Evapotranspiration in the Nile Basin: Identifying Dynamics and Drivers, 2002–2011

Alemu, Henok; Kaptué, Armel T.; Senay, Gabriel B.; Wimberly, Michael C.; Henebry, Geoffrey M.

doi:10.3390/w7094914

Cited by 16 publications

(13 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These results indicate that ET in the Nile basin generally decreased over the period of 35 years considered. This is in agreement with previous studies in the region [8,24,28].…”

Section: Long-term Trendssupporting

confidence: 94%

Evapotranspiration and its Components in the Nile River Basin Based on Long-Term Satellite Assimilation Product

Nooni

Wang

Hagan

et al. 2019

Water

View full text Add to dashboard Cite

Actual evapotranspiration (ET) and its individual components’ contributions to the water–energy nexus provide insights into our hydrological cycle in a changing climate. Based on long-term satellite ET data assimilated by the Global Land Evaporation Amsterdam Model (GLEAM), we analyzed changes in ET and its components over the Nile River Basin from 1980 to 2014. The results show a multi-year mean ET of 518 mm·year–1. The long-term ET trend showed a decline at a rate of 18.8 mm·year–10. ET and its components showed strong seasonality and the ET components’ contribution to total ET varied in space and time. ET and its components decreased in humid regions, which was related to precipitation deficits. ET increases in arid-semiarid regions were due to water availability from crop irrigation fields in the Nile Plain. Precipitation was the dominant limiting driver of ET in the region. Vegetation transpiration (an average of 78.1% of total ET) dominated the basin’s water fluxes, suggesting biological fluxes play a role in the regional water cycle’s response to climate change. This analysis furthers our understanding of the water dynamics in the region and may significantly improve our knowledge of future hydrological modelling.

show abstract

“…These results indicate that ET in the Nile basin generally decreased over the period of 35 years considered. This is in agreement with previous studies in the region [8,24,28].…”

Section: Long-term Trendssupporting

confidence: 94%

Evapotranspiration and its Components in the Nile River Basin Based on Long-Term Satellite Assimilation Product

Nooni

Wang

Hagan

et al. 2019

Water

View full text Add to dashboard Cite

show abstract

“…On the other side of SSA (i.e., in Eastern African countries especially Ethiopia, Nile Delta, and Uganda), Alemu et al (2015) observed similar negative correlations between ET and rainfall in irrigated croplands, wetlands, and forests. Moreover, from the seasonal distribution of ET over SSA (see Section 4.3), it is noted that except for the wet seasons (i.e., the April-June and July-September period), ET values are extremely low in these Sahelian countries (i.e.,…”

Section: Spatial Correlations Of Et With Twsc and Rainfallmentioning

confidence: 64%

Exploring evapotranspiration dynamics over Sub-Sahara Africa (2000–2014)

Ndehedehe

Okwuashi

Ferreira

et al. 2018

Environ Monit Assess

View full text Add to dashboard Cite

Monitoring changes in evapotranspiration (ET) is useful in the management of water resources in irrigated agricultural landscapes and in the assessment of crop stress and vegetation conditions of drought-vulnerable regions. Information on the impacts of climate variability on ET dynamics is profitable in developing water management adaptation strategies. Such impacts, however, are generally unreported and not conclusively determined in some regions. In this study, changes in MODIS (Moderate Resolution Imaging Spectroradiometer)-derived ET (2000-2014) over large proportions of Sub-Sahara Africa (SSA) are explored. The multivariate analyses of ET over SSA showed that four leading modes of observed dynamics in ET, accounting for about 90% of the total variability, emanated mostly from some sections of the Sudano-Sahel and Congo basin. Based on Man-Kendall's statistics, significant positive trends (α = 0.05) in ET over the Central African Republic and most parts of the Sahel region were observed. Over much of the Congo basin nonetheless, ET showed significant (α = 0.05) distributions of widespread negative trends. These trends in ET were rather found to be consistent with observed changes in model soil moisture but not in all locations, perhaps due to inconsistent trends in maximum rainfall and land surface temperature. However, the results of spatio-temporal drought analysis confirm that the extensive ET losses in the Congo basin were somewhat induced by soil moisture deficits. Amidst other prominent drivers of ET, the dynamics of ET over the terrestrial ecosystems of SSA appear to be a more complex phenomenon that may transcend natural climate variations.

show abstract

“…In cases of flux data unavailability, the water balance method could be used or ET products could be compared with global ET products in their research area. Some researchers directly applied this product to analyze the relationships between ET variability and vegetation dynamics without validating the reliability of the product in the Nile Basin, Africa [26,27]. To further improve the estimation of ET, the uncertainty of ET SSEBopYRB in this research area should be discussed.…”

Section: Discussionmentioning

confidence: 99%

A Comparison of SSEBop-Model-Based Evapotranspiration with Eight Evapotranspiration Products in the Yellow River Basin, China

Yin

Feng

et al. 2020

Remote Sensing

View full text Add to dashboard Cite

Accurate evapotranspiration (ET) estimation is important in understanding the hydrological cycle and improving water resource management. The operational simplified surface energy balance (SSEBop) model can be set up quickly for the routine monitoring of ET. Several studies have suggested that the SSEBop model, which can simulate ET, has performed inconsistently across the United States. There are few detailed studies on the evaluation of ET simulated by SSEBop in other regions. To explore the potential and application scope of the SSEBop model, more evaluation of the ET simulated by SSEBop is clearly needed. We calculated the SSEBop-model-based ET (ETSSEBopYRB) with land surface temperature product of MOD11A2 and climate variables as inputs for the Yellow River Basin (YRB), China. We also compared the ETSSEBopYRB with eight coarse resolution ET products, including China ETMTE, produced using the upscaling energy flux method; China ETCR, which is generated using the non-linear complementary relationship model; three global products based on the Penman–Monteith logic (ETPMLv2, ETMODIS, and ETBESS), two global ET products based on the surface energy balance (ETSEBS, ETSSEBopGlo), and integrated ET products based on the Bayesian model averaging method (ETGLASS), using the annual ET data derived from the water balance method (WB-ET) for fourteen catchments. We found that ETSSEBopYRB and the other eight ET products were able to explain 23 to 52% of the variability in the water balance ET for fourteen small catchments in the YRB. ETSSEBopYRB had a better agreement with WB-ET than ETSEBS, ETMODIS, ETCR, and ETGLASS, with lower RMSE (88.3 mm yr−1 vs. 121.7 mm yr−1), higher R2 (0.49 vs. 0.43), and lower absolute RPE (−3.3% vs. –19.9%) values for the years 2003–2015. We also found that the uncertainties of the spatial patterns of the average annual ET values and the ET trends were still large for different ET products. Third, we found that the free global ET product derived from the SSEBop model (ETSSEBopGlo) highly underestimated the annual total ET trend for the YRB. The poor performance of the land surface temperature product of MOD11A2 in 2015 caused the large ETSSEBopYRB uncertainty at eight-day and monthly scales. Further evaluation of ET based on the SSEBop model for site measurements is needed.

show abstract

Evapotranspiration in the Nile Basin: Identifying Dynamics and Drivers, 2002–2011

Cited by 16 publications

References 44 publications

Evapotranspiration and its Components in the Nile River Basin Based on Long-Term Satellite Assimilation Product

Evapotranspiration and its Components in the Nile River Basin Based on Long-Term Satellite Assimilation Product

Exploring evapotranspiration dynamics over Sub-Sahara Africa (2000–2014)

A Comparison of SSEBop-Model-Based Evapotranspiration with Eight Evapotranspiration Products in the Yellow River Basin, China

Contact Info

Product

Resources

About