from CORDEX models have been used as forcing climate for the eco-hydrological Soil and Water Integrated Model (SWIM) in order to assess future changes in mean and extreme river discharge and water availability across Burundi.</p><p>Our results indicate that unabated climate change will lead to faster and more severe warming over Burundi than the global mean. Precipitation will increase in the north of Burundi despite a possible prolongation of the dry season, and will decrease in the south, with the exception of the months core of the rainy season that show the highest rise along the year and across the country. <!-- Option 2. #Two different signals of change were found for future long-term annual mean precipitation in North (+) and South (-) Burundi. Higher increases would take place in the months core of the rainy season in the whole region, while the north may experience a prolongation of the dry season. -->The increase in the frequency, magnitude, and intensity of extreme climate events (daily temperature, dry and wet events) will characterize the future climate in this region according to CORDEX models.</p><p>These changes get translated into increases of discharge in North Burundi across the whole year in all future scenarios and periods (up to 196% in annual streamflow in small catchments and 40% in larger ones), and slight decreases in the south from February to October (up to 7%). The increase of daily and annual extreme river discharges, their probabilities of exceedance, and the decrease in their recurrence intervals implies a higher risk of floods in magnitude and frequency.</p><p>These findings indicate the critical importance of adaptation of land and water management to changing hydro-climatic conditions in Burundi to improve food security and support its development.</p>
The role of monitoring is changing due to the increasing awareness of complexity and uncertainty ... more The role of monitoring is changing due to the increasing awareness of complexity and uncertainty in environmental resources management. Monitoring systems are required to support critical reflection about the effectiveness of actions toward the achievement of management objectives. To this aim, monitoring should be based on a strong integrated and multi-scale approach. Monitoring costs could be prohibitive if the monitoring
A comprehensive rainfall-runoff database for the Mulde catchment in Central Germany was developed... more A comprehensive rainfall-runoff database for the Mulde catchment in Central Germany was developed to support flood risk assessment and flood management. A large number of randomly generated 20-day rainfall scenarios and several combinations of model initialization states are the basis for the simulation of basin response by applying a metric conceptual rainfall-runoff model. The rainfall scenarios are divided into three periods; a five day initialization period to represent pre-conditions, a two day storm period representing a rainfall extreme event, and a final period characterized by low rainfall volumes to study streamflow recession behaviour. The rainfall-runoff database can be used as an effective tool to easily assess possible streamflow situations assuming different rainfall volumes for the following days. The benefit of the database approach is that it can be easily used by persons who are not necessarily familiar with hydrologic modelling, because the modelling step has alr...
The precariousness of the rural population in Africa is often symbolized by the lack of potable a... more The precariousness of the rural population in Africa is often symbolized by the lack of potable and safe drinking water. This study investigates the physico-chemical and bacteriological characteristics of 32 water samples with respect to WHO standards. The water samples were collected from wells, boreholes and small drinking water supply systems (DWS) in and around the township of Bonkoukou (Niger). The Water Quality Index (WQI) tool was used to assess the overall water quality with different physico-chemical parameters. Where the pH of the samples was acceptable, the samples showed higher levels of mineralization and deoxygenation. Overall, the samples were slightly hard, chlorinated and sulfated but much alkaline and contained nitrate and nitrite ions 2-16 times higher than the WHO standards. The use of WQI shows that samples in the DWS are safe for drinking. Samples coming from wells are the most polluted (58.50%) compared to those taken from boreholes (53.00%), while the percent...
The Inner Niger Delta in the West African Sahel is one of the largest wetlands in the world. Grow... more The Inner Niger Delta in the West African Sahel is one of the largest wetlands in the world. Growing populations and developing living standards in the Upper Niger Basin are increasing the needs for food and energy and put enormous pressure on limited natural resources. The extension of irrigated agricultural areas and the construction of new dams and reservoirs to store and distribute water and to generate hydropower seem to be necessary strategies to satisfy the increasing demands. As a consequence, the natural water regime of the River Niger is modified and will be subject to further regulation with largely negative effects for the Inner Niger Delta in Mali. Climate projections, used in this study, in combination with reservoir control lead to a significant reduction of peak discharges and are thus a large threat for the wetland’s ecosystem functions. Hydropower generation requires water during the dry season and consequently, the low flows are considerably increased due to dam m...
