The role of environmental factors in the distribution of rural settlements with emphasis on natural hazards (Case study of Siyhrud basin, Rudbar city, Gilan province)

Introduction:

The environmental factors in different regions play the key role for the development of settlements. The rural settlement is affected by these factors too. On the other hand, human beings from the beginning of life up to now have been encountered with a variety of injuries and natural hazards and they have suffered various life and financial injuries [1]. The word natural hazards represent the occasion that our economic development is unacceptably fragile, and is too vulnerable to nature's behavior [2]. The aim of the research is to study the role of environmental factors for the settlement of villages focusing on natural hazards. The research scope is the natural boundary of Siyahrud watershed which is located in Gilan province, Rudbar city. Hence, such a question is raised in this research if natural hazards are considered to the distribution of rural settlements in the basin; which categories of hazards can play the role the most to the destruction of settlements? 

Material and Methods:

There have been seven environmental parameters considered in Rural Settlement which are: Altitude, Slope, Aspect, Fault, Soil, Land Use, Rivers and Roads. The effects of each parameter on the settlements investigated, too. Natural hazards were divided into two groups: Earthquake and Mass Movement. The hazard warning distance is considered 1000 meters from the epicenter of the Earthquake.The Inverse Distance Weight (IDW) method was used to interpolate the magnitude of the earthquake based on 281 points inside the basin. Aspect, Slope, Fault, Road, River and Geology have been the most effective perimeters in Mass Movement. So, they were overlaid with the 34 occurred- Landslide Points. Consequently, the final output of Landslide Zoning was obtained.

Conclusion:

The result of studies shows that Land Use, Altitude, Slope and Water in the past have played a key role to village settlement while other environmental factors such as Faults, Mass Movements and Geology have not been considered at all. Moreover, Road and Land Use have been considered after the construction of settlements. There are around 15000 people living in distance of 1000 meters from the fault and around 10000 people, 1000 meters from existing Mass Movements in the basin. So, this can be an alarm for the officials of Rudbar city, to renovate rural housing here.