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1

Interpolation of soil infiltration in furrow irrigation: Comparison of kriging, inverse distance weighting, multilayer perceptron and principal component analysis methods

100%
Alipour N., Nasseri A., Mohammbdi T. A., Pazira E.
Polish Journal of Soil Science
|
2019
|
tom 52
|
nr 1
Study on soil infiltration rate as part of water cycle is essential for managing water resources and designing irrigation systems. The present study was conducted with the aim to compare Kriging, inverse distance weighting (IDW), multilayer perceptron (MLP) and principal component analysis (PCA) methods in the interpolation of soil infiltration in furrow irrigation, and determine the best interpolation method. To conduct infiltration tests, furrows were made on the farm in four triad groups. Infiltration through the blocked furrows method was measured 10, 20, 30, 40, 50, 60, 90, 120, 150, 160, 180 and 210 min after irrigation at a 10-meter distance in each furrow. Data were analyzed by GS+ and Neuro Solutions (NS) software packages. In this study, the maximum error (ME), mean bias error (MBE), mean absolute error (MAE), root mean square error (RMSE), relative error (RE) and correlation coefficient (r) were used to compare the interpolation methods. The results of analysis of variance (ANOVA) indicated that differences in methods based on RMSE, MBE, MAE and ME indices were not significant; however, this difference was significant based on r and RE indices. According to the ANOVA results, it can be said that the PCA method with a r of 0.69 and RE of 31%, was predicted with a higher accuracy as compared to other methods.
2

The feasibility of using vegetation indices and soil texture to predict rice yield

100%
Yaghouti H., Pazira E., Amiri E., Masihabadi M. H.
Polish Journal of Environmental Studies
|
2019
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tom 28
|
nr 4
Identifying plant-environment interactions along with remote sensing provides grounds for designing management methods as well as predicting rice yield in different conditions; accordingly, it is very helpful to use vegetation indices for identifying the vegetation and greenness of farms. The regression between the local and high-yield varieties of rice in 2012 and the NDVI, SAVI, LAI, DVI, and RVI indices derived from Landsat 7 in northern Iran indicate the superiority of the NDVI index in the flowering stage of rice. Results show that the coefficient of determination of the fitted model for local and high-yielding varieties is 0.71 and 0.70, respectively, which indicates the good consistency of the results with the regional data. We evaluated the models for the local and high-yielding varieties in crop year 2013 with RMSE of 406 and 272 kg ha-1 and NRMSE of 12% and 6%, respectively. Moreover, the simulation results show that the yield of the models is well fitted with the observed values; besides, there is high correlation (R>0.80) between the real and predicted yield values. As shown by the investigation of the region’s soil texture, the fine-texture paddy fields have better yield.
3

Evaluation of some heavy metals contaminated soils around the Shahid Salimi power plant, Neka, Mazandaran Province, Iran

100%
Sedghi M., Torkashvand A. M., Asadi M. E., Pazira E.
Polish Journal of Soil Science
|
2019
|
tom 52
|
nr 1
One of the most important problems threatening the health of natural resources and, in turn, the food safety of societies is environmental contamination. Heavy metals are considered as the environmental pollutants. The entry of heavy metals into the soil is done through the atmospheric sources and mostly via melting plants, oil refieries and power plants. Due to the mazut consumption in some seasons, power plants are considered as a threat to the soil. This study was conducted with the aim of evaluating contamination of some heavy metals including copper, zinc, cadmium, lead, and nickel in the soils around the Shahid Salimi power plant, Neka located in Mazandaran province, north of Iran. One of the greatest threats is the possible contamination of cultivated paddy by pollutant elements. A number of 50 samples from the soil around the power plant were taken from a depth of 0–20 cm within the form of a regular grid and the concentration of the corresponding metals was measured in each of them. The mean background concentration of copper, nickel, lead, zinc, and cadmium was 36.2, 339.8, 90.8, 13.8, and 0.20 mg∙kg, respectively. The maximum mean contamination factor belongs to nickel, lead, copper, zinc, and cadmium, respectively. The frequency of the obtained contamination evaluation classes indicates that the majority of the analyzed samples have a medium level of contamination. Copper, nickel, and lead belong to the class of very high contaminants. By comparing the concentrations of the heavy metals of studied region with quality standard of Iranian soil resources, presented by the Department of Environment Protection of Iran, it was observed that the concentrations of cadmium, zinc, and copper have been signifiant at the level of 5% based on the standards determined by the agency for agricultural uses, environmental standard and groundwater level. In other words, they do not have conflct with the determined standard at any of the three levels.
4

Comparison of different interpolation methods for investigating spatial variability of rainfall erosivity index

88%
Khorsandi N., Mahdian M. H., Pazira E., Nikkami D., Chamheidar H.
Polish Journal of Environmental Studies
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2012
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tom 21
|
nr 6
The objective of our study was to expand the R factor of the RUSLE model, erosivity index by its estimation from more readily available rainfall erosivity indexes and parameters in stations without rainfall intensity data, and to determine the most accurate interpolation method for preparing an erosivity index map. Among different erosivity indexes and parameters based on rainfall amounts, only the modified fournier Index (FImod) was highly correlated with EI30 in 20 synoptic stations. A local model was used for estimating EI30 from FImod in the other 66 stations without rainfall intensity data. The spatial variability of the calculated EI30 in all of the stations was different at an azimuth of 32º when compared to the other directions. Moreover, the nuggetto- sill ratio of the semivariogram (0.27) confirmed a strong spatial correlation of EI30. The inverse distance weighting (IDW), spline, kriging, and cokriging methods with elevation as a covariable were compared by a cross-validation technique. The root mean square error (RMSE) value of the cokriging method when compared to that of the IDW, kriging, and spline methods in the study area declined by 11%, 3%, and 4%, respectively. The output maps for all of the interpolation methods followed similar decreasing trends from west to east, with the highest erosivity index (1,450 MJ·mm·ha⁻¹·h⁻¹·y⁻¹) found in the west. This pattern corresponds with the pattern of climatic change from subhumid to semiarid.
5
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Effect of some amendments on leachate properties of a calcareous saline-sodic soil

76%
Yazdanpanah N., Pazira E., Neshat A., Naghavi H., Moezi A., Mahmoodabadi M.
International Agrophysics
|
2011
|
tom 25
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nr 3
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