Document Type : Research Paper

Author

Assist. Professor, Department of Water Engineering, Faculty of Agriculture, Zabol University, Zabol, Iran

Abstract

Investigating the spatial variation of groundwater quality parameters is important in identifying the quality of the aquifer and contaminating resources, and determining the most appropriate management solutions. Geostatistical and GIS methods can be useful tools in this regard. The aim of this study was to evaluate the geostatistical methods in order to investigate and analyze the spatial amount of salinity, nitrate, and total dissolved solids of subsurface waters of Sistan Plain in northern Sistan and Baluchestan province. For this purpose, ordinary Kriging (OK) and simple Kriging (SK) and certain methods such as inverse distance weigthing (IDW), local polynomial interpolation (LPI), global polynomial interpolation (GPI) and radial basis function (RBF) were used. First, the normality of the data was investigated and the non-normal data were normalized by logarithmic method. Then analysis of variograms was performed. The results were evaluated using a cross-evaluation method. The fitting results of the models showed that the EC and TDS indices follow the Gaussian model and the nitrate index follows the spherical model, and simple kriging method is suitable for salinity and nitrate mapping and ordinary kriging for zoning maps of TDS. Moreover, based on the Schuller's diagram, in terms of TDS, sub-surface waters of the region are classified as good to acceptable and in terms of salinity for agricultural use in the moderate to severe problem class.

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Bameri A., Khormalali F., Kiani F. and Dehghani A. A. (2012). Spatial variability of soil organic carbon on different slope positions of loess hillslopes in Toshan area, Golestan Province. J. Water Soil Conserv., 19(2),43-61 [In Persian].
 
Lalehzari R. and Tabatabaei S. A. (2010). Groundwater quality analysis in Shahrekord aquifer. J. Environ. Studies, 36(53), 55-62 [In Persian].
 
Marofi S., Toranjeyan A. and Zare Abyaneh H. (2010). Evaluation of geostatistical methods for estimating electrical conductivity and pH of stream drained water in Hamedan-Bahar Plain. J. Water Soil Conserv., 16(2), 169-187 [In Persian].
 
Barcae E. and Passarella G. (2008). Spatial evaluation of the risk of groundwater quality degradation: A comparison between disjunctive kriging and geostatistical simulation. J. Environ. Monit. Assess.,137(13), 261-273.
 
Fetouani S., Sbaa M., Vanclooster M. and Bendra B. (2008). Assessing groundwater quality in the irrigated plain of Triffa (Nnorth-east Morocco). J. Ag. W. Man., 95, 133-142.
 
Moradi M., Vagharfard H., Khorani A. and Mahmoudinejad V. (2011). Evaluation of different interpolation methods in zoning of groundwater salinity using cross-validation technique (Case study of Shahrekurd plain). J. Remote. Sens. GIS., 3(1), 35-44 [In Persian].
 
Habibi Arbatani A., Ahmadi A. S. and Fattahi M. (2009). Modeling the spatial variation of some of the chemical properties of groundwater using statistical methods. J. Water Manag. Sci. Eng., 7(3), 23-33 [In Persian].
 
Osati Kh., Salajegh A. and Arekhi S. (2012). Spatial variations of nitrate concentrations in groundwater by geostatistics (Case study: Kurdan Plain). J. Range Watershed Manag., 65(4), 461-472 [In Persian].
 
Heshmati S. and Beigi Harchagani H. (2011). Zoning of Shahrekord underground water quality indices for use in designing irrigation systems. J. Water Res. Agri., 1(26), 44-59 [In Persian].
 
Shabani M. (2010). Evalaution geostatistical methods for mapping of groundwater quality and their zoning. Case study: Neyriz Plain, Fars Province. J. Nat. Geogr. Lar, 4(13), 9396 [In Persian].
 
Kurtulus B. and Razack M. (2010). Modeling daily discharge responses of a large karstic aquifer using soft computing methods: Artificial neural network and neuro-fuzzy. J. Hydrul. 381, 101–111.
 
Shabani M. (2009). Determination of the most suitable geostatistical method for the pH and TDS mapping in groundwater resources (Case study: the Arsanjan Plain). Water Eng., 1(1), 47-57 [In Persian].
 
Taghizadeh-Mehrjardi R., Zareian-Jahromi M., Mahmodi Sh. and Heidari A. (2008). Spatial distribution of groundwater quality with geostatistics (Case Study: Yazd-Ardakan Plain). World Appl. Sci. J., 4(1), 9-17.