Management Pattern of Natural Hazards with an Emphasis on the Sustainability of Urban and Rural Settlements (Case Study: Landslide in Rudbar Region)

One of the main tasks of hazard knowledge is to study the situation and value of the human environment that is vulnerable to all types of natural and human hazards. Hazards in the environment are caused by the instability of the characteristics of natural environment (land surface, biological phenomenon, climate) and human environment (security, technology, etc.), which appear as dangerous events due to human interventions and infrastructures caused by urban-rural developments. In general, it is necessary to take several steps towards designing management models to achieve and formally apply the perspectives of risk knowledge and reduce and manage environmental risks. Establishment of a relationship between the various components of environmental hazards requires the researchers to formulate hazard trends through a model so that this complex and multidimensional process can be easily understood and implemented. This pattern would be a theoretical and simplified representation of the real world. For researchers, who try to understand and apply the principles of risk knowledge in urban and rural settings, this model is a theoretical tool consisting of concepts, hypotheses, and indicators that facilitate selection and collection of the information needed to achieve the basic goals. This research tried to study the risk of landslides in Rudbar in the form of a management model, including risk identification, risk and hazard assessment, zoning, etc., so as to manage and alleviate hazards in the urban and rural areas of Rudbar region. At the same time, the roles of central government and local management in lowering risks were evaluated by reviewing the required measures. The related institutions have a pivotal position in the development and risk management of this area and are capable of taking executive measures to reduce risks and vulnerability within their frameworks, provide sustainability of urban and rural settlements against geomorphological hazards, highlight the challenges ahead, especially from a managerial perspective, and define and present solutions in this regard. 

In terms of methodology, this paper was based on a quantitative method (assessment and zoning of landslide hazards using a network-derived decision model) and a qualitative method (development of an environmental risk management model with an emphasis on sustainability of urban and rural areas). In the first part, a library method, including a review of theoretical studies of hazard knowledge, landslide analysis, drawing and analysis of related maps, etc., was utilized to develop a management model for environmental hazards. In the second part, by combining the library and field methods, i.e., scientific observation and regional study, several interviews were done with the executive community (governorate officials and district municipality), scientific community (environmental risk experts and urban and rural planners), and local community (natives of Rudbar and adjacent villages) to formulate management components and analyze the current situation for developing a management model of environmental hazards in the study area. The landslide risk zoning process was designed and evaluated within the framework of a network-derived decision model. Assessing and interpreting risk levels via a management model are very important since development of a model highly depends on the evaluation. If the prevailing risk situation in a region is favorable, its management issue may either be eliminated or appear different from the expected disastrous conditions.

 Findings

In general, environmental risk management requires interaction of geographical sciences with each other. Therefore, in the formulation and study of environmental risk management models in urban and rural areas, it is necessary to study geographical and other related sciences along with the knowledge of urban-rural planning and applied geomorphology. In this research, the position of each of them in the implementation steps of the environmental risk management modeling of Rudbar region was addressed. For formulating a conceptual model and routing the sustainable management of landslide hazards, various steps must be taken based on the mutual and effective roles of the academic community or researchers, the executive community or decision makers, and the indigenous community or local people with regard to demand resilience. A wide-range geosystem, including coastal and wind geosystems, etc., is associated with different geomorphic actions and reactions and therefore, each management style would be unique in nature. For example, the issues of resilience, prevention, risk preparedness, and special management capacity would generally require special areas. In this regard, the present research as a case study examined the most susceptible management model in the form of risk knowledge in 9 main steps (Fig. 3) through the implementation process. According to this proposed model, the first step began with the definitions, goals, and perspectives of risk and risk knowledge and the final step ended with a review of the measures taken with the objectives in mind. The scientific support of environmental risk management in the forms of a study and implementation requires a combination of theoretical, practical, technical, and executive studies. 

Hazard knowledge is a broad and continuous set of theoretical and field studies of risk management and executive measures. The goals and prospects of this knowledge can be achieved to reduce and manage environmental risks by identifying and taking various steps in line with management models. Therefore, in this paper, an attempt was made to develop a natural hazard management model, especially for landslides, that controls urban and rural areas. In this regard, after applying the theoretical foundations of hazardology, the natural hazards were classified by determining the dominant hazards in the study area with the help of theoretical and field studies. These hazards were then analyzed and zoned. At this stage, by determining the effective elements in the occurrence of landslide risks, including slope, slope direction, lithology, land use, average annual rainfall, distance from faults, waterways, and residential centers, and weighting these elements in relation to each other,  each element was zoned based on the experts’ opinions, study background, and field visits by using the network analysis method to assess the performance of urban landslide risks. The results showed that among the studied variables, the two factors of slope and lithology had the largest effective coefficients in the occurrence of landslide risk in Rudbar region. Only 22% of the areas with a slope class of less than 20% was within the specified range. This is while the appropriate slope range for urban construction based on sustainable urban planning standards is between 8 and 15 degrees. Among other hazardous elements playing a role in the urban landslide occurrence of Rudbar region, the lithological factor was shown to be vulnerable in terms of mass. In this region, the predominant lithological structure consisted of periodic Eocene volcanic rocks, sandstones alternating between shale layers, and Quaternary alluviums that were sensitive to human activities, such as construction of settlements, intercommunication routes, etc. In the next step, the results were evaluated and interpreted based on the status of urban and rural settlements so as to explore the areas of natural and human geographical capacities and components of risk reduction, while studying the hardware and software measures required by the central government of Gilan Province and Rudbar Municipality and reviewing services before and after the occurrence of danger, risk thresholds and resilience, and the residents’ levels of education. Finally, after achieving the knowledge of risks, the environmental risks were comparatively studied to properly manage them. Keywords: natural hazards, management model, network analysis process, environmental sustainability, Rudbar region .