Inverse Estimation of Soil Hydraulic and Transport Parameters of Layered Soils from Water Stable Isotope and Lysimeter Data

• DOI: 10.2136/vzj2017.09.0168
• Publication Date: 2018-05-17T22:05:31Z
• Authors: Jannis Groh; Christine Stumpp; Andreas Lücke; Thomas Pütz; Jan Vanderborght; Harry Vereecken
• Keywords: Lysimeter; Pedotransfer function; TRACER; Water Transport; Water potential

Core Ideas To determine the water retention curve from inverse modeling, θ and ψ need to be monitored. δ 18 O ratios contained information inversely estimate soil hydraulic parameters. Different observation types should combined in a single OF Averages of local measurement could described using effective Accurate fluxes at lysimeter boundaries improved model parameterization. estimates parameters dispersivities are crucial simulate flow solute transport terrestrial systems, particularly vadose zone. However, obtained modeling can ambiguous when identifying multiple simultaneously boundary conditions not well known. Here, we performed an study which estimated layered soils content, matric potential, stable isotope (δ O) measurements weighable systems. We used different optimization strategies investigate necessary for estimating Combining tracer (e.g., data one objective function (OF) was found best strategy that all observed variables. A sequential optimization, first with only variables subsequently optimized, slightly worse indicating additional Hydraulic were optimizing OFs either contents or potential predict non‐measured When bromide (Br − ) experiment simulated optimized parameters, arrival time pulse underestimated. This suggested Br sorbed onto clay minerals amorphous oxides under prevailing geochemical low pH values. accounting anion adsorption simulation, concentrations predicted, validated dispersivity