In recent years, rural settlements have undergone changes due to physio-spatial changes. The acceleration of these changes has been so much that many villages have undergone structural and physical changes, or sometimes slowly joined the body of cities. There are different spatial flows between the metropolitans and surrounding settlements. These flows have shaped many of the developments in the rural areas. The purpose of this study is to analyse the trend of spatial flows affected by rural-urban interactions and the physio-spatial transformation of rural settlements in the northern Tankaman district located around the Karaj metropolitan via the means of descriptive-analytic methods. Karaj metropolitan area is one of the most important areas of this spatial transformation - a space where the focus of capital, industries, facilities and services has brought about its physical and functional growth.  Such rapid growth and the ruling trends, from the physio-spatial perspective have implications such as comprehensive transformations in the construction and fabrication of peripheral villages, in particular in the pattern of housing, deformation for communication access, land-use change, severe service shortages, Inappropriate access and ... in peripheral villages.
The present study is a quantitative, functional and survey based in data gathering, which questionnaires and interview methods were used to collect data and information. According to the statistics of 1390, the total of ten villages in North Tankaman were selected. The ten villages have a total population of 11,509. Of these, 372 people were selected as the sample size using the Cochran formula. To determine the reliability of the questionnaire, Cronbach's alpha coefficient was used. The calculation of this amount was 0.80 for the authorities. The variables of the indicators were designed in the form of a questionnaire and provided to the rural population. To analyze and deduce, depending on the research objectives and the type of data available, descriptive statistics were used such as frequency and percentage and GIS software.
The results of the findings of the housing developments in the study area show that the overall average of the Likert spectrum for the increase in the number of residential units with the Urban Architecture model is 3.68, which is the most significant, reflecting the change in the pattern of rural housing architecture in the northern Takaman district, which is like other rural areas of the country. The change in the pattern of rural housing architecture and its similarity to urban housing pattern has been considered by most of its appearances and has grown more than other indicators such as resistance and improving the quality of housing. Part of livelihood units are assigned to commercial units, and some residential units are also allocated to livelihoods units. Analysis of the results of Pearson correlation test for research variables shows that there is a positive and direct relationship between rural-urban spatial interactions and physio-spatial transformation indices, in which all correlations are strong.
The physio-spatial system, as one of the sub regions of rural spaces, is not only influenced by the internal factors of this system but is also influenced by its external (external) elements along with other subsystems in transition. Among the external environmental factors, the system of cities and the type of their spatial interactions with rural areas is one of the most important factors influencing rural development, especially the physio-spatial system. The research findings have shown that the evolution of the physio-spatial system of the studied villages under its systems has been strongly underway. These developments, some of which have positive aspects and some also negatively, have had implications for the villages. Among the influencing factors, the type, form and scope of interactions of villages with peripheral cities has played a significant role in this development. The flow of goods and services, capital, along with the flow of people, which has a one-way and sometimes two-way structure (in line of providing the interests of the cities), has provided the basis for this transformation.