Assessing Groundwater Vulnerability in Lenjan district toTotal Organic Carbon, Nitrate and Cations and Anions using GIS in Pilot Scale

Subject Areas : environmental management

Afshin Ebrahimi ¹ , Mohammad Mahdi Amin ² , Mahdi Hajian ³ , Bijhan Bina ⁴

1 - PhD. Student of Environmental Health Engineering, Isfahan University of Medical Science, School of Public Health, Department of Environmental Health Engineering
2 - Assistant Professor of Environmental Health Engineering, Isfahan University of Medical Science, School of Public Health, Department of Environmental Health Engineering
3 - Assistant Professor of Civil engineering, Isfahan University, School of Engineering, Department of Civil Engineering
4 - Professor of Environmental Health Engineering, Isfahan University of Medical Science, School of Public Health

Received: 2009-09-16 Accepted : 2010-01-18 Published : 2014-12-22

Keywords: : Total Organic Carbon, Nitrate, Cations and anions, GIS, overlay,

Abstract :

Groundwaters can be polluted due to various natural and anthropogenic activities. These water resources are directly used as community’s drinking water. Therefor, pollution vulnerability assessment of them can help the local and national managers and decision makers in control of many discharged pollutants. For this purpose, the aquifer vulnerability of Najaf Abad plain (Lenjan District) has been surveyed in this study. Today, Geographical Information System (GIS) is used for assessment of vulnerability of groundwater systems. Therefor, GIS was also used to determine the different degrees of vulnerability in the study area. For this purpose, different information layers were prepared. These information layers included electrical conductivity, nitrate, total organic carbon, sulfate, chloride and total hardness concentration which were obtained from 25 wells in Lenjan district through sampling during 4 seasons from summer of 2008 to spring of 2009. Finally, after weight ratings and overlaying of the information layers, the vulnerability of areas were determined both seasonally and annually. Results of chemical analysis of the samples showed that the highest concentrations of nitrate, total hardness, chloride, sulfate and EC levels for spring of 2009 were 98, 3800, 6745, and 3780 mg/L and 14.5 mS/cm, respectively. In contrast, the highest concentration of TOC occurred in summer of 2008 was 21.6 mg/L. However, the lowest concentrations of these agrichemicals were recorded in summer and autumn of 2008. The results obtained with the help of GIS showed that the area in the center of Lenjan district, that had clay type of soil and average groundwater depth compared to the adjacent regions, had the lowest vulnerability to analyzed pollutants. Therefore, vulnerability of the areas increased by moving towards the east of Lenjan district. Thus, digging a well in this vulnerable area will be faced with water resources pollution

References:

1. Aslan, Türkman A. (2005), Combined biological removal of nitrate and pesticides using wheat straw as substrates. Process Biochemistry. 40(2):935-43.


2. Chowdary VM, Rao NH, Sarma PBS. (2005), Decision support framework for assessment of non-point-source pollution of groundwater in large irrigation projects. Agricultural Water Management. 75(3):194-225.


3. Worrall F, Besien T. (2005), The vulnerability of groundwater to pesticide contamination estimated directly from observations of presence or absence in wells. Journal of Hydrology. 303(1-4):92-107.


4. Antonakos AK, Lambrakis NJ. (2007), Development and testing of three hybrid methods for the assessment of aquifer vulnerability to nitrates, based on the drastic model, an example from NE Korinthia, Greece. Journal of Hydrology. 333(2-4):288-304.


5. Dixon B. (2005), Applicability of neuro-fuzzy techniques in predicting ground-water vulnerability: a GIS-based sensitivity analysis. Journal of Hydrology. 309(1-4):17-38.


6. Shahnia AJ. (1386), The quality monitoring of groundwater resources in Sarayan aquifers through GIS. Water and Environment Journal. 67, (in Persian).


7. Narouyee A. (1386), The vulnerability of Zahedan aquifer to petrochemicals. Water and Environment Journal. 67, (in Persian).


8. Gheysari MM, Houdaji M, Najafi P, Abd elahi A. (2007), Assessment of nitrate pollution of groundwater in south-east of Isfahan region. Environmental Studies. 33(42):43-50, (in Persian).


9. Mahvi AH, Nouri J, Babaei AA, Nabizadeh R. (2005), Agricultural activities impact on groundwater nitrate pollution. Int J Environ Sci Tech. 2(1):41-7.


10. Takizawa S. (2008), Groundwater Management in Asian Cities: Technology and Policy for Sustainability: Springer.


11. Amin, MM., Ebrahimi, A., Hajian, M., Iranpanah, N., Bina, B. (2010), Spatial analysis of three agrichemicals in groundwater of Isfahan using GS⁺. Iran. J. Environ. Health. Sci. Eng. 7(1): 71-80.


12. APHA. (2005), Standard methods for the examination of water & wastewater. 21 edi. Washengton, D.C.


13. Sheikhi narani T, Hafezi Moghadas N. (2007), Susceptivity Zonation for wastes landfill by using GIS (study in Qom Province). 1 ^th Conference of Urban GIS; 26-27 August; Shomal University, Amol, Iran, (in Persian).


14. Qasim SR, Motley EM, Zhu G. (2000), Water works engineering: planning, design, and operation: Prentice Hall.


15. Alabdula'aly AI, Al-Rehaili AM, Al-Zarah AI, Khan MA. (2010), Assessment of nitrate concentration in groundwater in Saudi Arabia. Environ Monit Assess. 161(1-4):1-9.


16. Sahoo GB, Ray C, Wade HF. (2005), Pesticide prediction in ground water in North Carolina domestic wells using artificial neural networks. Ecological Modelling. 183(1):29-46.


17. Brown J, Wyers A, Aldous A, Bach L. (2007). Groundwater and Biodiversity Conservation: A methods guide for integrating groundwater needs of ecosystems and species into conservation plants in the Pacific Northwest: The Nature Conservancy.


18. Chen J, Tang C, Sakura Y, Kondoh A, Shen Y. (2002), Groundwater flow and geochemistry in the lower reaches of the Yellow River: a case study in Shandang Province, China. Hydrogeology Journal. 10(5):587-99.