This document provides an abstract for a diploma thesis that implemented the rainfall-runoff model MIKE SHE in the mountainous Glafkos catchment in Greece. The thesis aimed to (1) improve calibration from a previous study and (2) investigate differences in simulation results using MIKE SHE modules for infiltration, snow melt, and interflow. Modifying detention storage values improved simulations by eliminating unrealistic runoff peaks. Simulations using the gravity flow infiltration module did not significantly improve results over the 2-Layer Water Balance Method but required more computation. Considering elevation differences across the catchment in simulations, such as using multiple interflow reservoirs and temperature zones, improved results by better representing catchment conditions. Different snow melt simulation methods