Soil Moisture Routing (SMR) Modeling of Targeted Biochar Amendment in Undulating Topographies: An Analysis of Biochar’s Effects on Streamflow

This research models biochar's ability to alter hydrologic fluxes in undulating topographies. Using numerical modeling and water balance/Soil moisture Routing (SMR) techniques, biochar was shown to influence lateral flow, streamflow, percolation, and evapotranspiration. In this repository, the 5-cell model that was developed is presented. This model relies upon the work done by Frankeburger et al., 1999 ("A GIS-based variable source area hydrology model"). This excel file includes the 5-cell model, sensitivity analysis, statistical analysis, and graphs that include storage and effects on each hydrologic fluxes. The model utilizes data from a nearby SNOTEL site (temperature, precipitation, etc...). Biochar's effect on soil hydraulic properties was measured by the HYPROP and WP4C from METER group. Palouse silt loam soil samples were mixed with two types of biochar, Redwood Sawdust (RSD) and Wheat Straw (WS), at concentrations of 4% and 7% by mass. The HYPROP and WP4C measure the key soil points along the water retention curve, as well as extrapolate the water retention curve in its entirety. These values are presented in a table in the 5-cell model. Changing the soil properties for each of the cells allows for the application of different biochar amendments (both type and concentration). Furthermore, the model can examine two different soil profiles, restricted and non-restricted layers. This is achieved by changing the K_sub values for either more or less restrictive.

The key purpose of this research and model is to provide baseline modeling work to analyze how biochar affects soil properties. Additionally, there is a benefit in the flexibility of the model due to it being rooted by experimental data. This allows for various soil and biochar types to be analyzed as long Van Genuchten parameters and key soil properties are known.