TREECS Hydro-Geo-Chemical Toolkit (HGCT)

The HGCT provides tools for estimating soil properties, soil erosion rates, hydrologic variables, and Darcy velocity for either point estimates (i.e., site average conditions) or spatially varying data associated with GIS map files. 

Soil texture (e.g., loam, sandy loam, etc.) is used to estimate soil properties of porosity, volumetric moisture content, dry bulk density, saturated hydraulic conductivity, and USLE erodibility K factor.    Properties can be estimated for site average or point soil texture or from spatially varying soil texture data.

Soil erosion rates are computed using the Universal Soil Loss Equation (USLE).  Soil texture, land use/land cover (LULC), and ground surface slope can be used to compute erosion rates using either point or spatially varying data.

Historical daily precipitation and air temperature data are used with the Soil Conservation Service (SCS) curve number method to estimate annual averages for precipitation, rainfall, number of rainfall events, runoff rate, infiltration rate, and evapotranspiration rate.  Point and spatial data for soil texture and LULC can be used to compute site average curve numbers and hydrology (See Figures 12 and 13).

Saturated hydraulic conductivity is used with information on well heads and distances to compute Darcy velocity.

Figure 12. Screen for point estimates for soil properties using point or site average soil texture

Figure 13. Site average estimates for soil properties using spatial soil texture data