A. Khanamani, H. Karimzadeh, R. Jafari,
Volume 17, Issue 63 (Spring 2013)
Abstract
Soil characteristics are the most powerful factors in desertification phenomenon. The purpose of this study was investigating soil characteristics as indices for evaluating desertification intensity. The most important indicators of the soil that affect desertification were selected in the present study. Soil samples were taken from Segzi desert vicinity located in the east of Isfahan city with surface area of 112,167 ha. Soil indices such as Soil texture, soil gypsum percentage, the content of HCO3-1, electrical conductivity (EC), pH, the percentage of the organic matter, the content of the soil sodium, chloral and sodium absorption ratio (SAR) were selected. All of these indices were calculated on the thirty four soil samples. After ensuring of the normality of the samples by Klomogrov-Smirnov test, the mentioned indices were imported into GIS for delineating soil characteristics maps. To delineate distribution maps of each soil indice, inverse distance weighting and ordinary and discrete Kriging methods were applied, and appropriate method was selected. Each layer was scored based on MEDALUS model, and the final characteristic maps were then generated using soil geometric mean indices. Results showed that the affected areas of the average, severe and very severe classes of desertification were calculated about 66000, 45650 and 517 ha, respectively. The results also revealed that the indices of the organic matter, soil gypsum percentage, electrical conductivity and SAR were the most influential indicators, which affected desertification in the study area.
A. Khanamani, E. Dodangeh, F. Soleymani , H. Karimzadeh, S. Soltani,
Volume 18, Issue 67 (Spring 2014)
Abstract
Underground water resources considered as a major source of fresh water. Increasing need to water in Iran, causing to
immensely utilization and ground water balance disorder, so that state of ground water in many of area is negative.The
purpose of this study is to investigate the trend of changes in some of the characteristics of groundwater during the
period 1374 to 1387 is Segzi plain. For this purpose, data gathered from the Organization of regional water and
homogenous test with Tom test (Run-test) at 95% confidence level was performed on the data. The independence of
data evaluated by time series auto correlated functions (ACF), to do this, the amount of auto correlated data computed
in different time delays and finally Mann- Kendall test used to evaluate the trend of time series properties in
groundwater. The results of Run-Test showed that all of used series in this study were homogenous (P value< 0.05).
The result of trend analysis test for region’s wells showed a significant increase in chlorine in underground water
resources (P value< 0.05). Calcium has an increasing Trend too about 3 units. Results also showed that all used series in
this study are random and Mann- Kendall trend analysis test can be an appropriate for trend evaluating in data series. As
regard to irregular utilization of underground water resources by increasing depth of water level, amount of different
salts such as chlorine and sodium increased, that causing to surface source degradation like soil and plant cover in
agricultural area.
