A multi-source satellite data approach for modelling Lake Turkana water level: calibration and validation using satellite altimetry data

Velpuri, Naga Manohar; Senay, Gabriel B.; Asante, K. O.

doi:10.5194/hess-16-1-2012

Cited by 84 publications

(75 citation statements)

References 66 publications

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“…Ideally, satellite-based precipitation data require a local calibration, as mentioned in Section 3.1.1, but without rain gauges installed over water surfaces, it is impossible to conduct a decent calibration. The original satellite precipitation data have been used to quantify precipitation over the lake in many studies, e.g., [2,51] for Lake Victoria and [52] for Lake Turkana. In this study, none of the available 20 rain gauge stations are located over the lake surface, and only five stations are located relatively near the shoreline (Figure 1).…”

Section: Precipitation Over the Lake (P Lake )mentioning

confidence: 99%

Estimation of Lake Outflow from the Poorly Gauged Lake Tana (Ethiopia) Using Satellite Remote Sensing Data

Duan

Gao

2018

Remote Sensing

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Lake Tana is the largest lake in Ethiopia, and its lake outflow is the source of the Blue Nile River that provides vital water resources for many livelihoods and downstream/international stakeholders. Therefore, it is essential to quantify and monitor the water balance of Lake Tana. However, Lake Tana is poorly gauged, with more than 50% of Lake Tana Basin being ungauged from in-situ measurements, making it difficult to quantify the lake inflow from surrounding basins. The lack of in-situ measurements highlights the need for the innovative application of satellite remote sensing. This study explores how freely accessible satellite remote sensing can be used to complement routine weather data to quantify the water balance of Lake Tana and its surrounding catchments. This study particularly investigates whether the outflow from Lake Tana can be estimated with sufficient accuracy as the residual of the lake water balance. Monthly inflow into lake was computed as the total runoff from the surrounding catchments; the runoff was estimated as the residual of the land-based catchment water balance using satellite precipitation improved with an integrated downscaling-calibration procedure, satellite evapotranspiration, and a correction term for changes in land total storage (soil moisture storage and deep percolation). The outflow from Lake Tana was estimated as the residual of lake water balance by combining satellite-based lake precipitation, changes in water storage, and lake inflow with estimated lake evaporation. Evaluation using limited available measurements showed that estimated annual runoff for two gauged subbasins agreed well with measurements, with differences within 4%. The estimated annual outflow from Lake Tana was also close to measured outflow, with a difference of 12%. However, the estimated monthly runoff from catchments and monthly lake outflow were unsatisfactory, with large errors.

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Section: Precipitation Over the Lake (P Lake )mentioning

confidence: 99%

Estimation of Lake Outflow from the Poorly Gauged Lake Tana (Ethiopia) Using Satellite Remote Sensing Data

Duan

Gao

2018

Remote Sensing

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“…Validation studies of RFE over the Ethiopian highlands using gauge data suggested that RFE can be reliably used for early warning systems to empower the decision making process (Dinku et al, 2008;Beyene and Meissner, 2010). Reliable use of RFE data to model Lake Turkana water levels with reasonable accuracy was demonstrated by Velpuri et al (2012). RFE data from January 1998 to December 2009 are used in this study.…”

Section: Data Usedmentioning

confidence: 99%

“…In this paper we use the lake level modeling approach presented by Velpuri et al (2012). This approach uses a multisensor multi-source approach to monitor lake water levels by integrating digital elevation data, satellite-based rainfall estimates, modeled ET, runoff data, and other satellite products.…”

Section: Lake Level Modeling Approachmentioning

confidence: 99%

Assessing the potential hydrological impact of the Gibe III Dam on Lake Turkana water level using multi-source satellite data

Velpuri

Senay

2012

Hydrol. Earth Syst. Sci.

