Introduction

The pattern of rural settlements is more than anything affected by environmental-ecological factors, to the extent that the pattern of rural settlements is fundamentally a reflection of factors and forces of the natural environment. The way of accessing water and soil resources, the type of prevailing climate, the type and density of vegetation, and the proximity and distance to large aquifers and watersheds can act as forcing or inhibiting factors. Ignoring the facilities and limitations of the physical bed of the village for its growth and development may cause environmental issues and problems such as erosion and waste of water and soil resources, extensive damage caused by devastating floods, reduction of forest and pasture products, and loss of fertility and productivity of agricultural lands. Reducing and mitigating adverse environmental consequences for rural communities requires knowledge of the abilities and restrictions of the natural environment and their role in the establishment and development of rural settlements. The current research was conducted with the aim of identifying and determining the relationship between various environmental factors and geographic distribution of villages in Ardabil County.



Methodology

The research method is descriptive-analytic and we used the Statistical-Spatial analysis to review and determine the relationship between environmental factors and distribution of villages. The data of selected variables including altitude, slope, climate type, lithology, distance to fault, landform, distance to stream, and distance to spring, distance to well, land use/land cover came from various library references. Determining the quality and quantity of the relationship between the environment variables and the geographical distribution of the villages was carried out through "overlap analysis". In this regard, preparation, management and analysis of data are fulfilled by geographic information system (GIS).

Ardabil County with area of 2166 square kilometers is located at latitudes 37° 54' 43" to 38° 38' 59" N and longitudes 47° 49' 56" to 48° 41' 41" E. This County has 2 cities, Namely Ardabil and Hir, 10 villages and 178 villages. The population of the County was 606,081 people, of which 531,454 people lived in cities and 74,536 people lived in villages. Due to the centrality of the County in Ardabil province, the villages of Ardabil have the highest level of economic and social development, and extensive agriculture and animal husbandry are prevalent there due to favorable natural conditions.



Results

The results of the spatial analysis showed that there is a close relationship between the environment variables and the distribution of villages. Most of the villages are in a semi-arid climate, altitudes below 2000 meters, slope below 10 degrees, andesite-dacite and quaternary sedimentary formations, 5 km distance to faults, rough and semi-rough terrain, 1 km distance to rivers, 2 km distance to wells, >2 km distance springs and in agricultural lands. In among the environmental variables, the geomorphology has a comprehensive and outstanding role in spatial distribution of the villages. The arrangement and configuration of the geomorphs are not only effective in the movement of rain-producing fronts and local instabilities, and ultimately, climate variability, but also provide the intensity and weakness of the surface runoff, as well as the formation and feeding of the aquifer through depressions and low altitudes. The erosion of the rocks of the highlands and the accumulation of sediments in the plains are due to geomorphic conditions.



Conclusion

In planning with aim of construction and regional development for rural settlements, it is necessary to firstly pay attention to all the opportunities and threads that are against the rural settlements depending on the possibilities and ecological limitations, and secondly, consider the comprehensive and systematic approach to the spatial analysis of the physical or natural bed. The current research, which was carried out by considering such an approach and research method, achieved significant and important results. At the whole, it can be said that the establishment of rural settlements in Ardabil County in the physical environment depends on the inter-relationship of the elements and factors of the physical environment. Meanwhile, Hydrogeomorphic factors have played a fundamental and important role in the establishment and development of rural settlements in Ardabil County. The concentration of villages in Ardabil plain, despite its semi-arid climate, is due to its geomorphic location, which promises the availability of massive water and soil resources, physical connections, ease of access, and other biological-livelihood and welfare facilities. The rural settlements of Ardabil County are exposed to the hazards such as earthquake, land destruction, subsidence, and flood, and it is necessary for the planners and policy makers of regional development and construction affairs to pay serious attention to these issues.