Grouping water storage properties of Indian soils for soil water balance model applications

Abstract Although the quantification of real evapotranspiration (ETr) is a prerequisite for an appropriate estimation of the water balance, precision and uncertainty of such a quantification are often unknown. In our study, we tested a combined growth and soil water balance model for analysing the temporal dynamics of ETr. Simulated ETr, soil water storage and drainage rates were compared with those measured by 8 grass-covered weighable lysimeters for a 3-year period (January 1, 1996 to December 31, 1998). For the simulations, a soil water balance model based on the Darcy-equation and a physiological-based growth model for grass cover for the calculation of root water uptake were used. Four lysimeters represented undisturbed sandy soil monoliths and the other four were undisturbed silty-clay soil monoliths. The simulated ETr-rates underestimated the higher ETr-rates observed in the summer periods. For some periods in early and late summer, the results were indicative for oasis effects with lysimeter-measured ETr-rates higher than corresponding calculated rates of potential grass reference evapotranspiration. Despite discrepancies between simulated and observed lysimeter drainage, the simulation quality for ETr and soil water storage was sufficient in terms of the Nash-Sutcliffe index, the modelling efficiency index, and the root mean squared error. The use of a physiological-based growth model improved the ETr estimations significantly.

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A Coupled Soil Water Balance Model for Simulating Depression-Focused Groundwater Recharge

Vadose Zone Journal ◽

10.2136/vzj2017.10.0176 ◽

2018 ◽

Vol 17 (1) ◽

pp. 170176 ◽

Cited By ~ 4

Author(s):

Saskia L. Noorduijn ◽

Masaki Hayashi ◽

Getachew A. Mohammed ◽

Aaron A. Mohammed

Keyword(s):

Water Balance ◽

Groundwater Recharge ◽

Soil Water ◽

Water Balance Model ◽

Soil Water Balance ◽

Balance Model

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A Daily Water Balance Model Based on the Distribution Function Unifying Probability Distributed Model and the SCS Curve Number Method

Water ◽

10.3390/w14020143 ◽

2022 ◽

Vol 14 (2) ◽

pp. 143

Author(s):

Marwan Kheimi ◽

Shokry M. Abdelaziz

Keyword(s):

Distribution Function ◽

Water Balance ◽

Soil Water ◽

Storage Tank ◽

Water Storage ◽

Curve Number ◽

Water Balance Model ◽

Balance Model ◽

Soil Water Storage ◽

Daily Water

A new daily water balance model is developed and tested in this paper. The new model has a similar model structure to the existing probability distributed rainfall runoff models (PDM), such as HyMOD. However, the model utilizes a new distribution function for soil water storage capacity, which leads to the SCS (Soil Conservation Service) curve number (CN) method when the initial soil water storage is set to zero. Therefore, the developed model is a unification of the PDM and CN methods and is called the PDM–CN model in this paper. Besides runoff modeling, the calculation of daily evaporation in the model is also dependent on the distribution function, since the spatial variability of soil water storage affects the catchment-scale evaporation. The generated runoff is partitioned into direct runoff and groundwater recharge, which are then routed through quick and slow storage tanks, respectively. Total discharge is the summation of quick flow from the quick storage tank and base flow from the slow storage tank. The new model with 5 parameters is applied to 92 catchments for simulating daily streamflow and evaporation and compared with AWMB, SACRAMENTO, and SIMHYD models. The performance of the model is slightly better than HyMOD but is not better compared with the 14-parameter model (SACRAMENTO) in the calibration, and does not perform as well in the validation period as the 7-parameter model (SIMHYD) in some areas, based on the NSE values. The linkage between the PDM–CN model and long-term water balance model is also presented, and a two-parameter mean annual water balance equation is derived from the proposed PDM–CN model.

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