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Abstract. Lake Turkana, the largest desert lake in the world, is fed by ungauged or poorly gauged river systems. To meet the demand of electricity in the East African region, Ethiopia is currently building the Gibe III hydroelectric dam on the Omo River, which supplies more than 80 % of the inflows to Lake Turkana. On completion, the Gibe III dam will be the tallest dam in Africa with a height of 241 m. However, the nature of interactions and potential impacts of regulated inflows to Lake Turkana are not well understood due to its remote location and unavailability of reliable in situ datasets. In this study, we used 12 yr (1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)) of existing multisource satellite and model-assimilated global weather data. We used a calibrated multi-source satellite data-driven water balance model for Lake Turkana that takes into account model routed runoff, lake/reservoir evapotranspiration, direct rain on lakes/reservoirs and releases from the dam to compute lake water levels. The model evaluates the impact of the Gibe III dam using three different approaches -a historical approach, a rainfall based approach, and a statistical approach to generate rainfall-runoff scenarios. All the approaches provided comparable and consistent results. Model results indicated that the hydrological impact of the Gibe III dam on Lake Turkana would vary with the magnitude and distribution of rainfall post-dam commencement. On average, the reservoir would take up to 8-10 months, after commencement, to reach a minimum operation level of 201 m depth of water. During the dam filling period, the lake level would drop up to 1-2 m (95 % confidence) compared to the lake level modeled without the dam. The lake level variability caused by regulated inflows after the dam commissioning were found to be within the natural variability of the lake of 4.8 m. Moreover, modeling results indicated that the hydrological impact of the Gibe III dam would depend on the initial lake level at the time of dam commencement. Areas along the Lake Turkana shoreline that are vulnerable to fluctuations in lake levels due to the Gibe III dam were also identified. This study demonstrates the effectiveness of using existing multi-source satellite data in a basic modeling framework to assess the potential hydrological impact of an upstream dam on a terminal downstream lake. The results obtained from this study could also be used to evaluate alternative damfilling scenarios and assess the potential impact of the dam on Lake Turkana under different operational strategies.

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“…The Omo basin is part of the large Turkana system with a catchment area of 131,000-145,500 km 2 covering southwestern Ethiopia and northern Kenya (Feibel 2011;Velpuri et al 2012). The Turkana system essentially consists of the Omo-Gibe (or simply, Omo) River and Lake Turkana.…”

Section: Study Sitesmentioning

confidence: 99%

“…One of these, the Omo-Turkana basin, spans a large part of the southwestern Ethiopian highlands and northern Kenya (Feibel 2011;Velpuri et al 2012) (Figure 1). …”

Section: Introductionmentioning

confidence: 99%

Ichthyofaunal diversity of the Omo-Turkana basin, East Africa, <span lang="EN-US">with specific reference to fish diversity within the limits of Ethiopian waters</span>

Wakjira

Getahun

2017

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Abstract:The freshwaters of the East African nation of Ethiopia are divided into nine main drainage basins. One of these, the Omo-Turkana basin, spans a large part of southwestern Ethiopian highlands and northern Kenya, and consists of the Omo-Gibe (or simply, Omo) River and a northern portion of Lake Turkana. Despite some development activities, including proposed dam construction with potential impacts on ichthyofaunal diversity, the Ethiopian part of the basin generally lacks comprehensive study or full scientific documentation. During the current surveys 31 species were identified from the lower Omo River and Ethiopian part of Lake Turkana, with some new records for the basin. The Omo River system was found to be richer in species while Lake Turkana has a higher abundance. Ichthyofaunal diversity within Ethiopian waters is specifically addressed, and an annotated checklist for native species of the basin is provided.

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A multi-source satellite data approach for modelling Lake Turkana water level: calibration and validation using satellite altimetry data

Cited by 84 publications

References 66 publications

Estimation of Lake Outflow from the Poorly Gauged Lake Tana (Ethiopia) Using Satellite Remote Sensing Data

Estimation of Lake Outflow from the Poorly Gauged Lake Tana (Ethiopia) Using Satellite Remote Sensing Data

Assessing the potential hydrological impact of the Gibe III Dam on Lake Turkana water level using multi-source satellite data

Ichthyofaunal diversity of the Omo-Turkana basin, East Africa, <span lang="EN-US">with specific reference to fish diversity within the limits of Ethiopian waters</span>

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