Aerosols, hydrologic transport

The problem of estimating aerosol transport is thus focused on the study of watershed media effects on the transport of substances in solution rather than in insoluble aerosol particles. Thus, sorption by watershed media is a prime factor in determining the hydrologic transport of soluble radioaerosols, such as cesium and strontium. Removal of soluble radioaerosol elements from runoff by formation of insoluble compounds is considered unlikely. 

The final step in the hydrologic transport of radioactive aerosols through a watershed is transmission through the channel system to the basin outlet. Aerosol input to the main channels in the basin from land surface runoff and interflow must pass through the channel system in a manner governed by the laws of hydraulics. Simulation of the timing of radioaerosol outflow from the basin must therefore include a consideration of channel transport. 

Much has been written in recent years about atmospheric inputs to the soil since the acid rain problem has been recognised. Soils receive both wet deposition, ie, precipitation as rain or snow and dry deposition in which aerosols are deposited on the surface. Although precipitation is very dilute it can be an important source for some elements, cyclic salts which are derived from the oceans and transported to the land surface in the normal hydrological cycling of elements. Fuge and Johnson (1986) concluded that most iodine in soils is derived from the atmosphere and, hence, the oceans. Normally, however, rain makes only a very small contribution to the composi-... 

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