Qualitative Priority of Pollutants in Taleghan Catchment Using Analytical Hierarchy Process

Transcription

1 2011 International Conference on Environment and Industrial Innovation IPCBEE vol.12 (2011) (2011) IACSIT Press, Singapore Qualitative Priority of Pollutants in Taleghan Catchment Using Analytical Hierarchy Process Mohammad Reza Mohammad Shafiee 1, Fatemeh Ghanbari 2, Farham Amin Sharee 3, Hadi Salehi 4 1,3 Faculty of Sciences, Islamic Azad University - Najafabad Branch, Najafabad, Esfahan, Iran 2Environment Research Center, Academic Center for Education 4 Faculty of Literature and Humanities, Najafabad Branch, Islamic Azad University, Najafabad, Isfahan, Iran Abstract. Water resources are considered as one of the main resources of supplying water for different uses including agriculture, drinking and industry. Due to the recent droughts, knowing and giving qualitative priority to the pollutants of these resources is one of the most important tasks in environmental management. The use of new models in water resources has an important role in the management of these resources. With a brief look at the condition of Iranian Taleghan catchment basin, we understand that the increase of population and raising the public welfare result in changing the land use and threat the natural resources and their reserves. This study aims to employ Expert Choice Software to give priority to different pollutants based on the type of the land use in the basin. In this research, Expert Choice Software was used to identify and classify pollutants in Taleghan catchment. This software works based on Analytical Hierarchy Process. The obtained results showed that sewage, agriculture, outdoor activities, industry, toll services, and restaurants respectively have the highest potential for polluting the basin. The employed model in this study can combine the comments and opinions together in great detail and high precision. The model can also determine the priority of effective variables on the pollution of water resources based on the kind of land use. Keywords: Pollutant, Taleghan catchment basin, Land use, Analytical Hierarchy Process, Expert Choice Software, Water resources 1. Introduction Water is one of the natural limited resources and shortage of water is considered as one of the critical issues in many regions of the world. More than 25 percent of the world population live in dry or semi-dry regions. Hence, the management and optimization of water resources are considered as a necessary task [1]. The uncontrolled activities of human beings in catchment basins (in water or in land) usually result in environmental pollutions and decrease the quality of water resources [2, 3, and 4]. The recognition and giving priority to these pollutants based on their significance can be effective in controlling and decreasing these pollutants. Various research studies have been conducted regarding the resources of surface run-off waters by different researchers. For example, Lashkari poor et. al. (2009) tried to recognize the contaminative resources of Kashfrood River and gain continuous awareness of qualitative changes of this river [5]. Moreover, a similar study was conducted by Dehghan et. al. (2008) on the water quality of this river [6]. Fadayi et. al. (2006) also used both the index of water quality and GIS together as a management tool to evaluate the quality of water in Dez River [7]. Another study was performed by Tavallayi Nejad et. al. (2006) to identify qualitative pollutants in the estuary of Karoon River. They suggested some guidelines regarding the improvement of river qualitative management based on qualitative analysis of water samples in nine Corresponding author. Tel.: address: mohammadreza.mohammadshafiee@gmail.com 154

2 stations [8]. Another study was done on the qualitative zonation of water in Karoon River by Karimian et. al. (2009). Four chemical and biological parameters were provided for evaluation by the use of ArcGIS software and the possibility of using different colors of qualitative zonation for Zohreh River [9]. Taleghan catchmentt basin is located in the province of Tehran and 120 km far from the northwest of the city of Tehran. Taleghan catchment basin is one of the subsidiary basins of Sefidroodd catchment basin whichh is bounded by Alamoot in the north, the region of Ziaran and Samgh Abad in the south, one section of Karaj catchment basin in the east, and Shahrood catchment basin in the west (see picture 1) ). This basin is located in a mountainous region with sharp steepnesses containing many stone outcrops, and the highest and lowest parts have 4300 and 1776 meters altitude, respectively, from the sea level. Picture 1: Catchment Basin of Taleghan Dam This basin consists of 19 subsidiary basins, each considered as an independent hydrologic branch in a way that Minavand subsidiary basin has the smallest area, 2.14 percent of the whole basin, and Mehran subsidiary basin has the greatest area, percent of Taleghan catchment basin. The land of this basin includes pastures, lands for dry farming, water lands, and regions with no use. Accordingly, the main part of the lands in this region, percent of the whole basin, consists of both rich and poor pastures. Table 1 shows the conditions of the present land use in Taleghan catchment basin. The technological development of computerized softwaress and the recognition of effective processes in water resources have provided a possibility to use various models. The Expert Choice Software and the AHP model have been employed in the present study to give priority to considered parameters and criteria. This study aims to examine the utilization of Expert Choice Software in the recognition and classification of main pollutants of water resources. Table 1: The present conditions of land use in Taleghan catchmentt basin Land use Mensuration (hectare) Percentage (mensuration) Pasture /37 Deserted dry farming /56 Garden and water farming 1651/16 2/05 Rocky rugged areas 3238/ /99 4/02 Commutative percent 89/37 93/93 95/ Materials and Methodology At first, on the basis of library studies and field visits in the year 2009, a list of contaminative factors in the region was provided. In this study, six factors including sewage of populous centers, outdoor activities, agriculture, tollway services, industry, and restaurants and hotels, and four criteria of sewage, pollution indicators, costs of refining the pollution, and the pollution management of the present conditions weree examined and evaluated. To calculate the weights and give them priority, Expert Choice Software whichh works based on the Analytical Hierarchy Process model was employed. Expert Choice is one of the strong 155

