Given the variety of environmental and ecological factors on the one hand, and the effect of social- economic and political conditions on the other, rural settlements in Iran have a particular spatial distribution. The natural parameters have been considered as influential factors contributing to the stabilization and spatial distribution patterns of population and rural settlements. These also play a very important role in improving the spatial development of rural settlements. In fact, the establishment and dispersion of rural settlements in Iranian plateau have been influenced by many parameters including natural, economic, social conditions and bureaucratic structures. Out of the parameters mentioned above, environmental factors and their elements including water, wind, soil, fault lines, topography slope…, are of utmost importance. These factors also contribute to the improvement of spatial patterns of rural settlements. The spatial improvement of rural settlement system regarding land development is closely related to the structural patterns, as well as economic development .

Obviously, the appropriate spatial patterns in settlement system generally and in rural settlements in  particular, is a requirement for achieving a balanced development in rural areas. That is, the   patterns and methods informed by objective knowledge of rural populations and rural residence locations. Thus, a thorough examination and knowledge of physical-spatial structure of rural settlements followed by  their subsequent improvement is a principal way for achieving a sustainable development including spatial justice.Aiming to achieve a suitable plan for spatial distribution of rural settlements in Doroh district in Sarbisheh township, this study seeks to identify safe and unsafe locations for rural settlement establishments with respect to natural hazards and assessment of sustainable and unsustainable settlement. Doroh district is located in south Khorasan province in eastern part of Iran and west of Afghanistan.  Environmental hazards and natural parameters in many occasions have influenced the rural settlements in Doroh district. Statistics indicate that , environmental disasters such as flood, earthquake ,land slide and faulty mountains in some villages located in mountainous  areas and plains, alongside social and economic factors such as unemployment, illiteracy, weakness of infrastructures have threatened  the settlement and the life of inhabitants.

This study is of descriptive- analysis type and is intended  to be applied. Data were collected through field study and documents survey. After receiving the data concerning natural factors influencing the formation and distribution of rural settlement, the capabilities and restrictions regarding the dispersion in the region as well as the maps of optimum locations for rural settlement were provided through spatial, statistical, and descriptive data. Finally, appropriate strategies and policies for spatial improvement were provided. They were used to classify the villages into four groups, from thoroughly sustainable to thoroughly unsustainable and their positions were located on the maps. All information analysis and their resulting outputs were based on Geographic Information Systems (GIS) . Analytical Hierarchy Process(AHP), as a credible model,   was also used in this study.

The results show that the natural factors contribute significantly to the establishment and dispersion of settlements in the area studied. The results also show that the rural areas are divided into four groups in terms of risk management a fact that needs to be taken into account for achieving a sustainable development.