Terrain

Please note: This page is currently being updated.

(In Dutch)

What is meant by Terrain?

The Tygron Platform uses the term terrain to describe the composition of the surface, subsurface and their elevation in a project. This does not include any features built upon it, which are known as constructions.

Editor → Current Situation (Ribbon tab) → Terrain (Ribbon bar)

Surface

The Tygron Platform differentiates between various types of terrain. Each terrain type has its own predefined attributes that may have an effect on various indicators and overlays, such as green, livability and rainfall flooding. A description of all available terrain types is listed in the table below.

EN	NL	Description
Concrete	Beton	Commonly found in urban and industrial areas.
Levee	Dijk	A construction usually built between a water body and low-lying land (polder) offering protection from flooding.
Dunes	Duinen	A naturally occurring landscape feature forming the division between the beach and the hinterland.
Breakwater	Golfbreker	A construction designed to protect the coastline from wave action.
Grassland	Grasland	Area dominated by grass vegetation.
Open land	Open land	The default terrain type for land surface. If an empty world is generated, this type will cover the entire map.
Waterway	Waterloop	A waterway which is often part of a 'managed' water system
Waterbody	Watervlakte	A water body which is often not part of a 'managed' water system.
Sand	Zand	Area largely consisting of sandy sediment.
Sea	Zee	Water that is part of a sea or ocean.

Each surface terrain type contains the following attributes:

Attribute	Unit	Description
BUILDABLE		Indication whether a terrain can be built upon or not.
GROUND_INFILTRATION_MD	m/d	Infiltration capacity of the surface soil into the subsoil. This attribute is used in calculations of the Rainfall Overlay.
HEAT_EFFECT	°C	Measure of impact on the heat stress overlay.
LIVABILITY_EFFECT		Measure of impact on the livability overlay.
POLDER_WATER		Value 1: it is possible to build a construction on top or near this terrain type. Value 0: the terrain is not buildable.
SAFETY
TERRAIN_MIX
TEXTURE_TYPE
WATER		Most constructions can only be built upon land, hence cannot occur on this terrain type. Water terrains play an important part in the calculations by the Water Module. Three types are distinguised; 1: waterways: inland and part of managed water system; 2: water bodies: inland but not part of a managed water system; 3: sea: sea or ocean. This distinguishing value is used for several tools and algorithms.
WATER_DEPTH_M	m	Whenever a new project is created by going through the new project wizard, the water terrains will have a value for the maximum depth. Respectively water: 2m and River water: 3m.
WATER_EVAPORATION_FACTOR		Multiplication factor of the reference evaporation (see Rainfall Overlay).
WATER_MANNING	s/m^1/3	Measure of surface roughness, used in the surface flow computation of the Water Module.

Subsurface

The Tygron Platform differentiates between various types of subsurface terrain types. Subsurface terrain data was originally acquired from FGR, however, as of version 2019.0.0 this has become BRO. The Subsurface Overlay shows the different soil types composing the subsurface, each having distinctive predefined attributes. The table below shows a division into the different terrain categories, which, in turn, have their own subdivisions into multiple subsurface soil types.

EN	NL	Description
Gravel	Grind
Clay	Klei
Chalk	Krijt
Loam	Leem
Loess	Löss
Unknown	Onbekend	Default, if no subsurface data is available.
Silt	Silt
Peat	Veen
Sand	Zand
Marine clay	Zeeklei

Each subsurface terrain type contains the following attributes:

Attribute	Unit	Description
ANGLE_OF_REPOSE	angle (0-90°)	The different subsurface types each attain a value for the maximum slope (Dutch: talud). This value is used for creating the water edge steepness and indirect for the water depth.
BUILDABLE	boolean	Attribute determining whether or not the subsurface tolerates the construction of new buildings.
GROUND_INFILTRATION_MD	m/d	Infiltration capacity of the surface soil into the subsoil. This attribute is used in calculations of the Water Overlay.
PEAT_FRACTION	fraction	The fraction of the subsurface which will be considered to be peat by the Subsidence Overlay.
TOPLAYER_THICKNESS	m	The depth of the clay soil layer, as considered by the Subsidence Overlay
WATER_STORAGE_PERCENTAGE	fraction	Fraction of the volume of water that can be stored per volume of soil, usually expressed as the saturated minus residual water-content properties of the soil.

Elevation

From the Terrain tab, the user can choose to manually change the current surface elevation model in the project, or to import one in the form of a GeoTIFF file. More information regarding the elevation model can be found on the terrain height page.