3 and valid softwares for evaluating several criteria together. This software is also approved and supported by Thomas L. Saati, the founder of Analytical Hierarchy Process model. Expert Choice Software has a unique potentiality to use two-by-two comparisons and extract the priorities, and combine different opinions with high precision and finally identify the overall priority of the variables. Moreover, this software can synthesize various judgments in a group model and render the overall results [10]. The Analytical Hierarchy Process, one of the most efficient techniques for making a decision, was proposed by Thomas L. Saati in 1998 for the first time [11]. This process was founded based on pair comparisons and makes it possible for the managers to examine different scenarios. The act of modeling with the use of this method includes the following steps: 1. Making a hierarchical structure for the issue, 2. Determining matrixes for pair comparison and calculating the weight of criteria and variables 3. Examining the compatibility of the system Making a hierarchical structure for the issue. To better understand an issue of Analytical Hierarchy process, it is firstly necessary to graphically determine different levels of the hierarchy and recognize the relations between the component parts of each level with the component parts of higher and lower levels (see Figure 1). Overall making priority list of contaminative factors in Taleghan catchment basin Pollution management of the present conditions Costs of refining the pollution Pollution indicators Sewage Restaurants and hotels Industry Tollway services Agriculture Outdoor activities Sewage of populous centers Figure 1: Hierarchical structure of contaminative factors in Taleghan Catchment basin. As it is shown in Figure 1, the first level is considered for the aim, the second level for the intended criteria to give priority to variables, and the third level shows the variable under study. After determining the structure of hierarchy, the matrixes for pair comparison should be determined based on the decision maker's opinion. The same process should be repeated distinctly for the variables of each level Calculating the weight in Analytical Hierarchy process The cat of calculating the weight in Analytical Hierarchy Process can be studied separately in the following two sections: Local priority Overall priority The local priority can be employed in different methods including the minimum ordinary squares, the minimum of Logarithmic squares, special vector, and estimated methods (such as mathematical mean) Examining the comparisons of the system 156

4 The matrixes for pair comparisons of the variables and the significance of the criteria should be compatible meaning that if the priority of variable A over variable B is two, and the priority of variable B over variable C is three, then the priority of variable A over variable C should be equal to six. Otherwise, the matrix will be incompatible and the rate of incompatibility should be calculated. To examine the compatibility of the matrixes, suppose we have n criteria of C 1, C 2,, C n and the matrix of their pair comparison is according to the following relation : A = [a ij ] i, j = 1, 2, 3,, n Relation 1) Where a ij shows the priority of element ci over element cj. If there is such a relation in the following matrix : a ik a kj = a ij i, j, k = 1, 2,, n Relation 2) then, we say that matrix A is compatible [12]. 3. Results The determined weighted priority between the criteria and existing variables which are used from the software output are mentioned below. The index of sensitivity of criteria and variables are shown in Figures 2 and % 5.3% 49.5% 35.0% 54.1% SEA VAGE 18.2% AGRI 13.1% OUT DOOR 6.9% INDUS 4.5% WAY 3.3% RESTU Figure 2: The index of sensitivity between criteria and variables Obj% Alt% AGRI.00 OVERALL.00 OUT DOOR Objectives Names INDUS WAY RESTU Figure 3: The index of sensitivity of variables Furthermore, a comparison between the priority of each criterion and the variable is illustrated in Figures 4, 5, 6, 7 and

