A Three‐Dimensional Structure and Process Model for Integrated Hydro‐Geo‐Pedologic Analysis of a Constructed Hydrological Catchment

Abstract

A structure model describes the boundary geometries and the three‐dimensional solid phase distributions of the catchment. In contrast to an established ecosystem, feedback relations can be assumed for an initial geosystem between the development of spatial structures and the water and element fluxes. The objective was to develop a hydrological catchment model as a three‐dimensional spatial database of the solid phase that allows an integrative analysis, a periodical mass balance, and the generation of distributed model parameters for the developing system. Data were from the constructed catchment “Chicken Creek.” The initial texture and bulk density distributions were generated by imitating sediment dumping, segregation, and compaction. Boundary geometries and changes in surface topography due to erosion and sedimentation processes were quantified on the basis of digital elevation models (DEMs) derived from aerial photographs. The catchment was visualized with the three‐dimensional software GoCad; the “emergence” of the water table and other structures (e.g., soil horizons, root zone) could be spatially assigned and quantified to identify regions with specific processes. A combination of three‐dimensional catchment with time‐dependent two‐dimensional surface models allowed generating the development of spatially distributed erosion–deposition patterns that formed new initial surfaces. The three‐dimensional distributed solid phase structure of the catchment allowed for a more direct comparison with observations using minimal invasive methods. The mass balance of the solids could be related with pedologic development and transfer to other geopedologic systems achieved by adapting sediment transport and deposition in the descriptions of the model. This model may help improve the integrative analysis of hydrological catchments.

Water Balance Dynamics during Ten Years of Ecological Development at Chicken Creek Catchment

“…To obtain the actual groundwater volume, the groundwater surfaces were combined with a three‐dimensional gridded model (SGrid) containing texture and bulk density information. Sediment distributions were generated beforehand using a structure generator program that calculates the typical sediment patterns and structures encountered on the catchment (Maurer et al, 2011, 2013; Gerke et al, 2013). The program generates a sequence of three‐dimensional structural elements specific to the technological formation processes (spoil cones), sequentially arranged along the known trajectories of the large‐scale dumping machinery (stacker) and conditioned to generate sediment compositions that fit with the actual soil sample measurements from the catchment.…”

“…In critical zone research, the need for experimental catchments with well‐known boundaries and conditions has been stressed repeatedly (Zacharias et al, 2011; Banwart et al, 2012). The principal advantage of a constructed catchment is that these conditions, namely the geometries of the surface and subsurface catchment areas and the spatial distribution of the solid phase, are well known (Gerke et al, 2013). A constructed catchment thus constitutes a near‐ideal “landscape laboratory” for investigating hydrological and ecological processes (Gerwin et al, 2009).…”

Spatial patterns of aboveground phytogenic Si stocks in a grass-dominated catchment – results from UAS-based high-resolution remote sensing

“…These dams act as a stabilization barrier preventing the sandy substrate from sliding downhill and serve as a funnel to direct groundwater flow into the artificial pond downstream (Gerwin et al, 2010). Due to the artificial construction, the lower boundary conditions of the catchment site are clearly defined including knowledge about the 3D sediment structures (Gerke et al, 2013;Schneider et al, 2011). The construction work left a bare land surface on which natural vegetation could develop without disturbance (natural succession) but also created a zonal pattern of soil properties caused by the natural heterogeneity of the parent material taken from different areas in the fore-field according to the progression of the mine (Gerwin et al, 2009) (Fig.…”

Processes and Modeling of Initial Soil and Landscape Development: A Review

“…This can be achieved by coupling three‐dimensional (3D) spatial models of initial sediment structures, flow modeling, and structure‐generating processes (i.e., erosion–deposition–crusting–vegetation; cf. Gerke et al, 2013). Figure 4 presents the structure of such a possible modeling framework developed for the Hühnerwasser catchment as an example.…”