References
Allen, R. G., Pereira, L. S., Raes, D., & Smith, M. 1998. FAO
Irrigation and Drainage Paper No. 56: Crop Evapotranspiration. FAO -
Food and Agriculture Organization of the United Nations: Rome, Italy.
Available at: http://www.kimberly.uidaho.edu/water/fao56/fao56.pdf
Allen, R. G., Tasumi, M., & Trezza, R. 2007. Satellite-Based Energy
Balance for Mapping Evapotranspiration with Internalized Calibration
(METRIC)—Model. Journal of Irrigation and Drainage Engineering 133
(4): 380–394. https://doi.org/10.1061/(ASCE)0733-9437(2007)133:4(380)
Allen, R. G., Pereira, L. S., Howell, T. A., & Jensen, M. A. 2011.
Evapotranspiration information reporting: I. Factors governing
measurement accuracy, Agricultural Water Management 98 (2011): 899–920.
https://doi.org/10.1016/j.agwat.2010.12.015
Ardö, J., Mölder, M., El-Tahir, B. A, & Elkhidir, H. A. M. 2008.
Seasonal variation of carbon fluxes in a sparse savanna in semi arid
Sudan. Carbon Balance and Management 3 (7): 1–18.
https://doi.org/10.1186/1750-0680-3-7
Atta, Y., Gaafar, I., Hassan, W., & El, A. 2015. Validation of Accurate
Determination of Maize Water Requirements in Nile Delta. In
International Commission on Irrigation and Drainage 26th
Euro-Mediterranean Regional Conference and Workshops, Innovate to
Improve Irrigation Performances, Montpellier; 4.
Bastiaanssen, W. G. M., Cheema, M. J M., Immerzeel, W. W., Miltenburg,
I. J., & Pelgrum, H., 2011. Surface energy balance and actual
evapotranspiration of the transboundary Indus Basin estimated from
satellite measurements and the ETLook model, Water Resources Research
48: W11512. https://doi.org/10.1029/2011WR010482
Bastiaanssen, W. G. M., Menenti, M., Feddes, R., & Holtslag, A. A.
1998. A remote sensing surface energy balance algorithm for land
(SEBAL). 1.Formulation. Journal of Hydrology 212–213(1998): 198–212.
DOI: https://doi.org/10.1016/S0022-1694(98)00253-4
Beck, H. E., De Roo, A., & Van Dijk A. I. J. M. 2015. Global Maps of
Streamflow Characteristics Based on Observations from Several Thousand
Catchments*. Journal of Hydrometeorology 16: 1478-1501.
https://doi.org/10.1175/JHM-D-14-0155.1
Blatchford , M. L., Mannaerts, C. M., Zeng, Y., Nouri, H., & Karimi, P.
2019. Status of accuracy in remotely sensed and in-situ agricultural
water productivity estimates: A review. Remote Sensing of Environment
234 (1 December 201: 111413. https://doi.org/10.1016/j.rse.2019.111413
Boulain, N., Cappelaere, B., Séguis, L., Favreau, G., & Gignoux, J.
2009. Water balance and vegetation change in the Sahel: A case study at
the watershed scale with an eco-hydrological model. Journal of Arid
Environments 73 (12): 1125–1135.
https://doi.org/10.1016/j.jaridenv.2009.05.008
De Bruin, H., Trigo, I., Bosveld, F., & Meirink, J. 2016.
Thermodynamically based model for actual evapotranspiration of an
extensive grass field close to FAO reference, suitable for remote
sensing application. Journal of Hydrometeorology 17 (5): 1373–1382.
DOI: https://doi.org/10.1175/JHM-D-15-0006.1
De Bruin, H. A. R., & Trigo, I.F. 2019. A new method to estimate
reference crop evapotranspiration from geostationary satellite imagery:
Practical considerations. Water 11 (2): 382.
https://doi.org/10.3390/w11020382
Chishugi, J. B., & Alemaw, B. F. 2009. The Hydrology of the Congo River
Basin: A GIS-Based Hydrological Water Balance Model. World Environmental
and Water Resources Congress 2009: Great Rivers. (pp. 1–16). Kansas
City, USA: ASCE.
