Kazem Nosrati; Frouzan Ahmadi; Ali Akbar Nazari Samani; Mohammad Reza Servati
Abstract
Soil erosion is one of the most destructive phenomena which cause significant ecological changes in many areas. Soil conservation and erosion control is essential because of the irreparable damage caused by soil erosion. Soil conservation programs will not achieve until to find adequate methods of combating ...
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Soil erosion is one of the most destructive phenomena which cause significant ecological changes in many areas. Soil conservation and erosion control is essential because of the irreparable damage caused by soil erosion. Soil conservation programs will not achieve until to find adequate methods of combating land degradation and ways to reduce the sediment. Therefore, we need to have enough knowledge of the sediment sources and identify places to be at high risk to soil erosion. In this study we used fingerprinting technique in the Taleghani catchment, Khorram Abad city, Lorestan Province to determine the contributions of sediment sources including agricultural, rangeland, and forest in sediment yield. In view of this, 39 soil were collected from different sources: agriculture, rangeland, forest and channel bank and 19 sediment samples including 11 samples from bed sediment and 8 samples from suspended runoff, respectively. 11 tracers including C, N, P, Na, K, Cu, Zn, Mg, Mn, Fe and Ca were selected as the primary tracers. The results showed that discriminant function analysis were selected Mg, C, Zn and Ca as the optimum set of tracers that can discriminate 3 sediment sources. Mixing model results showed that the contribution of each sediment source is 53.37, 30.37, and 16.26 percent for agriculture, rangeland, and forest, respectively. These results were consistent with the evaluation results of nitrogen and organic carbon stocks. The results of this study can be used in selecting most appropriate erosion control method the study area and generalized to similar areas.
ali azareh; Gholamreza Zehtabian; Aliakbar Nazari Samani; Hassan Khosravi
Abstract
In management, the monitoring means systematic collection and storage of data from activities and strategies that provide assessment and report about the overall condition of the study area. In this research, among different existing methods, IMDPA model was selected for monitoring desertification in ...
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In management, the monitoring means systematic collection and storage of data from activities and strategies that provide assessment and report about the overall condition of the study area. In this research, among different existing methods, IMDPA model was selected for monitoring desertification in Garmsar plain. Based on the study area two criteria including agriculture and water were selected as the main effective criteria on desertification and desertification intensity was evaluated on the basis of seven indices including: groundwater table fluctuation, electrical conductivity, sodium absorption ratio, agricultural mention cropping pattern, agriculture yield according to land suitability, irrigation method and highly inappropriate utilization of machinery, fertilizer and pesticide chemicals. The results showed that the average weights of agriculture criterion were 2.17 and 2.27 in 2002 and 2011 respectively classified in medium class of desertification. Also, the index of irrigation method classified in very high class of desertification was the most effective factor on land degradation among studied indices in during 2002-2011. Studying the average weight of numerical value, it is distinguished that the intensity of desertification for the total area were 1.93 and 2.10 in 2002 and 2011 respectively.
golaleh ghaffari; Hassan Ahmadi; Omid Bahmani; Ali akbar Nazari samani
Abstract
In Iran due to the lack of long experience in the implementation of Soil Conservation and Watershed Management Plans, these measures have not been evaluated quantitatively and specific methods for this purpose have not been provided. In this research effort is to investigate the effect of watershed management ...
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In Iran due to the lack of long experience in the implementation of Soil Conservation and Watershed Management Plans, these measures have not been evaluated quantitatively and specific methods for this purpose have not been provided. In this research effort is to investigate the effect of watershed management operations performed in Can Basin in 1379, on the amount of erosion and sedimentation and rate of project success or failure and its causes. So after providing the required information and statistics and being sure about the authenticity and accuracy of statistics and statistical reconstruction of defects with conventional methods, to investigate the effect of implemented projects on erosion and sedimentation rates, average of suspended sediments in the period before project implementation (1986-2000) and in the period after project implementation (2001-2008) was calculated using sediment rating curves through intermediate technique class, and using daily water discharge, watershed erosion and deposition were also calculated using MPSIAC model. Specific erosion and deposition map was provided in the period after project implementation using Arc GIS software and finally the amount of efficiency and effect of this operation on the amount of erosion and deposition rates was judged. The results of studies showed that due to operating this plan, the average amount of suspended sediment has changed from 47892 tons per year during the statistical period before the plan to 22365 tons per year during the eight-year statistical period after it. The amount of erosion and sedimentation has shifted from 66758 tons to 50549 tons, which shows the positive effect of plan on reducing the amount of suspended sediment and the lack of effective role in reducing the rate of erosion. The main reasons for the low efficiency of Watershed Management Plan implemented in relation to decreasing the amount of erosion are: lack of suitable biological operations in the basin (less than 25 percent of the volume of the proposed action), focusing on mechanical operations, weaknesses in project monitoring and evaluation During all stages of its implementation, failure to observe the standards and technical points such as non-conforming structures built between locations and proposed locations, lack of standards in building the necessary structures and inappropriate dimensions of structures, destruction of floor section in mortar stone structures and etc.
