Your search found 6 records
1 Tesema, M.; Schmitter, Petra; Nakawuka, Prossie; Tilahun, S. A.; Steenhuis, T.; Langan, Simon. 2016. Evaluating irrigation technologies to improve crop and water productivity of onion in Dangishta watershed during the dry monsoon phase. Paper presented at the International Conference of the Advancement of Science and Technology, Bahir Dar, Ethiopia, 17-18 July 2016. 10p.
Crop production ; Crop management ; Water productivity ; Water use efficiency ; Water conservation ; Water management ; Onions ; Monsoon climate ; Dry season ; Watershed services ; Wet cultivation ; Soil moisture ; Soil water balance ; Rhizosphere ; Rain ; Agriculture ; Fertilizer application / Ethiopia / Dangishta Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H047635)
(611 KB)
2 Worqlul, A. W.; Dile, Y. T.; Schmitter, Petra; Jeong, J.; Meki, M. N.; Gerik, T. J.; Srinivasan, R.; Lefore, Nicole; Clarke, N. 2019. Water resource assessment, gaps, and constraints of vegetable production in Robit and Dangishta watersheds, Upper Blue Nile Basin, Ethiopia. Agricultural Water Management, 226:105767. [doi: https://doi.org/10.1016/j.agwat.2019.105767]
Water resources ; Assessment ; Agricultural production ; Vegetables ; Crop yield ; Tomatoes ; Onions ; Irrigation water ; Rain ; Groundwater recharge ; Watersheds ; Water use efficiency ; Fertilizer application ; Farmers ; Farmer-led irrigation ; Models / Ethiopia / Upper Blue Nile Basin / Robit Watershed / Dangishta Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H049376)
https://www.sciencedirect.com/science/article/pii/S0378377418314021/pdfft?md5=769bfc34b80853a9a6b06c0b86106dda&pid=1-s2.0-S0378377418314021-main.pdf
https://vlibrary.iwmi.org/pdf/H049376.pdf
https://vlibrary.iwmi.org/pdf/H049376.pdf
(2.00 MB) (2.00 MB)
The vast majority of farmers in sub-Saharan Africa depend on rainfed agriculture for food production and livelihood. Various factors including but not limited to rainfall variability, land degradation, and low soil fertility constrain agricultural productivity in the region. The objectives of this study were to 1) estimate the water resources potential to sustain small-scale irrigation (SSI) in Ethiopia during the dry season so as to expand food supply by growing vegetables, and 2) understand the gaps and constraints of vegetable production. The case studies were conducted in the Robit and Dangishta watersheds of the Upper Blue Nile Basin, Ethiopia. To document farmers’ cropping practices, field-level data were collected from 36 households who had been cultivating tomato (Solanum lycopersicum L.) and onion (Allium cepa L.) during the dry season (November – April). Two components of the Integrated Decision Support System (IDSS) - the Soil and Water Assessment Tool (SWAT) and Agricultural Policy Environmental eXtender (APEX) – were respectively used to assess impacts of SSI at the watershed and field-scale levels. Results suggest that there is a substantial amount of surface runoff and shallow groundwater recharge at the watershed scale. The field-scale analysis in the Robit watershed indicated that optimal tomato yield could be obtained with 500 mm of water and 200 to 250 kg/ha of urea applied with 50 kg/ ha of diammonium phosphate (DAP). In Dangishta, optimum onion yield can be obtained with 400 mm of water and 120 to 180 kg/ha of urea applied with 50 kg/ha of DAP. The field-scale simulation indicated that the average shallow groundwater recharge (after accounting for other groundwater users such as household and livestock use) was not sufficient to meet tomato and onion water demand in the dry season (October to April). The fieldscale analysis also indicated that soil evaporation attributed a significant proportion of evapotranspiration (60% for onion and 40% for tomato). Use of mulching or other soil and water conservation interventions could optimize irrigation water for vegetable production by reducing soil evaporation and thereby increasing water availability in the crop root zone.
