Both of them are correct. Such simulations which model hydraulic behaviour are considered as hydraulic modelling. In contrast, prognostication of hydrological parameters are the hydrological modeling.

I think any "XYZ or UVW" question is meaningful if you compare apples to apples and oranges to oranges. These are not two same type of modeling, so I do not know what is the answer.

Either clarify your question or mention why you are asking this question, and discuss about your physical system and the analysis you want to carry out.

Both are important each of the rest are interdependent

Dear Dr Abdelghani

It is better to know the difference between Hydrology and hydraulics:

Hydrology: problems & questions linked to the evolution of

water resources (quantity, distribution, evolution)

Ex.:

- Extreme rain events to floods

- Consequences of climate scenarios

- Impact of deforestation, agricultural practices, etc.

hydraulic: water issues

Ex.:

- Calculation of structures (canals, valves, pumps, dams)

- Networks (sanitation, water supply)

- Flood propagation

- Water quality (natural or artificial pollution)

For this, each science characterized by its modeling.

Best reagrds

I strongly agree with# Abderrahmane Noui. If you want to use hydraulic model (like HEC-RAS, Hy8, WaterCAD, SewCAD, etc), you may be expected to take as input for hydraulic model from the output of hydrologic model (HEC-HMS, SWAT, HBV,etc)

Dear Abdelghani,

On the regional scale, you can use hydrological modeling, and for the small area, you can use hydraulic modeling. The outputs of variables of the hydrological and hydraulic models could be different.

Hi ! I am working in the field of River Engineering, and working on hydraulic modeling for a long time (30 years or so !).

Now reply to your question

The hydraulic modeling and hydrological modeling are of different types and purposes. The hydraulic modeling is to work with hydraulic (Water) forces and Hydrological modeling will work out the discharges, discharge hydrographs, G-Q curves, etc. As the purposes, model requirements, etc are different, the data required is also different, and thus the results are also different ! You may have to refine your question by stating your requirements, purposes, and Goals, . . . Regards

Usually Hydraulic mean human intervention like dams, irrigation canals , pumping wells ... For hydrological is process through natural water cycle... depend on your application if you study rainfall , evaporation, natural infiltration or groundwater movement are hydrology model... for pumping drawdown, open channel or irrigation canals or water supply network... etc is hydraulic modeling

No doubt, the problems are initiated or caused by human intervention. However, the statement like "Hydraulic mean human intervention" may not be fully correct. For example, anti-erosion measures for riverbank erosion, etc may not be necessarily a human intervention. It can be to protect against the fury of or the wrongdoing of nature ( say Riverbank erosion)

I can repeat again, "hydraulic" modeling would be used for the estimation of water forces at the desired location. How to use that knowledge (Weir, Dam, bank protection, wells, etc) is left to the engineers.

"Hydrological" model would help to quantify the resource (Surface water, groundwater, stream flows, tidal fluxes, etc, etc)

Thank you for illustration. I mad my comments based on my noticed in some of the text book of groundwater. For the chapter that talk about the groundwater movement they say groundwater hydrology. For the chapter talk abou using Darcy law for pumping wells they call it groundwater hydraulics. For the course of hydrology they are usually talk about only the activities occur during the hydrological water cycle. For the open channel and hydraulic structure they are talking about hydraulic of the canals.. etc. I believe if I am not wrong for the river activities they call it river mechanics. I agree with you It’s confusing when we study the rivers.

Both modelings are of different types and used for different purposes.

Both are different and are important in one or the other way in their applications and outputs. Very informative answers are provided by Abderrahmane Noui , Niguse Abebe , Ravindra Oak. The concepts are very clear.

Hydrological model

I agree with Vikas Poonia