Chiti, T., Certini, G., Grieco, E., & Valentini, R. 2010. The role of
soil in storing carbon in tropical rainforests: The case of Ankasa Park,
Ghana. Plant and Soil 331 (1–2): 453–461. DOI:
https://doi.org/10.1007/s11104-009-0265-x
Cleverly, J., Chen, C., Boulain, N., Villalobos-Vega, R., Faux, R.,
Grant, N., … & Eamus, D. 2013. Aerodynamic Resistance and
Penman–Monteith Evapotranspiration over a Seasonally Two-Layered Canopy
in Semiarid Central Australia. Journal of Hydrometeorology 14 (5):
1562–1570. https://doi.org/10.1175/jhm-d-13-080.1
Córdova, M., Carrillo-Rojas, G., Crespo, P., Wilcox, B., & Célleri, R.
2015. Evaluation of the Penman-Monteith (FAO 56 PM) Method for
Calculating Reference Evapotranspiration Using Limited Data. Mountain
Research and Development 35 (3): 230–239.
https://doi.org/10.1659/mrd-journal-d-14-0024.1
Degefu, D. M., Weijun, H., Zaiyi, L., Liang, Y., Zhengwei, H., & Min,
A. 2018. Mapping Monthly Water Scarcity in Global Transboundary Basins
at Country-Basin Mesh Based Spatial Resolution. Scientific Reports 8
(1): 1–10. https://doi.org/10.1038/s41598-018-20032-w
Dembélé, M., & Zwart, S.J. 2016. Evaluation and comparison of
satellite-based rainfall products in Burkina Faso, West Africa.
International Journal of Remote Sensing 37 (17): 3995–4014.
https://doi.org/10.1080/01431161.2016.1207258
Dhungel, R., Allen ,R. G., Trezza, R., & Robison, C. W. 2014.
Comparison of latent heat flux using aerodynamic methods and using the
penman-monteith method with satellite-based surface energy balance.
Remote Sensing 6 (9): 8844–8877. https://doi.org/10.3390/rs6098844
Dinku, T., Funk, C., Peterson, P., Maidment, R., Tadesse, T., Gadain,
H., & Ceccato, P. 2018. Validation of the CHIRPS satellite rainfall
estimates over eastern Africa. Quarterly Journal of the Royal
Meteorological Society 144 (April): 292–312.
https://doi.org/10.1002/qj.3244
FAO. 1997. Irrigation potential in Africa: A basin approach. FAO: Rome,
Italy.
FAO. 2020a. WaPOR Database methodology, V2 release (not yet published).
Rome, Italy.
FAO. 2020b. WaPOR - The FAO portal to monitor Water Productivity through
Open access or Remotely sensed derived data, FAO, Rome, Italy,
https://wapor.apps.fao.org/home/1, date accessed: 26-10-2019.
Funk, C., Peterson, P., Landsfeld, M., Pedreros, D., Verdin, J., Shukla,
S., … & Michaelsen, J. 2015. The climate hazards infrared
precipitation with stations—a new environmental record for monitoring
extremes. Scientific Data 2: 150066.
https://doi.org/10.1038/sdata.2015.66
Gao F., Masek J., Schwaller, M., & Hall, F. 2006. On the blending of
the Landsat and MODIS surface reflectance: predicting daily Landsat
surface reflectance. IEEE Transactions on Geoscience and Remote Sensing
44 (8): 2207–2218. https://doi.org/10.1109/TGRS.2006.872081
Gebrechorkos, S. H., Hülsmann, S., & Bernhofer, C. 2018. Evaluation of
multiple climate data sources for managing environmental resources in
East Africa. Hydrology and Earth System Sciences 22 (8): 4547–4564.
https://doi.org/10.5194/hess-22-4547-2018
Ghilain, N., Arboleda, A., & Gellens-Meulenberghs, F. 2011.
Evapotranspiration modelling at large scale using near-real time MSG
SEVIRI derived data. Hydrology and Earth System Sciences 15: 771–786.
