Your search found 13 records
1 Mellouli, H. J.; van Wesemael, B.; Poesen, J.; Hartmann, R. 2000. Evaporation losses from bare soils as influenced by cultivation techniques in semi-arid regions. Agricultural Water Management, 42(3):355-369.
(Location: IWMI-HQ Call no: PER Record No: H025591)
2 Kosmas, C.; Marathianou, M.; Gerontidis, S.; Detsis, V.; Tsara, M.; Poesen, J.. 2001. Parameters affecting water vapor adsorption by the soil under semi-arid climatic conditions. Agricultural Water Management, 48(1):61-78.
Arid zones ; Climate ; Soil water ; Monitoring ; Rain ; Evaporation ; Lysimetry ; Water potential ; Crop production ; Precipitation ; Lysimetry ; Evaporation ; Soil properties ; Soil texture / Greece / Sparta / Thiva / Antissa / Vatousa
(Location: IWMI-HQ Call no: PER Record No: H028138)
3 Nyssen, J.; Haile, M.; Descheemaeker, K.; Deckers, J.; Poesen, J.; Moeyersons, J.; Hailemariam, T. 2003. Promoting global watershed management towards rural communities: the May Zeg-zeg initiative. In McCornick, P. G.; Kamara, A. B.; Tadesse, G. (Eds). Integrated water and land management research and capacity building priorities for Ethiopia: proceedings of a MoWR/EARO/IWMI/ILRI International Workshop held at ILRI, Addis Ababa, Ethiopia, 2-4 December 2002. Nairobi, Kenya: International Livestock Research Institute (ILRI); Colombo, Sri Lanka: International Water Management Institute (IWMI); Addis Ababa, Ethiopia: Ethiopian Ministry of Water Resources; Addis Ababa, Ethiopia: Ethiopian Agricultural Research Organization. pp.192-195.
(Location: IWMI-HQ Call no: IWMI 333.91 G636 MCC Record No: H032462)
(Location: IWMI-HQ Call no: IWMI 631.45 G000 VAL Record No: H037485)
5 Valentin, Christian; Poesen, J.; Li, Y. 2005. Gully erosion: impacts, factors and control. Catena, 63:132-153.
Erosion ; Environmental effects ; Farming systems ; Drainage ; Sedimentation ; Land use ; Soil conservation / China
(Location: IWMI-HQ Call no: IWMI 631.45 G000 VAL Record No: H038188)
6 Poesen, J.; Valentin, Christian. 2003. Preface. Catena, 50:87-89.
(Location: IWMI-HQ Call no: IWMI 631.45 G000 POE Record No: H038784)
7 Poesen, J.; Nachtergaele, J.; Verstraeten, G.; Valentin, Christian. 2003. Gully erosion and environmental change: importance and research needs. Catena, 50(2-4):91-133.
Water erosion ; Soil erosion ; Erosion control ; Soil degradation ; Environmental control ; Climate change ; Land use ; Infiltration ; Drainage ; Models
(Location: IWMI-HQ Call no: IWMI 631.45 G000 POE Record No: H038785)
8 Nyssen, J.; Poesen, J.; Descheemaeker, Katrien; Haregeweyn, N.; Haile, M.; Moeyersons, J.; Frankl, A.; Govers, G.; Munro, N.; Deckers, J. 2008. Effects of region-wide soil and water conservation in semi-arid areas: the case of northern Ethiopia. Zeitschrift für Geomorphologie, 52(3):291-315.
Soil conservation ; Water conservation ; Highlands ; Erosion ; Bunds ; Reservoirs ; Sedimentation / Ethiopia / Tigray
(Location: IWMI HQ Call no: e-copy only Record No: H041844)
(0.94 MB)
Studies on the impacts of environmental rehabilitation in semi-arid areas are often conducted over limited space and time scales, and do typically not include detailed biophysical components. This study makes a multi-scale assessment over a time span of 30 years of environmental rehabilitation in one of the world's most degraded areas: the Tigray highlands of Northern Ethiopia. The study shows that in Tigray sheet and rill erosion rates have decreased by approximately 68%, infiltration and spring discharge are enhanced and vegetation cover has improved. These impacts are evidenced and quantified by a comprehensive comparison of the current landscape with a coverage of 30-year old photographs and substantiated by field investigations. The positive changes in ecosystem service supply that result from these conservation activities in the Tigray highlands are an issue of global concern.
9 Descheemaeker, Katrien; Poesen, J.; Borselli, L.; Nyssen, J.; Raes, D.; Haile, M.; Muys, B.; Deckers, J. 2008. Runoff curve numbers for steep hillslopes with natural vegetation in semi-arid tropical highlands, northern Ethiopia. Hydrological Processes, 22:4097-4105.
