Morteza Heidarimozaffar; Morteza Shahavand
Abstract
Introduction Iran is mostly located in arid and semi-arid regions, and groundwater is its only water resource. The present study introduces a method based on spatial zoning evaluation which takes advantage ofFuzzy Logic and Geospatial Information System to design possible sites for an underground dam, ...
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Introduction Iran is mostly located in arid and semi-arid regions, and groundwater is its only water resource. The present study introduces a method based on spatial zoning evaluation which takes advantage ofFuzzy Logic and Geospatial Information System to design possible sites for an underground dam, and ranks them according to their suitability. The usability of this method for the construction of an underground dam in Kabodarahang Plain in the north of Hamedan Provincewas evaluated in the present study. Materials & Methods Groundwater use is considered to be a solution of water scarcity in arid and semi-arid regions. Lack of sufficient financial resources and adequate technology as well as specific physical conditions make it difficult to provide clean water in arid areas of most developing countries. Over the past few years, underground dams has been considered as a way to overcome water scarcity in arid and semi-arid regions. The present study seeks to identify suitable locations for the construction of an underground dam in Kabodarahangplain in north of Hamadan province using fuzzy logic in GIS environment. As one of the case study areas of Qareh Chai River,KabodarahangPlain isthe largest plain of Hamedan province with an area of 3448 square kilometers and an average height of about 1789 meters above the sea level.It is located between 48°14ˊ 51 ̋ to 49° 5ˊ 11 ̋ eastern longitude and 34° 50ˊ 6 ̋ to36°14ˊ 31 ̋ Northern latitude. To reach the goal of the present study, effective parameters in the constructionof underground dam, such as land slope, positionof wells, springs and aqueducts, rivers channels, positionof faults, location of villages and cities, position of paths and the thickness of alluvium were collected from the study area. Based onthe possibility of performing different spatial analyses in geographic information system environment, zoning ofKaboodarahang plain was evaluated from the point of view of an underground dam construction usingfuzzy logic and GIS tools in the present study. Results & Discussion Similar to membership in classical series,“And” operatorin Fuzzy Logic is used when two or more different criteria can help in solving an issue. This operator extracts the minimum membership level of pixel units in a specified positionand use it in the final map.Fuzzy multiplication operator multiplies membership level of pixel units in specified positionsof different factors and use the result in the final map. This operator is used when mapsof different criteria have a subtractive effect on each other.Fuzzy gamma operator is the general form of algebraic multiplication of fuzzy multiplication and addition operators to the power of gamma. It is used when increasing and decreasing effects are present in the relations between different criteria. Following the preparation of layers in Arc Map software, Euclidean distance operator and interpolation based on triangulation method were used to convert parameters to raster layers. Based on the background research and standards used, the criteria maps were combined using fuzzy operators. Using Fuzzy membership operator, an area of 3342 hectares, using fuzzy multiplier operator an area of2393 hectare (around one percent of the study area) and using the fuzzy gamma operator, an area of 35574 hectares (10.32% of the study area) was selected as having a very good potential for underground dam construction.Slope Map is also one of the most important criteria in determining areas appropriate for underground dam construction. It is suggested to use a larger-scale topographic map to improve the accuracy and increase the possibility of errors. Intelligent algorithms can also be used to determine the threshold level for standardization of the criteria. Since different organizationswork in the field of data collection, it is also suggested to providea suitable mechanism to assess the potential of other plains through consultation and coordination with other relevant organizations. It is recommended to use other parameters and factors affecting the selection of suitable areas for the construction of underground dams, such as soil type or physical and chemical properties of soil in future studies. Conclusion Zoning maps prepared by fuzzy logic in GIS environment can be used to determine the appropriate location forthe constructionof underground dams. Fuzzy operators provide special conditions which make them more reliablecompared to traditional methods.Appropriate areas for construction of underground dam were identified in GIS environment. A decision making model can also be produced based on the input parameters.It is suggested to enter general information of the area to perform the initial investigation of potential areas and then add field study information to complete the model.
