عنوان مقاله [English]
Urbanization is one of the major challenges of the contemporary world, and at least 0.5% of the land area is found in cities (Schneider et al., 2009, 2).Urban development as a human category occurs in the context of geomorphology.Therefore, urban geomorphology, in addition to studying geomorphic limitations in urban development (Kuek, 1984, 22), the suitability of landforms for urban use, the impact of urban activities on land surface processes and landforms created by urbanization Is evaluated and studied (Douglas & James, 2015, 52).The city of Kermanshah is located in Kermanshah Navidese plain in terms of geomorphology and is composed of different landforms.Each of these landforms plays an important role in urban development.Also, urban development has had a great impact on geomorphologic landforms and so far no studies have been carried out in these areas within the city of Kermanshah.Considering the specific geomorphological conditions of the city of Kermanshah and its risks, recognizing the interactions between geomorphology and urban development on each other will play an important role in the planning and management of Kermanshah.The purpose of this research is to evaluate the effects of geomorphology on the urban development of Kermanshah over a period of 40 years.It is impossible to achieve this without the availability of suitable data.
materials and methods
In the present study, library, historical, cartographic and remote sensing methods are used.Map of geomorphologic complications of the city and surrounding areas of Kermanshah is based on the analysis of the land systems.Then, the extent and directions of physical development of Kermanshah city are determined during 40 years in selected years of 1977, 1986, 1996, 2006, and 2017 using Landsat satellite satellite imagery, MSS, TM and OLI.The supervised classification method has the maximum probability and selection of educational samples based on visual interpretation, false color combinations, and land surveys to determine the city's boundaries.Then, by mapping the map of geomorphologic complications with Kermanshah districts in selected years, the city's developmental extent in each of the geomorphologic traits has been determined and changes in the geomorphologic complications caused by the expansion of the city are also estimated.
The increase in the area of Kermanshah in the 40-year period has been around 5.5 times. Alluvial plain land has the largest area for the remainder of the year except for 1977 and has been affected by increasing area in all years. Alluvial fan landforms, hillside plains and regular slope have a upward trend in terms of area and area during 5 years, which suggests the development of a city in the territory of these landforms.The land flood plain has increased in terms of area, and the two hills and the irregular slopes have a limited area and have been located in urban areas only in the last two years.In Kermanshah, urban development has been affected by the existence of alluvial plain land so that the most development on this landform is in northern, northwest, northeast, western and eastern directions.The physical expansion of the city of Kermanshah has had an impact on the geomorphological prospects of Kermanshah plain.Alluvial plain landforms, flood plains alluvial fan rivers and river valleys have become urban landscapes.The subterranean rivers of the waterfall and Cham Bashir have become narrow underground channels and are no longer visible on the surface of the earth, and the development of their substrate has been stopped.
Landforms of geomorphology determine how urban development is.Alluvand plain landform has the largest role in this field and more than half of the area of Kermanshah is located on this landform.The three flat landforms of alluvial plain, alluvaih fan and hillside plains account for 72% of the total area of the city of Kermanshah in 2017.The plain landform, the old town nucleus, is about 16% of the city's total area.The limiting or hazardous landforms of the flood plain, regular slopes, irregular slopes, river valleys and hill meadows account for about 12% of the area of the city of Kermanshah.The urban development of Kermanshah has had an impact on geomorphologic landforms and has led to significant changes and destruction of landforms.The drainage network of the region and Cham Bashir and Aashoran rivers have been completely destroyed, which could have adverse effects on water resources and residential areas around them.Other landforms such as alluvial plain, alluvial fan ,hillside plain and floodplain have become urban landscape and their evolutionary process has been stopped.Expansion of the city on hazardous landfills (flood plains) and limiting (irregular ranges, hill, etc.) in the future can lead to a risk to urban areas.