Hydrology ; Soil conservation ; Water conservation ; Rangelands ; Highlands ; Vegetation ; Eucalyptus ; Rainfall-runoff relationships / Ethiopia
(Location: IWMI HQ Call no: e-copy only Record No: H041539)
(0.30 MB)
Daily runoff from 27 plots (5 m ð 2 m) recorded during two rainy seasons in the Tigray highlands (Ethiopia) were analysed together with daily rainfall to calculate runoff curve numbers for hillslopes covered by semi-natural vegetation in varying stages of vegetation restoration. Curve number model parameters were derived using a least squares fitting procedure on the collected rainfall–runoff datasets. Curve numbers varied from 29 to 97. Land use type was an important explanatory factor for the variation in curve numbers, whereas hydrologic soil group was not. Curve numbers were negatively correlated with vegetation cover. Taking into account antecedent soil moisture conditions did not improve runoff prediction using the curve number method. As runoff prediction was less accurate in areas with low curve numbers, two separate regression functions relating curve numbers with vegetation cover were proposed for different land use types.
10 Descheemaeker, Katrien; Raes, D.; Nyssen, J.; Poesen, J.; Haile, M.; Deckers, J. 2009. Changes in water flows and water productivity upon vegetation regeneration on degraded hillslopes in northern Ethiopia: a water balance modelling exercise. Rangeland Journal, 31(2):237-249. [doi: https://doi.org/10.1071/RJ09010]
Water balance ; Simulation models ; Soil water ; Measurement ; Experiments ; Highlands ; Sloping land ; Grazing lands ; Pastures ; Vegetation ; Regeneration ; Water productivity ; Percolation ; Evapotranspiration ; Runoff / Ethiopia
(Location: IWMI HQ Call no: IWMI 636 100 AME Record No: H042211)
(0.61 MB)
The establishment of exclosures (i.e. areas closed for grazing and agriculture) is a common practice to reverse land degradation through vegetation regeneration in the semiarid highland areas of northern Ethiopia. In order to assess the effect of exclosures on water flows, the water balance components for different vegetation regeneration stages were assessed through field measurements and modelling. Successful model calibration and validation was done based on soil water content measurements conducted during 2 years in 22 experimental plots. In the protected areas, vegetation regeneration leads to an increase in infiltration and transpiration and a more productive use of water for biomass production. In areas where additional lateral water (runon) infiltrates, source–sink systems are created. Here, up to 30% of the annual rainfall percolates through the root-zone towards the groundwater table. Increased biomass production in exclosures leads to possibilities for wood harvesting and cut and carry of grasses for livestock feeding. Together with water conservation and more productive use of water, the latter contributes to increased livestock water productivity. At the landscape scale, the creation of vegetation filters, capturing resources like water and nutrients, reinforces the rehabilitation process and healthy landscape functioning.
11 Nyssen, J.; Descheemaeker, Katrien; Zenebe, A.; Poesen, J.; Deckers, J.; Haile, M. 2009. Transhumance in the Tigray Highlands (Ethiopia) Mountain Research and Development, 29(3):255-264. [doi: https://doi.org/10.1659/mrd.00033]
Highlands ; Grazing lands ; Pastures ; Livestock ; Rangelands ; Transhumance / Ethiopia / Tigray Highlands
(Location: IWMI HQ Call no: e-copy only Record No: H042534)
(0.80 MB)
Transhumance, the seasonal movement of herds occurring between two points and following precise routes repeated each year, is practiced on a broad scale in the open field areas of Tigray (North Ethiopia). This article presents a characterization of the practice, factors that explain its magnitude, and recent changes. Eleven villages were selected randomly, semistructured interviews were conducted, and data on the sites were collected both in the field and from secondary sources. The transhumance destination zones are characterized as better endowed with water and fodder resources, essentially due to their great extent. The sample villages can be classified into three groups: annual transhumance (average one-way traveling distance 8.1 km), home range herding (average traveling distance 2.2 km), and keeping livestock near homesteads. Movements are basically induced by the fact that there is little to no space for livestock near the villages during the crop-growing period—not by the significantly different temperature or rainfall conditions in the grazing lands. Adults will only herd the flocks when the distance for transhumance is great or considered unsafe; otherwise, young boys tend the livestock for the entire summer rainy season. Faced with social (schooling) and technological (reservoir construction and establishment of exclosures) changes, transhumance in Tigray has adjusted in a highly adaptive way, with new routes being developed and others abandoned. Transhumance does not lead to major conflicts in the study area even when livestock are brought to areas that belong to other ethnic groups (Afar, Amhara).
