On the assessment of ground water parameter uncertainty over an arid aquifer

Abstract

Uncertainty assessment of groundwater modeling is important for sustainable groundwater management and planning. The purpose of this study is to assess parameter uncertainty of groundwater modeling in the Birjand plain, Iran. This arid aquifer was modeled using MATLAB-based MODFLOW to avoid propagating uncertainty associated with hydraulic conductivity and recharge parameters. So, the aquifer was divided into 17 hydraulic conductivity homogenous zones; besides, 9 recharge zones were considered separately. Parameter uncertainty was evaluated using the Monte Carlo (MC) sampling technique, namely, the generalized likelihood uncertainty estimation (GLUE). The results indicated that the performance of the GLUE based on the inverse error variance likelihood function was satisfied, because it gave the higher bracketing of observations equal to 86 %. Parameter uncertainty is well defined in the zones where they are not influenced directly by an inflow or outflow stream while hydraulic conductivity parameters of these zones follow approximately a normal distribution. In addition, groundwater modeling leads to a uniform exponential distribution in the zones with inflow or outflow streams.

How Critical Is the Assimilation Frequency of Water Content Measurements for Obtaining Soil Hydraulic Parameters with Data Assimilation?

“…Additionally, when comparing the temporal evolution of soil hydraulic parameters and RMSE at the same time, periods with varying soil hydraulic parameters but RMSE remaining almost constant can be observed; this fact highlights the nonuniqueness set of parameters able to provide good simulations. The presence of equifinality problems (Beven and Binley, 1992; Hamraz et al, 2015; Mannina et al, 2010) is expected to increase with more complex soil profiles where the number of model parameters also increases.…”

Groundwater Single‐ and Multiobjective Optimization Using Harris Hawks and Multiobjective Billiards‐Inspired Algorithm

“…Any ambiguity, such as measurement error, specified initial and boundary conditions, or the overall conceptual model, has a significant influence on modelling. Although Hamraz et al [3] examined the parameter uncertainty associated in identifying the recharging ground water parameters; the emphasis of our study is on optimization approaches (by reducing error and misfit). According to the error indices, the HHO significantly decreased error and misfit by indicating the lowest error throughout the calibration and validation phases as well as reducing the CPU time.…”

“…In the issue of rising groundwater demand, new models are desperately needed to develop novel decision-making tools and improve aquifer system drawdown [2]. Groundwater simulations have traditionally been conducted with the use of simulation/optimization algorithms [3,4]. ese models have been used to address construction and process issues of groundwater hydraulic control, water supply, and remediation [5,6].…”

Application of MODFLOW with Boundary Conditions Analyses Based on Limited Available Observations: A Case Study of Birjand Plain in East Iran

“…A comprehensive study (e.g., lithology and geology studies) has been done in this research to be able to model the aquifer The aquifer geometry is determined according to the RWCSK data. A comprehensive study (e.g., lithology and geology studies) has been done in this research to be able to model the aquifer boundaries (i.e., aquifer geometry) accurately in the model [35,[56][57][58][59][60][61][62]. The bottom boundary (i.e., the bedrock in the aquifer) is also determined using the limited available geophysical study (geoelectrical soundings) carried out in Birjand Plain in 1971 ( Figure 8).…”

“…Water 2019, 11, 1904 9 of 21 boundaries (i.e., aquifer geometry) accurately in the model [35,[56][57][58][59][60][61][62]. The bottom boundary (i.e., the bedrock in the aquifer) is also determined using the limited available geophysical study (geoelectrical soundings) carried out in Birjand Plain in 1971 ( Figure 8).…”