Pouria Kharazi; mohammad reza Yazdani; Haideh Ara; payam khazaealpour
Abstract
Extended Abstract 1. Introduction Problem related to water scarcity has always been one of the most important issues to be considered in arid and semi-arid regions. Due to the seasonality of surface water drainages and subsurface structures in these regions, it is necessary to use structures which ...
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Extended Abstract 1. Introduction Problem related to water scarcity has always been one of the most important issues to be considered in arid and semi-arid regions. Due to the seasonality of surface water drainages and subsurface structures in these regions, it is necessary to use structures which control and store the water flow in order to be used during arid seasons. One of these types of structures is underground dam to control the flow of water in the subsurface. In semiarid and arid areas in which deserts are progressing, exploitation of water has been focused on underground surface water resources having the trouble of stability (Ouerdachi, L., et al., 2012). These conditions require the use of surface and underground short dams for exploiting water in developing countries with arid weather situations. At present, these kinds of structures have been desirably featured in terms of both implication and efficacy in performance (Nilsson 1986, Cavalcanti, N.B., 2001). 2. Materials and methods The area studied is part of Semnan province and its surroundings are 216467 hectares in width which geographically have the coordinates of 53D 81M to 53D 15M eastern longitude and 35D 13M to 35D 85M northern latitude. Evaluation of station climes studied by both Domarten and Amberje indicates that the studied span has a semi dry-cold climate at heights reaching cold-arid climate where lower-height areas exist. The situation of considered area is shown in Figure 1. With respect to climatic conditions, there are many syllabic flows throughout side hills of the area where underground dam’s establishment is a proper way to control aridity problem in arid seasons of this area. The most significant data of this study are related to topography, geology, underground water, and aqueduct resources. Software used in this research are both expert choice to prioritize and Geography information systems to combine data. In this research, basic criteria of evaluation including water, pedestals, fountain, economic-social criteria have been targeted at the highest range placing indicators and incidentals criteria at other categories of AHP. Then, proper locations for underground dam establishment have been prioritized. 3. Results and discussion Based on Gorry and Morton method, decision-making supportive systems are either the systems capable of transporting data or computerized systems which can be used to solve our problems clearly or partly clearly known or unknown respectively (Gorry, G. A., and Morton, M.S., 1971). Decision-making supportive systems are models which receive vast majority of data and deliver many solutions specifically designed to overcome the existing problem (Klosterman, R.E., 1997). Decision support systems (DSs) used in identifying proper location to underground dam establishment possess AHP mode and are used in three stages. 4. Conclusion Considering climatic conditions over the area studied and existing stream, Underground dam establishment highly affects both performance revising and balancing act in underground water removal. Using new methods instead of traditional and time-consuming ones, can highly help with saving time and cost to underground dam location-finding. In the first step of this research, presented DSs considering eliminating criteria in the area of 216467 hectares in width assign suitable pedestal in each limit which is capable of potential underground dam establishment. Then, in the second step, the most suitable strait in each limit is assigned to the underground dam establishment. In the latest step after weighting each main criterion at its related map and as well adding total values of map pixels together in a software called GIS, 8 locations to underground dam establishment at the second step of location-finding in fifth scenario were prioritized as follows: First scenario (weights equality of four main criteria) locations: 5, 3, 2, 4, 6, 1 Second scenario (priority with water criterion) locations: 5, 3, 2, 6, 1, 4 Third scenario (priority with pedestals criterion) locations: 5, 6, 4, 3, 1, 2 Forth scenario (priority with fountain criterion) locations: 3, 6, 4, 5, 1, 2 Fifth scenario (priority with economic-social issues) locations: 3, 1, 5, 4, 2, 6 As shown in most scenarios, pedestals A and D mostly take first to third place. Furthermore, theses pedestals as the best ones catering for all groups’ opinion to underground dam establishment can be offered.
