Figure 11-2. Machu Picchu, Peru
Human-Altered and Human-Transported Soils (HAHT) soils can be identified not only by diagnostic features in the soil profile but also by their association with anthropogenic landforms, whether manufactured items are found in the profile or not. This ancient urban area has geometric hillslope terraces on cut-and-fill landforms (foreground and lower right) created by humans in mountainous terrain to allow grazing, farming, and house building on formerly steep slopes. It demonstrates intentional human modification and transportation of soil. (Photo by Pedro Szekely)
Soils in urban areas are commonly human-transported (e.g., fill) or human-altered (e.g., truncated or mixed in situ) to significant depth. They generally exhibit a wide variety of conditions, and many are covered with impervious surfaces (e.g., buildings and pavements). The same situation occurs in suburban and low-density urban areas, but the proportion of less altered soils is higher and the proportion of buildings and pavements is lower. In many areas with HAHT soils, surface geomorphology and hydrology have been intensely altered. Other highly modified landscapes contain significant amounts of human-transported materials, such as steep farmland with closely spaced hillslope terraces and areas of intense activity, such as mines, oilfields, and highway corridors.
Spoils from land-leveling, filling, construction, mining, dredging, waste disposal, and manufacturing operations become parent materials for new soils, which are commonly used to extend urban areas or airports into shallow water or to fill wetlands. Major areas of human-altered materials occur where agricultural areas have been deeply ripped to loosen impervious subsoil horizons, such as in the Central Basin of California. There is a need to identify, describe, and map HAHT soils because these soils have been modified enough from their original state that former soil maps do not provide the correct information or there is no information on them at all.
Soil Survey Manual, Ag. Handbook 18, 2017, (p. 528).
Figure 11-2. Machu Picchu, Peru
Human-Altered and Human-Transported Soils (HAHT) soils can be identified not only by diagnostic features in the soil profile but also by their association with anthropogenic landforms, whether manufactured items are found in the profile or not. This ancient urban area has geometric hillslope terraces on cut-and-fill landforms (foreground and lower right) created by humans in mountainous terrain to allow grazing, farming, and house building on formerly steep slopes. It demonstrates intentional human modification and transportation of soil. (Photo by Pedro Szekely)
Soils in urban areas are commonly human-transported (e.g., fill) or human-altered (e.g., truncated or mixed in situ) to significant depth. They generally exhibit a wide variety of conditions, and many are covered with impervious surfaces (e.g., buildings and pavements). The same situation occurs in suburban and low-density urban areas, but the proportion of less altered soils is higher and the proportion of buildings and pavements is lower. In many areas with HAHT soils, surface geomorphology and hydrology have been intensely altered. Other highly modified landscapes contain significant amounts of human-transported materials, such as steep farmland with closely spaced hillslope terraces and areas of intense activity, such as mines, oilfields, and highway corridors.
Spoils from land-leveling, filling, construction, mining, dredging, waste disposal, and manufacturing operations become parent materials for new soils, which are commonly used to extend urban areas or airports into shallow water or to fill wetlands. Major areas of human-altered materials occur where agricultural areas have been deeply ripped to loosen impervious subsoil horizons, such as in the Central Basin of California. There is a need to identify, describe, and map HAHT soils because these soils have been modified enough from their original state that former soil maps do not provide the correct information or there is no information on them at all.
Soil Survey Manual, Ag. Handbook 18, 2017, (p. 528).