HSPF

Criterion

Explanation

General Description

HSPF is a continuous simulation model developed for both natural and developed watershed and water systems. It simulates land surface and subsurface hydrology, stream/lake hydraulics, and water quality processes. It is based upon the original Stanford Watershed Model IV and a consolidation of the Agricultural Runoff Management Model (ARM), Non-point Source Runoff Model (NPS) and Hydrological Simulation Program (HSP). HSPF is a lumped parameter approach (limited spatial definition) and includes a simplified representation of urban drainage system components (pipes, culverts, CSOs). The model also provides tools for data management and storage, statistical analysis, and operations. HSPF is the core watershed model in EPA BASINS and Army Corps Watershed Modeling System (WMS). The model is developed and maintained by EPA and USGS. The model website is at: http://www.aquaterra.com/resources/hspfsupport/index.php

Model Domain

Watershed land and stream processes

Developer

Aqua Terra, USGS, EPA

Hardware computing requirements

Windows

Code language

FORTRAN

Original application

Urban and suburban environments

Public/proprietary and cost

Public; freely available

Physically or empirically based

Physically based

Mathematical methods used

Runoff: water balance; Infiltration: Green-Ampt or Maryland Method; Flow Routing: kinematic wave and Chezy- Manning equation for overland flow (turbulent); Water Quality: Single organic chemicals and their transformation products (hydrolysis, oxidation, photolysis, biodegradation, volatilization and sorption can be modeled. Sorption (only in reaches/streams) is modeled as a first-order kinetic process (user specified desorption rate and equilibrium partition coefficient). Sediment transport simulated for sand, clay, or silt and washoff is modeled as an exponential function or a constant unit removal rate by overland flow.

Input data requirements

Precipitation (hourly), temperature, evaporation, wind speed, solar radiation, potential evapotranspiration, dew point temperature, cloud cover snow, soil properties, pollutant location and load, land use/cover, soil properties, DEM, hydrography, watershed characterization, channel and bed characteristics. Calibration/validation: flow, sediment, and water quality data.

Outputs

Flow and water quality by reach

Pre-processing and post-processing tools

HSPF is part of EPA's Basins modeling framework. Several user interfaces have been developed for HSPF including WinHSPF.

Representation of uncertainty

Uncertainty analysis is not integrated into the model.

Prevalence

High. There have been hundreds of applications of HSPF all over the world.

Ease of use for public entities

Training and user support available.

Ease of obtaining information and availability of technical support

Training and user support available.

Source code availability

The source code is publicly available.

Status of model development

The model is mature.

Challenges in integration

HSPF is designed to be used in an integrated framework like EPA's Basins, therefore challenges to integration are few.