Scenario‐Based Three‐Dimensional Distributed Sediment Structures for a Constructed Hydrological Catchment

Many processes in a developing catchment can only be fully understood if the spatial heterogeneity is adequately described. Process‐based modeling allows reproducing specific key structural elements of catchments. Constructed catchments are ideal test objects because of the well‐known spatial conditions. In our study, we (i) modeled the entire process chain of catchment construction, (ii) established a consistent sediment mass/volume balance between the excavated outcrop and the generated catchment model, and (iii) provided consistent three‐dimensional distributions of texture and bulk density for deriving soil hydraulic properties. Data are from the 6 ha Hühnerwasser catchment (Chicken Creek, Lower Lusatia, Germany), which was constructed from overburden sediments in an open‐cast lignite mine. Uncertainty about the parent material origin was captured in a multiscenario approach based on a geological model of the outcrop site and the simulation of excavation procedures. Generated distributions are incorporated in a gridded three‐dimensional volume model (GOCAD), and results were evaluated by semivariogram analysis and by quantifying point‐to‐point deviations. Filling and compaction are modeled based on three‐dimensional volume analysis and mass balances of dumped sediments. Heterogeneities reflect both the batch‐wise sediment variation and the succession of excavated geological units. The scale of the generated spatial models can be adjusted for three‐dimensional hydrological catchment modeling while three‐dimensional sediment mass balances can be used for analyzing soil and ecosystem development processes.