Shirin Mohammahkhan; Hamid Ganjaeian; Laila Garosi; Zahra Zanganetabar
Abstract
Extended Abstract
Introduction
The land subsidence is the descending or collapse of the land under the influence of natural and human factors. The land subsidence is one of the issues that are being exacerbated by human factors, including excessive exploitation of groundwater. Subsidence can affect ...
Read More
Extended Abstract
Introduction
The land subsidence is the descending or collapse of the land under the influence of natural and human factors. The land subsidence is one of the issues that are being exacerbated by human factors, including excessive exploitation of groundwater. Subsidence can affect many constructions and facilities, causing problems for the industry, the environment, etc. This phenomenon is one of the most important environmental hazards that have been less considered than other natural phenomena due to the low human losses. The Qorveh plain is considered as one of the plains which have been introduced as a forbidden plain in the province of Kurdistan in recent years due to the over-exploitation of groundwater. Considering the amount of groundwater level drop and its direct impact on the subsidence level of the region, the present study evaluates the subsidence rate of the Qorveh plain during the period of 2017.12.19 to 2016.01.11. In this research, in order to evaluate the status of the groundwater drop, the statistical data from the Regional Water Organization of Kurdistan province has been used, and the Sentinel-1 images and the SBAS method were used (due to the unique capabilities of this method in terms of dimension, cost, time and accuracy compared to other remote sensing techniques) to estimate the subsidence rate of the region.
Material and Methods
In this research, first, the status of the groundwater of the Qorveh plain and the drop rate of its level has been investigated. Then, the subsidence rate of the area and its relation with the groundwater drop has been investigated. Radar interferometry and SBAS were used to evaluate the subsidence of the study area. Radar interferometry method is one of the most powerful tools for monitoring the subsidence phenomenon. By comparing the phases of two radar images taken from a region at two different times, this method can determine the land surface changes at that time interval. The phase taken from a feature on the land surface is proportional to its distance to the radar sensor. Therefore, making any changes in this distance affects the measured phase. In this research, the Sentinel-1 images (2017.12.19 and 2016.01.11) have been used to perform the radar interferometry.
Discussion and results
The hydrograph of the alluvial aquifer of the Qorveh plain has been provided for the water years of 1966-1676 to 2010-2011. During the 24 yeas, the groundwater level fluctuations in this plain are -13.29 meters, with an annual average of -0.55 meters. The least rate of dropping in the wells is in the wells located south of the Qorveh plain, and the rate increases toward the eastern and northeastern parts. In this research, the subsidence rate of the Qorveh Plain was estimated from 2017.12.19 to 2016.01.11 using the SBAS method. The final map indicates that during this period, the study area subsided between +61 and 216 cm, with the lowest subsidence occurring in the southern areas of the Qorveh plain, which corresponding to the sedimentary heights and slopes of Badr and Parishan and the rate has increased toward the east and west of the Qorveh plain.
Conclusion
The results of this study indicate that Qorveh Plain has witnessed a sharp drop in groundwater level over the recent years. Considering that the southern parts of the Qorveh plain corresponds to the heights and slopes of Badr and Parishan, and the rate of exploiting groundwater in these parts is lower, the rate of subsidence is less. The plain has also subsided further towards theeastern, western and northern parts and the outlet of the Shoor River, due to the growing increase of exploitation. The results indicate that the rate of subsidence is consistent with the rate of groundwater drop so that in the southern part which corresponds to the Badr and Parishan slopes, the rate was less than 10 millimeters during the period of 2017.12.19 to 2016.01.11. The results of the SBAS method indicate that the study area had subsidence of 216 mm during the 2 years and also a 61 mm uplift. Based on the final result, the highest rate of subsidence was related to the eastern and western parts of Qorveh plain and on the outskirts of the city of Dezaj and the villages of Ghasem-Abad, Shokuh-Abad, Avangan, Ganji, and others. A series of the aforementioned factors suggests that the Qorveh plain subsides about 20 centimeters per year. This is due to the over-exploitation of the groundwater. Unlike some areas where the displacement (subsidence and uplift) is due to the tectonic conditions, the results of this study have shown that in the Qorveh plain, the subsidence has a direct relationship to the drop of the groundwater. Therefore, it is necessary to monitor the use of groundwater, especially in the agricultural sector, and the rate of the exploitation should be proportional to the amount of recharge because in addition to the water shortage problems, the continuous use of the groundwater can lead to the irreversible risks of subsidence.
