Expertise: Hydrologist
Expertise Group: Engineering
Consultant Source: International
TOR Keywords: Hydrologist
Objective and Purpose of the Assignment
The specialist will support the preparation of the Ayakchi reservoir project and Obizarang reservoir
project in the Amu Darya River basin in Uzbekistan to confirm technical viability of hydrological aspect
and to ensure the quality design of the project as suitable adaptation measure under the climate change.
Scope of Work
The specialist will provide expert review, advice and conduct data collection, hydrological technical
due diligence for the Ayakchisay river basin and Obizarang river basin by constructing hydrological and
hydraulic models. The specialist’s intermittent inputs will be delivered over an approximately 5-month
period.
Detailed Tasks and/or Expected Output
The specialist’s activities are expected to include but not be limited to:
- Review the draft feasibility report for the Ayakchi reservoir project and the Obizarang reservoir
project prepared by the government of Uzbekistan, and identify necessary additional data collection and
verifications required for the dam design from a hydrological perspective. - Conduct data collection (recent and historical) and data verifications related to precipitation in
the target river basins, water levels and discharges along the river systems, using a high resolution
Digital Elevation Model (DEM) as well as characteristics of river basins by conducting field studies,
communicating with the relevant authorities and local/regional institutions, etc. The remote sensing
global data shall be used to supplement the lack of dataset. If necessary, the ground truthing methods
and correlation to similar/neighboring will be considered. - Develop hydrological and hydraulic models for the target river basins and reservoirs, using the data
as described above by supervising a national specialist. The hydrologic model should also simulate
relevant snow accumulation and melt. The computed output needs to be verified based on the historical
observation data. The assumptions, discrepancies, uncertainties as well as limitations should be clearly
described. Once the model has been verified for historical conditions, medium- and long-term climate
change scenarios (SSP3-7.0 and SSP5-8.5) for inflows, sedimentation, flood return periods, and extreme
dry periods should be conducted to assess technical viability under changing climate conditions. - Conduct the following scenario simulations and analyses using the verified models by supervising a
national specialist: (i) Inflow under various hydrological conditions; (ii) flood flow propagation and
inundation along downstream reach of the dam under the flood conditions with various return periods;
(iii) reservoir storage and filling using hydraulic model based on the predicted inflows by the
hydrological model and the planned outflows for irrigation and other purposes. The planned outflow
volume shall be examined properly, and necessary adjustment shall be made; (iv) provision of input for
water requirements and balance study for assessing impact for irrigation systems; and (v) any other
analysis by using the verified models should be conducted if needed for checking technical viability. - Identify necessary assessments, associated with the feasibility study, and establish the scope of the
technical due diligence to be conducted. - Support to any other tasks assigned by the project officer. The specialist may recruit and supervise
a research assistant under this contract to support the assigned work.
Minimum Qualification Requirements
The specialist should be a graduate, preferably post graduate, degree in engineering, hydrology, water
resources, irrigation, flood management, or a related discipline. He/she has at least 10 years of
professional experience, civil engineering in the field of river basin management or water resources
management. The well-knowledge with hydrology and hydrometrics model including reservoirs and the
regional or experience in the central Asian region will be preferred.
Minimum General Experience: 10 Years
Minimum Specific Experience (relevant to assignment): 10 Years
