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Abstract In this study, to investigate situation of soil erosion and sediment yield in the Sorkh Abad watershed of Mazandaran province, first measured the specific sediment observed by aspects of sediment accumulated behind two of stone and mortar dam in the output of the mentioned watershed was considered then using models FSM, PSIAC and EPM performance of each of these models to estimate the amount of erosion and sediment yield was evaluated. According obtained results of the observed and measured sediment rate behind dams in the study area was 390.997 ton per square kilometer per year, which were obtained for FSM (equation 10), PSIAC and EPM models 611.411, 239.157 and 280.436 ton per square kilometer per year respectively. Also, the relative error percentage calculated for the above models, respectively 22, 36 and 50 percent. According to the results, the EPM model with relative error percentage less than other models used was better performance to estimate of erosion and sediment yield in the Sorkh Abad watershed.

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Tourism development at any geographical location may cause positive as well as negative economic and social consequences, along with environmental impacts that if the later appears in negative outcomes and continues it can bring irreparable damages. Today, the sustainable tourism in the framework of sustainable development planning has been considered to prepare environmental protection. In this regard, the purpose of this study is to assess attitudes and intensions of owners of tourist resorts toward sustainable tourism in some selected resorts in Mazandaran province. Population of the study included owners of tourist resorts in those cities which 121 people were selected by simple random sampling. T conduct the survey a survey method was applied and questionnaire was the instrument of collecting data. Findings of the study showed that the surveyed people had positive attitudes towards sustainable tourism and the level of this tendency varied based on the respondents’ age, education and work experience. Furthermore, the result of the research showed that there was a direct relationship between the subjective and practical dimensions of sustainable tourism. Finally, the findings indicated that the owners’ level of commitment to the sustainable tourism in the three cities studied was different.

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As a developed and institutionalized concept, sustainable development has become a comprehensive framework for understanding and analyzing the issues that cities face. As geographical systems, small towns have been created under the influence of space-making factors and forces in a spatial-temporal process, and have always been developed by internal and external process (social, economic, environmental and spatial). As a vital and inseparable ring of settlement at the national, regional and local levels, these towns consist of interrelated components and their sustainable development will result in local and regional sustainable development. Therefore, sustainable development of small towns is an important process and fundamental approach which formed the main framework of the present study. In this regard, physical sustainability concept in the sustainability framework of small towns shows the balance and vibrancy of these small settlements in relation to physical – spatial structures, so that it guarantees the sustainability of settlements in the spatiotemporal trends. So it can be considered a process of development and change, with the aim of improving the quality and quantity of the city's physical structure, among which identifying and strengthening the physical sustainability indicators seeking to improve the physical quality of human settlements and living and working environments of all people, especially poor people, on the way to sustainability is an issue of paramount importance. Therefore, this study is aimed to identify and explain the trend of development changes in physical-infrastructural structure of small towns, and to increase the conceptual-functional importance of physical indicators in small towns of the province. Sustainability Barometer model and radar were used for analyzing the data. The statistical population used in this study consisted of small towns in Mazandaran province. The results show that only the component of functional integration in small towns was in moderate sustainability level, and components of places and facilities qualities were in poor sustainability conditions. Overall, the results indicate that there is weak sustainability in physical dimension of urban sustainable development in small towns.