Regional Hydrology Lab - UM

Ecohydrologic model (ECH2O)

ECH2O is a spatially-distributed echydrologic model that couples together an energy balance scheme, a hydrologic model and e forest growth component. A full description of the model can be found HERE, with this errata.

A two-layer energy balance (canopy and understory) is solved for the soil, plant atmosphere column using 1D first-order, local-closure description of energy fluxes using a flux-gradient similarity approach. The energy balance is solved using canopy and ground surface temperature as closure variables. The energy balance equations of the understory include energy exchanges with a single-layer snowpack.

The hydrologic model uses the Green and Ampt simplification of Richards equation to calculate infiltration into the soil. Lateral transfers of water are described using a 1D solution of the kinematic wave on a finite difference grid. Forest production is a function of incoming solar radiation, transpiration, air temperature and age of trees.

Multiple plant types or specices are allowed in each computational unit in the domain. A carbon allocation scheme based on 3PG and allometric relationships based on TREEDYN govern the growth of trees. A grass/pasture dynamics component has been recently added and is described in a forthcoming paper.

The model is fully written in C++ and can be easily modified and expanded to include new functionality or cmpmonents. To assist in data pre and post processing, the model ingests and produces data that can be manipulated and read with the free GIS PCRASTER

Outputs include time series at selected location or time series of maps describing the spatial and temporal variability of many state variables includign soil temperature and moisture, latent and sensible heat fluxes, ground heat fluxes, net primary production, evaporation, transpiration and many others.

Please, contact us for more information about this model.