Editing Trench warfare (section)

=== Geography ===

The confined, static, and subterranean nature of trench warfare resulted in it developing its own peculiar form of [[geography]]. In the forward zone, the conventional transport infrastructure of roads and rail were replaced by the network of trenches and [[trench railways]]. The critical advantage that could be gained by holding the high ground meant that minor hills and ridges gained enormous significance. Many slight hills and valleys were so subtle as to have been nameless until the front line encroached upon them. Some hills were named for their height in metres, such as [[Battle of Hill 60 (Western Front)|Hill 60]]. A farmhouse, windmill, quarry, or copse of trees would become the focus of a determined struggle simply because it was the largest identifiable feature. However, it would not take the artillery long to obliterate it, so that thereafter it became just a name on a map.

The battlefield of [[Flanders]] presented numerous problems for the practice of trench warfare, especially for the Allied forces, mainly British and Canadians, who were often compelled to occupy the low ground. Heavy shelling quickly destroyed the network of ditches and water channels which had previously drained this low-lying area of Belgium. In most places, the [[water table]] was only a metre or so below the surface, meaning that any trench dug in the ground would quickly flood. Consequently, many "trenches" in Flanders were actually above ground and constructed from massive [[breastwork (fortification)|breastwork]]s of sandbags filled with clay. Initially, both the parapet and parados of the trench were built in this way, but a later technique was to dispense with the parados for much of the trench line, thus exposing the rear of the trench to fire from the reserve line in case the front was breached.

[[File:1917 ortler vorgipfelstellung 3850 m highest trench in history of first world war.jpg|thumb|right|Soldiers in a trench on the Ortler, at an elevation of {{convert|3850|m|ft}} (1917).]]
In the [[Alps]], trench warfare even stretched onto vertical slopes and deep into the mountains, to heights of {{convert|3900|m|ft|abbr=on}} above sea level. The [[Ortler]] had an artillery position on its summit near the front line. The trench-line management and trench profiles had to be adapted to the rough terrain, hard rock, and harsh weather conditions. Many trench systems were constructed within glaciers such as the [[Adamello-Presanella]] group or the famous city below the ice on the [[Marmolada]] in the [[Dolomites]].