Journal of Spatial Analysis

Risk is an inevitable part of life, every day people are somehow at risk. Different risks in various forms and perspectives have different functions. Kurdistan province, with various heights and relatively good rainfall, It results the country's cold spots. Since most of seasonal rainfall occurs in winter, Snow cover is often the domain and passes it hillsides. One of the concerns of people in the mountainous area is a snow avalanche phenomenon. Sudden loss of massive snow is avalanche snow that may include rocks, soil, plants or ice. It seems that the name of the snow avalanche adopted from the eleventh month of the solar year. The possibility of snow in mountainous areas during this month of year is more than other months. Snow avalanches every year around the world, especially in alpine impose huge human and financial losses. Statistics and local evidence also show that the province of Kurdistan expect or accept to soil erosion and destruction of infrastructure and natural resources had a casualty. Actually, this is the most vital reason why zoning area danger avalanche was conducted in this study.

 First, avalanche pathways was recognised and selected as a field visit by department of urban development The purpose of the visit was to extract the geography’s coordinates of the avalanche. The Background of the study shows some of the land criteria are more important than others. For this purpose we performed a literature survey to explore indicators that had a significant impact on avalanche snow like such as; slope, aspect, elevation, convexity and concavity, distance to roads and land. To facilitate greater accuracy, all criteria were used in geographic information system (GIS) for mapping. Thereafter, produced map can be categorised into four classes of low, moderate, high and very high. In the next step. Analytic hierarchy process (AHP) and Analytic Network Process (ANP) model were used for weighting and ranking all criteria (slope, aspect, elevation, convexity and concavity, distance to roads and land use) by using pairwise comparisons with judgments that represent the dominance of one element over another with respect to a property that they share. The Analytic Hierarchy Process (AHP) is a method for decision making which includes qualitative factors. In this method, ratio scales are obtained from ordinal scales which are derived from individual judgments for qualitative factors using the pairwise comparison matrix. The Analytic Network Process (ANP) is a more general form and extension of Analytical Hierarchy Process also uses a pairwise comparison matrix to obtain ratio scales. The difference between these two methods appears in modelling the problem and computing the final priorities for the criteria from ratio scales previously obtained. The ANP feedback approach replaces hierarchies with networks, and emphasizes interdependent relationships among all decision criteria were used in this study).

 Based on the resultant Maps, AHP and ANP had a good overlap with visited points and with high accuracy lay in areas of high risk and very high risk. According to the map provided by Analytic Hierarchy Process from the total number of 30 hillsides, thirteen of them lay in very high risk and seventeen of them in the area of high risk. Thereafter, resultant maps of Analytic network Process shows from the total number of 30 hillsides twelve of them lay in very high risk area and eighteen of them in the high risk area.

The results of (AHP) indicates that from the total area of Kurdistan province, about 1049.7 square kilometres is classified in the low risk area, 11.392 square kilometres in moderate, 14.341 in the high risk area and 2009.1 square kilometres in very high risk area, respectively . In view of the process of the network as map about 978 square kilometres is in low risk area, 10245 square kilometres in moderate risk area, 15410 square kilometres in the high danger area and 2158 square kilometres is located in very high danger area. Therefore, we can use ground data for snow avalanche zoning areas along with Analytic Hierarchy Process and Analytic Network in zoning areas avalanche risk which is applicable. Weather parameters like snow, wind and temperature have an important role in terms of snow avalanche. Decreasing rainfall from west to east of study area. The number of freezing and snowing days indicates the critical situation for snow avalanche in the highlands and the pathways. More prevailing wind direction in the cities are in the Southern west, Southern and in area with high elevation blowing from western direction. Looking at the range of high and very high can be seen, mostly in the North and South and North East which show the impact of prevailing wind upon snow and putting snow in hillsides that can produce snow avalanches

. The hillsides show most of avalanche dangers are at west, northwest and south of Kurdistan thus they are compatible with rainy areas. To build any recreation centred including, winter sports, road construction and expansion, snow avalanche risk areas should be considered. Now pathways don’t have any risk signs warning about avalanches. The warning signs of avalanche at the pathways are essential.In the hierarchical model 198 villages lay at low-risk areas and 20 villages in the area were extremely dangerous. Also in the network model 184 villages in low-risk areas and 23 villages in the area were very dangerous.

