This tutorial is a class exercise at Arba minch university, Ethiopia to show postgraduate students how to build, run and import/export a MODFLOW model using ModelMuse GUI.

Tutorial Video

Problem for the tutorial

The problem we will be solving in this tutorial is a Basin. The model grid will be discretized uniformly to 100 m. Assume the elevation of the top and bottom of the aquifer will be flat.

Packages;

DRN Package: use the river shapefiles attributes field values for elevation and bed conductance

RCH Package: Recharge rate = 3.80E-9, recharge location= Top active cell

EVT Package: EVT Rate = 3.17E-8, EVT surface =Model Top, EVT depth = 0.5, EVT location=Top layer

Aquifer Properties

4 aquifer layers:

Model_ Top (0 m),

Alluvial (ModelTop-15 m),

Layer 2((Model_Top – 100m) * 0.85))

Layer 3(Model_Top – 300m)

Layer 4 =800 m

Variable Horizontal Hydraulic Conductivity of, 5E-5, 5E-7, 8E-8, 1E-8 from the 1^st to 4^th layer and assume Isotropic aquifer.

Aquifer type: The last aquifer is confined and the others are convertible

Spatial datasets:

In this MODFLOW Exercise you are provided the following spatial datasets:

1. A polygon shapefile of the Basin, called Basin.shp
2. A line shapefile of the river, called River.shp

MODFLOW Initial head = 200m

1. Run a steady state model using no flow boundary and find the distributions of hydraulic head at the end of the steady state period. Was the budget converging with acceptable limit?
2. Run the model by assuming a GHB at the south of the study area. Compare the results with 1. Use a constant boundary head 200 m and conductance of 0.002.

Input files link to download

basin-1y9dbhb

river-1fvs7gx