Introduction

Sustainable development is actually a process towards sustainability. It can be conceptually classified within other concepts such as social reorganization, transition to a better future, conserving the quality of the environment, people empowerment, creating new capacities, and respecting indigenous knowledge and information. All these concepts are considered to be the main axis of sustainable development by contributing to the elimination of the need of new generation, regarding the need of future generations.

Hence, sustainable rural development is a multidimensional process that can come off through the bottom-up approach and ongoing, shared use of local supply and resources. "Social capital" is one of the most important social components and a basic aspect of local sustainable development. Social and economic capitals can strongly affect the trends of community-based management of villages. By amplifying the capitals and their optimization, their effect on rural development will be promoted.

In this research, regarding the fact that social capital plays a key role in the realization of rural development, we have used social network analysis method before and after the implementation of a community-based project of rural management to investigated different aspects of bonding and bridging social capital of rural micro-credit fund in Bstaq village of Srayan county, South Khorasan. In this village, mobilizing financial resources has been already done by the establishment of micro-credit funds. It is obvious that the physical sustainability of economic structure of the Fund requires the sustainability of social capital in local network of its beneficiaries. Therefore, social capital needs to get evaluated over time among members of rural micro-credit fund.

Methodology

Social analysis and assessment of relations between members of rural micro-credit fund of Bastag, in the form of various subgroups, were done using the approach of social network analysis. Efficiency and impact of RFLDL project has been already evaluated for all the indicators and studied cases in two times, one before the implementation of the project in 1390 and one after that in 1394. We have first identified members of microcredit fund in Bastag using survey research and the study of documents in RFLDL project. Then, a network analysis questionnaire was developed and completed doing direct observations and interviews with different individuals. Rural micro-credit fund of Bastag consists of 13 groups. These include Aba-Abdellah, Azahra, Imam Reza, Amir-al- momenin, Sar-Allah, Javad-al-Aeme, Abolfazl, Sahbalzman, Kosar, Musa ibn Ja'far alMahdi, vali-e-asr, and Yas-e-nabi groups. The number of people who completed the questionnaires are 190 people among the group members and 13 heads of the funds. The head of the groups are determined by members in a local election. Data analysis has been done by analyzing and investigating the bonding relations between the group members or bridging communications between leaders in the form of rural micro-credit funds. Network analysis used in this research is a method of full network in which all network members are examined. Finally, collected data were analyzed in UCINET 6.507 software and then the intended indicators were analyzed as well.

Discussion and conclusion

The most significant ides contributing to the establishment of micro-credit fund is to achieve development goals to decrease poverty, mobilize financial resources of rural communities and organize local societies in aligned groups. In this research, we have examined trust-partnership bonds and evaluated various indicators of density, reciprocity links, transition and average geodesic distance using social network analysis method to assess bonding and bridging social capital between members or heads of the groups or between leaders of micro-credit funds of Bastag located in Sarayan and studied in RFLDL project.

Results show that the average density of trust-partnership bonds between members of rural micro-credit funds is high. In the next step of doing RFLDL project, the same indicator increased compared to before. In this village, two groups named Kosar and Azahra have been reported with moderate downwards density of trust- partnership bonds. In other groups this indicator is at its moderate upwards level. In Bastag, mutual trust is high and mutual partnership is up to the middle. The sustainability of communication networks and the institutionalization of various links in the village is assessed as moderate upward. This indicator is also high between the head groups of the village. After project reviews by accomplishing participating activities for rural sustainable development show more density between members of micro-credit fund comparing to before. However, respiratory was noticeably high between the head of the groups.

The velocity of Trust and Participation is high between the members of the Fund in the village of Bastaq. The amount has even increased more after the implementation of the project. The velocity of trust and partnership between the heads of micro-credit fund has respectively increased from 1 to 1.18 and 1.08 to 1.25. Furthermore, people linked together in the shortest possible time and at highest speed. Thanks to the great social :union: and solidarity among people, mobilization of social and financial resources will be possible at a higher speed. Considering the results of social capital assessment before and after the project, it can be said that RFLDL project acted successfully in building trust and creating good chances to strengthen the spirit of partnership and cooperation between members of the fund in Bastag.