Mehran Maghsoudi; Hamid Ganjaeian; Lila Garosi; Anvar Moradi
Abstract
Extended abstract
Introduction
Geomorphology tourism or geotourismis one of the areas ofmodern studies in geoscience and tourism studies based on the identification of geomorphosites or special geomorphological sites. Geomorphosites are of new concepts that have entered the tourism literature with ...
Read More
Extended abstract
Introduction
Geomorphology tourism or geotourismis one of the areas ofmodern studies in geoscience and tourism studies based on the identification of geomorphosites or special geomorphological sites. Geomorphosites are of new concepts that have entered the tourism literature with an emphasis on the location of special sites, therefore, it emphasizes on a set of geographical, geological andgeoarchaeology features. They also havescientific, ecological, cultural and economic values simultaneously and are utilized to understand and exploit human tourism. Geosites, which are a branch of geotourismgive rise to sustainable development in that region, due to their unique attractions. This new economy is completed in a network of cultural heritage and natural resources managements. Geosites of the region must be identified and introduced prior to any planning. Geosites in east Kurdistan province are very less known and only some of them have superficially drawn attentions,therefore, it has been tried to evaluate the capabilities of these geosites in this research while introducing them. This area, along with the attractions of geotourism has also sensitivities and limitations that can be severely damaged, if the red lines are violated. In fact, the purpose of this is to introduce Kurdistan geositeswith the aim of becoming more familiar with the capabilities of this geosite, as well as investigating the geotourist problems of the region in order to pay attention to the planning related to the tourism industry that can be economically effective on areas with geosites.
Materials and methods
This is an applied research, and descriptive-analytical method was used to analyze information and data. The final analysis has been carried out based on the results obtained from the evaluation of the values and criteria of geotourism. Survey procedure, field visits and field studiesas well as library and documentary studies have been used to collect information. The combination of library and field information will determine the overall value of the region’s geotourism. Two methods of Comanescu and Fassoulaswere used to evaluate the geosites in this research. In addition to evaluating geosites, the areas susceptible to geotourism development in the study area were zoned, and two Fuzzy and ANP models were used for this purpose. The methodology is in a way that the data layers first became fuzzy and comparable, using fuzzy model. Then, the obtained weight was multiplied by each one of the data layers, and thefinal map was obtained by integrating the data layers in Arc GIS. Finally, geosites which are susceptible to geotourism development were selected using the final results obtained from the zoning as well as the results obtained from the geosites evaluation by the use of two Comanescu and Fassoulasmodels.
Discussion and results
After identifying the geosites, Comanescu and Fassoulas methods were used to evaluate them. For this purpose, library methods and experts’ opinionshavebeenused. First, the geosites were evaluated according to the criteria of Comanescu method, and based on the final results obtained from the evaluations, the GhalehQomchoqayhas the highestvaluewith a totalof 84 scores. After the GharQomchoqay, SarabQorveh and CheshmehTangzhave the highest valueswith 76 and 69 scores, respectively. Then the geosites were evaluated using the Fassoulas method, and according to the final results, GhalehQomchoqay and SarabQorveh with a total of 17.5 and 13 scores have the highest values, respectively. The results obtained from the evaluation by both Comanescu and Fassoulasmethods indicate the high value of GharQomchoqay and SarabQorveh for geotourism purposes. In the present research, in addition to the geosites evaluation, areas susceptible to development have been identified using the intended criteria and two Fuzzy and ANP models have been used for this purpose.
Conclusion
After the evaluation done by the methods of Comanescu and Fassoulas,zoning of the areas susceptible to geotourism development was carried out,using the intended criteria. The results indicate that among the geosites of the study area, 8 geosites including GhalehQomchoqay,SarabQorveh, CheshmehTangz and Baba GoorGoor’sEzhdaha Mount, Badr and Parishan mountains, GharGolestaneh, KoohNesar and SarabBijar have a high Potential for the purposes of geotourism development. In most important of researches done in the country, the evaluation methods have only been used. However, the most important advantage of this research is that all the necessary criteria have been evaluated and the final result has been the outcome of the multi-criteria evaluation. In fact, in addition to the evaluation methods, the zoning methods have also been used. The use of zoning methods has led to taking the environmental factors into consideration in the selection of top sites and the sites selected as sexemplary sites need to meet all the necessary requirements for the development of geotourism infrastructure.
