document

Simulation of Groundwater-Surface Water Interactions under Different Land Use Scenarios in the Bulang Catchment, Northwest China

Yang, Z. (author), Zhou, Y. (author), Wenninger, J. (author), Uhlenbrook, S. (author), Wan, L. (author)

Groundwater is the most important resource for local society and the ecosystem in the semi-arid Hailiutu River catchment. The catchment water balance was analyzed by considering vegetation types with the Normalized Difference Vegetation Index (NDVI), determining evapotranspiration rates by combining sap flow measurements and NDVI values,...

journal article 2015

document

Inter-annual and seasonal trends of vegetation condition in the Upper Blue Nile (Abay) Basin: Dual-scale time series analysis

Teferi, E. (author), Uhlenbrook, S. (author), Bewket, W. (author)

A long-term decline in ecosystem functioning and productivity, often called land degradation, is a serious environmental challenge to Ethiopia that needs to be understood so as to develop sustainable land use strategies. This study examines inter-annual and seasonal trends of vegetation cover in the Upper Blue Nile (UBN) or Abbay Basin. The...

journal article 2015

document

Inter-annual and seasonal trends of vegetation condition in the Upper Blue Nile (Abbay) basin: Dual scale time series analysis (discussion paper)

Teferi, E. (author), Uhlenbrook, S. (author), Bewket, W. (author)

A long-term decline in ecosystem functioning and productivity, often called land degradation, is a serious environmental challenge to Ethiopia that needs to be understood so as to develop sustainable land use strategies. This study examines inter-annual and seasonal trends of vegetation cover in the Upper Blue Nile (UBN) or Abbay Basin. The...

journal article 2015

document

Assessment of surface water resources availability using catchment modelling and the results of tracer studies in the mesoscale Migina Catchment, Rwanda

Munyaneza, O. (author), Mukubwa, A. (author), Maskey, S. (author), Uhlenbrook, S. (author), Wenninger, J.W. (author)

In the present study, we developed a catchment hydrological model which can be used to inform water resources planning and decision making for better management of the Migina Catchment (257.4 km2). The semi-distributed hydrological model HEC-HMS (Hydrologic Engineering Center – the Hydrologic Modelling System) (version 3.5) was used with its...

journal article 2014

document

Identification and simulation of space–time variability of past hydrological drought events in the Limpopo River basin, southern Africa

Trambauer, P. (author), Maskey, S. (author), Werner, M. (author), Pappenberger, F. (author), Van Beek, L.P.H. (author), Uhlenbrook, S. (author)

Droughts are widespread natural hazards and in many regions their frequency seems to be increasing. A finer-resolution version (0.05° × 0.05°) of the continental-scale hydrological model PCRaster Global Water Balance (PCR-GLOBWB) was set up for the Limpopo River basin, one of the most water-stressed basins on the African continent. An irrigation...

journal article 2014

document

Climate trends and impacts on crop production in the Koshi River basin of Nepal

Bhatt, D. (author), Maskey, S. (author), Babel, M.S. (author), Uhlenbrook, S. (author), Prasad, K.C. (author)

Understanding crop responses to climate is essential to cope with anticipated changes in temperature and precipitation. We investigated the climate–crop yield relationship and the impact of historical climate on yields of rice, maize and wheat in the Koshi basin of Nepal. The results show significant impact of growing season temperature and...

journal article 2014

document

Characterisation of stable isotopes to identify residence times and runoff components in two meso-scale catchments in the Abay/Upper Blue Nile basin, Ethiopia

Tekleab, S. (author), Wenninger, J.W. (author), Uhlenbrook, S. (author)

Measurements of the stable isotopes oxygen-18 (18O) and deuterium (2H) were carried out in two meso-scale catchments, Chemoga (358 km2) and Jedeb (296 km2) south of Lake Tana, Abay/Upper Blue Nile basin, Ethiopia. The region is of paramount importance for the water resources in the Nile basin, as more than 70% of total Nile water flow originates...

journal article 2014

document

Phosphorus transport and retention in a channel draining an urban, tropical catchment with informal settlements

Nyenje, P.M. (author), Meijer, L.M.G. (author), Foppen, J.W. (author), Kulabako, R. (author), Uhlenbrook, S. (author)

rban catchments in sub-Saharan Africa (SSA) are increasingly becoming a major source of phosphorus (P) to downstream ecosystems. This is primarily due to large inputs of untreated wastewater to urban drainage channels, especially in informal settlements (or slums). However, the processes governing the fate of P in these catchments are largely...

journal article 2014

document

Transport and retention of phosphorus in surface water in an urban slum area

Nyenje, P.M. (author), Meijer, L.M.G. (author), Foppen, J.W. (author), Kulabako, R. (author), Uhlenbrook, S. (author)

The transport of excessive phosphorus (P) discharged from unsewered informal settlements (slums) due to poor on-site sanitation is largely unknown. Hence, we investigated the processes governing P transport in a 28km2 slum-dominated catchment in Kampala, Uganda. During high runoff events and a period of base flow, we collected hourly water...

journal article 2014

document

Identification and simulation of space-time variability of past hydrological drought events in the Limpopo river basin, Southern Africa

Trambauer, P. (author), Maskey, S. (author), Werner, M. (author), Pappenberger, F. (author), Van Beek, L.P.H. (author), Uhlenbrook, S. (author)

journal article 2014

document

A three-component hydrograph separation based on geochemical tracers in a tropical mountainous headwater catchment in northern Thailand

