Historical Evidence Flashcards
Siltation from soil erosion in uplands resulted in sedimentation that clogged irrigation canals and depopulated cities
Bablylon/Iraq
Flooding of delta with sediment-rich water-maintained soil productivity for over 6000 years.
Nile Valley, Egypt
Villages in uplands were abandoned due to the loss of topsoil. Where terraces are present, some agriculture remains. The rate of abandonment of land reflects the loss of topsoil.
Judea/Israel
Topsoil lost by erosion. Area is depopulated desert.
100 Dead Cities/Syria
Forests of cedar cleared for agriculture on steep slopes. Soil erosion denuded of topsoil except where rock walled terraces built and maintained from bottom to the top of slopes.
Lebanon terraces
Mountains kept barren of cedars by grazing livestock
Lebanon livestock
Riverbeds built high above flood plain by deposition of silt eroded from headwaters, resulting in the risk of flooding and death.
China Yellow River
Gullies 600 feet deep caused by erosion
China Loess Plateau
Great agricultural areas with olive groves are now covered in wind deposits, overgrazing of vegetation, causing runoff and soil erosion, and lowering water table is likely cause.
Timgad, Algeria (North Africa)
Terraces have sustained production cultivation of 2500 years on slopes up to 100%.
Southern France
Large-scale deforestation since 1950’s resulted in serious damage to slopes and burying of rice fields in valleys.
China Forests
Experts in soil and water conservation. Built bench terraces 3-10 feet tall using stone.
Incas of Peru
Complex systems of bench terraces, dams and diversions.
Maya /Central America Southern Mexico