Your search found 7 records
1 Betrie, G. D.; Mohamed, Yasir Abbas; van Griensven, A.; Popescu, I.; Mynett, A. 2009. Modeling of soil erosion and sediment transport in the Blue Nile Basin using the Open Model Interface approach. In Awulachew, Seleshi Bekele; Erkossa, Teklu; Smakhtin, Vladimir; Fernando, Ashra (Comps.). Improved water and land management in the Ethiopian highlands: its impact on downstream stakeholders dependent on the Blue Nile. Intermediate Results Dissemination Workshop held at the International Livestock Research Institute (ILRI), Addis Ababa, Ethiopia, 5-6 February 2009. Colombo, Sri Lanka: International Water Management Institute (IWMI). pp.132-140.
Erosion ; Highlands ; Sedimentary materials ; Simulation models ; River basin management ; Reservoirs / Ethiopia / Blue Nile River Basin / Roseires Reservoir / Sennar Reservoir
(Location: IWMI HQ Call no: IWMI 333.9162 G100 AWU Record No: H042513)
(0.41 MB)
Rapid land use change due to intensive agricultural practices in the Ethiopian Highlands, results in increasing rates of soil erosion. This manifested in significant impacts downstream by reducing the storage capacity of reservoirs (e.g., Roseires, Sennar), and high desilting costs of irrigation canals. Therefore, this paper aims to provide a better understanding of the process at basin scale. The Soil and Water Assessment Tool (SWAT) was used to model soil erosion in the upper catchments of the Blue Nile over the Ethiopian Plateau. The SWAT output forms the input sediment load for SOBEK, a river morphology model. The two models integrated using the principles of the Open Model Interface (OpenMI) at the Ethiopia-Sudan border. The Nash-Sutcliffe coefficient was found to be 0.72 and 0.66 for results of SWAT daily sediment calibration and validation, respectively. The SOBEK results also show a good fit of the simulated river flows at Roseires and Sennar reservoirs, both for calibration and validation. The results of the integrated modeling system showed 86 million tonnes/year of sediment load from the Upper Blue Nile, while SOBEK computes on average 19 Mm3/year of sediment deposition in the Roseires Reservoir. The spatial variability of soil erosion computed with SWAT showed more erosion over the northeastern part of the Upper Blue Nile, followed by the northern part. The overall exercise indicates that the integrated modeling is a promising approach to understand soil erosion, sediment transport, and sediment deposition in the Blue Nile Basin. This will improve the understanding of the upstream-downstream interdependencies, for better land and water management at basin scale.
2 Zsuffa, I.; Cools, J.; Vlieghe, P.; Debels, P.; van Griensven, A.; van Dam, A.; Hein, T.; Hattermann, F.; Masiyandima, Mutsa; de Grunauer, M. P. C. R.; Kaggwa, R.; Baker, C. 2008. The WETwin project: enhancing the role of wetlands in integrated water resources management for twinned river basins in EU, Africa and South America in support of EU Water Initiatives. Paper presented at the IWA 11th International Specialized Conference on Watershed and River Basin Management, Budapest, Hungary, 4-5 September 2008. 7p.
Water management ; Wetlands ; Research projects ; Sanitation ; Drinking water ; Ecology ; River basin management ; Stakeholders ; European Union / Africa / South America
(Location: IWMI HQ Call no: e-copy only Record No: H044730)
(0.05 MB) (48.24KB)
An international project called ‘WETwin’ has been launched in June 2008 within the frame of the 7th Framework Programme of the European Commission (EC). The overall objective of the project is to enhance the role of wetlands in basin-scale integrated water resources management, with the aim of improving the community service functions while conserving good ecological status. Strategies will be identified for:
· utilizing the drinking water supply and sanitation potentials of wetlands for the benefit of people living in the basin, while maintaining the ecosystem functions
· adapting wetland management to changing environmental conditions
· integrating wetlands into river basin management
· improving stakeholder participation and capacity building with the aim of supporting sustainable wetland management.
The project will work on 'twinned' case study wetlands from Europe, Africa and South America. Management solutions will be worked out for these wetlands with the aim of supporting the achievement of the above objectives. Knowledge and experiences gained from these case studies will be summarized in general guidelines aiming to support integrated wetland management on global scale. Stakeholder participation, capacity building and dissemination will be essential components of the project.
· utilizing the drinking water supply and sanitation potentials of wetlands for the benefit of people living in the basin, while maintaining the ecosystem functions
· adapting wetland management to changing environmental conditions
· integrating wetlands into river basin management
· improving stakeholder participation and capacity building with the aim of supporting sustainable wetland management.