Hugenschmidt, C. (author), Ingwersen, J. (author), Sangchan, W. (author), Sukvanachaikul, Y. (author), Duffner, A. (author), Uhlenbrook, S. (author), Streck, T. (author)

Land-use change in the mountainous parts of northern Thailand is reflected by an increased application of agrochemicals, which may be lost to surface and groundwater. The close relation between flow paths and contaminant transport within hydrological systems requires recognizing and understanding the dominant hydrological processes. To date, the...

journal article 2014

document

Comparison of different evaporation estimates over the African continent

Trambauer, P. (author), Dutra, E. (author), Maskey, S. (author), Werner, M. (author), Pappenberger, F. (author), Van Beek, L.P.H. (author), Uhlenbrook, S. (author)

Evaporation is a key process in the water cycle with implications ranging, inter alia, from water management to weather forecast and climate change assessments. The estimation of continental evaporation fluxes is complex and typically relies on continental-scale hydrological models or land-surface models. However, it appears that most global or...

journal article 2014

document

Assessment of surface water resources availability using catchment modeling and the results of tracer studies in the meso-scale Migina Catchment, Rwanda

Munyaneza, O. (author), Mukubwa, A. (author), Maskey, S. (author), Wenninger, J.W. (author), Uhlenbrook, S. (author)

In the last couple of years, different hydrological research projects were undertaken in the Migina catchment (243.2 km2), a tributary of the Kagera river in Southern Rwanda. These projects were aimed to understand hydrological processes of the catchment using analytical and experimental approaches and to build a pilot case whose experience can...

journal article 2013

document

A review of seawater intrusion in the Nile Delta groundwater system – the basis for assessing impacts due to climate changes and water resources development

Mabrouk, M.B. (author), Jonoski, A. (author), Solomatine, D.P. (author), Uhlenbrook, S. (author)

Serious environmental problems are emerging in the River Nile basin and its groundwater resources. Recent years have brought scientific evidence of climate change and development-induced environmental impacts globally as well as over Egypt. Some impacts are subtle, like decline of the Nile River water levels, others are dramatic like the...

journal article 2013

document

Identifying residence times and streamflow generation processes using ?18O and ?2H in meso-scale catchments in the Abay/Upper Blue Nile, Ethiopia

Teklaeb, S. (author), Wenninger, J.W. (author), Uhlenbrook, S. (author)

Measurements of the stable isotopes oxygen-18 (18O) and deuterium (2H) were carried out in two meso-scale catchments, Chemoga (358 km2) and Jedeb (296 km2) south of Lake Tana, Abay/Upper Blue Nile basin, Ethiopia. The region is of paramount importance for the water resources in the Nile basin. Stable isotope composition in precipitation, spring...

journal article 2013

document

Transport and retention of phosphorus in surface water in an urban slum area

Nyenje, P.M. (author), Meijer, L.M.G. (author), Foppen, J.W. (author), Kulabako, R. (author), Uhlenbrook, S. (author)

The transport of excessive phosphorus (P) discharged from unsewered informal settlements (slums) due to poor on-site sanitation is largely unknown. Hence, we investigated the processes governing P transport in a 28 km2 slum-dominated catchment in Kampala, Uganda. During high runoff events and a period of base flow, we collected hourly water...

journal article 2013

document

Expected changes in future temperature extremes and their elevation dependency over the Yellow River source region

Hu, Y. (author), Maskey, S. (author), Uhlenbrook, S. (author)

Using the Statistical DownScaling Model (SDSM) and the outputs from two global climate models, we investigate possible changes in mean and extreme temperature indices and their elevation dependency over the Yellow River source region for the two future periods 2046–2065 and 2081–2100 under the IPCC SRES A2, A1B and B1 emission scenarios. Changes...

journal article 2013

document

Groundwater–surface water interactions, vegetation dependencies and implications for water resources management in the semi-arid Hailiutu River catchment, China – a synthesis

Zhou, Y. (author), Wenninger, J. (author), Yang, Z. (author), Yin, L. (author), Huang, J. (author), Hou, L. (author), Wang, X. (author), Zhang, D. (author), Uhlenbrook, S. (author)

During the last decades, large-scale land use changes took place in the Hailiutu River catchment, a semi-arid area in northwest China. These changes had significant impacts on the water resources in the area. Insights into groundwater and surface water interactions and vegetation-water dependencies help to understand these impacts and formulate...

journal article 2013

document

Comparison of different evaporation estimates over the African continent

Trambauer, P. (author), Dutra, E. (author), Maskey, S. (author), Werner, M. (author), Pappenberger, F. (author), Van Beek, L.P.H. (author), Uhlenbrook, S. (author)

Evaporation is a key process in the water cycle, with implications ranging from water management, to weather forecast and climate change assessments. The estimation of continental evaporation fluxes is complex and typically relies on continental-scale hydrological or land-surface models. However, it appears that most global or continental-scale...

journal article 2013

document

A framework to assess the realism of model structures using hydrological signatures

Euser, T. (author), Winsemius, H.C. (author), Hrachowitz, M. (author), Fenicia, F. (author), Uhlenbrook, S. (author), Savenije, H.H.G. (author)

The use of flexible hydrological model structures for hypothesis testing requires an objective and diagnostic method to identify whether a rainfall-runoff model structure is suitable for a certain catchment. To determine if a model structure is realistic, i.e. if it captures the relevant runoff processes, both performance and consistency are...

journal article 2013