Environmental Erosion Research Journal

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Dust storms can have significant impacts on both local and global climates, as they contribute to the transport of suspended particles in the atmosphere, potentially leading to climatic changes, air quality degradation, and increased health risks for humans. This phenomenon is particularly important in arid and semi-arid regions, such as Alborz province, which faces specific climatic and geographical challenges. The spatial analysis indicated that AOD levels increased significantly in the southern and southwestern regions of Alborz province during the study period. The assessment of minimum, maximum, and average annual AOD levels revealed an increasing trend between 2008 and 2011. The highest AOD value was recorded in 2009 at 0.4, while in 2008, 2010, and 2011, the values were 0.29, 0.34, and 0.29, respectively. Additionally, the results showed that the area of different AOD classes fluctuated across the 5-year intervals. A decreasing trend was observed in the very low and high classes, while a significant increase occurred in the very high class. For instance, the area of the very high AOD class increased from 3.01% in 2001 to 8.02% in 2020, indicating an intensification of dust storm events in recent years. The findings of this study highlight a notable increase in the concentration of suspended dust particles, particularly in the southern and southwestern regions of Alborz province over the past two decades. This upward trend may be attributed to multiple factors, including climate change, reduced vegetation cover, and increased human activities such as urbanization and unsustainable agricultural practices. These results can serve as an important resource for environmental management planning and decision-making aimed at mitigating the adverse effects of dust storms and improving air quality in the province. Furthermore, there is a need for further studies to more precisely identify the contributing factors to these changes and to predict future trends.
 

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Delta areas are dynamic features with changes occurring at many spatial and temporal scales due to catastrophic events. Change detection and providing a fluvial map of changes are the main requirements for environmental and zonal planners in many studies. Geomorphic changes such as temporal and periodic changes in riverbeds are common events in all delta areas. The Mehran river delta is located in the west of Hormozgan Province. Changes in various geomorphic features, shuch as riverbed migration, during a 21-year period, were detected and identified using landsat TM and ETM satellite data and topographic maps. Simple band subtraction and linear directional mean were used to identify changes in the case study. The results of this study showed that the Mehran river channel has migrated several times over the last 21 years so that several meanders and ox-bow lakes remain as a result of migration. Moreover, a slight change in coast line toward the Persian Gulf has been identified as a result of migration and deposition. The changes in the vegetation cover area in this zone which has a mangrove vegetation cover have been noticeable, so that these covers have incremental trend according to undergone action in artificial forests. The results of this study may be used in an integrated coastal zone information system as it has been proposed for the Mehran river delta.

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The use of new methods of Remote Sensing (RS) and Geographical Information System (GIS) in zoning the flooding potential and its variations in a particular geographical area (Tang-e-Bostanak Catchment Area) constitutes the main subjects of this study. In this regard, the production, combination, and composition of effective information layers such as K index and run off in identifying these zones have been noted, highlighting the capacity of GIS. Theaim is the identification and percent of flood zoning and their variations within an 18-year period by RS and land use variation maps. In this study, we have observed excess rainfall under the curve number (CN). According to the results, the above mentioned area isexperiencing a 15% increase in flooding during the 18-year period.

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The use of new methods, remote sensing (RS) and geographical information system (GIS) in zoning the water erosion in a particular geographical area (Tang-e-Bostanak catchment area) constitute the main subjects of this study. The production, combination, and composition of effective information layers in identifying these zones have been noted, highlighting the capacity of GIS and RS. In this study the erosion and sediment rates of Tange Bostanak watershed have been estimated according to the EPM method. In this model environmental factors were studied with RS and GIS. In the EPM model the yearly specific erosion rate was 1174.89 and the sediment yield rate was 869.41. There have been high, medium, and very high erosion risks of 58.9, 40.92 and 0.21 percent of the basin area, respectively. The results indicate that the EPM model with use of RS and GIS is acceptable in estimating erosion and sediment.

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The aim of this research is exploring the impact of changes in runoff and sediment of the upstream catchment on the changes in the area and amount of canopy in Gabric-Jask mangrove. Hence, hydro-climatological parameters including amount of precipitation, discharge, and sediment in Gabric catchment during the statistical period of 1993 to 2010 were selected and the annual standardized index related to each parameter respectively including SRI, SPI, and SSI were calculated. Also, satellite images of Landsat of TM and ETM⁺ sensors were used in order to explore the changes in the canopy by the use of NDVI and the area was prepared and its calculations were done. Cross correlation function and moving average of 3, 5, and 7 years were used to explore the relation between hydro-climatologic factors and the area and canopy of mangrove. Based on the results related to the canopy changes there was two increasing periods and one decreasing period and the area changes had an increasing trend during the study statistical period. Results of exploring the relation between incoming precipitation, discharge, and sediment to the mangrove forests show that NDVI changes and the area of mangrove forests have a significant relationship with three years moving average of SPI, SRI, and SSI indices with the correlation coefficients of 0.6, 0.8, and 0.56, respectively. Finally, results showed an increase in the rate of NDVI index with an amount of 0.33 and an increase in the area of Gabric-Jask mangrove forests with an amount of 0.22 ha/year.

