In a previous class we discussed erosion. Removal of vegetation can result in increased runoff and soil loss upslope and sedimentation downslope. Alluvium can also contain cultural artifacts that become deposited in various horizons as well. Analyses of these horizons can therefore tell us something about past conditions, their sequences, and events. For example, remnants of decrepit terraces on a slope and large sediment deposits downslope bear witness to human efforts to thwart erosion, efforts which eventually failed.
Water obviously plays a frequent roll in landscape evolution.
In arid lands well are frequently dug to tap groundwater for various purposes, not the least of which is irrigation. First, when water is applied to the surface much evaporates leaving a layer of mineral salts which eventually affect crop production. Also, if drawn from a distant source, irrigation waters can raise local ground water levels exacerbating the problem. And, gullying can occur in those place where the water is extracted and the water table drops. There are several detailed techniques for measuring landscape change.