Application of Cs-137 radionuclides in estimation of forest soils erosion with different parent material in Shast kalateh region, Golestan province

Bachground and Soil erosion is one of the most serious and irreversible threat for the sustainable development in each region. Cesium has been produced due to nuclear testing in the last decades and entered into the stratosphere, and then comes to the soil by rainfall. These radionuclides have an importance in soil erosion studies because it is absorbed by the clay soil in a way that it is exchanged hardly.
This study was conducted to investigate the use of 137Cs in measuring the rate of soil erosion and distribution of sediments in forest and unforest soils and on different parent material. So, six regions (three in forest with loess, Jurassic material, alluvium loess and other in cultivated area) were selected. Samples were taken from surface to 100 cm depth.
Gamma spectrometry results showed the pollution of these soils to Cs. Layer analysis in forest profiles demonstrates stability in exponentially reduced trend. High activity was measured in forest loess area. Cs activities in alluvium loess deposits have changed in different sediment layers.
Conclosion: The results showed that erosion has amount between 16 to 45 ton per hectare per year in different landuses. The highest soil erosion occurred in crop lands and the lowest occurred in forest soils. Forest in study area has major limitations for selecting as a reference point.