MODFLOW-SDA – MODFLOW-SDA is a new MODFLOW package to improve the computational efficiency and reduce the computational noises for stream depletion analyses using MODFLOW. Using the assumption of unchanged flow coefficients between the baseline and scenario runs, the nonlinear groundwater flow system is linearized for solving the flow equations. The new package has been successfully applied to a regional groundwater model in Nebraska to simulate responses to flow perturbations such as streamflow depletion induced by new pumping wells.

MODFLOW-CSR – The Cross-Section streamflow Routing (CSR) package is developed to simulate the streamflow and the interaction between streams and aquifers for streams with a width larger than the MODFLOW grid size. In the CSR package, a cross-section is described by a number of streambed points that determine the geometry and hydraulic properties of the streambed. A rapid algorithm is used to compute the submerged area of the MODFLOW grid. The streambed conductance of a grid cell is computed based on its submerged area, streambed hydraulic conductivity and thickness.

PPSGS – PPSGS is a geostatistical tool developed for stochastic groundwater modeling with pilot point parameterization using sequential Gaussian simulation. PPSGS can be used with PESTPP-IES for model calibration. By implementing the similar concept in PLPROC/PPFAC, PPSGS generates the Kriging weighting factor files that can be used during calibration to recreate various stochastic parameter fields retained in each respective realization. PPSGS can improve uncertainty quantification by taking the kriging errors into account.

CHUMP – The Configuration-Based Uniform Model Post-processor (CHUMP), a framework for post-processing data and model results. CHUMP simplifies the process through a configuration file that uses intuitive keywords to define data abstraction and manipulation parameters, providing coding-level flexibility without requiring programming knowledge. With generalized input, CHUMP directly reads a variety of data and model outputs and applies a series of data processing operations to create consistent, precise, and publication-quality figures and animations.

SWAT-MODFLOW – SWAT-MODFLOW is an integrated surface-water groundwater interaction model that couples SWAT and MODFLOW by a soil water module (SWM), which is developed based on a non-iterative solution of the 1D Richards equation. SWM explicitly represents infiltration, soil evaporation, unsaturated water flow, root water update, and lateral drainage and solves them simultaneously. Taking advantage of the simulation capacities of SWAT, MODFLOW and SWM, the integrated model can simulate the physical hydrologic processes in three domains and their interactions.

Ou, G., 2020. Development of GUI Applications for Groundwater Modeling Using Python. Groundwater, v. 58, no. 4, pp. 496-497. doi: 10.1111/gwat.12979

Ou, G., F. Munoz-Arriola, D.R. Uden, D. Martin, C.R. Allen and N. Shank, 2018. Climate change implications for irrigation and groundwater in the Republican River Basin, U.S.A. Climatic Change, v. 151, no. 2, pp. 303-316. doi: 10.1007/s10584-018-2278-z

Li, R., G. Ou*, M. Pun, and L. Larson, 2018. Evaluation of Groundwater Resources in Response to Agricultural Management Scenarios in the Central Valley, California. Water Resources Planning and Management, v. 144, no. 12: 04018078. doi: 10.1061/(ASCE)WR.1943-5452.00010

Ou, G., R. Li, M. Pun, C. Osborn, J. Bradley, J. Schneider, and X. Chen, 2016. A MODFLOW Package to Linearize Stream Depletion Analysis. Journal of Hydrology, v. 532, no. 1, pp. 9-15. doi: 10.1016/j.jhydrol.2015.11.025

Li, R., M. Pun, J. Bradley, G. Ou, J. Schneider, B. Flyr, J. Winter, and S. Chinta, 2016. Evaluating Hydrologically Connected Surface Water and Groundwater Using a Groundwater Model. JAWRA Journal of the American Water Resources Association, v. 52, no. 3, pp. 799-805. doi: 10.1111/1752-1688.12420

Ou, G., X. Chen, R.J. Bitner, and M. Krausnick, 2015. SMPP: The Spreadsheet-Based MODFLOW Pre-Processor. Groundwater, v. 53, no. 5, pp. 675-676.

Dong, W., G. Ou*, X. Chen, and Z. Wang, 2014. Effect of Temperature on Streambed Vertical Hydraulic Conductivity. Hydrology Research v. 45, no. 1, p. 89. doi:10.2166/nh.2013.021

Ou, G., X. Chen, A. Kilic, S. Bartelt-Hunt, Y. Li, and A. Samal, 2013. Development of a Cross-Section Based Streamflow Routing Package for MODFLOW. Environmental Modelling & Software, v. 50, no. 12, pp. 132-143.

Ou, G., X. Chen, C. She, Z. Hu, and X. Li, 2009. Three Dimensional Visualization of Groundwater Simulation Based on VTK. Journal of China Hydrology, v. 29, no. 1.