Abstract Representation of land-use and hydrologic interactions in respective models has traditio... more Abstract Representation of land-use and hydrologic interactions in respective models has traditionally been problematic. The use of static land-use in most hydrologic models or that of the use of simple hydrologic proxies in land-use change models call for more integrated approaches. The objective of this study is to assess whether dynamic feedback between land-use change and hydrology can (1) improve model performances, and/or (2) produce a more realistic quantification of ecosystem services. To test this, we coupled a land-use change model and a hydrologic mode. First, the land-use change and the hydrologic models were separately developed and calibrated. Then, the two models were dynamically coupled to exchange data at yearly time-steps. The approach is applied to a catchment in South Africa. Performance of coupled models when compared to the uncoupled models were marginal, but the coupled models excelled at the quantification of catchment ecosystem services more robustly.
Close to the border with Sudan, Ethiopia is currently building the largest hydroelectric power pl... more Close to the border with Sudan, Ethiopia is currently building the largest hydroelectric power plant in Africa with a storage volume corresponding to approximately 1.5 years of the mean discharges of the Blue Nile. This endeavor is controversially debated in the public and the scientific literature. Contributing to this discussion, by shading some light on climate change issues, an eco-hydrological model, equipped with a reservoir module, was applied to investigate downstream hydrological impacts during filling and regular operation, the latter considering climate change projected by an ensemble of 10 global and regional climate models. Our results show that at the earliest after 20 months, the dam could produce hydroelectric power. Full supply level may be reached after four years or not at all, depending on filling policies and assumptions of seepage rates. Under recent hydro-climatic conditions, the dam may produce 13 TWh − a , which is below the envisaged target of 15.7 TWh − a ...
This study aims to compare impacts of climate change on streamflow in four large representative A... more This study aims to compare impacts of climate change on streamflow in four large representative African river basins: the Niger, the Upper Blue Nile, the Oubangui and the Limpopo. We set up the eco-hydrological model SWIM (Soil and Water Integrated Model) for all four basins individually. The validation of the models for four basins shows results from adequate to very good, depending on the quality and availability of input and calibration data. <br><br> For the climate impact assessment, we drive the model with outputs of five bias corrected Earth system models of Coupled Model Intercomparison Project Phase 5 (CMIP5) for the representative concentration pathways (RCPs) 2.6 and 8.5. This climate input is put into the context of climate trends of the whole African continent and compared to a CMIP5 ensemble of 19 models in order to test their representativeness. Subsequently, we compare the trends in mean discharges, seasonality and hydrological extremes in the 21st centur...
State-of-the-art hydrological impact studies are based on weather data from regional climate mode... more State-of-the-art hydrological impact studies are based on weather data from regional climate model ensembles and require a certain degree of accuracy. Despite regional downscaling to finer resolution, RCM simulations often show considerable biases when compared to observed data and bias-correction is an attempt to improve the quality and reliability. However, correction methods are based on the stationarity assumption which presumes that future physical processes in the atmosphere are comparable to the period used to correct the simulations. This dataset provides bias-corrected daily precipitation, min/mean/max air temperature of ten CORDEX RCM runs covering the country of Ethiopia for historical (1970-1999) and over the 21st century for RCP 4.5 and RCP 8.5.
Die Rolle der Wissenschaft im Rahmen des Umweltmanagements ist es, Methoden zu entwickeln, die au... more Die Rolle der Wissenschaft im Rahmen des Umweltmanagements ist es, Methoden zu entwickeln, die aus Rohdaten relevante Informationen erzeugen, um umweltrelevante Entscheidungen zu unterstützen. Diesbezüglich wurden zwei innovative Methoden entwickelt, deren Anwendbarkeit anhand zweier Fallstudien, im Kontext geringer Datenverfügbarkeit, demonstriert wird. Integration von qualitativen und quantitativen Informationen in ein technisch-basiertes Monitoringund Bewertungssystem zur Bodenversalzung. Die Methode verbindet technisches und lokales Wissen über Bodenversalzung und Nutzungspraktiken im unteren Amudarya-Einzugsgebiet in Usbekistan. Entwicklung einer synthetischen Niederschlags-Abfluss-Datenbank für das Hochwasserrisiko- Management. Es handelt sich um ein effektives Werkzeug zur Einschätzung des Abflussverhaltens unter gegebenen Niederschlagseinschätzungen. Um die Anwendbarkeit in Regionen mit geringer Datenverfügbarkeit zu gewährleisten, wurde ein minimalistischer Ansatz verfolgt.