12 Nyssen, J.; Clymans, W.; Descheemaeker, Katrien; Poesen, J.; Vandecasteele, I.; Vanmaercke, M.; Zenebe, A.; Van Camp, M.; Haile, M.; Haregeweyn, N.; Moeyersons, J.; Martens, K.; Gebreyohannes, T.; Deckers, J.; Walraevens, K. 2010. Impact of soil and water conservation measures on catchment hydrological response: a case in north Ethiopia. Hydrological Processes, 24(13):1880-1895. [doi: https://doi.org/10.1002/hyp.7628]
Catchment areas ; Water conservation ; Soil conservation ; Hydrology ; Runoff ; Water table ; Measurement ; Water balance / Ethiopia
(Location: IWMI HQ Call no: e-copy only Record No: H042876)
(0.59 MB)
Impact studies of catchment management in the developing world rarely include detailed hydrological components. Here, changes in the hydrological response of a 200-ha catchment in north Ethiopia are investigated. The management included various soil and water conservation measures such as the construction of dry masonry stone bunds and check dams, the abandonment of post-harvest grazing, and the establishment of woody vegetation. Measurements at the catchment outlet indicated a runoff depth of 5 mm or a runoff coefficient (RC) of 1Ð6% in the rainy season of 2006. Combined with runoff measurements at plot scale, this allowed calculating the runoff curve number (CN) for various land uses and land management techniques. The pre-implementation runoff depth was then predicted using the CN values and a ponding adjustment factor, representing the abstraction of runoff induced by the 242 check dams in gullies. Using the 2006 rainfall depths, the runoff depth for the 2000 land management situation was predicted to be 26Ð5 mm (RC D 8%), in line with current RCs of nearby catchments. Monitoring of the ground water level indicated a rise after catchment management. The yearly rise in water table after the onset of the rains ( T) relative to the water surplus (WS) over the same period increased between 2002–2003 ( T/WS D 3Ð4) and 2006 ( T/WS >11Ð1). Emerging wells and irrigation are other indicators for improved water supply in the managed catchment. Cropped fields in the gullies indicate that farmers are less frightened for the destructive effects of flash floods. Due to increased soil water content, the crop growing period is prolonged. It can be concluded that this catchment management has resulted in a higher infiltration rate and a reduction of direct runoff volume by 81% which has had a positive influence on the catchment water balance.
13 Assaye, H.; Nyssen, J.; Poesen, J.; Lemma, H.; Meshesha, D. T.; Wassie, A.; Adgo, E.; Frankl, A. 2021. Curve number calibration for measuring impacts of land management in sub-humid Ethiopia. Journal of Hydrology: Regional Studies, 35:100819. [doi: https://doi.org/10.1016/j.ejrh.2021.100819]
Land management ; Subhumid zones ; Catchment areas ; Land use ; Land cover ; Farmland ; Hydrology ; Forecasting ; Models ; Rain ; Runoff ; Soil erosion ; Vegetation / Ethiopia / Lake Tana Basin / Enkulal Catchment
(Location: IWMI HQ Call no: e-copy only Record No: H050402)
https://www.sciencedirect.com/science/article/pii/S2214581821000483/pdfft?md5=811f24334ecf439a5dd45030e6fb5ebc&pid=1-s2.0-S2214581821000483-main.pdf
https://vlibrary.iwmi.org/pdf/H050402.pdf
https://vlibrary.iwmi.org/pdf/H050402.pdf
(7.40 MB) (7.40 MB)
Study Region: We investigate the event runoff response in six sub-catchments in the Lake Tana sub-basin, headwater of the Blue Nile basin, northwest Ethiopia. Steep and mountainous terrains surround floodplains, imposing runoff and soil erosion in the upper catchments and flooding and sedimentation at floodplains. This study was conducted in the upland runoff source catchments.
Study Focus: The focus is to investigate catchment characteristics that control the event runoff response in upland catchments, and how recent land management practices may have contributed to improved hydrological conditions. Event rainfall and runoff data were obtained at five-minute time steps through automated divers and tipping bucket rain gauges and related to catchment characteristics.
New Hydrological Insights for the Region: Our results show that the catchment event quickflow response was controlled by different factors of both natural and anthropogenic nature of which forest and shrubs, bund density and soil organic matter content were found to be the most important to reduce event quickflow. On the contrary, increase in cropland area caused an increase in quickflow. Through least square fitting procedure of the Natural Resources Conservation Service Curve Number method (NRCS-CN), a site specific abstraction ratio ( ) value of 0.01, rather than the commonly used 0.2 or 0.05, was found to be most appropriate for the sub-humid highlands of Ethiopia.
Study Focus: The focus is to investigate catchment characteristics that control the event runoff response in upland catchments, and how recent land management practices may have contributed to improved hydrological conditions. Event rainfall and runoff data were obtained at five-minute time steps through automated divers and tipping bucket rain gauges and related to catchment characteristics.
New Hydrological Insights for the Region: Our results show that the catchment event quickflow response was controlled by different factors of both natural and anthropogenic nature of which forest and shrubs, bund density and soil organic matter content were found to be the most important to reduce event quickflow. On the contrary, increase in cropland area caused an increase in quickflow. Through least square fitting procedure of the Natural Resources Conservation Service Curve Number method (NRCS-CN), a site specific abstraction ratio ( ) value of 0.01, rather than the commonly used 0.2 or 0.05, was found to be most appropriate for the sub-humid highlands of Ethiopia.
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