# How to insert a Geological Fracture on a Hydrogeological Model with MODFLOW and Model Muse

/Model Muse is a software for the pre and post data processing of hydrogeological 3D models in MODFLOW. Both Model Muse and MODFLOW are developed by the USGS (usgs.gov). Model Muse is designed to work with objects and datasets, a powerful model construction methodology that allows the quick setup of boundary conditions, a simple way of progressive refinement and interesting features as inserting geological fractures on the numerical models.

This tutorial show the whole procedure for the conceptualization of several fractures based on some known fracture information as a point on the fracture, the azimuth and the elevation. The tutorial deals with the theorethical determination of the fracture plane equation, the construction of a dataset with the desired equation plus the implementation of object that represents the fracture with the relevant hydrogeological features.

## Video

## Formulas

Formulation of a plane equation (sorry, it is in Spanish):

These are the equations on the Model Muse notation for three fractures:

**Fault 1 Formula:**

3925 - (1 / Sin(DegToRad(-60))) * (Sin(DegToRad(-45)) * Cos(DegToRad(-60)) * (X-625215) + Cos(DegToRad(-45)) * Cos(DegToRad(-60)) * (Y-8356925))

**Fault 2 Formula:**

3416 - (1 / Sin(DegToRad(-80))) * (Sin(DegToRad(80)) * Cos(DegToRad(-80)) * (X-623822) + Cos(DegToRad(80)) * Cos(DegToRad(-80)) * (Y-8357089))

**Fault 3 Formula:**

3800 - (1 / Sin(DegToRad(-60))) * (Sin(DegToRad(30)) * Cos(DegToRad(-60)) * (X-624230) + Cos(DegToRad(30)) * Cos(DegToRad(-60)) * (Y-8357230))

## Input Data

Download the required data for this tutorial here.

## Additional references

http://tutorial.math.lamar.edu/Classes/CalcIII/EqnsOfPlanes.aspx

https://math.stackexchange.com/questions/1150232/finding-the-unit-direction-vector-given-azimuth-and-elevation

https://en.wikipedia.org/wiki/Azimuth