## Research on More Precise Definition of the Components of the River Water Balance of the Amu Darya and its Main Tributaries and Development of XLSX Routine

**Client:** BWO Amu Darya

**Contractor:** SIC ICWC

**Implementation period:** 01.01.31.12.2021

**Project objective:** Carrying out research, developing and testing the routine for calculation of components of water balance of the Amu Darya River and reservoirs in the reaches from Kelif g/s Bir-Ata g/s, Bir-Ata g/s Tuyamuyun g/s (Tuyamuyn reservoir), Tuyamuyun g/s Kipchak g/s, Kipchak g/s Samanbay g/s.

**Work done:**

- Collected and analyzed source information for the period from 1991 to 2020.
- Developed work methodology.
- Worked out methodology for calculation of the components of Amu Darya river water balance in the reaches from Kelif g/s Bir-Ata g/s, Bir-Ata g/s Tuyamuyun g/s (Tuyamuyn reservoir), Tuyamuyun g/s Kipchak g/s, Kipchak g/s Samanbay g/s.
- Drafted progress report, including the methodology and test calculations shaped as XLSX routine.
- The outputs submitted to BWO Amu Darya.

Taking into account the results of the research work in 2020 and 2021, BWO "Amudarya" has been equipped with the methodological, calculation and information base for calculating components of river water balance and reservoir water balance for 4 balancing sites, starting from Kelif g/s to Samanbai g/s, as well as with recommendations on estimation of water losses.

This work allowed defining more precisely the components of water balance of the Amu Darya river in its middle and lower reaches and water balance of Tuyamuyun Hydroscheme reservoirs. As a result, a river water balance mathematical model and algorithms were developed and a relevant routine was implemented to calculate:

- Water losses through evaporation in river reaches,
- Seepage losses in the river and underflow discharge into river reaches,
- Return flow into the river,
- Water losses through evaporation in Tuyamuyun Hydroscheme reservoirs,
- Seepage losses in Tuyamuyun Hydroscheme reservoirs.

Test calculations show that the calculation of the above balance items in the AmuDarya river water balance increases the accuracy river water balance and hence planning of flow distribution and regulation in the Amu Darya and reduces balance discrepancies.