Archeological Considerations The past is key to the future In archeological strata there are artifacts that record events and processes during millennia of human occupations of different soils Soils in landscapes have a dominant influence upon the land use Archeological Considerations Continuing prosperity of a nation is in part related to the land resources and husbandry of the soils through centuries of use and occupation Archeological considerations for the most part provide a pessimistic record of the abuse of soils and the social ramification are negative Case Studies Tikal Guatemala Phoenix AZ The Hohokam Indians lived on the Salt and Gila Rivers about A D 500 to A D 1400 They constructed several hundred miles of canals to provide irrigation water for crops Soil management became a major problem Salts accumulated in the fields because the soils became waterlogged from excessive irrigations and inadequate drainage Case Studies Phoenix con t Salts accumulated in the fields because the soils became waterlogged from excessive irrigation and inadequate drainage Sediments later filled the canals Salt erosion caused adobe walls to become unstable Modern agriculture still has problems with soil erosion and salinity Tikal Guatemala The Maya s in general managed the soils well Soils included modern Mollisols Vertisols Inceptisols and Entisols The Vertisols were located in swampy areas and were avoided as building sites due to wetness cracks churning and gilgai relief The Mollisols were located on hills which were shallow to limestone bedrock AZ The Hohokam Indians Tikal Guatemala These soils were used for building sites and as garden sites These Mollisols were very productive when left fallow for 10 years In general the first years crop would be 1000kg ha the 2nd years crop would be 750kg ha the third years crop would be 500 kg ha and the fourth years crop would only be 250kg ha without fertilizer The land would then be left fallow was shortened and the soils deteriorated and eroded 1 Mesa Verde Colorado Soils eroded after the forest was cut Negev Desert Arab countries Overgrazing resulted in wind erosion and sand dune formation Mexico City Mexico Aztecs built heavy buildings on low bearing strength lacustrine soils Rajasthan Desert India Once had many fields but cattle which were holy creatures eat all the vegetation that they could reach resulting in the lost of vegetation and soil abuse In addition the human population cut all the trees for firewood Sardis Turkey Due to the military significance of the location the area was subject to many invasions The steep soils Inceptisols eroded and the alluvial valleys were subjected to floods droughts famines and fires 2
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