River Research Institute (RRI)

Hydraulic Research Department


Hydraulic Research Directorate

There are three divisions in Hydraulic Research Directorate such as (i) River & Coastal Hydraulics (ii) Hydraulic Structure & Irrigation and (iii) Mathematical Model. These three divisions conduct model tests, studies and researches in the field of Flood Control and Drainage, Bank Protection and Stabilization, Coastal Engineering, Hydraulic Structure and Irrigation etc by means of physical and mathematical modelling. 


Physical Modelling

  • Physical modelling is a best tool, which can be used confidently to verify the effectiveness of any structural intervention by reproducing the natural phenomena of river hydro-morphology at a reduced scale. The problems related to river bank erosion and siltation are identified and how it can be mitigated is studied using this tool.
  • Local scour, 3-dimensional phenomena, morphological processes and development etc are reproduced well in the physical model.
  • The important design parameters such as local scour, flow field, maximum velocity, length, spacing, location and orientation etc of the hydraulic structures can be obtained by physical modelling.
  • The physical process/phenomena, which are not possible to reproduce well by Empirical Formula and Mathematical Expression, can be easily reproduced more precisely in physical modelling. Moreover, the real phenomena that are happening in the field are only possible to visualize in physical modelling.


Necessity of Physical Modelling

Models are important for at least two reasons. One reason is the prediction of future behaviour and the other is the need for testing of understanding the river processes in an integrated way. Physical Modelling technique can be used for solution of the problems occurring during the ongoing construction of bridge, river training works and also for the future maintenance of the river training works against the critical hydrodynamic and morphological changes. 

Physical Models are necessary for the following reasons.

  • To understand the prevailing river condition.
  • To determine the most suitable option for river training. 
  • To determine the effects of hydraulic structures on present flow pattern and river morphology.
  • To determine the effectiveness of the proposed works.
  • To find out the most suitable design parameters for hydraulic structures.
  • To predict future changes in the river morphology and flow regime. 
  • To have reliable results.


Areas where Physical Models are Applicable


  • River training
  • Bank protection and stabilization
  • River sedimentation
  • Flood control
  • Irrigation and drainage
  • Navigation

  • Bridge hydraulics
  • River morphology
  • River bed regulation
  • Shore protection
  • Beach nourishment



Mathematical Modelling

Mathematical modelling is complementary to physical modelling for correlation of results and any sound engineering judgement. RRI received mathematical modelling hardware and software under SICT project through Planning Commission, Government of Bangladesh. RRI established mathematical model facilities besides physical modelling. It is expected that RRI will contribute vital role in the water resources sector as well as in other related sector to make the project cost effective and sustainable. It is noted that RRI already completed mathematical model study for detail engineering design of Kurigram Irrigation Project (South Unit).