Environmental hazards

Geomorphological events with a direct effect on human are especially important for applied geomorphologists. Our discussion in this article is limited to geomorphological hazards. Hazards happen after passing a threshold. Some hazards like earthquake are completely natural, but some others are quite related to human activity. Here we describe the main geomorphological hazards and their influences. Unfortunately, the wide range of geomorphological hazards is not completely understood, therefore table 1 provides a list of geomorphological hazards. Moreover, their catastrophic results are not understood and table 2 provides a list of the world most important natural disasters caused by geomorphological events. Some parts of the world are unfortunate enough to experience a large number of geomorphological hazards. There are two main discussions regarding hazards. First, some hazards like volcano, earthquakes, corrosions fault are results of structural motions of the earth crust and actually they act in a very short time interval. Second and more interestingly, some hazards caused by geomorphological procedures happen in a short period of time-within days, or even hours. River floods, sea floods and land slide are examples of these procedures. Events are transient and odd and they can catastrophically be described in more than one way.