&lt;p&gt;Burundi is one of the poorest countries in the world with about 65% of the popul... more &lt;p&gt;Burundi is one of the poorest countries in the world with about 65% of the population living below the poverty line and suffering from alarming food insecurity. Its population is highly dependent on rain-fed agriculture, which makes them extremely sensitive to climate variability and extremes for their subsistence. During the last decades, heavy rains, floods, and landslides suffered by Burundi&amp;#8217;s population have led to severe famines, death, conflicts, and internal displacement among other fatalities, indicating the high vulnerability of this region to extreme events. Therefore, it is of vital importance to provide detailed information about the potential impacts of climate change in order to enhance adaptation options and preparedness in a country for which little information about climate projections and hydro-climatic impacts is available.&lt;/p&gt;&lt;p&gt;In this work, we investigated the changes in future climate over Burundi projected by a set of 13 regional climate models, for two future periods, under RCP4.5 and RCP8.5. The projections from CORDEX models have been used as forcing climate for the eco-hydrological Soil and Water Integrated Model (SWIM) in order to assess future changes in mean and extreme river discharge and water availability across Burundi.&lt;/p&gt;&lt;p&gt;Our results indicate that unabated climate change will lead to faster and more severe warming over Burundi than the global mean.&amp;#160;Precipitation will increase in the north of Burundi despite a possible prolongation of the dry season, and will decrease in the south, with the exception of the months core of the rainy season that show the highest rise along the year and across the country. &lt;!-- Option 2. #Two different signals of change were found for future long-term annual mean precipitation in North (+) and South (-) Burundi. Higher increases would take place in the months core of the rainy season in the whole region, while the north may experience a prolongation of the dry season. --&gt;The increase in the frequency, magnitude, and intensity of extreme climate events (daily temperature, dry and wet events) will characterize the future climate in this region according to CORDEX models.&lt;/p&gt;&lt;p&gt;These changes get translated into increases of discharge in North Burundi across the whole year in all future scenarios and periods (up to 196% in annual streamflow in small catchments and 40% in larger ones), and slight decreases in the south from February to October (up to 7%). The increase of daily and annual extreme river discharges, their probabilities of exceedance, and the decrease in their recurrence intervals implies a higher risk of floods in magnitude and frequency.&lt;/p&gt;&lt;p&gt;These findings indicate the critical importance of adaptation of land and water management to changing hydro-climatic conditions in Burundi to improve food security and support its development.&lt;/p&gt;
The role of monitoring is changing due to the increasing awareness of complexity and uncertainty ... more The role of monitoring is changing due to the increasing awareness of complexity and uncertainty in environmental resources management. Monitoring systems are required to support critical reflection about the effectiveness of actions toward the achievement of management objectives. To this aim, monitoring should be based on a strong integrated and multi-scale approach. Monitoring costs could be prohibitive if the monitoring
A comprehensive rainfall-runoff database for the Mulde catchment in Central Germany was developed... more A comprehensive rainfall-runoff database for the Mulde catchment in Central Germany was developed to support flood risk assessment and flood management. A large number of randomly generated 20-day rainfall scenarios and several combinations of model initialization states are the basis for the simulation of basin response by applying a metric conceptual rainfall-runoff model. The rainfall scenarios are divided into three periods; a five day initialization period to represent pre-conditions, a two day storm period representing a rainfall extreme event, and a final period characterized by low rainfall volumes to study streamflow recession behaviour. The rainfall-runoff database can be used as an effective tool to easily assess possible streamflow situations assuming different rainfall volumes for the following days. The benefit of the database approach is that it can be easily used by persons who are not necessarily familiar with hydrologic modelling, because the modelling step has alr...
