Evaluation of vulnerability and degradation of Geomorphological heritage affected by Khorramabad urban development

In recent years, the ideas of urban geological heritage, urban geomorphological heritage, and urban geotourism have become increasingly important among scientists and specialists. Although cities often included the perspectives created by artificial elements (buildings, roads, bridges, etc.), they often have unique geological and geomorphological phenomena; but urban development and the construction of infrastructural structures affect the urban land and sometimes completely destroy the landforms. Therefore urban geomorphological heritage is prone to degradation due to human activities related to urban development and the creation of infrastructure. To understand the effect of urban development on geomorphological heritage and the need to conservation this valuable heritage, the present study was conducted in Khorramabad, Iran. Khorramabad is one of the few cities that despite having great geomorphological potential for attracting tourists and developing the city's geotourism industry, because of lack of study and proper planning remains in isolation. According to preliminary studies, Khorramabad city has a special topography and valuable geomorphic heritage that is needs to be recognized, inventory and survey. Therefore, the main goal of this research is accurate inventory of geomorphological heritage of the Khorramabad city boundary and its surroundings to introduce a valuable collection to tourists and researchers and also an analysis of the importance of consernation this valuable heritage for the urban community. Furthermore, investigating the effect of urbanization growth, city development and physical expansion and human activities on the geomorphological heritage of the city of Khorramabad is the other objectives of this research.

Research data is obtained through fieldwork, thematic maps and available visual resources. This research has been conducted with an innovative approach through the integration of fieldwork, remote sensing and quantitative assessment. In the first instance, the geomorphological heritage of Khorramabad urban area has been important in several stages of fieldwork. In the next stage, the amount of urban development in Khorramabad during the last three decades has been extracted through satellite images and its effects on geomorphological heritage have been investigated. Finally, the degradation risk of each geomorphological heritages in Khorramabad based on the Brilha (2016) degradation risk index has been determined.

In urban environments, two categories of geomorphic heritage have been known so far. 1- Each geomorphosite (a landform that defined as a heritage by a scientific community) located in urban spaces, such as waterfalls, caves, moraine and etc. 2- A specific place that helps to mutual understand between geomorphology and urban development. According to the results obtained from the inventory of geomorphosits, 33 typical geomorphosites were inventory in the boundary of Khorramabad city and surrounding it. These geomorphosites can be classified into four main categories of karstic geomorphosites (such as caves, springs and karstic mirages, natural vault, karens), rivers (such as Robat rivers, Karganeh and Khoramabad, golden waterfall, close of Shabikhun), tectonics (such as Makhmalkooh, Khorramabad roof), and anthropogenic or human-made (such as keeyow lake, hill of Sangar mahi bazan and hill of Masur). Khorramabad city has been influenced geomorphologically and linearly along the Khorramabad River. In general, the residential area of Khorramabad has more than tripled from 1990 to 2018; that during it also twelve geomorphosites have been in residential area because of human activities. So with the city's physical development process, increasing population pressures and easier access of human societies to urban geomorphologic heritage, road construction and construction of passages, establishing of inharmonic and unplanned promenades and also the process of smoothing and excavating mountainous regions to create residential homes often illegal in downhill, disposal of garbage and municipal wastes, use and exploits of private; and following it lack of a synchronized program with this fast development, to create buffer zone for conservation and legal prohibition to prevent of destruction of these geomorphosites, has led to increasing pressure and as a result destroy more than before within the geomorphocytes range.

The results showed that the urban area of Khorramabad increased about three times during the period from 1990 to 2018. During this time, many of the geomorphological heritage works were destroyed or its major values (aesthetics, science, education, tourism, etc.) they are removed. The results of degradation risk assessment also showed that geomorphosites of Makhmalkooh, golden waterfall, Konji cave. due to the rapid growth of residential development, uncontrolled or even illegal, they are exposed to the greatest damage caused by human activities, including construction, clearing and road construction, waste disposal, private use and exploitation, and so on. Accordingly, it is necessary to the allocation of conservation for them, including the determination of the legal core zone and buffer zone.