The project will work on 'twinned' case study wetlands from Europe, Africa and South America. Management solutions will be worked out for these wetlands with the aim of supporting the achievement of the above objectives. Knowledge and experiences gained from these case studies will be summarized in general guidelines aiming to support integrated wetland management on global scale. Stakeholder participation, capacity building and dissemination will be essential components of the project.
3 Yalew, S.; Pilz, T.; Schweitzer, C.; Liersch, S.; van der Kwast, J.; Mul, Marloes L.; van Griensven, A.; van der Zaag, P. 2014. Dynamic feedback between land-use and hydrology for ecosystem services assessment. In Ames, D.P., Quinn, N.W.T., Rizzoli, A.E. (Eds.). Proceedings of the 7th International Congress on Environmental Modelling and Software, San Diego, California, USA, 15-19 June 2014. Manno, Switzerland: International Environmental Modelling and Software Society (iEMSs). 8p.
Hydrology ; Ecosystem services ; Land use ; Catchment areas ; Grasslands ; Biomass ; Soils ; Case studies / South Africa / uThukela Catchment
(Location: IWMI HQ Call no: e-copy only Record No: H046491)
http://www.iemss.org/sites/iemss2014/papers/iemss2014_submission_255.pdf
https://vlibrary.iwmi.org/pdf/H046491.pdf
https://vlibrary.iwmi.org/pdf/H046491.pdf
(0.48 MB) (495.82 KB)
Ecosystem services assessment requires an integrated approach, as it is influenced by elements such as climate, hydrology and socio-economics, which in turn influence each other. However, there are few studies that integrate these elements in order to assess ecosystem services. Absence of integrated approach to modelling hydrological and land-use changes, for instance, often oversights the dynamic feedback between the two processes. Dynamic changes in land-use should be fed into hydrological models and vice-versa at each time-step for a more realistic representation. In this study, this approach is demonstrated with a case study of the uThukela catchment, South Africa. There is an increasing pressure on grasslands in the catchment. The grassland supports livestock grazing, one of the main economic and social service for the communal farmers. High livestock population causes degradation of the grasslands, and increasing demand for agricultural lands decreases the extent of the grazing lands. In addition, this is further influenced by changes in climate, and has multiple impacts, such as increased erosion and changing flow regime. The SITE (SImulation of Terrestrial Environments) land-use change model and the SWIM (Soil and Water Integrated Model) hydrological model were coupled at code level to account for these processes. The two models exchange land-use maps (from SITE) and biomass production (from SWIM). SWIM was modified to produce biomass output. Grassland capacity for grazing service is determined through biomass coming from SWIM. Likewise, the simulated land-use change is passed back to the hydrological model to determine effects of land-use change on hydrological components. Preliminary result of the interactions between the two models and its use for estimating grazing capacity show that through the coupled models, sustainable level of grassland grazing locations were easily identifiable.
4 Yalew, S. G.; van Griensven, A.; Mul, Marloes L.; van der Zaag, P. 2016. Land suitability analysis for agriculture in the Abbay basin using remote sensing, GIS and AHP techniques. Modeling Earth Systems and Environment, 2:1-14. [doi: https://doi.org/10.1007/s40808-016-0167-x]
Land suitability ; Farmland ; Remote sensing ; Geographical Information Systems ; River basins ; Land cover ; Land degradation ; Intensification ; Extensification ; Erosion ; Catchment areas ; Agricultural production ; Soil properties ; Soil water / Ethiopia / Blue Nile River Basin / Abbay River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H047628)
http://link.springer.com/content/pdf/10.1007%2Fs40808-016-0167-x.pdf
https://vlibrary.iwmi.org/pdf/H047628.pdf
https://vlibrary.iwmi.org/pdf/H047628.pdf
To meet growing population demands for food and other agricultural commodities, agricultural land-use intensification and extensification seems to be increasing in the Abbay (Upper Blue Nile) basin in Ethiopia. However, the amount, location and degree of suitability of the basin for agriculture seem not well studied and/or documented. From global data sources, literature review and field investigation, a number of agricultural land suitability evaluation criteria were identified. These criteria were preprocessed as raster layers on a GIS platform and weights of criteria raster layers in determining suitability were computed using the analytic hierarchy process (AHP). A weighted overlay analysis method was used to compute categories of highly suitable, moderately suitable, marginally suitable and unsuitable lands for agriculture in the basin. It was found out that 53.8 % of the basin’s land coverage was highly suitable for agriculture and 23.2 % was moderately suitable. The marginally suitable and the unsuitable lands were at 11 and 12 % respectively. From the analysis, regions of the basin with high suitability as well as those with higher susceptibility for land degradation and soil erosion were identified.
