Identifying erosion hotspots in Lake Tana Basin from a multisite Soil and Water Assessment Tool validation: Opportunity for land managers

Land Degradation and Development - Tập 30 Số 12 - Trang 1449-1467 - 2019
Hanibal Lemma1,2, Amaury Frankl1,3, Ann van Griensven4, Jean Poesen5, Enyew Adgo6, Jan Nyssen1
1Department of Geography, Ghent University, Ghent 9000, Belgium
2School of Civil and Water Resources Engineering, Bahir Dar University, Bahir Dar, 1094 Ethiopia
3Research Foundation Flanders (FWO), Brussels, 1000, Belgium
4Department of Hydrology and Hydraulic Engineering, Vrije Universiteit Brussels, Brussels, 1050 Belgium
5Division of Geography and Tourism, KU Leuven, Heverlee, 3001 Belgium
6Department of Natural Resources Management, Bahir Dar University, Bahir Dar, 5501 Ethiopia

Tóm tắt

AbstractExtensive catchment degradation throughout the Ethiopian Highlands induced by long‐term intensified land use, erosion‐prone topography, and climate causes substantial soil erosion that limits agricultural productivity and results in lake sedimentation. However, before taking soil conservation measures, management of the soil loss problem essentially needs catchment‐level modelling to estimate the geographic distribution of erosion hotspots. With the increasing availability of sediment and spatial data and development of physically based models, this study aims multisite calibration of Soil and Water Assessment Tool (SWAT) to map erosion hotspot areas and to assess the effect of well‐known land management alternatives in sediment reduction in the Lake Tana Basin. The SWAT simulations indicated that the goodness of fit between predicted and observed data was satisfactory for all gauge stations except for one, and the model performance was within acceptable evaluation ratings. Simulated average sediment yield (SY) for the period 2001–2016 at subbasin level varies from negligible to about 169 Mg ha−1 yr−1 (basin average 32 Mg ha−1 yr−1). High potential SY (>50 Mg ha−1 yr−1) was simulated for 23% of the subbasins in Megech, upper Rib, upper Gumara, and Gilgel Abay catchments due to steep slope topography, aggressive rainfall, croplands dominance, and low rock fragment cover. The differences in level of erosion risk among subbasins help to prioritize and target specific areas of the basin that need urgent soil conservation activities. Scenario analysis also showed that implementing stone bunds, Acacia decurrens‐based crop rotation, reforestation, and grass contour strips reduces the existing SY by 51–61% at basin level. The potential sediment production could reach tolerable levels by implementing stone bunds, tree‐based crop rotation, reforestation in steep slope areas, and grass contour strips on gentle slopes. Overall, the multisite calibration of SWAT model using the measured run‐off and sediment data produces reasonable results that may support decision makers and planners to implement relevant land management measures and thereby reduce the alarming problems of soil loss in the basin and sedimentation of Lake Tana.

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Tài liệu tham khảo

Abbaspour K. C.(2015).SWAT‐CUP4: SWAT calibration and uncertainty programs manual (version 4). Dübendorf Switzerland Eawag: Swiss Federal Institute of Aquatic Science and Technology.

10.2136/vzj2004.1340

10.4081/jae.2014.430

Addis H. K., 2016, Modeling streamflow and sediment using SWAT in Ethiopian Highlands, International Journal of Agricultural and Biological Engineering, 9, 51

Arnold J. G. Kiniry J. R. Srinivasan R. Williams J. R. Haney E. B. &Neitsch S. L.(2013).Soil and Water Assessment Tool: Input/output documentation (version 2012). Texas USA: Texas Water Resources Institute.

10.13031/2013.42256

10.2478/v10104-011-0020-9

Awulachew S. B. McCartney M. Steenhuis T. S. &Ahmed A. A.(2008).A review of hydrology sediment and water resource use in the Blue Nile Basin. Sri Lanka: International Water Management Institute (IWMI) Working Paper 131.

Awulachew S. B., 2012, The Nile River Basin: Colombo, Water, agriculture, governance and livelihoods

10.3390/w9100782

10.1007/s11707-017-0656-x

10.5194/hess-15-807-2011

10.1002/hyp.5933

Colot C.(2012).Soil‐landscape relation at regional scale in Lake Tana Basin (Ethiopia). MSc Thesis. Faculteit Bio‐ingenieurswetenschappen KU Leuven.

10.1016/j.earscirev.2005.02.002

10.1016/j.jhydrol.2014.12.049

10.5194/hess-14-1827-2010

10.1016/j.geomorph.2017.12.020

10.1016/j.scitotenv.2018.08.273

Ercan M. B., 2014, Proceedings of the 7th International Congress on Environmental Modelling and Software, 2325

FAO. (2011).Sustainable land management in practice: Guidelines and best practices for Sub‐Saharan Africa. Rome: FAO.

