Introduction

Common development capitals such as financial (economic) capitals, human capital, physical capital, environmental capital and social capital are considered as key elements in analyzing the potentials of development for people, organizations, societies and even governments. By presenting the concept of social capital, planning strategies are formed by cooperative, communicative and interactional planning along with an approach to people's participation and according to sustainable development framework which concentrate on some indicators such as assessment of social capital, sustainability, flexibility and participation; considering a relative advantage, every district and settlement had freedom of action in putting sustainable development policies into practice in this type of planning. From an international development perspective, social capital has a special position as a part of movement toward development using a "bottom-up" design. Regarding this, the amount of relations and impacts of different types of capitals are studied because of the great importance of different types of capitals especially social capital in rural development. The most important questions in this study are as follow:
"What is the relation between different types of capital (economic capital, human capital, environmental, and physical capital) with social capital?" and "How do different types of capitals impact on social capital?”

Methodology

This study is conducted by a geographical approach, and a descriptive-analytic method which is based on qualitative and quantitative research method. For determining the sample population size out of 1162 villages with more than 20 households in Khorasan Razavi province, 67 villages were in accordance with all the criteria in table 2. Since these villages are homogenous in three levels, 18 villages (6 villages in each level) from 14 counties were categorized randomly in GIS environment and were chosen by Hawths Analysis Tools. Statistical population encompasses of two grouping including local people of the village and local officials (council members and municipal official). To evaluate the validity and stability of questionnaire, SPSS software has been used. According to this method, by using KMO Test, validity of determinative indicators of social capital, economic capital, human capital, physical capital and environmental capital are 0.071, 0.72, 0.58, 0.64 and 0.57 respectively and for the whole questionnaire, this number is 0.68. According to the results of construct validity test, Cronbach's Alfa coefficient which is obtained from the designed questionnaire for evaluating different types of development capitals in the studied villages is equal to 0.89, therefore, the validity of the questionnaire is confirmed.

Discussion and Conclusion

Today, one of the challenges that rural development face to, is neglecting social capital; recognition of social capital leads to facilitating the process of rural development planning for experts in this field and also it is followed by rural inhabitants' contribution for better implementation of the plans. Regarding to theories and studies in this field, it can be said that different types of development capitals are interrelated and interchangeable. In pursuing development issues especially sustainable rural development, social capital is extremely focused in recent decades. Since many researchers and experts believe that social capital is subordinate to other capitals, this study aims to evaluate the impacts of different types of capitals including economic capital, human capital, environmental capital and physical capital on social capital in rural districts and also it aims to determine their relationships. Results showed a meaningful relation between economic capital, human capital and social capital and a lack of meaningful statistical relation between environmental and physical capital and social capital in studied villages. Moreover, according to the results, coefficient of determination (R2) for economic capital is 0.0906 and coefficient of determination for human capital is 0.176 and these two indicators had the most impact on social capital respectively. In other words, economic capital determines 90.6 % of social capital rate and human capital determines 17.6% of social capital rate in studied villages.