Assessing the Hydrology of a Data-Scarce Tropical Watershed Using the Soil and Water Assessment Tool: Case of the Little Ruaha River Watershed in Iringa, Tanzania
The hydrology of the Little Ruaha River which is a major catchment of the Ihemi Cluster in the Southern Agricultural Growth Corridor of Tanzania (SA-GCOT) has been studied. The study focused on the hydrological assessment through analysis of the available data and developing a model that could be used for assessing impacts of environmental change. Pressures on land and water resources in the watershed are increasing mainly as a result of human activities, and understanding the hydrological regime is deemed necessary. In this study, modeling was conducted using the Soil and Water Assessment Tool (SWAT) in which meteorological and streamflow data were used in the simulation, calibration and evaluation. Calibration and evaluation was done at three gauging stations and the results were deemed plausible with NSE ranging between 0.64 and 0.80 for the two stages. The simulated flows were used for gap filling the missing data and generation of complete daily time series of streamflow at three gauging stations of Makalala, Ihimbu and Mawande. Results of statistical trends and flow duration curves, revealed decline in magnitudes of seasonal and annual flows indicating that streamflows are changing with time and may have implications on envisioned development and the water dependent ecosystems.
References
[1]
Carpenter, S.R. and Biggs, R. (2009) Freshwaters: Managing across Scales in Space and Time, in Principles of Ecosystem Stewardship. Springer, New York, 197-220.
https://doi.org/10.1007/978-0-387-73033-2_9
[2]
MEA (2005) Millenium Ecosystems Assessment: Ecosystems and Human Well-Being. Vol. 5, Island Press, Washington DC.
[3]
Dudgeon, D., et al. (2006) Freshwater Biodiversity: Importance, Threats, Status and Conservation Challenges. Biological Reviews, 81, 163-182.
https://doi.org/10.1017/S1464793105006950
[4]
WLE (2014) Ecosystem Services and Resilience Framework. CGIAR Research Program on Water, Land and Ecosystems (WLE). International Water Management Institute (IWMI), Colombo, 46p. https://doi.org/10.5337/2014.229
[5]
FAO (Food and Agriculture Organization of the United Nations) (2011) FAOSTAT Database. http://faostat3.fao.org/download/E/EL/E
[6]
Foley, J.A., DeFries, R., Asner, G.P., Barford, C., Bonan, G., Carpenter, S.R., Helkowski, J.H., et al. (2005) Global Consequences of Land Use. Science, 309, 570-574.
https://doi.org/10.1126/science.1111772
[7]
Foley, J.A., Ramankutty, N., Brauman, K.A., Cassidy, E.S., Gerber, J.S., Johnston, M., Balzer, C., et al. (2011) Solutions for a Cultivated Planet. Nature, 478, 337-342.
https://doi.org/10.1038/nature10452
[8]
World Bank (2014) World Development Indicators: Agricultural Inputs.
http://wdi.worldbank.org/table/3.2
[9]
Tumbo, S.D., Kahimba, F.C., Mbilinyi, B.P., Rwehumbiza, F.B., Mahoo, H.F., Mbungu, W.B. and Enfors, E. (2012) Impact of Projected Climate Change on Agricultural Production in Semi-Arid Areas of Tanzania: A Case of Same District. African Crop Science Journal, 20, 453-463.
[10]
URT, Ministry of Agriculture, Food Security and Cooperatives (MAFC) (2015) Tanzania Agriculture Climate Resilience Plan, 2014-2019. Report 83, Ministry of Agriculture, Food Security and Cooperatives (MAFC), Dar Es Salaam.
http://www.agriculture.go.tz/publications
[11]
Fischer, G., Shah, M., Tubiello, F.N. and Van Velhuizen, H. (2005) Socio-Economic and Climate Change Impacts on Agriculture: An Integrated Assessment, 1990-2080. Philosophical Transactions of the Royal Society B: Biological Sciences, 360, 2067-2083. https://doi.org/10.1098/rstb.2005.1744
[12]
Cassman, K.G., Dobermann, A., Walters, D.T. and Yang, H. (2003) Meeting Cereal Demand While Protecting Natural Resources and Improving Environmental Quality. Annual Review of Environment and Resources, 28, 315-358.
https://doi.org/10.1146/annurev.energy.28.040202.122858
[13]
URT (2012) Tanzania National Climate Change Strategy. Division of Environment, Vice President’s Office, 92.
[14]
Mbungu, W. (2015) Climate Change Vulnerability Assessment in the Lake Rukwa Basin. Lake Rukwa Basin Water Board, Mbeya, 61.
[15]
Mbungu, W.B. (2016) Impacts of Land Use and Land Cover Changes, and Climate Variability on Hydrology and Soil Erosion in the Upper Ruvu Watershed, Tanzania. PhD Dissertation at Virginia Tech, Blacksburg.