10.1155/2018/1598195

Fulajtár E., 2001, Sustaining the global farm, 1075

10.1016/j.iswcr.2016.01.002

10.1007/s11629-014-3151-9

10.15517/rbt.v62i0.15924

10.1016/j.scitotenv.2016.09.019

10.1016/S0167-8809(02)00120-2

10.1371/journal.pone.0169748

10.1016/j.agee.2004.06.002

Hurni H.(1985).Erosion‐productivity‐conservation systems in Ethiopia. InThe 4th international conference on soil conservation(pp. 654–674). Maracay Venezuela.

10.2307/3673438

Hurni H.(1998).Agroecological belts of Ethiopia. University of Bern Switzerland and Ministry of Agriculture Ethiopia.

Hurni H., 2016, Soil and water conservation in Ethiopia: Guidelines for development agents

10.1659/0276-4741(2005)025[0147:TIOCIP]2.0.CO;2

Hurni H. Zeleke G. Kassie M. Tegegne B. Kassawmar T. Teferi E. Moges A. Tadesse D. Ahmed M. Degu Y. Kebebew Z. Hodel E. Amdihun A. Mekuriaw A. Debele B. Deichert G. &Hurni K.(2015).Soil degradation and sustainable land management in the rainfed agricultural areas of Ethiopia: An assessment of the economic implications. Water and Land Resource Centre Ethiopia and University of Bern Switzerland.

IIRR & ACTN, 2005, Conservation agriculture, 81

10.1016/j.jenvman.2017.11.044

10.1016/j.iswcr.2018.02.001

10.1002/esp.4256

Lemma H., 2017, Classifying land cover from an object‐oriented approach—Applied to LANDSAT 8 at the regional scale of the Lake Tana Basin (Ethiopia), Geophysical Research Abstracts, 19

McCartney M. Alemayehu T. Shiferaw A. &Awulachew S. B.(2010).Evaluation of current and future water resources development in the Lake Tana Basin Ethiopia. Colombo. Sri Lanka: International Water Management Institute (IWMI) Research Report 134.

10.1016/j.catena.2016.08.036

10.1007/978-94-007-0689-7_10

10.1002/ldr.1146

10.1016/j.catena.2018.05.035

10.1016/S1364-8152(03)00078-1

10.1016/j.ecohyd.2018.08.004

Miserez A.(2013).Soil erodibility and mapping in different hydrological land systems of Lake Tana Basin Ethiopia. MSc Thesis. Faculteit Bio‐ingenieurswetenschappen KU Leuven.

10.13031/2013.23153

Neitsch S. L., 2011, Soil and Water Assessment Tool: Theoretical documentation (version 2009)

10.1007/s11842-016-9352-z

National Planning Commission, 2015, Growth and transformation plan II (GTP II): 2015–2020

10.1016/j.agee.2005.11.009

10.1016/j.still.2006.07.011

10.1007/978-94-017-8026-1_21

10.1016/S0012-8252(03)00078-3

10.1016/j.jhydrol.2004.12.016

Oliveira A. H., 2013, Soil processes and current trends in quality assessment, 111

10.1016/j.catena.2016.08.002

10.1016/0341-8162(94)90058-2

10.1080/17445647.2013.801000

10.1016/S0341-8162(01)00161-8

Sefelnasr A.(2013).Hotspot delineation in the Eastern Nile Abbay/Blue Nile Basin as a criterion for the optimal risk assessment and watershed management of the basin. InProceedings of Basic and Applied Sciences(pp. 493–505). Hurghada Egypt.

10.2174/1874378100802010049

10.1002/hyp.7476

10.1111/j.1752-1688.2010.00431.x

10.1016/j.iswcr.2017.05.008

10.1080/02723646.2017.1302869

10.1016/j.iswcr.2017.05.004

10.1080/02723646.2013.832098

Tefera F.(1983).The effect of narrow grass strips in controlling soil erosion and runoff on sloping land. Master Thesis. Department of Agricultural Engineering University of Nairobi Kenya.

Tesemma A. B.(2007).Useful trees and shrubs of Ethiopia: Identification propagation and management for 17 agroclimatic zones. International Centre for Research in Agroforestry (ICRAF) Nairobi Kenya.

10.2166/hydro.2007.104

10.5194/hess-16-3371-2012

10.1016/j.scitotenv.2015.08.095

Webb D. B., 1984, A guide to species selection for tropical and sub‐tropical plantations

10.1111/j.1752-1688.1975.tb01817.x

Winchell W., 2013, ArcSWAT interface for SWAT2012: User's guide

10.1659/MRD-JOURNAL-D-16-00082.1

10.1016/j.catena.2017.12.040

Zeleke G., 2000, Landscape dynamics and soil erosion process modelling in the north‐western Ethiopian Highlands

10.13031/2013.25407

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Land Degradation and Development

Tập 30 Số 12

1449-1467

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