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Extended abstract
1- Introduction
The Hedijan coastal plain around the Zohreh River is a hub for essential agriculture, fisheries, trade, and the military. Any change in the regime and territory of the Zohreh River will have significant economic, social, and security effects in the region. Due to the privation of the region and preserve the available resources and capital, it is necessary to carefully study the hydraulic parameters affecting the morphological changes and the complex pattern of the meandering of the Zohre River. In this study, considering the special conditions of this coastal plain, it has been tried to study geometric features such as curvature coefficient, curvature radius, central angle, and river arc length in three time periods by studying and examining satellite images in a GIS environment.
 
2- Methodology
In this study, to study the morphological changes and meandering pattern of the Zohre River in the coastal plain of Hindijan, Google Earth satellite images from 2000 and 2014 were used. Based on these two images, the old route of the Zohreh River can be identified in the study area. In the next step, to investigate the meandering and morphological changes of the river, the route drawn from Google Earth entered the GIS environment. Using the ArcMap 10.2 software, to examine essential parameters in river morphological changes, circles with a suitable radius tangent to the existing curves in the river path were drawn. In the old route, 35 meanders were detected, and in the 2000 and 2014 routes, 21 meanders were identified and examined.
 
3- Results 
In order to study the morphology and meandering pattern of the Zohre River in the study area, various parameters such as bending coefficient, central angle, arc length, half-wavelength, and radius of curvature were calculated. According to Wolfert (2001), four types of rivers, including direct, sinusoidal, meander, and more meander, have been introduced in terms of the degree of curvature of rivers. According to this criterion, the Zohre River can be placed in a meandering river in the study area. Also, the number of meander from previous years, 2000 and 2014, was 35, 21, and 21. The maximum radius of the meander of this river was 450.1, 661.8, and 632.3 m. The lengths of the arch were 1197, 1118.2, and 1154.6 m, respectively. There have been alternating positive and negative changes in the values of the central angles in all three study periods. The average central angle from the old route to 2000 has been declining, and from 2000 to 2014, it has been increasing. In the old route, based on the size of the central angles, 57.14% of the torsions are in the overdeveloped area, 14.30% of the torsions are in the developed inverted 11.42% are in the undeveloped area. 17.14% was the size of a cow's horn, and no percentage was found for quasi-twisting curves. In 2000, based on the size of central angles, 42.86% of turns were over-developed, 14.30% of the turns were over-developed, and 23.80% of the turns were twisted. The average amount of radius in the old path increased from 450.1 to 66.81, and from 2000 to 2014, it decreased to 632.3. In total, this parameter has increased over three time periods. Finally, the obtained values for this parameter indicate that the river is meandering and the morphological changes in these three periods.
 
4- Discussion & Conclusions
The results showed that significant changes have taken place and are taking place over the years under study. During the three times of periods, four significant shortcuts and other significant morphological changes occurred. It is predicted that in the place of the 18th meander at the location of the existing bottleneck, there will be a shortcut in the future, which will eliminate the existing meander and create new ones.
Also, according to the Wolfert classification criterion based on the bending coefficient (1.5-2) and the Corneiss classification based on the central angle (158-296), the Zohreh River is located in the Hindijan Plain is in the category of meandering and the meander is overdeveloped.

