A.W. Harbaugh's scientific contributions

... However, it is a challenge to characterize the heterogeneity of complex multi-layer hydrogeological structures in finite-difference grids with reasonable partitioning and stratification (Burns et al., 2010). The Hydrogeologic Unit Flow package (HUF) (Anderman and Hill, 2000) of MODFLOW-2005(Harbaugh, 2005Hill et al., 2000) can address this challenge. HUF allows hydrogeological units to be defined independently of model layers, eliminating the need to determine how to delineate model layers to match highly heterogeneous structures. ...

... The temperature throughout the year in the city is almost constant, showing little variation throughout the course of the year. Average temperatures are typically between 25°c and 28°c, in the city" [13][14][15][16]. ...

... While the PHA did not calculate time-period-specific, individualized increased cancer 204 risk, it provided helpful guidance and concluded that Marines living at locations serviced by all three 205 water treatment plants were exposed to levels of various chemicals contributing to an increased risk of 206 cancer or other adverse health effects (ATSDR, 2017). 207 208 3. Methods results for a single contaminant dissolved in groundwater (Harbaugh & McDonald, 1996;Zheng & 213 Wang, 1999). A more accurate exposure to VOCs was modeled with the second model, which looked 214 at PCE and its degradation by-products, TCE, DCE, and VC, using a three-dimensional multi-species 215 model, TechFlow MP (Maslia et al., 2007). ...

... One of the benefits of using finite element methods over alternative models is that the sensitivity of leakage rates to changes in lateral aquifer heterogeneity may be tested. While standard groundwater modeling approaches (e.g., that of Modflow [16]) can easily simulate heterogeneous systems of the type modeled here, and semi-analytical approaches such as that of [20] are exceptionally adept at simulating leakage from laterally homogeneous aquifer systems, tools that can properly handle multiscale phenomena such as passive well leakage in heterogeneous domains with a reasonable computational budget are not currently available. Fig. 6 depicts the problem setup for a hypothetical aquifer system where the geometry of the interfaces between the aquifers and aquitards are represented using a double cosine function. ...

... The theoretical and practical values were different when measuring the absorbance of a standard turbidity solution and a mixture containing Chlorella. Many factors, including the absorption of colored soluble substances, particle size, temperature, and salinity of dissolved substances may affect the results [36,37]. When a spectrophotometer is used for analysis, the absorption curve is an important basis for selecting the wavelength of incident light in quantitative analysis. ...

... The MODFLOW computer code developed and released by the US Geological Survey was selected to develop the groundwater model in this study. MODFLOW was developed based on the concept of mass balance and Darcy's Law and is primarily utilized to simulate 3D constant-density groundwater flow through porous media (Harbaugh and McDonald, 1996). The governing equation is described in partial differential form: ...