Optimization of DRASIC Model for assessment of groundwater vulnerability to nitrate pollution in Kashan Aquifer using statistical methods and sensitivity analysis
Subject Areas :
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Keywords: Specific vulnerability DRASTIC RASIC-LU Kashan aquifer Correlation coefficient Sensitivity analysis. ,
Abstract :
In this study, the optimized DRASTIC model parameters and land use layer (LU) were used to assess specific vulnerability in Kashan aquifer using statistical methods. Information layers were prepared, rated (deterministic and fuzzy-statistical), weighted (original and statistical) and combined (by Index-Overlay method) in GIS environment. For optimization of DRASTIC model, nonlinear regression for fuzzy-statistical rating (scaling) and Pearson correlation coefficients between nitrate concentrations and scaling parameters of DRASTIC model and sensitivity analysis (removal and single-parameter) were performed to determine and modify weighted parameters. As a result, RASIC-LU model with statistical rating and weighting, single-parameter sensitivity analysis, determined the best selection model based on correlation coefficient = 61.1%, P-Value= 0.001 and with parameters of net recharge, aquifer media, soil media, impact of vadose zone, hydraulic conductivity and land use with weight values of 2.50, 4.63, 4.15, 3.03, 1.96 and 2.00 respectively. According to this model, western and southern parts of the aquifer has a high and very high pollution risk due to high net recharge, pollutant land use and coarse-grain material in the impact of vadose zone, soil and aquifer media. In addition, sensitivity analysis based on mean squares error (MSE) indicated that this model is more sensitive to removal and increase of parameters weight of land use, soil media, impact of vadose zone, aquifer media, net recharge and hydraulic conductivity, and shows a decreasing ternd, respectivily.
احمدي، ع. و آبرومند، م.، 1388. بررسی پتانسیل آلودگی آبخوان خاش با استفاده از سامانه اطلاعات جغرافیایی. زمین‌شناسی کاربردي، 5، 1، 11-1.
سطح آبهای زیرزمینی دشت کاشان، 1390. سازمان آب کاشان.
صمدی، ج.، 1394. ارزیابی تأثير کاربری اراضی و آسیب‌پذیری آبخوان کاشان بر آلودگی آبهای زیرزمینی با استفاده از روش DRASTIC و مدل تخریب. تحقیقات منابع آب ایران، 11، 1، 20-13.
صمدی، ج.، 1394. مدل‌سازی مکانی – زمانی تراز سطح آبهای زيرزمينی مناطق شهری و روستایی آبخوان کاشان با استفاده از GIS. علوم و تکنولوژی محیط‌زیست، 17، 4.
طیبیان، آ.، 1390. ارائه الگوريتم توسعه شاخص آسيب‌پذيري آبخوان در مناطق خشك و نيمه خشك. دومین کنفرانس ملی پژوهش‌های کاربردی منابع آب ایران، 16.
متکان، ع.ا، ناصری، ح.ر. و هاشمی، ز.، 1387. تصحيح روش DRASTIC مبتني بر GIS با استفاده از روش‌هاي آماري و تحليل سلسله مراتبي، مطالعه موردي دشت همدان - بهار. سومین کنفرانس مدیریت منابع آب ایران. 9.
محمدی، ک.، جوادی پیربازاری، س. و کاوه‌کار، ن.، 1387. واسنجی روش DRASTIC نسبت به آلودگی نیترات در ارزیابی آسیب‌پذیری آبخوان آستانه- کوچهصفهان با استفاده از روش‌های آماری و GIS. چهارمين كنگره ملي مهندسي عمران، دانشگاه تهران. 8.
نقشه قابلیت انتقال آبخوان کاشان، 1388. سازمان آب و خاک کشور.
یون نیترات آبهای زیرزمینی کاشان، 1391. سازمان آب و فاضلاب کاشان.
Aller, L., Bennet, T., Leher, J.H., Petty, R.J. and Hackett, G., 1987. DRASTIC: A standardized system for evaluating ground water pollution potential using hydrogeologic settings, E.P.A., Report, No.600/2-87-035, 622.
Baier, K., Schmitz, K.S., Azzam, R. and Strohschön, R., 2014. Management tools for sustainable ground water protection in mega urban areas – small scale land use and ground water vulnerability analysis in Guangzhou, China. International Journal of Environmental Research, 8, 2, 249-262.
Evans, T.A. and Maidment, D.R., 1995. A spatial and statistical assessment of vulnerability of Texas groundwater to nitrate contamination. Center of Research in Water Resources, The University of Texas at Austin, USA, 257.
Harter, T. and Wlker, I.G., 2001. Assessing vulnerability of groundwater. US Natural Resources Conservation Service, 13.
Hentati, I., Zairi, M. and Ben Dhia, H., 2011. A statistical and geographical information system analysis for groundwater intrinsic vulnerability: a validated case study from Sfax–Agareb, Tunisia. Water and Environment, 25, 400-411.
Javadi, S., Kavehkar, N., Mohammadi, K., Khodadadi, A. and Kahawita, R., 2011. Calibrating DRASTIC using field measurements, sensitivity analysis and statistical methods to assess groundwater vulnerability. Water International, 36, 6, 719-732.
Krishna, R., Iqbal, J., Gorai, A.K., Pathak, G., Tuluri, F. and Tchounwon, P.B., 2014. Groundwater vulnerability to pollution mapping of Ranchi district using GIS. Appled Water Sciences, 4, 12, 14.
Lindstrom, R., 2005. Groundwater vulnerability assessment using process-based models. Trita-Lwr PhD Thesis 1022, Stockholm, Sweden, 36.
Lodwick, W.A., Monson, W. and Svoboda, L., 1990. Attribute error and sensitivity analysis of map operations in geographical information systems: suitability analysis. Geographic Information System, 4, 4, 413–28.
Napolitano, P. and Fabbri, A.G., 1996. Single-parameter sensitivity analysis for aquifer vulnerability assessment using DRASTIC and SINTACS HydroGIS, 96: application of geographical information systems in hydrology and water resources management. Proceedings of Vienna Conference, 235, 559–66.
Panagopoulos, G.P., Antonakos, A.K. and Lambrakis, N.J., 2006. Optimization of the DRASTIC method for groundwater vulnerability assessment via the use of simple statistical methods and GIS. Hydrogeology, 14, 6, 894-911.
Pearson, K., 1896. Mathematical contributions to the theory of evolution. III. Regression, heredity and panmixia, Philosophical Transactions of the Royal Society of London, 187, 253-318.
Piscopo, G., 2001 Groundwater vulnerability map explanatory notes, Castlereagh Catchment, NSW. Department of Land and Water Conservation, Australia. Rosen, L.A., 1994. A study of the DRASTIC methodology with emphasis on Swedish conditions. Groundwater, 32, 2, 278-285.
Sorichetta, A., Masetti, M., Ballabio, C., Sterlacchini, S. and Beretta, G.P., 2011. Reliability of groundwater vulnerability maps obtained through statistical methods. Journal of Environmental Management, 92, 4, 1215-1224.
Spitz, K. and Moreno, J., 1996. Practical guide to groundwater and solute transport modeling. John Wiley & Sons, New York, 461.
Vrba, J. and Zaporozec, A., 1994. Guidebook on mapping groundwater vulnerability. IAH, International Contribution for Hydrogeology, Vol 16, 131.