DOI: https://doi.org/10.5194/hess-15-771-2011
Glenn E. P., Huete, A. R., Nagler, P. L., Hirschboeck, K. K., & Brown,
P. 2007. Integrating Remote Sensing and Ground Methods to Estimate
Evapotranspiration. Critical Reviews in Plant Science 26 (3): 139–168.
https://doi.org/10.1080/07352680701402503
Glenn, E. P., Huete, A. R., Nagler, P. L., & Nelson, S. G. 2008.
Relationship between remotely-sensed vegetation indices, canopy
attributes and plant physiological processes: what vegetation indices
can and cannot tell us about the landscape. Sensors 8 (4): 2136–2160.
https://doi.org/10.3390/s8042136
Guillevic, P. C., Olioso, A., Hook, S. J., Fisher, J. B., Lagouarde, J.
P., & Vermote, E. F. 2019. Impact of the revisit of thermal infrared
remote sensing observations on evapotranspiration uncertainty-A
sensitivity study using AmeriFlux Data. Remote Sensing 11 (5): 573.
https://doi.org/10.3390/rs11050573
Hills, R. C. 1978. The Structure of the Inter-Tropical Convergence Zone
in Equatorial Africa and Its Relationship to East African Rainfall.
Transactions of the Institute of British Geographers Transactions of the
Institute of British Geographers 4 (3): 329–352.
https://doi.org/10.2307/622055
Hobbins, M. T., Ramírez, J. A, & Brown, T. C. 2001. The complementary
relationship in regional evapotranspiration: An enhanced
advection-aridity model. Water Resources Research 37 (5): 1389–1403.
https://doi.org/10.1029/2000WR900359
Hu G., Jia L., & Menenti, M. 2015. Comparison of MOD16 and LSA-SAF MSG
evapotranspiration products over Europe for 2011. Remote Sensing of
Environment 156 (January): 510–526.
https://doi.org/10.1016/j.rse.2014.10.017
Kottek, M., Grieser, J., Beck, C., Rudolf, B., & Rubel, F. 2006. World
map of the Köppen-Geiger climate classification updated. Meteorologische
Zeitschrift 15 (3): 259–263.
https://doi.org/10.1127/0941-2948/2006/0130
LBPTC. 2010. Joint Limpopo River Basin Study Scoping Phase Final Report.
Federal Ministry for Economic Cooperation and Development and DFID.
http://www.limpopo.riverawarenesskit.org/LIMPOPORAK_COM/_SYSTEM/DMSSTORAGE/3451EN/LIMCOM2010_SCOPINGSTUDY_ENG.PDF
Leca, A., Parisi, L., Lacointe, A., & Saudreau, M. 2011. Comparison of
Penman–Monteith and non-linear energy balance approaches forestimating
leaf wetness duration and apple scab infection, Agricultural and Forest
Meteorology151 (2011): 1158–1162.
https://doi.org/10.1016/j.agrformet.2011.04.010
Lehner, B., & Grill, G. 2013. Global river hydrography and network
routing: baseline data and new approaches to study the world’s large
river systems. Hydrological Processes, 27 (15): 2171–2186.
https://doi.org/10.1002/hyp.9740
Li, K. Y., Coe, M. T., & Ramankutty, N. 2005. Investigation of
hydrological variability in West Africa using land surface models.
Journal of Climate 18 (16): 3173–3188.
https://doi.org/10.1175/JCLI3452.1
Liu, W., Wang, L., Zhou, J., Li, Y., Sun, F., Fu, G., & Li, X. 2016. A
worldwide evaluation of basin-scale evapotranspiration estimates against
the water balance method, Journal of Hydrology 238: 82-95.
https://doi.org/10.1016/j.jhydrol.2016.04.006
Majozi, N. P., Mannaerts, C .M., Ramoelo, A., Mathieu, R., Mudau, A. E.,
& Verhoef, W. 2017a. An intercomparison of satellite-based daily
evapotranspiration estimates under different eco-climatic regions in
South Africa. Remote Sensing 9 (4): 307.