[16]
Mbungu, W.B., Mahoo, H.F., Tumbo, S.D., Kahimba, F.C., Rwehumbiza, F.B. and Mbilinyi, B.P. (2015) Using Climate and Crop Simulation Models for Assessing Climate Change Impacts on Agronomic Practices and Productivity, in Sustainable Intensification to Advance Food Security and Enhance Climate Resilience in Africa. Springer, New York, 201-219. https://doi.org/10.1007/978-3-319-09360-4_10
[17]
Mourice, S.K., Mbungu, W. and Tumbo, S.D. (2017) Quantification of Climate Change and Variability Impacts on Maize Production at Farm Level in the Wami River Sub-Basin, Tanzania, in Quantification of Climate Variability, Adaptation and Mitigation for Agricultural Sustainability. Springer, New York, 323-351.
https://doi.org/10.1007/978-3-319-32059-5_13
[18]
Elisa, M., Gara, J.I. and Wolanski, E. (2010) A Review of the Water Crisis in Tanzania’s Protected Areas, with Emphasis on the Katuma River—Lake Rukwa Ecosystem. Ecohydrology & Hydrobiology, 10, 153-165.
[19]
Kajembe, G.C., Mbwilo, A.J., Kidunda, R.S. and Nduwamungu, J. (2003) Resource Use Conflicts in Usangu Plains, Mbarali District, Tanzania. The International Journal of Sustainable Development & World Ecology, 10, 333-343.
https://doi.org/10.1080/13504500309470109
[20]
Nindi, S.J., Maliti, H., Bakari, S., Kija, H. and Machoke, M. (2014) Conflicts over Land and Water Resources in the Kilombero Valley Floodplain, Tanzania.
[21]
Mtahiko, M.G.G., Gereta, E., Kajuni, A.R., Chiombola, E.A.T., Ng’umbi, G.Z., Coppolillo, P. and Wolanski, E. (2006) Towards an Ecohydrology-Based Restoration of the Usangu Wetlands and the Great Ruaha River, Tanzania. Wetlands Ecology and Management, 14, 489-503. https://doi.org/10.1007/s11273-006-9002-x
[22]
SAGCOT (Southern Agricultural Growth Corridor of Tanzania) (2011) Southern Agricultural Growth Corridor of Tanzania Investment Blueprint. Dar Es Salaam.
[23]
Kadigi, R.M., Mdoe, N.S., Lankford, B.A. and Morardet, S. (2005) The Value of Water for Irrigated Paddy and Hydropower Generation in the Great Ruaha, Tanzania. Proceedings of the East Africa Integrated River Basin Management Conference, Morogoro, 7-9 March 2005, 265-278.
[24]
Kashaigili, J.J., Kadigi, R.M., Lankford, B.A., Mahoo, H.F. and Mashauri, D.A. (2005) Environmental Flows Allocation in River Basins: Exploring Allocation Challenges and Options in the Great Ruaha River Catchment in Tanzania. Physics and Chemistry of the Earth, Parts A/B/C, 30, 689-697.
[25]
Kashaigili, J.J, Kadigi R.M.J.,Mbungu, W.B., Sikira, A., Sirima, A., Placid, J.K., Mbwambo, E. and Minde, A. (2016) Laying the Foundations for Effective Landscape-Level Planning for Sustainable Development in the SAGCOT Corridor: Ihemi Agricultural Development Cluster (LiFELand). Draft Report Submitted to TNC, Sokoine University of Agriculture, Morogoro, 153 p.
[26]
Arnold, J.G., et al. (1998) Large Area Hydrologic Modeling and Assessment Part I: Model Development 1. Wiley Online Library, Hoboken.
[27]
Baker, T.J. and Miller, S.N. (2013) Using the Soil and Water Assessment Tool (SWAT) to Assess Land Use Impact on Water Resources in an East African Watershed. Journal of Hydrology, 486, 100-111.
https://doi.org/10.1016/j.jhydrol.2013.01.041
[28]
Mulungu, D.M. and Munishi, S.E. (2007) Simiyu River Catchment Parameterization Using SWAT Model. Physics and Chemistry of the Earth, Parts A/B/C, 32, 1032-1103. https://doi.org/10.1016/j.pce.2007.07.053
[29]
Ndomba, P., Mtalo, F. and Killingtveit, A. (2008) SWAT Model Application in a Data Scarce Tropical Complex Catchment in Tanzania. Physics and Chemistry of the Earth, Parts A/B/C, 33, 626-632. https://doi.org/10.1016/j.pce.2008.06.013
[30]
Birhanu, B.Z. (2009) Hydrological Modeling of the Kihansi River Catchment in South Central Tanzania Using SWAT Model. International Journal of Water Resources and Environmental Engineering, 1, 1-10.