Ecologically-based Management Factors and criteria of River-Valleys in Tehran metropolis-Case Study: River-Valleys of Kan
 
Abstract:
Iran has seasonal rivers because of dry climate, low rainfall and different topography. These river- valleys have main role in forming, genesis, and sustainability of human settlements and provide different ecological services. The main services include beauty, store of green spaces, water supply, reduce and create temperature differences, local air flow and natural ventilation which are part of the functions. Tehran is roughly the same area as 730 square kilometers and its population is 8.7 million people. It is located in51^° and 17^´ to 51^° and 33^´ east longitude and 35^° and 36^´ to 35^° and 44^´ north latitude. The height of this city is 900 to 1800 meters. The north and north east of this city are located in peculiarity range of the southern part of the middle Alborz. This city includes 7 river valleys to the names Darabad, Golabdareh, Darband, Velenjak, Darakeh, Farahzad and Kan. The ecological role of these river valleys is reduced because of non- ecological axis developmental interventions by urban management and citizens. These interventions have changed river valleys to high risk space of skirt movements and flood. Kan is the most important river valley because of the breadth of the basin and permanent water discharge rate. The part of this river valley has changed to park (Javanmardan) by municipality. The purpose of this research is that to provide factors and criteria of ecosystem based management to organize this river valley.
ANP has been used in this research. To use this method for analyzing   factors and criteria of ecosystem based management to organize this river valley, firstly, these factors have been identified by library studies and scrolling. These factors include 4 criteria (natural: 15 sub criteria, social: 3, management:  6, economic: 2). the books, journals, reports, maps, aerial photos, satellite images and internet sites have been studied in library studies. In site studies, some information from library studies have been edited. After that, the findings of these two methods in form of questionnaire called factors and criteria of ecosystem based management to organize Kan River valley, was in charge academics and professionals. They were elected among pundits of urban management science, urban planning, geography and environment in Tehran. At first the number of them was 30 people came to agreement in two process about 4 factors and 18 criteria and determined importance and priority by Delphy method. Findings in Delphy method were analyzed through ANP and SUPER DECISIONS. In this process, firstly, a conceptual model and relation inter and intra clusters and nodes determined. These relations in this process are very important because paired comparison depends on this process. Assumption of equality of effects and similar relations in these factors is illogical because there are the grading of effects and relations in this research. Second, the factors have been compared to each other to create a super matrix based on paired comparison. Generally, in this process decision makers compare two different factors to each other and paired comparisons have grading of between1to9. In double- sided valuation, each factor is used to show initial inverse comparison. Inconsistent rate in paired comparison must be less than 0.1 like AHP. Third initial super matrix is created. It is the weights created from paired comparison and identified the importance of each factor in each cluster. Forth, the weighted super matrix was created. The weights of clusters was calculated in this process to identify the weight of final super matrix. Fifth, limited super matrix was created. The weighted super matrix reached for infinity band each row convergenced to a number and that number was the weight of factor. By this way limited super matrix was reached.
Based on ANP and table 1, management: 46%, natural – ecological: 26% and economic and social factors: 14% are important respectively in ecosystem based management to organize Kan River valley. Based on reached results, inconsistent rate is 0.003 and it shows that the weight is valid and review is not necessary. Among sub criteria in management factor, organizational pattern: 32%, method of management: 23% and policies: 21% are the most important respectively in ecosystem based management to organize Kan River valley. Among sub criteria in natural- ecological factor, flood, domain movements and building and texture of soil are the most important respectively 23%, 18% and 11.5% also in social factor, participation, security and public trust have the importance respectively equal to 49% 31% 19%. In economic factor, environmental assets and stakeholder’s economic participation have the same importance.
Based on this research, management factor (organizational pattern and the method of management) is the most important in ecosystem based management. But this approach, the management pattern and intervention to organize this river valley, need comprehensiveness and integrity of the subject (nature, society, management and economic), purpose (protection, resuscitation and use), factors (government, city council, municipality, private sector and people), duties (policy making, planning, designing and perform), method (collaborative), tools (knowledge, skill, rule, program, budget, machinery and materials) and management domain. Use of these factors and criteria need some infrastructure and reforms. The most important reform is reform of management structure, production of subject matter and topical program special to organize river valleys by ecological approach to release Kan of loading and contradictory grabbing.so this management can follow protection, resuscitation, sustainable use and continuity of ecological services.
 
Key words: ecosystem, ecosystem based management, analytic network process, river valley of Kan