https://doi.org/10.3390/rs9040307
Majozi, N. P., Mannaerts, C. M., Ramoelo, A., Mathieu, R., Nickless, A.,
& Verhoef, W. 2017b. Analysing surface energy balance closure and
partitioning over a semi-arid savanna FLUXNET site in Skukuza, Kruger
National Park, South Africa. Hydrology and Earth System Sciences 21 (7):
3401–3415. https://doi.org/10.5194/hess-21-3401-2017
Mamadou, O., Cohard, J. M., Galle, S., Awanou, C. N., Diedhiou, A.,
Kounouhewa, B., & Peugeot, C. 2014. Energy fluxes and surface
characteristics over a cultivated area in Benin: daily and seasonal
dynamics. Hydrology and Earth System Sciences 18: 893–914.
https://doi.org/10.5194/hess-18-893-2014
Matondo, J. I., & Mortensen, P. 1998. Water resource assessment for the
Zambezi River Basin. Water International 23 (4): 256–262.
https://doi.org/10.1080/02508069808686780
McDonald, J. E. 1961. On the Ratio of Evaporation to Precipitation.
Bulletin of the American Meteorological Society 42 (3): 185–189.
https://doi.org/10.1175/1520-0477-42.3.185
Merbold, L., Ardö, J., Arneth, A., Scholes, R. J., Nouvellon, Y.,
Grandcourt, A., … & Kergo, W.L. 2009. Precipitation as driver of
carbon fluxes in 11 African ecosystems, Biogeosciences. Biogeosciences 6
(6): 1027–1041. https://doi.org/10.5194/bg-6-1027-2009
Morisette, J. T., Privette, J. L., & Justice C. O. 2002. A framework
for the validation of MODIS Land products. Remote Sensing of Environment
83 (1–2): 77–96. https://doi.org/10.1016/S0034-4257(02)00088-3
Morisette, J. T., Privette, J. L., Justice C. O., & Running S. W. 1998.
MODIS Land Validation Plan. (September).
https://modis.gsfc.nasa.gov/data/atbd/land_val.pdf
Mu, Q., Heinsch, F. A., Zhao, M., & Running, S. W. 2007. Development of
a global evapotranspiration algorithm based on MODIS and global
meteorology data. Remote Sensing of Environment 106 (3): 285–304.
https://doi.org/10.1016/j.rse.2007.04.015
Mu, Q., Zhao, M., & Running, S. W. 2011. Improvements to a MODIS global
terrestrial evapotranspiration algorithm. Remote Sensing of Environment
115 (8): 1781–1800. https://doi.org/10.1016/j.rse.2011.02.019
Mu, Q., Zhao, M., & Running, S. W. 2013. Algorithm Theoretical Basis
Document: MODIS Global Terrestrial Evapotranspiration (ET) Product (NASA
MOD16A2/A3) Collection 5. NASA Headquarters.
https://modis-land.gsfc.nasa.gov/pdf/MOD16ATBD.pdf
Mueller, B., Seneviratne, S. I., Jimenez, C., Corti, T., Hirschi, M.,
Balsamo, G., … & Kergo, W.L. 2011. Evaluation of global
observations-based evapotranspiration datasets and IPCC AR4 simulations.
Geophysical Research Letters 38 (6): 1–7.
https://doi.org/10.1029/2010GL046230
Muthoni, F. K., Odongo, V. O., Ochieng, J., Mugalavai, E. M., Mourice,
S. K., Hoesche-Zeledon, I., … & Bekunda, M. 2019. Long-term
spatial-temporal trends and variability of rainfall over Eastern and
Southern Africa. Theoretical and Applied Climatology 137: 1869–1882.
https://doi.org/10.1007/s00704-018-2712-1
Nagler, P. L., Glenn, E. P., Nguyen, U., Scott, R. L., & Doody, T.
2013. Estimating riparian and agricultural actual evapotranspiration by
reference evapotranspiration and MODIS enhanced vegetation index. Remote
Sensing 5 (8): 3849–3871. https://doi.org/10.3390/rs5083849
Nouri, H., Glenn, E. P., Beecham, S., Boroujeni, S. C., Sutton, P.,
Alaghmand, S., … & Nagler, P. 2016. Comparing three approaches
of evapotranspiration estimation in mixed urban vegetation: field-based,
remote sensing-based and observational-based methods. Remote Sensing 8
(6): 492. https://doi.org/10.3390/rs8060492
Odongo, V. O., Van der Tol., C., Becht, R., Hoedjes, J. C. B., Ghimire,
C. P., & Su, Z. 2016. Energy partitioning and its controls over a
heterogeneous semi-arid shrubland ecosystem in the Lake Naivasha Basin,
Kenya. Ecohydrology 9 (7): 1358–1375. https://doi.org/10.1002/eco.1732
Paw, K. T. 1992. A discussion of the Penman form equations and
comparisons of some equations to estimate latent energy flux density.
