Using soil hydromorphy degree for adjusting steady-state water table simulations along catenas in semiarid Russia

Estimation of Infiltration Volumes and Rates in Seasonally Water-Filled Topographic Depressions Based on Remote-Sensing Time Series

“…Here, we used the steady-state continuity equation in kinematic wave form parameterized using expert knowledge of the links between typical water table depth (WTD) and redoximorphic features of soils with different hydromorphy degrees [22]. In this simulation, we were able to account for variation in infiltration rates in the catena using real data on depressions' positions within the transect.…”

“…The result allowed identification of the volume of intercepted water during snowmelt and calculation of the rate of water recession and infiltration rates in closed depressions for the first time for the study region. Use of the horizontal variation in parameters obtained along the studied transect substantially improved results of the shallow ground water model developed in the cited study [22].…”

“…A 2D profile of the steady-state shallow water table depth was obtained by the analytical form of continuity equation with calibration based on soil redoximorphic features. In [22] the hypothesized relationship between archived morphological properties (redoximorphic features as indicators of gleyic conditions) of soils and a current hydrological process indicator (WTD) were established based on the expert knowledge of soil types, WTD co-occurrence, then verified under a hillslope flow continuity constraint expressed mathematically as a steady-state solution with two free parameters: hydraulic conductivity and recharge rate. Here the input horizontal transect of groundwater recharge rate was taken as a time integral of Equation (7).…”

“…For example, if very poorly drained soils (under depression bed) are present in M unit intervals, those in which Figure 7 illustrates the simulations of the shallow groundwater level for cases with the recharge rate either constant or spatially varied along the transect. The parameter N/k was restricted by the requirement for correspondence between the simulated WTD and range of WTD for soils of each type from expert knowledge (Table 2 in [22]) in distance intervals across the catena's whole toposequence. For example, if very poorly drained soils (under depression bed) are present in M unit intervals, those in which WTD > 3 m (too deep) were counted with 0 weight and the others with 1 weight.…”

“…One of the key hypotheses developed during the 1960s is that the major source of recharge for shallow groundwater in areas such as the Oka-Don Lowland of the Tambov region in European Russia is depression-focused infiltration during snowmelt [21]. In a very recent study an indirect method was used to calibrate the groundwater recharge to hydraulic conductivity ratio for application in an analytical steady-state solution of the 2D shallow groundwater flow equation using soil redoximorphic features of typical classified catenas of the Samovetc catchment in this lowland [22]. In the cited study, the same recharge rate was prescribed for all points along a topographical transect.…”