Expertise: Hydrologic and Hydraulic Modeler
Expertise Group: Biological Sciences & Ecology
Consultant Source: International
TOR Keywords: Hydrologic and Hydraulic Modeler
Objective and Purpose of the Assignment
- The Asian Development Bank (ADB) will engage consultants following the ADB Procurement Policy (2017,
as amended from time to time) and its associated project administration instructions and/or staff
instructions. ADB will lead the identification, evaluation, and selection of the technical assistance
(TA) consultants. This Terms of Reference (TOR) refers to the consulting service under Output 3, using
individual consultants’ recruitment. - ADB will supervise and monitor the consultants’ output to be delivered. The output will be reviewed
by both the executing agency and ADB, and the consultants will incorporate comments and suggestions
before finalizing the deliverables. - There are three outputs under the TA: (i) sector regulatory capacity developed; (ii)
Dushanbevodokanal management effectiveness improved; and (iii) Dushanbevodokanal’s climate adaptive
capacity increased. A multidisciplinary team of international and national experts will be recruited to
develop and implement TA activities under Output 3. Output 1 is sector regulatory capacity developed and
Output 2 is Dushanbevodokanal management effectiveness improved. - Output 3: Dushanbevodokanal’s climate adaptive capacity increased. The output’s objective is to build
resilience at DVK and ensure that WSS investments adequately address climate change and disaster risks.
The TA will undertake a systems-level resilience analysis of DVK, develop risk-based investment planning
and processes, and embed climate actions into corporate and operational documents. The TA team, in close
coordination with DVK, will collect data, hold consultations, develop climate models, assess climate
change impact and vulnerability, identify risk mitigation measures, prepare reports and presentations,
and organize training workshops to increase awareness of climate change risks and disaster risk
management. Based on these assessments, the TA will support the feasibility and preliminary design of a
Type 2B adaptation project. - International and national consultants will conduct systems-level climate resilience analysis,
stakeholder consultations, identification of priority projects, and carry out the feasibility study
covering concept design, in addition to required ADB due diligence with respect to economic, financial,
environment safeguards, social safeguards, gender, social development, climate change and procurement.
The consultants will also prepare draft documents for ADB’s RRP including related sector assessment,
problem tree, cost estimates, and timeline. The team leader will be responsible for overall coordination
of the team of consultants, overall quality of documentation prepared, and liaison with the client and
other consultants. In collaboration with the DVK engineering team, the consultants will prepare
strategic procurement planning, draft procurement plan, preliminary design incorporating climate
proofing measures with bill of quantities, cost estimates and proposed packaging of all civil works,
goods and consultancy services completed in all respect and accepted by the DVK and ADB. The
deliverables will be a joint responsibility of the implementing agency, and international and national
consultants. - The consultants will be responsible for completing feasibility study and ensuring compliance with ADB
and government requirements. The feasibility study will involve conceptual and preliminary design for a
priority project based on the climate change risk assessment. It is essential that the work complements
the outputs of climate change experts, with the aim of enhancing DVK’s resilience at the system level.
Scope of Work
The specialist will be responsible for delivering a water balance analysis in collaboration with Water
Sector Engineer, Climate Change Specialist, and National Coordinator, and contribute to preparing the
project’s CRA and CCA. The required water balance analysis takes into consideration the existing
situation as well as likely future scenarios based on projected climate change scenarios provided by the
climate change specialist. The primary objective is to develop a robust water balance model that i)
simulates long-term (50 years or more) hydrological conditions under different climate change scenarios,
ii) integrates key hydrological components: rainfall, surface water, groundwater, and
evapotranspiration; and iii) produces probability distributions for key water quantity variables, aiding
in risk assessment and resource management.
Detailed Tasks and/or Expected Output
The project will be carried out in the following tasks:
(i) Data collection and review
• Data Collection: Gather all relevant data on rainfall, surface water, groundwater, evapotranspiration,
and climate projections.
• Literature Review: Review existing models, methodologies, and best practices for water balance
modeling.
(ii) Model Development
• Conceptual Model Design: Develop a conceptual model outlining the interactions between different
components of the hydrological cycle.
• Mathematical Model Formulation: Formulate the mathematical and statistical relationships governing the
water balance components.
• Model Integration: Integrate rainfall, surface water, groundwater, and evapotranspiration data into
the model framework.
(iii) Calibration and Validation
• Calibration: Calibrate the model using historical data to ensure accuracy.
• Validation: Validate the model by comparing simulated outputs with observed data.
(iv) Simulation and Scenario Analysis
• Baseline Scenario: Simulate the water balance under current climatic conditions.
• Climate Change Scenarios: Implement various climate change scenarios using climate projection data,
ensuring consistency with climate scenarios for CRA. It may include SSP2-4.5 and SSP5-8.5 scenarios
• Long-Term Simulations: Conduct mid-term (30+ years) and long-term continuous simulations (50+ years)
for each scenario.
(v) Output Generation and Analysis
• Probability Distributions: Generate probability distributions for key water quantity variables (e.g.,
streamflow, groundwater levels, evapotranspiration rates). Options likely to comprise of combinations of
demand allocation amendments and/or adjustments, changes to operations and loss reductions.
• Sensitivity Analysis: Assess the sensitivity of the model to changes in input parameters.
• Uncertainty Analysis: Evaluate the uncertainties associated with the model predictions.
(vi) Reporting and Dissemination
• Prepare a comprehensive report detailing the methodology, results, and recommendations for reference
and future use.
• Stakeholder Workshop, staff capacity sessions.
• Model Documentation: Provide detailed documentation of the model for future reference and use.
• recommend modelling and analytics software/toolkits suitable to DVK to integrate climate change in
planning, project development, and O&M decisions; assess feasibility of integration with DVK’s existing
information and asset management systems
Minimum Qualification Requirements
The specialist will have an advanced degree in civil or water resources engineering or a related field
at least a master’s degree in civil or water resource engineering or a related field in hydrological
studies, with specialized experience of at least 7 years. The consultant should be conversant with data
processing, hydrological analysis techniques, water balance modeling and statistical analysis. The
specialist will have a strong grasp of climate adaptation in water sector and have demonstrated working
experience with relevant institutions in the region.
Minimum General Experience: 10 Years
Minimum Specific Experience (relevant to assignment): 7 Years