3 Yimam, A. Y.; Bekele, A. M.; Nakawuka, Prossie; Schmitter, Petra; Tilahun, S. A. 2019. Rainfall-runoff process and groundwater recharge in the Upper Blue Nile Basin: the case of Dangishta Watershed. In Zimale, F. A.; Nigussie, T. E.; Fanta, S. W. (Eds.). Advances of science and technology. Proceedings of the 6th EAI International Conference on Advancement of Science and Technology (ICAST 2018), Bahir Dar, Ethiopia, 5-7 October 2018. Cham, Switzerland: Springer. pp.536-549. (Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering (LNICST) Volume 274) [doi: https://doi.org/10.1007/978-3-030-15357-1_43]
Groundwater recharge ; Rainfall-runoff relationships ; Watersheds ; Stream flow ; Groundwater table ; Infiltration ; Soil moisture ; Estimation ; Irrigation water ; Wells ; Land use / Ethiopia / Upper Blue Nile Basin / Dangishta Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H050164)
(0.56 MB)
For planning, development and management of water resources, understanding runoff mechanism and groundwater recharge is useful especially to watershed management and groundwater use for domestic and irrigation water supply. During the period of the study, stream flow, groundwater levels, infiltration tests, rainfall and soil moisture measurements were conducted. The result from these measurement showed that saturation excess runoff were dominant in Dangishta watershed while infiltration excess runoff also contributes in some parts of the upslope area. This result was also corroborated by better correlation of (R2 = 0.82) at the main outlet than upstream sub watershed outlet (R2 = 0.56) using SCS runoff equation. The result from groundwater level measurement using water table fluctuations approach showed that the total annual groundwater recharge were found to be 400 mm (i.e. 24% of the total annual rainfall) which is a significant amount likely because of the interflow processes to each well.
4 Sishu, F. K.; Bekele, A. M.; Schmitter, Petra; Tilahun, S. A.; Steenhuis, T. S. 2021. Phosphorus export from two contrasting rural watersheds in the (sub) humid Ethiopian highlands. Frontiers in Earth Science, 9:762703. [doi: https://doi.org/10.3389/feart.2021.762703]
Highlands ; Phosphorus ; Watersheds ; Rural areas ; Runoff ; Soil loss ; Precipitation ; Discharges ; Land use ; Sediment / Africa South of Sahara / Ethiopia / Dangishta Watershed / Robit Bata Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H050851)
https://www.frontiersin.org/articles/10.3389/feart.2021.762703/pdf
https://vlibrary.iwmi.org/pdf/H050851.pdf
https://vlibrary.iwmi.org/pdf/H050851.pdf
(4.00 MB) (4.00 MB)
Establishing worldwide sustainable and phosphorus efficient cropping systems is urgently needed because the supply of suitable phosphate rock is limited, and excess phosphorus in streams causes eutrophication. One of the impediments in the developing world for sustainable P practices is the lack of studies on P transport and its eventual disposition in the environment. One of these regions with few studies is the Ethiopian Highlands, with permeable volcanic soils. The objective was to establish baseline data on P watershed export in the (sub)humid highlands. Two contrasting watersheds were selected near Lake Tana. For 2 years, stream discharge and sediment, total P, dissolved P, and bioavailable particulate P concentrations were determined at the watershed outlet. The first watershed is the 57 km2 Dangishta, with lava intrusion dikes, forcing subsurface flow through faults to the surface and preventing gully formation. Subsurface flow was half of the 1745 mm annual precipitation, and surface runoff and erosion were minimal. The second watershed is the 9 km2 Robit Bata with 1,420 mm precipitation. The banks of several river banks were slumping. The upper part of the watershed generates saturation excess runoff. A hillslope aquifer in the lower part provided interflow. The average sediment concentrations of 10.5 g L-1 in the stream in Robit Bata (11 times that in Dangishta) reflected the sediments from banks slipping in the stream. The hydrology and the soil loss directly affected the phosphorus export. In Dangishta, the total P concentration averaged 0.5 mg L-1 at the outlet. In Robit Bata, the average total P concentration was 2 mg L-1 . The bioavailable particulate P concentration was only twice the concentration in the runoff water. The low phosphorus content of the subsoil slipping in Robit Bata moderated biologically available particulate P at the outlet. Average dissolved P concentrations for both watersheds were around 0.1 mg L-1 in the low range found in temperate climates. It reflects the difference in length of time that phosphorus fertilizers have been applied. Our research concludes that commonly implemented practices such as strengthening river banks and stabilizing gully might not lead to improved water quality in Lake Tana.