[31]
Natkhin, M., Dietrich, O., Schafer, M.P. and Lischeid, G. (2015) The Effects of Climate and Changing Land Use on the Discharge Regime of a Small Catchment in Tanzania. Regional Environmental Change, 15, 1269-1280.
https://doi.org/10.1007/s10113-013-0462-2
[32]
Neitsch, S.L., Arnold, J.G., Kiniry, J.R., Williams, J.R. and King, K.W. (2002) Soil and Water Assessment Tool Theoretical Documentation. USDA-ARS Publication GSWRL 02-01 BRC 02-05 TR-01, USDA-ARS Publication, Washington DC.
[33]
Arnold, J.G. and Fohrer, N. (2005) SWAT2000: Current Capabilities and Research Opportunities in Applied Watershed Modelling. Hydrological Processes, 19, 563-572. https://doi.org/10.1002/hyp.5611
[34]
Arnold, J. and Allen, P. (1996) Estimating Hydrologic Budgets for Three Illinois Watersheds. Journal of Hydrology, 176, 57-77.
https://doi.org/10.1016/0022-1694(95)02782-3
[35]
Dessu, S.B. and Melesse, A.M. (2012) Modelling the Rainfall-Runoff Process of the Mara River Basin Using the Soil and Water Assessment Tool. Hydrological Processes, 26, 4038-4049. https://doi.org/10.1002/hyp.9205
[36]
Perrin, J., Ferrant, S., Massuel, S., Dewandel, B., Maréchal, J.C., Aulong, S. and Ahmed, S. (2012) Assessing Water Availability in a Semi-Arid Watershed of Southern India Using a Semi-Distributed Model. Journal of Hydrology, 460-461, 143-155.
https://doi.org/10.1016/j.jhydrol.2012.07.002
[37]
Asres, M.T. and Awulachew, S.B. (2010) SWAT Based Runoff and Sediment Yield Modelling: A Case Study of the Gumera Watershed in the Blue Nile Basin. Ecohydrology & Hydrobiology, 10, 191-199.
[38]
White, E.D., Easton, Z.M., Fuka, D.R., Collick, A.S., Adgo, E., McCartney, M., Steenhuis, T.S., et al. (2011) Development and Application of a Physically Based Landscape Water Balance in the SWAT Model. Hydrological Processes, 25, 915-925. https://doi.org/10.1002/hyp.7876
[39]
Jha, M., Pan, Z., Takle, E.S. and Gu, R. (2004) Impacts of Climate Change on Streamflow in the Upper Mississippi River Basin: A Regional Climate Model Perspective. Journal of Geophysical Research: Atmospheres, 109.
https://doi.org/10.1029/2003JD003686
[40]
Neitsch, S.L., Williams, J.R., Arnold, J.G. and Kiniry, J.R. (2011) Soil and Water Assessment Tool Theoretical Documentation Version 2009. Texas Water Resources Institute, College Station.
[41]
Arnold, J.G., Moriasi, D.N., Gassman, P.W., Abbaspour, K.C., White, M.J., Srinivasan, R., Kannan, N., et al. (2012) SWAT: Model Use, Calibration, and Validation. Transactions of the ASABE, 55, 1491-1508. https://doi.org/10.13031/2013.42256
[42]
Gassman, P.W., Reyes, M.R., Green, C.H. and Arnold, J.G. (2007) The Soil and Water Assessment Tool: Historical Development, Applications, and Future Research Directions. Transactions of the ASABE, 50, 1211-1250.
https://doi.org/10.13031/2013.23637
[43]
Breiman, L. (2001) Random Forests. Machine Learning, 45, 5-32.
https://doi.org/10.1023/A:1010933404324
[44]
Rodriguez-Galiano, V.F., Ghimire, B., Rogan, J., Chica-Olmo, M. and Rigol-Sanchez, J.P. (2012) An Assessment of the Effectiveness of a Random Forest Classifier for Land-Cover Classification. ISPRS Journal of Photogrammetry and Remote Sensing, 67, 93-104. https://doi.org/10.1016/j.isprsjprs.2011.11.002
[45]
De Pauw, E. (1984) Soils, Physiography and Agroecological Zones of Tanzania. Ministry of Agriculture, Dar-es-Salaam, Tanzania/FAO, Rome.
McCuen, R.H. (2003) Modeling Hydrologic Change: Statistical Methods. Lewis Publishers, Boca Raton, 433 p.