Agricultural and Forest Meteorology 57 (4): 297–304.
https://doi.org/10.1016/0168-1923(92)90125-N
Paw, U. K. T., & Gao, W. 1988. Applications of solutions to non-linear
energy budget equations. Agricultural and Forest Meteorology 43:
121–145. https://doi.org/10.1016/0168-1923(88)90087-1
Ramier, D., Boulain, N., Cappelaere, B., Timouk, F., Rabanit, M., Lloyd,
C. R., … & Wawrzyniak, V. 2009. Towards an understanding of
coupled physical and biological processes in the cultivated Sahel - 1.
Energy and water. Journal of Hydrology 375 (1–2): 204–216.
https://doi.org/10.1016/j.jhydrol.2008.12.002
Rana, G., & Katerji, N. 1998. A Measurement Based Sensitivity Analysis
of the Penman-Monteith Actual Evapotranspiration Model for Crops of
Different Height and in Contrasting Water Status. Theor. Appl. Climatol.
60: 141–149. https://doi.org/10.1007/s007040050039
Rienecker, M. M., Suarez, M. J., Gelaro, R., Todling, R., Bacmeister,
J., Liu, E., … & Woollen, J. 2011. MERRA: NASA’s modern-era
retrospective analysis for research and applications. Journal of Climate
24: 3624–3648. https://doi.org/10.1175/JCLI-D-11-00015.1
Rockström, J., Falkenmark, M., Lannerstad, M., & Karlberg, L. 2012. The
planetary water drama: Dual task of feeding humanity and curbing climate
change. Geophysical Research Letters 39 (15): 1–8.
https://doi.org/10.1029/2012GL051688
Rodell, M., Famiglietti J. S., Wiese, D. N., Reager, J. T., Beaudoing,
H. K., Landerer, F. W., & Lo, M. H. 2018. Emerging trends in global
freshwater availability. Nature 557: 651–659.
https://doi.org/10.1038/s41586-018-0123-1
Rubel, F., & Kottek, M. 2010. Observed and projected climate shifts
1901-2100 depicted by world maps of the Kӧppen-Geiger climate
classification. Meteorologische Zeitschrift 19 (2): 135–141.
https://doi.org/10.1127/0941-2948/2010/0430
Schneider, P., Ghent, D., Prata, F., Corlett, G. K., & Remedios, J. J.
2012. AATSR Validation: LST Validation Protocol. ESA Contract Number:
19054/05/NL/FF.
http://lst.nilu.no/Portals/73/Docs/Reports/UL-NILU-ESA-LST-LVP-Issue1-Rev0-1604212.pdf
Sebhat, M. Y., & Wenninger, J. 2014. Water balance of the Juba and
Shabelle Rivers basins the Horn of Africa. International Journal of
Agricultural Policy and Research 2 (6): 238–255
Sharma V., Kilic A., & Irmak S. 2016. Impact of scale/resolution on
evapotranspiration from Landsat and MODIS images. Water Resources
Research 52 (3): 1800–1819. https://doi.org/10.1002/2015WR017772
Steduto, P., Todorovic, M., Caliandro, A., & Rubino, P. 2003. Daily
reference evapotranspiration estimates by the Penman-Monteith equation
in Southern Italy. Constant vs. variable canopy resistance. Theoretical
and Applied Climatology 74 (3–4): 217–225.