5 Sishu, F. K.; Tilahun, Seifu A.; Schmitter, Petra; Steenhuis, T. S. 2023. Investigating nitrate with other constituents in groundwater in two contrasting tropical highland watersheds. Hydrology, 10(4):82. (Special issue: Editorial Board Members’ Collection Series: Integrated Surface Water and Groundwater Resources Management) [doi: https://doi.org/10.3390/hydrology10040082]
Groundwater table ; Nitrates ; Watersheds ; Highlands ; Volcanic areas ; Aquifers ; Wells ; Precipitation ; Rainfall ; Chlorides ; Ammonia ; Fertilizers ; Runoff / Africa South of Sahara / Ethiopia / Lake Tana Basin / Dangishta Watershed / Robit Bata Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H051839)
https://www.mdpi.com/2306-5338/10/4/82/pdf?version=1680523739
https://vlibrary.iwmi.org/pdf/H051839.pdf
https://vlibrary.iwmi.org/pdf/H051839.pdf
(8.28 MB) (8.28 MB)
Nitrate is globally the most widespread and widely studied groundwater contaminant. However, few studies have been conducted in sub-Saharan Africa, where the leaching potential is enhanced during the rainy monsoon phase. The few monitoring studies found concentrations over drinking water standards of 10 mg N-NO3 - L -1 in the groundwater, the primary water supply in rural communities. Studies on nitrate movement are limited to the volcanic Ethiopian highlands. Therefore, this study aimed to evaluate the transport and fate of nitrate in groundwater and identify processes that control the concentrations. Water table height, nitrate, chloride, ammonium, reduced iron, and three other groundwater constituents were determined monthly in the groundwater in over 30 wells in two contrasting volcanic watersheds over two years in the Ethiopian highlands. The first watershed was Dangishta, with lava intrusion dikes that blocked the subsurface flow in the valley bottom. The water table remained within 3 m of the surface. The second watershed without volcanic barriers was Robit Bata. The water table dropped rapidly within three months of the end of the rain phase and disappeared except near faults. The average nitrate concentration in both watersheds was between 4 and 5 mg N-NO3 - L -1 . Hydrogeology influenced the transport and fate of nitrogen. In Dangishta, water was blocked by volcanic lava intrusion dikes, and residence time in the aquifer was larger than in Robit Bata. Consequently, nitrate remained high (in several wells, 10 mg N-NO3 - L -1 ) and decreased slowly due to denitrification. In Robit Bata, the water residence time was lower, and peak concentrations were only observed in the month after fertilizer application; otherwise, it was near an average of 4 mg N-NO3 - L -1 . Nitrate concentrations were predicted using a multiple linear regression model. Hydrology explained the nitrate concentrations in Robit Bata. In Dangishta, biogeochemistry was also significant.
6 Sishu, F. K.; Tilahun, Seifu A.; Schmitter, Petra; Steenhuis, T. S. 2024. Revisiting the Thornthwaite Mather procedure for baseflow and groundwater storage predictions in sloping and mountainous regions. Journal of Hydrology X, 24:100179. (Online first) [doi: https://doi.org/10.1016/j.hydroa.2024.100179]
Groundwater table ; Water storage ; Sloping land ; Aquifers ; Highlands ; Watersheds ; Groundwater recharge ; Stream flow ; Water balance ; Precipitation ; Discharge ; Models / Ethiopia / Dangishta Watershed / Robit Bata Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H052843)
https://www.sciencedirect.com/science/article/pii/S2589915524000099/pdfft?md5=fcd021fe86a9e1229d0a54c3a5071e78&pid=1-s2.0-S2589915524000099-main.pdf
https://vlibrary.iwmi.org/pdf/H052843.pdf
https://vlibrary.iwmi.org/pdf/H052843.pdf
(4.69 MB) (4.69 MB)
Hillslope aquifers regulate streamflow and are a critical potable and irrigation water source, especially in developing countries. Knowing recharge and baseflow is essential for managing these aquifers. Methods using available data to calculate recharge and baseflow from aquifers are not valid for uplands. This paper adapts the Thornthwaite and Mather (T-M) procedure from plains to sloping and mountainous regions by replacing the linear reservoir with a zero-order aquifer. The revised T-M procedure was tested over four years in two contrasting watersheds in the humid Ethiopian highlands: the 57 km2 Dangishta with a perennial stream and the nine km2 Robit Bata, where the flow ceased four months after the end of the rain phase. The monthly average groundwater tables were predicted with an accuracy ranging from satisfactory to good for both watersheds. Baseflow predictions were “very good” after considering the evaporation from shallow groundwater in the valley bottom during the dry phase in Dangishta. We conclude that the T-M procedure is ideally suited for calculating recharge, baseflow and groundwater storage in upland regions with sparse hydrological data since the procedure uses as input only rainfall and potential evaporation data that are readily available together with an estimate of the aquifer travel time.
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