Water Resource Associates

A network of consultants in: water resources, hydrology, hydraulics, hydrogeology and water quality

HYSIM (HYdrological SImulation Model)
 

HYSIM is a hydrological simulation model (rainfall-runoff model) which uses rainfall and potential evaporation data to simulate the hydrological cycle (surface runoff, percolation to groundwater and river flow) on a continuous basis.

HYSIM’s parameters define in a realistic way the hydrology and hydraulics of the whole river basin (watershed). Such a model is likely to perform well in climatic conditions more extreme than those in its calibration period

The diagram to the right shows the conceptual basis of the hydrological component of the model.

HYSIM can use data on rainfall, potential evaporation (PET), snow melt and abstractions from, or discharges to, both groundwater and surface water. Only rainfall and PET are essential. The data can be daily or any time step less than a day. The simulation time step can be daily or less than a day.

Not only is HYSIM flexible in its data requirements, it is also flexible in terms of catchment definition: a river basin can be defined as a number of sub-catchments and the reaches for flow routing can be either channels or reservoirs. Flow routing uses the kinematic method.

Typical uses of HYSIM have included:

• Using long-term rainfall and PET data to produce long-term flow records.
• Flow naturalisation.
• Studying the effects of climate change.
• Flood studies.
• Effects of improved drainage.
• Groundwater recharge.

The output from the model includes: overland flow, impermeable area runoff, snow storage, soil moisture storage, interflow, groundwater recharge, groundwater storage, total surface runoff, routed flow and actual evapotranspiration.

Output from HYSIM can be go directly into Modflow (as recharge) or Isis (either runoff to channels or routed flow at the upstream boundary).

Complex rivers basins (catchments, watersheds) can be simulated as a series of linked sub-basins. To represent hydrological or climatic variations within a sub-catchment, up to three zones, each with its own parameters and data, can be defined.

HYSIM runs under Windows XP and earlier version such as NT and 2000.

In addition to the simulation model HYSIM includes facilities for plotting data and simulated and observed flows and tools for data manipulation.

HYSIM is compiled as an ActiveX component and can be run with the Aquator water resources simulation model developed by Oxford Scientific Software working with Water Resource Associates. For more details on Aquator click here.

You can also download an evaluation version of HYSIM. Before you do that have a look at this file which shows you what can you do with the trial version.

To download the model (5Mb) click here. This is a single zip file which has to be expanded before use. It has three files: HYSIM.CAB (the program file in a compressed format), SETUP.LST (a list of all files included) and SETUP.EXE (the program which will install HYSIM on your computer). You can also download trial data.

To download the documentation (MS Word, 1Mb) click here.

For existing users, you can download the latest version of HYSIM here as a compressed file.

For more information see the HYSIM Information Pack or contact Ron Manley