Uitgangspunten falen keringen template

This page describes the assumptions that are used as input for the falen keringen template and manual.

Introduction

The manual describes the steps that need to be taken to quickly and in an efficient manner create a new Tygron Platform project with a flooding scenario. The following settings/presence of data influences the accuracy and outcome of the calculation (in order of importance):

• The size of the breach
• The upstream (?)water level of the breach
• Capacity of water body upstream(?) breach (how quickly does the water level lower as a result of the breach?)
• Grid size
• Culverts in (the to be) inundated area
• Initial water level in (the to be) inundated area

Below these are explained in more detail.

Breach size

A breach is a modification to the terrain height, with an optional in- or outflow of water for the hydrological model.

Breach water level area

In the Tygron Platform there are two methods of determining the amount of water that will flow through the breach: with an internal area or an external area. For this falen keringen template, the external area is used, since it is easier to determine in the wizard the parameters for the external area

Grid size

The grid cell size influences the accuracy and the calculation time of the project. Depending on the project size, the grid cell size is set to 2 x 2m. Also, the calculation preference is set to normal.

Culverts

By default in the Tygron Platform in the Netherlands and where available, culverts are imported from the IMWA dataset. Due to the unknown culvert diameter of these hydrological constructions, the default diameter of 1m is used. Through tests, this default diameter proved to show differences in Flooding results, therefore in the manual, culverts with their known diameter need to be imported. Other hydrological constructions such as weirs and pumps proved to be insignificant for this use case.