Editing Terrain (section)

== Importance ==
The understanding of terrain is critical for many reasons: 
* The terrain of a region largely determines its suitability for human settlement: flatter [[alluvial plain]]s tend to have better farming soils than steeper, rockier uplands.<ref>{{cite journal |last1=Dwevedi |first1=Alka |title=15 - Soil sensors: detailed insight into research updates, significance, and future prospects |date=January 1, 2017 |url=https://www.sciencedirect.com/science/article/pii/B9780128042991000163 |journal=[[New Pesticides and Soil Sensors]] |pages=561–594 |editor-last=Grumezescu |editor-first=Alexandru Mihai |publisher=[[Academic Press]] |language=en |isbn=978-0-12-804299-1 |access-date=October 11, 2022 |last2=Kumar |first2=Promod |last3=Kumar |first3=Pravita |last4=Kumar |first4=Yogendra |last5=Sharma |first5=Yogesh K. |last6=Kayastha |first6=Arvind M.|doi=10.1016/B978-0-12-804299-1.00016-3 |url-access=subscription }}</ref>
* In terms of [[environmental quality]], [[agriculture]], [[hydrology]] and other interdisciplinary sciences;<ref name=baker2011>{{cite book|last1=Baker |first1=N.T. |last2=Capel |first2=P.D. |date=2011 |chapter=Environmental factors that influence the location of crop agriculture in the conterminous United States |title=U.S. Geological Survey Scientific Investigations Report 2011–5108 |publisher=[[U.S. Geological Survey]] |page=72}}</ref> understanding the terrain of an area assists the understanding of [[drainage divide|watershed boundaries]], [[drainage basin|drainage characteristics]],<ref>{{cite book |last=Brush |first=L. M. |date=1961 |title=Drainage basins, channels, and flow characteristics of selected streams in central Pennsylvania |pages=1–44 |work=U.S. Department of the Interior, GEOLOGICAL SURVEY |location=Washington D.C. |publisher=[[U.S. Geological Survey]] |access-date=October 29, 2017 |url=https://pubs.usgs.gov/pp/0282f/report.pdf}}</ref> [[drainage system (geomorphology)|drainage systems]], [[hydrogeology|groundwater systems]], [[drainage|water movement]], and impacts on [[water quality#Environmental water quality|water quality]]. Complex arrays of relief data are used as input parameters for [[hydrology transport model]]s (such as the [[SWMM|Storm Water Management Model]] or [[DSSAM Model]]s) to allow prediction of river [[water pollution|water quality]]. 
* Understanding terrain also supports [[soil conservation]], especially in agriculture. [[Contour ploughing]] is an established practice enabling [[sustainable agriculture]] on sloping land; it is the practice of ploughing along lines of equal elevation instead of up and down a slope.
* Terrain is [[military|militarily]] critical because it determines the ability of armed forces to take and hold areas, and move [[troop]]s and material into and through areas. An [[Military geography#Types of terrain|understanding of terrain]] is basic to both defensive and offensive strategy. The military usage of "terrain" is very broad, encompassing not only landform but land use and land cover, surface transport infrastructure, built structures and [[human geography]], and, by extension under the term [[Human Terrain System|human terrain]], even psychological, cultural, or economic factors.<ref>{{cite web|url=https://irp.fas.org/doddir/dod/jp1_02-april2010.pdf |title=Joint Publication 1-02 |website=Department of Defense Dictionary of Military and Associated Terms |quote=* "compartmentation ... [involves] areas bounded on at least two sides by terrain features such as woods..."<br>* "culture — A feature of the terrain that has been constructed by man. Included are such items as roads, buildings, and canals; boundary lines; and, in a broad sense, all names and legends on a map."<br>* "key terrain — Any locality, or area, the seizure or retention of which affords a marked advantage to either combatant."<br>* "terrain intelligence — Intelligence on the military significance of natural and manmade characteristics of an area."}}</ref>

* Terrain is important in determining [[weather]] patterns. Two areas geographically close to each other may differ radically in [[precipitation]] levels or timing because of elevation differences or a [[rain shadow]] effect.
* Precise knowledge of terrain is vital in [[aviation]], especially for low-flying routes and maneuvers ([[Terrain awareness and warning system|see terrain collision avoidance]]) and airport altitudes. Terrain will also affect range and performance of radars and terrestrial [[radio navigation]] systems. Furthermore, a hilly or mountainous terrain can strongly impact the implementation of a new [[aerodrome]] and the orientation of its runways.