The precariousness of the rural population in Africa is often symbolized by the lack of potable a... more The precariousness of the rural population in Africa is often symbolized by the lack of potable and safe drinking water. This study investigates the physico-chemical and bacteriological characteristics of 32 water samples with respect to WHO standards. The water samples were collected from wells, boreholes and small drinking water supply systems (DWS) in and around the township of Bonkoukou (Niger). The Water Quality Index (WQI) tool was used to assess the overall water quality with different physico-chemical parameters. Where the pH of the samples was acceptable, the samples showed higher levels of mineralization and deoxygenation. Overall, the samples were slightly hard, chlorinated and sulfated but much alkaline and contained nitrate and nitrite ions 2-16 times higher than the WHO standards. The use of WQI shows that samples in the DWS are safe for drinking. Samples coming from wells are the most polluted (58.50%) compared to those taken from boreholes (53.00%), while the percent...
The Inner Niger Delta in the West African Sahel is one of the largest wetlands in the world. Grow... more The Inner Niger Delta in the West African Sahel is one of the largest wetlands in the world. Growing populations and developing living standards in the Upper Niger Basin are increasing the needs for food and energy and put enormous pressure on limited natural resources. The extension of irrigated agricultural areas and the construction of new dams and reservoirs to store and distribute water and to generate hydropower seem to be necessary strategies to satisfy the increasing demands. As a consequence, the natural water regime of the River Niger is modified and will be subject to further regulation with largely negative effects for the Inner Niger Delta in Mali. Climate projections, used in this study, in combination with reservoir control lead to a significant reduction of peak discharges and are thus a large threat for the wetland’s ecosystem functions. Hydropower generation requires water during the dry season and consequently, the low flows are considerably increased due to dam m...
Abstract Representation of land-use and hydrologic interactions in respective models has traditio... more Abstract Representation of land-use and hydrologic interactions in respective models has traditionally been problematic. The use of static land-use in most hydrologic models or that of the use of simple hydrologic proxies in land-use change models call for more integrated approaches. The objective of this study is to assess whether dynamic feedback between land-use change and hydrology can (1) improve model performances, and/or (2) produce a more realistic quantification of ecosystem services. To test this, we coupled a land-use change model and a hydrologic mode. First, the land-use change and the hydrologic models were separately developed and calibrated. Then, the two models were dynamically coupled to exchange data at yearly time-steps. The approach is applied to a catchment in South Africa. Performance of coupled models when compared to the uncoupled models were marginal, but the coupled models excelled at the quantification of catchment ecosystem services more robustly.
Close to the border with Sudan, Ethiopia is currently building the largest hydroelectric power pl... more Close to the border with Sudan, Ethiopia is currently building the largest hydroelectric power plant in Africa with a storage volume corresponding to approximately 1.5 years of the mean discharges of the Blue Nile. This endeavor is controversially debated in the public and the scientific literature. Contributing to this discussion, by shading some light on climate change issues, an eco-hydrological model, equipped with a reservoir module, was applied to investigate downstream hydrological impacts during filling and regular operation, the latter considering climate change projected by an ensemble of 10 global and regional climate models. Our results show that at the earliest after 20 months, the dam could produce hydroelectric power. Full supply level may be reached after four years or not at all, depending on filling policies and assumptions of seepage rates. Under recent hydro-climatic conditions, the dam may produce 13 TWh − a , which is below the envisaged target of 15.7 TWh − a ...
This study aims to compare impacts of climate change on streamflow in four large representative A... more This study aims to compare impacts of climate change on streamflow in four large representative African river basins: the Niger, the Upper Blue Nile, the Oubangui and the Limpopo. We set up the eco-hydrological model SWIM (Soil and Water Integrated Model) for all four basins individually. The validation of the models for four basins shows results from adequate to very good, depending on the quality and availability of input and calibration data. <br><br> For the climate impact assessment, we drive the model with outputs of five bias corrected Earth system models of Coupled Model Intercomparison Project Phase 5 (CMIP5) for the representative concentration pathways (RCPs) 2.6 and 8.5. This climate input is put into the context of climate trends of the whole African continent and compared to a CMIP5 ensemble of 19 models in order to test their representativeness. Subsequently, we compare the trends in mean discharges, seasonality and hydrological extremes in the 21st centur...
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