Investigating the role of geomorphology in Assessment of the environmental Capacity of urban development using the GIS-based preference logic scoring method (case study: Karaj metropolis)

With the implementation of any study plan, the first changes will be made in the landforms of the earth's surface, and if a scientific study is not done, it will have dangerous consequences for the natural and human environment of the region. Therefore, considering that the knowledge of geomorphology deals with the study of the forms and processes of the earth's surface, it is necessary to pay attention to the landforms, features and processes affecting the landforms in order to Assessment of the environmental Capacity of urban development. The purpose of the current research is to Assessment the environmental potential in the urban development of Karaj metropolis from the perspective of geomorphology and using the method of scoring the logic of preference. The criteria of geomorphology, geology, soil, hydrology, and vegetation were considered as environmental capability potential, and flood potential and seismicity criteria were considered as environmental hazard potential. By preparing a questionnaire and using the Delphi technique, experts' opinions were obtained about these criteria. After forming the decision tree, the weighting stage and the ability to replace the criteria and features were done. First, a weight was determined for each criterion, and a separate weight was assigned to each subsection that is created by connecting two criteria and to each branch that is created by connecting two subsections. Substitutability or coexistence means determining important features and criteria in decision making. So that their little or big effect on the final decision was determined with a positive and negative numerical interval. By implementing the LSP model, the environmental capability potential map and the environmental risk potential map of Karaj metropolis were prepared, and by combining these two, the environmental capability map of the urban development of Karaj metropolis was prepared.

The aim of the current research is to evaluate the environmental potential in the urban development of Karaj metropolis from the perspective of geomorphology and using the method logic scoring of preference. logic scoring of preference method is one of the improved methods of multi-criteria evaluation in the preparation of land use capability maps. This method includes three main components of attribute tree, preliminary criteria and LSP cumulative structure. The criteria of geomorphology, geology, soil, hydrology, and vegetation were considered as environmental capability potential, and flood potential and seismicity criteria were considered as environmental hazard potential. By preparing a questionnaire and using the Delphi technique, experts' opinions were obtained about these criteria. After forming the decision tree, the weighting stage and the ability to replace the criteria and features were done. First, a weight was determined for each criterion, and a separate weight was assigned to each subsection that is created by connecting two criteria and to each branch that is created by connecting two subsections. Substitutability or coexistence means determining important features and criteria in decision making. So that their little or big effect on the final decision was determined with a positive and negative numerical interval. By implementing the LSP model, the environmental capability potential map and the environmental risk potential map of Karaj metropolis were prepared, and by combining these two, the environmental capability map of the urban development of Karaj metropolis was prepared.

Based on the evaluation map of the environmental capability of urban development, it was found that 16.13 percent (equivalent to 112.68 km2) of the studied area has very low environmental capability for urban development, 23.36 percent (equivalent to 163.18 km2) has low environmental capability for urban development, 24.5 percent (equivalent to 171. 17 km2) has medium urban development environmental capability, 18.51% (equivalent to 129.35 km2) has high urban development environmental capability, 17.47% (122.05 km2) has very high urban development environmental capability.

Suitability maps of LSP method are useful and justifiable results. The analysis and reliability of the LSP method is theoretically calculated. But in the field of working with spatial data, it should be investigated more. This method with excellent quality in land for various applications of land development and evaluators can have different programs from small aspects to form and quality in achieving possible outputs in land suitability.The aim of the present study is to present a new method in land evaluation. In evaluating environmental capability, the role of geomorphological factors, environmental dynamics, and landforms on the earth's surface is obvious and clear, and the knowledge of geomorphology has a practical and important role in evaluating environmental power. While in most methods of evaluating ecological capability, the criteria of slope and direction of slope and height are used as geomorphological criteria, and the role of form and process in these evaluations is very weak.The most sensitive areas of urban environmental capability around the river in the Karaj alluvial landform are mountainous areas with high slopes and shallow soil. LSP is a suitable tool for discussing and reviewing the opinions of stakeholders, decision makers, planners and other experts in land planning.Due to the change in the direction of the Braided river on the surface of the alluvial fan, its dynamic level is more and noticeable in the short term compared to the plain and alluvial plain landforms. This function of Braided river on the surface of the alluvial fan shows the activeness of the eastern part of the Karaj alluvial fan, and therefore it is necessary to consider this dynamic in environmental planning. Failure to pay attention to the activeness of this part of the fan cone causes irreparable risks to human constructions and facilities.