[49]
Weedon, G.P., Balsamo, G., Bellouin, N., Gomes, S., Best, M.J. and Viterbo, P. (2014) The WFDEI Meteorological Forcing Data Set: WATCH Forcing Data Methodology Applied to ERA—Interim Reanalysis Data. Water Resources Research, 50, 7505-7514. https://doi.org/10.1002/2014WR015638
[50]
Abbaspour, K., Vejdani, M. and Haghighat, S. (2007) SWAT-CUP Calibration and Uncertainty Programs for SWAT. MODSIM 2007 International Congress on Modelling and Simulation, December 2007, 1596-1602.
[51]
Van Griensven, A. and Bauwens, W. (2003) Multiobjective Autocalibration for Semidistributed Water Quality Models. Water Resources Research, 39.
https://doi.org/10.1029/2003wr002284
[52]
Abbaspour, K.C., et al. (2009) Assessing the Impact of Climate Change on Water Resources in Iran. Water Resources Research, 45.
https://doi.org/10.1029/2008WR007615
[53]
Betrie, G.D., Mohamed, Y.A., Griensven, A.V. and Srinivasan, R. (2011) Sediment Management Modelling in the Blue Nile Basin Using SWAT Model. Hydrology and Earth System Sciences, 15, 807-818. https://doi.org/10.5194/hess-15-807-2011
[54]
Lim, K.J., Park, Y.S., Kim, J., Shin, Y.C., Kim, N.W., Kim, S.J., Engel, B.A., et al. (2010) Development of Genetic Algorithm-Based Optimization Module in WHAT System for Hydrograph Analysis and Model Application. Computers & Geosciences, 36, 936-944. https://doi.org/10.1016/j.cageo.2010.01.004
[55]
Recha, J.W., Lehmann, J., Walter, M.T., Pell, A., Verchot, L. and Johnson, M. (2012) Stream Discharge in Tropical Headwater Catchments as a Result of Forest Clearing and Soil Degradation. Earth Interactions, 16, 1-18.
https://doi.org/10.1175/2012EI000439.1
[56]
Longobardi, A. and Villani, P. (2008) Baseflow Index Regionalization Analysis in a Mediterranean Area and Data Scarcity Context: Role of the Catchment Permeability Index. Journal of Hydrology, 355, 63-75.
https://doi.org/10.1016/j.jhydrol.2008.03.011
[57]
Moriasi, D.N., Arnold, J.G., Van Liew, M.W., Bingner, R.L., Harmel, R.D. and Veith, T.L. (2007) Model Evaluation Guidelines for Systematic Quantification of Accuracy in Watershed Simulations. Transactions of the ASABE, 50, 885-900.
https://doi.org/10.13031/2013.23153
[58]
Nash, J.E. and Sutcliffe, J.V. (1970) River Flow Forecasting through Conceptual Models Part I—A Discussion of Principles. Journal of Hydrology, 10, 282-290.
https://doi.org/10.1016/0022-1694(70)90255-6
[59]
Gupta, H.V., Sorooshian, S. and Yapo, P.O. (1999) Status of Automatic Calibration for Hydrologic Models: Comparison with Multilevel Expert Calibration. Journal of Hydrologic Engineering, 4, 135-143.
https://doi.org/10.1061/(ASCE)1084-0699(1999)4:2(135)
[60]
Mbungu, W., Ntegeka, V., Kahimba, F.C., Taye, M. and Willems, P. (2012) Temporal and Spatial Variations in Hydro-Climatic Extremes in the Lake Victoria Basin. Physics and Chemistry of the Earth, Parts A/B/C, 50, 24-33.
https://doi.org/10.1016/j.pce.2012.09.002
[61]
Ndomba, P.M. (2014) Streamflow Data Needs for Water Resources Management and Monitoring Challenges: A Case Study of Wami River Subbasin in Tanzania, in Nile River Basin. Springer, New York, 23-49.
https://doi.org/10.1007/978-3-319-02720-3_3
[62]
Kim, M., Baek, S., Ligaray, M., Pyo, J., Park, M. and Cho, K.H. (2015) Comparative Studies of Different Imputation Methods for Recovering Streamflow Observation. Water, 7, 6847-6860. https://doi.org/10.3390/w7126663
[63]
Mann, H.B. (1945) Non-Parametric Test against Trend. Econometrica, 13, 245-259.
https://doi.org/10.2307/1907187
[64]
Kendall, M.G. (1975) Rank Correlation Methods. Charles Griffin, London.
[65]
Castellarin, A., Camorani, G. and Brath, A. (2007) Predicting Annual and Long-Term Flow-Duration Curves in Ungauged Basins. Advances in Water Resources, 30, 937-953. https://doi.org/10.1016/j.advwatres.2006.08.006
[66]
Yokoo, Y. and Sivapalan, M. (2011) Towards Reconstruction of the Flow Duration Curve: Development of a Conceptual Framework with a Physical Basis. Hydrology and Earth System Sciences, 15, 2805-2819.
https://doi.org/10.5194/hess-15-2805-2011
