Morteza Khodagholi; Razieh Saboohi
Abstract
The genus of Astragalus accounts for 31.4 percent of area of Isfahan Province with Astragalus verus Olivier as a foremost species. This study aimed to investigate the contributing climatic variables to distribution of this species. Moreover, the trends of climatic variables and their influence on the ...
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The genus of Astragalus accounts for 31.4 percent of area of Isfahan Province with Astragalus verus Olivier as a foremost species. This study aimed to investigate the contributing climatic variables to distribution of this species. Moreover, the trends of climatic variables and their influence on the species mortality. In doing so, 56 climatic variables relating to January, March, July, and the entire year were utilized. The Principal Component Analysis was employed to trim down the number of variables and their trends were analyzed using the Mann-Kendall test. The correlation analysis was ultimately used to investigate the association between climatic changes and mortality of Astragalus verus. Results showed that cooling temperature contributed most in the distribution of the species. The trend of temperature also indicated that mean temperature followed an upwards trend in most months of the year. Except Ardestan, Isfahan, Eastern Isfahan, and Kaboutar-Abad, annual precipitation declined but not significantly at the level of 1 and 5 percent. The dried up stands observed in Naeen region was estimated to be around 25 percent where the largest decreasing precipitation and increasing temperature was recorded. This estimate was only around 8 percent in Khansar and Chadegan whose increasing temperature and wind speed as well as decreasing precipitation were compensated by having a good growing potential.
TAYYEBEH MESBAHZADEH; ali azareh; Elham Rafiiei sardooi; Fateme FarzanePei
Abstract
Soil moisture, as the soil hydrologic parameters, can be affected by soil temperature and controls various hydrological processes. Given the importance of this issue, in this study, the efficiency of artificial neural network was studied to simulate soil temperature at 5- 100 cm depth. Recorded meteorological ...
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Soil moisture, as the soil hydrologic parameters, can be affected by soil temperature and controls various hydrological processes. Given the importance of this issue, in this study, the efficiency of artificial neural network was studied to simulate soil temperature at 5- 100 cm depth. Recorded meteorological parameters in the Isfahan synoptic station were used to simulate the soil temperature at different depths. The structure of the neural network was formed with an input layer, a hidden layer and an output layer and network training was done by Levenberg–Marquardt algorithm. Also test and error was done to determine a number of suitable neurons in hidden layer. The results showed that error in both neural network and ANFIS model increases with depth increase that can be due to the weak correlation between soil temperature changes in the lower layers and climatic parameters.
Omid Bayat; Hamid Karimzadeh; Mostafa Eghbal; Hossein Khademi
Abstract
Despite of suitable geological and climatic conditions for forming and evolution of alluvial fans and importance of this landform as soil and water resources in arid regions, there are limited studies about this landform in Iran. In the present study, evolution and pedogenic development of geomorphic ...
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Despite of suitable geological and climatic conditions for forming and evolution of alluvial fans and importance of this landform as soil and water resources in arid regions, there are limited studies about this landform in Iran. In the present study, evolution and pedogenic development of geomorphic surfaces of an alluvial fan in Eastern Isfahan were studied by using remote sensing, field and laboratory analyses. Results show that watershed of studied alluvial fan was tectonically active and two main depositional events were occurred for fans of Eastern Isfahan. Geomorphic surfaces were identified according to topographic position and pedogenic development. Geomorphic surfaces of studied alluvial fan were identified using topographic position, dissection rate and pedogenic development of soils. Using of dissection index for geomorphic surfaces suggest that this index is more expedient for use in active surfaces. Soils on geomorphic surfaces are calcareous with distinctive carbonates morphology. Results of dissection index are in corroboration with carbonates morphology in soils of geomorphic surfaces. So, morphology of pedogenic carbonates can be considered as an index of relative age of geomorphic surfaces. Usage of clay accumulation index also show great corroboration with results of dissection index and morphology of carbonates and application of this index is recommended for paleosols. Suggested systems for paleosol classification truly able to classify paleosols and application of these modern models recommend for other regions.
