====== Land type parameters ======

The distribution of land types, as calculated by the [[l3dt:algorithms:cli:am_algo|land type assignment]] algorithm, is dependent on the value of several parameters and coefficients, listed below. These settings are accessed from the [[l3dt:userguide:climates:ltedit:pane2|parameters tab]] of the [[l3dt:userguide:climates:ltedit|land type editor]] dialog, as seen below.

{{ l3dt:userguide:dialogs:ltedit_pane2.png?220 }}

===== Base score =====

The //base score// value is the default 'score' of the land type in the [[l3dt:algorithms:cli:am_algo|land type assignment]] calculation. The various other coefficients add to or subtract from this score. The //Base score// is modified by the //[[l3dt:algorithms:cli:land_type:altrange|altitude range]]// values, such that the land type has an effective //base score// of 0 outside the defined altitude bands.

Typically the //base score// is set so that the maximum score of a land type is around 100. For example, a grass land type with a //[[#Water|water coefficient]]// of 20 (and 0 for other parameters) would be given a //base score// of 80, and so the 'high score' of this type would be 100. This is not a hard-and-fast rule, but merely a guideline for saving sanity.

===== Gradient =====

The //gradient// coefficient determines how the score of a land type changes with the gradient (or steepness) of the terrain. The //gradient// coefficient is usually high for cliffs (say ~100), zero for grass, and negative for land types that are not usually found on slopes, such as sand.

===== Curvature =====

The //curvature// coefficient determines how the score of the land type changes with curvature (or 'bumpiness'). Normally the //curvature// coefficient is set to zero, but on rocky rocky terrain types it may be positive, and on loose/sandy/snow land types it may be negative. 



===== Water =====

The //water// coefficient determines how the score of the land type changes with the water-level in the [[l3dt:reference:maps:wm|water map]]. Typically values for some land types are:

^  Land type  ^  //Water// coefficient  ^
|  Shoreline (sand, mud)  |  50 ... 100  |
|  Grass  |  0 ... ~20  |
|  Desert  |  -100 ... -500  |
|  Rocks  |  0  |

<note tip>
You do not strictly need to use the //water// coefficient if you are only flooding the water map using a water plane. In such cases it may be easier to control the coverage of sandy land types using the [[l3dt:algorithms:cli:land_type:altrange|altitude range]] settings. For an example of both approaches, please consult the [[bundywiki>tutorials:l3dt:newclimate:02|climate tutorial]].
</note>

<note>
Land types that have a high affinity only for salty water (eg. beach sand) will have a comparatively low //water// coefficient, which is compensated by a high //[[#Salinity|salinity]]// coefficient (see below).
</note>

===== Salinity =====

The //salinity// coefficient determines how the score of the land type changes with the salinity in the water map. For most land types, this will be zero. This can however be positive for land types that are only found near the sea (e.g. beach sand) and may be negative for land types that are only found away from the sea (e.g. lake mud). The effect of the //salinity// coefficient is to increase the //water// coefficient in areas where the water map has high salinity (see [[l3dt:reference:maps:ws|salinity map]]). The //salinity// coefficient has no effect if the //water// coefficient is zero.

====== Notes ======

A recommended method of setting the value of land type coefficients is provided in the [[bundywiki>tutorials:l3dt:newclimate|making a new climate]] tutorial. Two things to note from that tutorial are that:
  - Most land types will have only a few non-zero coefficients, as otherwise it becomes very complicated. 
  - The actual values of these coefficients is somewhat irrelevant, as it is only the //relative// differences between land types that makes one land type score higher than another. Just how you balance these coefficients is a matter of taste.