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.本研究针对生物炭在起伏地形中调控水文通量的能力开展建模工作。本研究采用数值模拟与水量平衡/土壤水分汇流（Soil moisture Routing, SMR）技术，证实生物炭可对侧向流、河川径流、渗透及蒸散发产生显著影响。本开源仓库中提供了本次研发的五单元模型，该模型基于Frankeburger等人1999年发表的《基于GIS的可变源区水文模型》研究成果构建。本Excel文件包含五单元模型、敏感性分析、统计分析结果，以及存储与各水文通量影响相关的可视化图表。该模型采用了邻近雪情遥测站（SNOTEL）的气温、降水等观测数据。生物炭对土壤水力特性的影响，通过METER集团旗下的HYPROP与WP4C设备完成测定。本研究以帕卢斯粉壤土（Palouse silt loam）为供试土壤，分别按质量占比4%和7%的比例，将其与两类生物炭——红杉锯屑炭（Redwood Sawdust, RSD）与小麦秸秆炭（Wheat Straw, WS）——混合制备试样。HYPROP与WP4C可测定土壤持水曲线的关键特征点，并完整外推得到整条持水曲线。上述测定值已整理为表格，收录于五单元模型文件中。通过调整各单元的土壤特性参数，可实现不同类型与浓度的生物炭改良方案的模拟应用。此外，该模型可模拟两类不同的土壤剖面结构：限制层与非限制层，通过调整K_sub参数即可实现更严格或更宽松的限制层设置。 本研究与所建模型的核心目标，是提供一套基准建模框架，用于分析生物炭对土壤特性的影响机制。此外，该模型基于实验数据构建，具备良好的灵活性：只要获取目标土壤的范·吉努赫滕（Van Genuchten）参数与核心土壤特性数据，即可对多种土壤与生物炭组合开展模拟分析。