5 Yalew, S. G.; Mul, Marloes L.; van Griensven, A.; Teferi, E.; Priess, J.; Schweitzer, C.; van Der Zaag, P. 2016. Land-use change modelling in the Upper Blue Nile Basin. Environments, 3(3):1-16. [doi: https://doi.org/10.3390/environments3030021]
Land use ; Land cover change ; Environmental modelling ; Environmental factors ; River basins ; Catchment areas ; Socioeconomic environment ; Plantations ; Forest management ; Erosion ; Vegetation ; Grasslands / Ethiopia / Upper Blue Nile Basin / Abbay Basin / Jedeb Catchment
(Location: IWMI HQ Call no: e-copy only Record No: H047679)
(1.24 MB)
Land-use and land-cover changes are driving unprecedented changes in ecosystems and environmental processes at different scales. This study was aimed at identifying the potential land-use drivers in the Jedeb catchment of the Abbay basin by combining statistical analysis, field investigation and remote sensing. To do so, a land-use change model was calibrated and evaluated using the SITE (SImulation of Terrestrial Environment) modelling framework. SITE is cellular automata based multi-criteria decision analysis framework for simulating land-use conversion based on socio-economic and environmental factors. Past land-use trajectories (1986–2009) were evaluated using a reference Landsat-derived map (agreement of 84%). Results show that major land-use change drivers in the study area were population, slope, livestock and distances from various infrastructures (roads, markets and water). It was also found that farmers seem to increasingly prefer plantations of trees such as Eucalyptus by replacing croplands perhaps mainly due to declining crop yield, soil fertility and climate variability. Potential future trajectory of land-use change was also predicted under a business-as-usual scenario (2009–2025). Results show that agricultural land will continue to expand from 69.5% in 2009 to 77.5% in 2025 in the catchment albeit at a declining rate when compared with the period from 1986 to 2009. Plantation forest will also increase at a much higher rate, mainly at the expense of natural vegetation, agricultural land and grasslands. This study provides critical information to land-use planners and policy makers for a more effective and proactive management in this highland catchment.
6 Yalew, S. G.; Pilz, T.; Schweitzer, C.; Liersch, S.; van der Kwast, J.; van Griensven, A.; Mul, Marloes L.; Dickens, Chris; van der Zaag, P. 2018. Coupling land-use change and hydrologic models for quantification of catchment ecosystem services. Environmental Modelling and Software, 109: 315-328. [doi: https://doi.org/10.1016/j.envsoft.2018.08.029]
Ecosystem services ; Catchment areas ; Land use ; Hydrological factors ; Models ; Couplings ; Calibration ; Environmental assessment ; Stream flow ; Biomass ; Grasslands ; Grazing lands
(Location: IWMI HQ Call no: e-copy only Record No: H048890)
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.
7 Carlino, A.; Wildemeersch, M.; Chawanda, C. J.; Giuliani, M.; Sterl, S.; Thiery, W.; van Griensven, A.; Castelletti, A. 2023. Declining cost of renewables and climate change curb the need for African hydropower expansion. Science, 381(6658):eadf5848. [doi: https://doi.org/10.1126/science.adf5848]
Climate change ; Hydropower ; Energy generation ; Energy demand ; River basins ; Water availability ; Socioeconomic aspects ; Models ; Greenhouse gas emissions ; Energy security / Africa
(Location: IWMI HQ Call no: e-copy only Record No: H052117)
(1.24 MB)
Across continental Africa, more than 300 new hydropower projects are under consideration to meet the future energy demand that is expected based on the growing population and increasing energy access. Yet large uncertainties associated with hydroclimatic and socioeconomic changes challenge hydropower planning. In this work, we show that only 40 to 68% of the candidate hydropower capacity in Africa is economically attractive. By analyzing the African energy systems’ development from 2020 to 2050 for different scenarios of energy demand, land-use change, and climate impacts on water availability, we find that wind and solar outcompete hydropower by 2030. An additional 1.8 to 4% increase in annual continental investment ensures reliability against future hydroclimatic variability. However, cooperation between countries is needed to overcome the divergent spatial distribution of investment costs and potential energy deficits.
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