5 Weighted head to head between SEA VAGE and AGRI <> Overall 50.80% 38.10% 25.40% 12.70% 0% 12.70% 25.40% 38.10% 50.80% Figure 4: Weighted head to head between sewage and agriculture Weighted head to head between SEA VAGE and OUT DOOR <> Overall 50.80% 38.10% 25.40% 12.70% 0% 12.70% 25.40% 38.10% 50.80% Figure 5: Weighted head to head between sewage and outdoor activities Weighted head to head between OUT DOOR and AGRI <> Overall 50.80% 38.10% 25.40% 12.70% 0% 12.70% 25.40% 38.10% 50.80% Figure 6: Weighted head to head between outdoor activities and agriculture 158

6 Weighted head to head between INDUS and AGRI <> Overall 50.80% 38.10% 25.40% 12.70% 0% 12.70% 25.40% 38.10% 50.80% Objectives Names Alternatives Names SEA VAGE AGRI OUT DOOR INDUS WAY RESTU SEA VAGE AGRI OUT DOOR INDUS WAY RESTU Figure 7: Weighted head to head between industry and agriculture AGRI INDUS OUT DO RES OOR ESTU SEA VAGE WAY (L:.053) (L:.350) (L:.103) (L:.495) Figure 8: Comparison of each of the index weights and the variable Synthesis: Summary Synthesis with respect to: Goal: TALEGHAN WATERSHED QUALITY Overall Inconsistency =.21 SEA VAGE.541 AGRI.182 OUT DOOR.131 INDUS.069 WAY.045 RESTU.033 Figure 9: Overall making priority list As it can be shown in Figure 9, sewage, agriculture, outdoor activities, industry, tollway services, and restaurants respectively have the highest potential for polluting Taleghan catchment basin. This figure represents the combination of overall model. In case of an ideal synthesis, the overall priority is calculated through the following steps: 159

7 First, for each criterion, the priority of the variables will be divided by the most important variable's priority. Then, the obtained value will be multiplied in the priority of obtained criterion and by adding the values for each variable, a value will be obtained for each variable. 1. Sewage (L:.103) 2. Pollution indicators (L:.053) 3. Costs of refining the pollution (L:.495) 4. Pollution management of the present conditions (L:.350) 4. Discussion and Conclusion In this model, the conducted analyses of sensitivity on the intended aims show the sensitivity of variables in relation to all existing criteria. In general, there are five types of analyses of sensitivity in this software. They are dynamic, efficiency, gradient, head to head, and two-dimentional analyses of sensitivity. The head to head figuress used in this study show that how two variables together are compared in relation to one criterion in making the decision. The variable in the left side is always constant and it will be used to be compared with other variables. To make a decision, if the left side variable in relation to the existing criterion has priority over right side variable, a sign toward the left side will be seen on that criterion showing the rate of priority. If the two variables have equal priority, there will be no sign on the variables. The overall result of these comparisons indicates the priority of one variable over another variable considering all the existing criteria in making the decision. Moreover, the obtained results indicate the point that the employed model can combine the opinions with high precision and identify the overall priority of effective variables over the pollution of water resources. With the use of analysis of sensitivity, we can determine how changing the significance of a criterion affects the selective variables. Considering the significance and proportion of effective parameters in the pollution of Taleghan catchment basin, the following managerial guidelines are proposed: Sewage refining and decreasing nutritive materials of sewage or producing a diverging course for sewage. Alteration or optimization of farming patterns aiming to decrease spraying insecticides, using chemical fertilizers, and producing less drainage. Altering land use or preventing land use alteration. Controlling the erosion and sediment. Implementing watershed management projects. Determining the amount of self-refining of surface water resources and continuous protection. 5. References [1] Kondili, E., Kaldellis, J.K., Papapostolou, C., A Novel Systemic Approach to Water Resources Optimization in Areas with limited Water Resources. Desalination 250 (2010) [2] Erturk, A., et al. Water Quality Assessment and Meta Model Development in Melen Watershed Turkey. Journal of Environmental Management 3 (2010) [3] Davenport, T.E., Phillips, N.J., Kirschner, B.A., Kirschner, L.T., The Watershed Protection Approach: A Framework for Ecosystem Protection. Water Sci. Technol. 33 (4/5), [4] Brady, D.J., The Watershed Protection Approach. Water Sci.Technol. 33 (4/5), [5] Lashkaripour, G.R., Ghafouri, M., Mousavi Madah, S.M., Babaei, M. A Study of the Origin and Effective Factors in the Pollution of Kashfroud River Surface and Subsurface Water Resource, First Conference on Ground Water, 2009, Behbahan Azad University, Behbahan. [Persian] [6] Dehghan, P., Ghafouri, M., Alami, S. The Effects of Pollutants on the Quality of Kashfroud River, Third Conference on Water Resource Management, 2008, The University of Tabriz. Tabriz. [Persian] 160

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