https://doi.org/10.1007/s00704-002-0720-6
Su, Z. 2002. The Surface Energy Balance System (SEBS) for estimation of
turbulent heat fluxes. Hydrology and Earth System Sciences Discussions 6
(1): 85–100. https://doi.org/10.5194/hess-6-85-2002
Sugita, M., Matsuno, A., El-Kilani, R. M. M, Abdel-Fattah, A., &
Mahmoud, M. A. 2017. Crop evapotranspiration in the Nile Delta under
different irrigation methods. Hydrological Sciences Journal 62 (10):
1618–1635. https://doi.org/10.1080/02626667.2017.1341631
Swinnen, E., Van Hoolst, R., & Toté, C. 2015 Gio Global Land Component
- Lot I “Operation of the Global Land Component”. Framework Service
Contract N° 388533 (JRC). Quality Assessment Report. Dry Matter
Productivity (DMP) - PROBA-V., Algorithm Theoretical Basis Document,
Issue I1.01. VITO, EC Copernicus Global Land, Brussels.
https://land.copernicus.eu/global/sites/cgls.vito.be/files/products/GIOGL1_QAR_DMP300m_V1_I1.12.pdf
Tagesson, T., Fensholt, R., Guiro, I., Rasmussen, M. O., Huber, S, Mbow,
C., … & Ardö, J. 2015. Ecosystem properties of semiarid savanna
grassland in West Africa and its relationship with environmental
variability. Global Change Biology 21 (1): 250–264.
https://doi.org/10.1111/gcb.12734
The Nile Basin Initiative Secretariat. 2014. Nile Waters Technical
BUlletin from THe Nile Basin Initiative Secretariat, Understanding Nile
Basin Hydrology Mapping Actual Evapotranspiration over the Nile Basin.
Entebbe, Ethiopia. Available at: www.nilebasin.org
Trigo I. F., De Bruin H., Beyrich F., Bosveld F. C., Gavilán P., Groh
J., & López-Urrea R. 2018. Validation of reference evapotranspiration
from Meteosat Second Generation (MSG) observations. Agricultural and
Forest Meteorology 259 (15 September 2018): 271–285.
https://doi.org/10.1016/j.agrformet.2018.05.008
USAID. 2016. Southern Africa Drought - Fact Sheet #4 - Fiscal Year (FY)
2016. 6 May 2016 (pp 1–9). DOI:
https://www.usaid.gov/sites/default/files/documents/1866/southern_africa_dr_fs02_05-06-2016.pdf
Voisin, N., Wood, A. W., & Lettenmaier, D. P. 2008. Evaluation of
Precipitation Products for Global Hydrological Prediction. Journal of
Hydrometeorology 9: 388–407. https://doi.org/10.1175/2007JHM938.1
Wang, D., & Alimohammadi, N. 2012. Responses of annual runoff,
evaporation, and storage change to climate variability at the watershed
scale. Water Resources Research 48: W05546.
https://doi.org/10.1029/2011WR011444
Weerasinghe, I., Van Griensven, A., Bastiaanssen, W., Mul, M., & Jia,
L. 2019. Can we trust remote sensing ET products over Africa? Hydrology
and Earth System Sciences Discussions, in review, 2019.
https://doi.org/10.5194/hess-2019-233
Wilson, K., Goldstein, A., Falge, E., Aubinet, M., Baldocchi, D. D.,
Berbigier, P., … & Verma, S. 2002. Energy balance closure at
FLUXNET sites. Agricultural and Forest Meteorology 113 (1–4): 223–243.
https://doi.org/10.1016/S0168-1923(02)00109-0
Zeng, Y., Su, Z., Barmpadimos, I., Perrels, A., Poli, P., Boersma, K.F.,
… & Timmermans W. 2019. Towards a Traceable Climate Service:
Assessment of Quality and Usability of Essential Climate Variables.
Remote Sensing 11 (10): 1186. https://doi.org/10.3390/rs11101186
Zeng, Y., Su, Z., Calvet, J. C., Manninen, T., Swinnen, E., Schulz, J.,
Roebeling, R., … & Meurey, C. 2015. Analysis of current
validation practices in Europe for space-based climate data records of
essential climate variables. International Journal of Applied Earth
Observation and Geoinformation 42 (October 2015): 150–161.
https://doi.org/10.1016/j.jag.2015.06.006
Zhang, Y., Leuning, R., Chiew, F. H. S., Wang, E., Zhang, L., Liu, C.,
… & Jung, M. 2012. Decadal Trends in Evaporation from Global
Energy and Water Balances. Journal of Hydrometeorology 13 (1): 379–391.
https://doi.org/10.1175/JHM-D-11-012.1