Dear Shwetha,

Whatever software of distributed or lumped models you are interested to use, initially you need these datas:

The accuracy of your computation is directly depended on your input data accuracy and temporal and spatial scale. All  other parameters could be selected from softwares interface for computation and analysis. 

Wish you success

dear Shwetha,

the hydrologic modelling of watershed required (catchment area, length and slope of the main stream, and rainfall hyetograph) as well as the losses (for eg. infiltration, evaporation, and depression storage), it is required the runoff hydrograph as the boundary condition) 

best wishes

Thanks for the answer!..:)

What about SWAT?

I would also like to know what are the parameters, other than rainfall and runoff, that can be obtained from these softwares and the data required for it

Dear Shwetha,

For SWAT model you need DEM, land use map, soils map, weather data (precipitation, solar radiation, relative humidity, wind speed) and monitoring flow gauges; those are the basic data to run SWAT. It depends of your goals, you can add more variables, but for a simple modeling the above data are enough. With monitoring flow gauges you can calibrate and validate your model, I'll recommend to you to run the model for at least a 10 years period and 1 year for warm-up.

You can obtain flow in reaches by sub-basins and ET as the most important result of SWAT simple model. But also you can obtain surface flow, lateral flow, groundwater flow, percolation, tile discharges, etc.)

best!!!

Dear Shwetha,

SWAT and HEC-HMS are software for hydrologic modeling, and HEC-RAS for hydraulic modeling. As for hydrologic modeling, SWAT and HEC-HMS and also other hydrologic models usually have similar input but different format, such as topography (DEM) for watershed delineation, landuse or land cover, soil type, and rainfall data. It had better also has discharge measurement data for calibration process.

However, HEC-RAS is a hydraulic model which need totally different with hydrologic model above. It needs some data at least river/canal geometry and two boundary conditions (BCs). Water discharge for upstream BC and water elevation for downstream BC.

good luck

sigit

Dear Shwetha,

Whatever software of distributed or lumped models you are interested to use, initially you need these datas:

The accuracy of your computation is directly depended on your input data accuracy and temporal and spatial scale. All  other parameters could be selected from softwares interface for computation and analysis. 

Wish you success

Dear Shwetha, for SWAT take a look in the following PDF document: http://swat.tamu.edu/documentation/2012-io/

All three models are VERY DIFFERENT. so there is no answers to your question I am afraid. For instance, HEC-HMS is a lumped hydrology model so you might need area, slope, perviousness,... while HEC-RAS is more of a distributed hydraulic model where you might need to collect data on rivers morphology. Not to mention coupling practices. I would suggest you read the user manuals from Page 1 

Well, many of the researchers have provided a long list of data requirements. I would suggest you to define your objective precisely. These three models different data requirements and altogether different output also. If you wish to model rainfall runoff on a various spatial scales or aim at modelling ET under changing climatic scenarios, SWAT can be more useful, given the data requirements as highlighted by Mohammad Assem Mayar. 

If you do hydrological modelling using SWAT that itself will be very good work...Since collecting data for hydrological modelling consumes more time.... The  Data of runoff, Precipitation, Soil moisture, Evaporation , infiltration and ET should be taken....

Dear Shwetha

I hope you find much information about SWAT and HEC RAC as said by others.

For rainfall runoff modeling main input you needed are

Long term rainfall series, DEM of study area, Climatic data, Soil data, LULC map

and other data depending upon your objectives. If you specify the objective then, RG community may help in better way.

Good Luck

Dear Shwetha,

What, all the friends suggested for you, are fine. You can first specify your objective and then choose the model. With regard to SWAT model, you refer to this link, you will get a good impression of the model.

http://swat.tamu.edu/documentation/

Dear Shwetha,

for hydrological modelling you need three type of data,

1-Hydraulic Data,

1-D flow models require, at a minimum, three forms of hydraulic data:

a) Stream geometry,

b) Streambed resistance factors, and

c) Time-series flow and/or stage head boundary conditions.

2- Geometric Data, cross sections for the river or channel 

3-Hydrologic Data

Hydrologic data is the output response of a precipitation (storm) hyetograph input to a watershed system. The output response is a flow (runoff) hydrograph for each individual watershed in the system.

best wishes