Spatial Variability Analysis of Hydraulic Conductivity in tilled and no-tilled soils in Sistan plain

Shamsabadi, V. (2011) Spatial Variability Analysis of Hydraulic Conductivity in tilled and no-tilled soils in Sistan plain. Masters thesis, University of Zabol.

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Abstract

Knowledge of spatial variability of hydraulic conductivity is necessary in many processes such as drainage projects design. This study aimed to examine the spatial variability of hydraulic conductivity in an area of 5000 square meters. Data were collected from tilled and no-tilled soils and at two different scales. In large-scale a number of 47 and 111 samples were taken from tilled and no-tilled soils, respectively, and in small-scale, 66 samples were taken in both tilled and tilled soils. Three methods of Kriging, log kriging and inverse distance weighting (IDW) for Estimation. The methods performance is evaluated using cross-validation technique with the comparison criteria of mean absolute error (MAE), mean bias error (MBE) and the root mean square error (RMSE). The results showed that the spatial structure of hydraulic conductivity in large-scale, in no-tilled soil with and without logarithmic transformation follows a spherical model. Spatial correlation is also weak. In large scale and in tilled soil the semi variogram of hydraulic conductivity and its logarithmic follow a Gaussian model. In this case the spatial correlation is also strong. The semi-variogram of hydraulic conductivity in small-scale, in no- tilled soil with and without logarithmic transformation and follows a linear model. In this case a strong weak correlation is observed. After Plowing the land the best fitted model semi-variogram is the exponential and spherical model for logarithnics and raw data, respectively. The spatial correlation is weak in this case. The results of cross-validation indicate that the Kriging method estimates hydraulic conductivity more accurate.

Item Type: Thesis (Masters)
Uncontrolled Keywords: Estimation ordinary kriging, log normal kriging, IDW, hydraulic conductivity, Sistan
Subjects: S Agriculture > S Agriculture (General)
Depositing User: admin admin1 admin2
Date Deposited: 13 Nov 2016 09:17
Last Modified: 13 Nov 2016 09:17
URI: http://eprints.uoz.ac.ir/id/eprint/1012

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