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Doc Maryam Ilanloo, Doc Amir Karam,
Volume 20, Issue 56 (3-2020)
Abstract

The destruction of the rivers and, consequently, the need to reconstruct them, is one of the known important problems in throughout the world. However, suitable methods for assessing the morphological changes (morphology) associated with this action, as well as the cognition of the effect of the morphological factors in order to intervention in the process of river reconstruction, are still being explored. The JAJROOD and LATYAN-dam areas in the north east of Tehran due to the pleasant weather have always been and are in Eco tourists and nature interested people noteworthy. For this reason, during the recent decades and because of human manipulations, the JAJROOD River basin and its margins have been heavily affected. Hence the study of hydro morphological changes in this river is strongly needed. The object of this research is to evaluate the hydro morphological conditions of one part of JAJROOD River using the MQI method. Accordingly, Landsat 8 satellite images of 2018 and Landsat 4 in 1976 were prepared and were take placed several field observations. The results of the research show that all areas of the region are in poor and very weak conditions regarded to the MQI method. These problems are caused by the cutting of trees in order to create human structures, harvesting sand, creating numerous promenades along the river's estuaries and changing the river pattern.

 
Shila Hajehforosh, Amir Karam,
Volume 21, Issue 60 (3-2021)
Abstract

River management, including strategies that effectively have an effect on the behavior. Geomorphological management, is the study of shapes, nature, and origin, processes of emergence, development and use of human and material composition of the Earth.  The assessment of river character and behavior in Stage 1 is based on analysis of the assemblage of geomorphic units (channel and floodplain landforms) along any reach. Arangeh River basin were identified in 1and 3 styles, including: Headwater, Gorge style in confined valley setting, planform controlled, floodplain bed, low sinuosity cobble, low sinuosity gravel, bedrock controlled sand, meandering gravel, unconfined low sinuosity cobble with Side stabilized, partly-confined low sinuosity cobble with Side stabilized, partly confined Asymmetric valley with cobble, , partly confined symmetric valley with cobble  ,Artificial bed.Geomorphic conditions of each of the styles were evaluated in the two stage of river style framework. at this stage of adjustment of Each style is determined to the confusion of peak flow by using criteria such as channel characteristics (size, shape, morphology Bank and plants channels), channel plan form (sinuosity, lateral stability, geomorphic units into the channel and River flood plain and plants) and features bed . Two Style had good geomorphic conditions (floodplain bed bedrock controlled sand, unconfined low sinuosity cobble with Side stabilized) show the potential of a good adjustment, and the reach has a good of potential adjustments are more sensitive to changes . In the fourth stage of rehabilitation is carried out in reach scales, basins and river basin based on forecasts of possible changes in the future and potential of Geomorphic River Recovery. Each style is proposed management priorities in accordance with the geomorphic and recycling potential.

Saideh Eiyni, Dr Saeide Eini,
Volume 21, Issue 60 (3-2021)
Abstract

The aim of this research is to investigate drought stress in rangeland rangelands in Ardabil province. According to the monthly rainfall data, 4 synoptic stations of Ardebil province (Ardebil, Khalkhal, Meshgin Shahr and Parsabad Moghan) during the statistical period of 2016-1996 were used to calculate drought index (SEPI) index for 4 periods of 1, 3, 6 and 9 months. Landsat TM and OLI satellite imagery was also used to prepare landslide classification maps based on the maximum probability model and calculation of vegetation indices NDVI, EVI, SAVI and LAI. In order to investigate the relationship between the studied indices, Pearson correlation coefficient (R) and root mean square error (RMSE) have been used. The results of the classification showed that the extent of the rangelands of Ardebil province in 1394 in the year 1377, both in the rangeland and in the rangelands, is a significant decrease. According to the results of SPI, the drought condition during 2011-2015 is more than the other periods studied. Vegetation dispersal maps were based on decision tree tree classification algorithm and according to NDVI index for the studied months. Also, according to the results of the evaluation, the highest correlation was observed between the NDVI index and the 6-month SEPI index, and the lowest mean squared error was found between the SAVI index and the 6-month SEPI index, but in general, the most suitable indicator for Drought monitoring in Ardebil province pastures is a 6-month NDVI and SEPI indicator.
 


Mr Mohammad Safaei, Dr Hani Rezayan, Dr Parviz Zeaiean Firouzabadi, Dr Ali Asghar Torahi,
Volume 22, Issue 65 (6-2022)
Abstract

Examining the effects of climate change on the oak spatial distribution, as the main species of Zagros forests and its ecological and economic values is of significant importance. Here, we used species distribution models for simulating current climatic suitability of oak and its potential changes in 2050 and 2070. For this purpose, five regression-based and machine learning approaches, four climatic variables related to temperature and precipitation and two optimistic (RCP 2.6) and pessimistic (RCP 8.5)  greenhouse-gas scenarios were used. The results of measuring the accuracy of models by AUC indicated the good performance of all algorithms and Random Forest achieved the highest accuracy (AUC = 0.95) among other methods. The results showed that in both time periods and under both scenarios, changes will occur in oak spatial distribution and the most severe one would be a 42.9 percent loss in the oak climatic suitability in 2070 under pessimistic scenario (RCP 8.5).
 

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