نوع مقاله : مقاله پژوهشی
1 گروه جغرافیای طبیعی، دانشکده جغرافیا، دانشگاه تهران
2 گروه ژئومورفولوژی، دانشگاه کردستان
3 گروه جغرافیای طبیعی، دانشکده جغرافیا،دانشگاه تهران
عنوان مقاله [English]
Switch land regardless of its inherent talents of the most common human interference in nature is and always phenomena such as floods and soil erosion to follow. Because of the Lifeline Rivers and cities as the core and aggregation deployments are human so are of particular importance. The river bed can be as effective to deploy a range of applications to be considered commensurate with its potentialities. In terms of land use, including the most important issues that the region has suffered in recent years, Integration of heterogeneous and unplanned growth of urban space and surrounding villages such as Naysar, Hassan Abad, is Gerizeh and Doushan. No doubt such cases contradictory to the riverbed and despite changes in its morphology, Increased threats such as flooding and flooding in the future. Present study is the first to identify hazards at the sides of the river bed in Gheshlagh and went on zoning the area for different uses.
Area of study
Gheshlagh located in the West River flows from the mountains north of Sanandaj stems. About 17 small river in Gheshlagh from a merger between 10 and 25 km in length is formed. Land along the river in most studied gender differences in Sanandaj shale flow And 6 fault line cut perpendicular to the river. But the study area study, a range of 55 km from dam wall Unity (Gheshlagh) started in 12 km from the city of Sanandaj And to continue Zhavh dam under construction. In this study, the zoning Gheshlagh river bed in the study area to a distance of 3000 meters above the right and left banks of the river will be discussed.
Data and Methods
Digital topographic maps and geological research tools as well as application of GIS and fuzzy logic models have formed. The data consists mainly of previous reports and resources, climate and hydrological data and field data have been. The research and its applications, and cross-reference data through the software Arc GIS, Excel, Google Earth has been analyzed. To analyze the roughness of the Cross in four selected points during the period studied was collected through surveys and ground control. Then-related features are line-water flood, distance from the river, faults, slope and harvested in the form of separate layers were grouped in Arc GIS software. In the next step in the application data through weighting method served, as well as experts, have given weight. The most appropriate weight for residential and commercial applications and then depending on the human density to less important applications has been allocated barren land. Finally, using the left and right banks of the river zoning gamma fuzzy model to a distance of 3000 meters from the main stream has been paid. The results obtained are presented in the form of use maps for different purposes and as well as existing land use map applications also predicted by the findings of the study have been compared and analyzed table.
Result and discussion
For the zone of Gheshlagh river bed of the 5 parameters, slope and distance from the river, faults and away from line-water flood For residential and commercial applications, services, municipal sites, agriculture and farming, green space and parks and other areas have been selected. In many mountain areas, as the slope is the most important limiting factor. The maximum slope that the city is suitable for deployment should not exceed 11 percent. Slope gradient of 15% as the upper limit applicable for urban construction will be considered. In areas of low slope gradient map layer Fuzzy high points and low points Pass mark for steep areas are included. Establishment of human society, regardless of the distance from the river always has great human and financial losses. In the present study suitable location for residential and commercial applications such as rivers, dense 900 meters away. For the establishment of low-density closer distances than marked. Since the seismic potential latent faults and seismic are Distance from the fault must also land use planning as an important factor to be considered the map faults, fuzzy function is defined in such a way that the distance of the pixel values is greater fault lines. Given that much of the area investigated in this study are located in the metropolitan area surrounding the city of Sanandaj, Due to overcrowding the space for concrete to be felt. As a result, around bed for residential and commercial applications, municipal services sites, agricultural lands and agricultural and green spaces and parks are considered And very steep area near the intersection of faults and rivers are known for wasteland.
The results show that in areas close to the metropolitan area of Sanandaj, space for commercial and residential use is widespread enough about 30 percent of the total area allocated to the range. Low slope, distance from active fault lines and possibility of planning and demarcation principles for river channel in the area of the main reasons for the proposal. At the beginning and end of the study area due to frequent faults and steep, Very little space to expand the use of the high density of human needs have been considered Since that within the context of the presence of thick alluvium, relatively flat slope, topography and access to water resources River Gheshlagh conditions favorable for agricultural land is arable and The result left the shores of the river lands have been appropriate for this function. But the right bank of the substrate is intended for green space and parks. Because these users require less energy than agriculture As a result, the range is covered more area behind the sun. Finally, parts of the area that was not suitable for any of the applications were identified as other an area is 22/75% of the study area. This range is recommended for the protection of soil and limit erosion.