Asghar Tavakkoli Fard; Aliakbar Nazari Samani; Naser Mashhadi; Hoda Ghasemieh; Mojtaba Hodayi Arani
Abstract
Kashan Erg is one of the most important sand dunes complexes in Iran. It is included the most important various type of sand dunes in Iran. This study was performed to compare the granulometry of aeolian sediments in different sand dunes and also from plinth to crest of transverse dunes that located ...
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Kashan Erg is one of the most important sand dunes complexes in Iran. It is included the most important various type of sand dunes in Iran. This study was performed to compare the granulometry of aeolian sediments in different sand dunes and also from plinth to crest of transverse dunes that located in Kashan Erg’s north. In order to determining different statistical variables, aeolian sediment sampling was conducted in different sand dunes. Then, the sample’s granulometry test was done based on dry sieve analysis. Finally, statistical parameters such as mean diameter, Sorting, Skewness, Kurtosis, d10, and d90 were determined. The results showed that the mean diameter, Sorting, d10 and d90 parameters have significant differences at the 95% significance level between the stabilized sand dunes and active ones. Moreover, it was found that in transverse sand dunes, there are a significant difference at the 95% significance level between mean diameter and d90 parameters in bottom of the stoss side and lee side.
Aliakbar Nazari Samani; Fatemeh Avazadeh Tavakoli; Hassan Ahmadi; Gholamreza Rahi
Abstract
Gully erosion is one of the most destructive types of channeled water erosion that removes aconsiderable volume of soil as it develops. This type of erosion consists of complex a geomorphicprocess that has been known as an indicator of accelerated soil erosion. In this research theadvancement of 25 headcuts ...
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Gully erosion is one of the most destructive types of channeled water erosion that removes aconsiderable volume of soil as it develops. This type of erosion consists of complex a geomorphicprocess that has been known as an indicator of accelerated soil erosion. In this research theadvancement of 25 headcuts were assessed through digital interpretation of multi-temporal aerialphotos, field observations and GIS data analysis over the two periods of 1967-1995 and 1995-2008.Moreover, the stepwise regression analysis procedure was applied to extract the effective factors ongully head advancement (such as topography, physico-chemical soil attributes and morphology ofgully). The results indicated that the mean of gully head advancement over the periods of 1967-1995,1995-2008 and the mean of two periods were measured 1.36, 1.23 and 1.3 m/y, respectively. Further,regression analysis revealed that headcut's contribution area, distance of gully-head to ridge, height ofgully head cut and SAR are the main factors on gully head advancement. Therefore, distance to ridge,headcut high and presence of plunge pool could use as suitable criteria to distinguish the active gulliesin order to prioritizing the conservation activities.
Aliakbar Nazari Samani; Hesam Heravi; Mehdi Panahi; Masoud Jafari Shalamzari
Abstract
Natural landscape alternation is a problem that has been under debate for a long time. Landutilization techniques like agriculture, forest and rangelands, residential and urban are amonginfluential criteria affecting erosion severity and sediment yield in a given region. In this respect,land management ...
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Natural landscape alternation is a problem that has been under debate for a long time. Landutilization techniques like agriculture, forest and rangelands, residential and urban are amonginfluential criteria affecting erosion severity and sediment yield in a given region. In this respect,land management is a promising option to mitigate it. Thus, acquaintance with quantitative soilerosion owing to land-use changes is of great importance for estimating disadvantages andlatent and intangible symptoms of erosion. Strategic planning for sustainable developmentcould be benefited from such knowledge. The current research considered a statistical periodfrom 1970 to 2004. This period was sub-divided into two separate periods from 1970 to 1987and from 1987 to 2004. During these periods, statistics relating to sedimentation, climatology(precipitation) and hydrology were analyzed. Results revealed that the sediment reduction inthese two periods under similar rainfall would be as a result of an increase in abandoned areas.