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Extended Abstract
1-Introduction
Gully erosion is the most obvious form of soil erosion, which leads to reduced production capacity, significant soil losses, and the production of large amounts of sediment and restricting land use. It can be a severe risk to agricultural areas and villages' roads and structures. Due to the lack of information on soil erosion and sediment production in many watersheds of the country, the use of new technologies such as remote sensing and GIS is necessary so that the use of this technology can be a valuable source of information to understand the trend of Gully changes. The study area is located in the west of Bandar-e-Lengeh city in the Hormozgan provinc. The approximate geographic coordinat is 54° 19¢ 11² to  54° 30¢ 40 longitudes and 26° 40¢ 57² to 26° 56¢ 04² latitude. The study area is mainly formed by sedimentary rocks belonging to the Mesozoic period (Fars group formations) with low permeability. This factor, along with the low rainfall and very high intensity, has destructive effects on natural resource ecosystems.
2- Methodology
This research is focused on gully erosion mapping and monitoring at multiple spatial scales using multi-source Arial photo and remote sensing data for gullies extend in the past decades. Aerial photos of 1957, Landsat satellite images of 1994, 1984, 2004, and GeoEye satellite images for 2014 and 2016 have been used to study the long-term changes in the growth of Gully erosion. Image visual interpretation with field verification was employed to map the geometric gully features and evaluate the growth of the gully in the last 60 years.
3- Results
The results showed the gully areas increased from 112 hectares to 206 hectares from 1984 to 2004. The results also show that during the period 2004 to 2014, the gully areas increased from 206 hectares to 316 hectares and 370 hectares in 2014 to 2016.
50 gullies were studied to investigate the longitudinal growth of ditches in the study area. The results show the annual rate of gullies' longitudinal growth is 4.9 meters for1984-2004 and 6.8 and 2.95 meters for 2004 to 2012 and 2012 to 2016 periods, respectively.
4- Discussion & Conclusions
The long-term growth rate of gullies in the study area (1975-2016) is an average of 5.2 meters per year, which is very high comparing to researches conducted in the world and Iran. For example, in their study, Ghezelsofloo et al. (2018) estimated the annual erosion rate of 0.99 m for the Shurdreh catchment, and Ahmadi et al. (2007) estimated the annual growth rate of 0.206 m for the Hablehroud basin.
In other studies, conducted by Rostamizad et al. (2015), the annual growth rate of 0.85 m for the city of Darhshahr, Tavakoli Rad et al. (2014) 1.29 m in the Samal Basin of Bushehr, Nazari Samani et al. (2014), growth 1.3 meters for the Kore Dareh catchment.
In other countries, Malik (2007) estimated the average erosion rate of the small gully at 0.63 m per year. Millington et al. (2013) also estimated the average rate of gully erosion on slopes from 0.21 to 0.51 m per year on the southern plateau of Poland.
 In another study, the growth rate of the ditch was calculated by Pellikka et al. (2005) for the Tiata hills of Kenya as 0.1 to 0.7 m per year.
In addition, the research results show that the High sensitivity of Fars Group formations to erosion, arid climate, weakness and degradation of vegetation and very high intensity of 24-hour rainfall in the study area, lack of flood management are main reasons for the high longitudinal growth of gully in the study area. Other reasons are human manipulation in flood diversion and concentration, a very high percentage of soil silt, release of rainfed lands and the existence of a wide network of local access roads. The resuls are consistent with the results of Karimi et al. (2007), Mohammad Ebrahimi et al. (2017), Asghari Sarskanrood (2017), Besharati et al. (2018). 

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1- Introduction
The Dust storm is one of the most important climatic phenomena of the present age in arid and semi-arid regions of the world. Due to its characteristics, this phenomenon can have various environmental and climatic effects in different atmospheric systems, oceans and continents. Dust storms play a very important role in the earth's atmospheric cycle, so that dust particles are one of the factors of atmospheric warming, as well as reducing air quality and affecting human health. Dust particles have direct effects on absorbing or scattering radiation waves, which results in a significant decrease in visibility. The west and the northwest of Iran are facing the dust storm phenomenon and its problems periodically.
2- Methodology
In this study, the frequency of dust phenomenon and its occurrence causes have been analyzed in the northwest and west of Iran, including Ardabil, East Azerbaijan, West Azerbaijan, Kurdistan, Zanjan, Hamedan, Kermanshah and Ilam provinces. At First, the occurrence of dust in the study area was investigated. To identify the source of the dust storm, dust storms of 15-20 July 2000 & 17-22 June 2012 (as case study) were described using MODIS satellite images. Modis sensor images were used to detect and monitor the dust storms. The reason for choosing these days for analysis was the high intensity and concentration of dust in those days in most of the stations. For the synoptic analysis of dust storms, re-analyzed data of sea level pressure, geopotential height, vector wind, vorticity, wind direction and omega at 500mb level were used. These data were obtained from National Oceanic and Atmospheric Administration (NOAA) which was prepared by the National Center for Environmental Prediction (NECP). The maps were drawn and synoptically analyzed using Grads software.
3- Results
The results showed that the highest frequency of dust storm codes occurred in the studied stations was related to code 6, which indicated the presence of dust in the sky. In terms of monthly distribution, June, July, April, and May has the dustiest days in the studied area. The occurrence of dust had an increasing trend from the early hours of the night to noon. The frequency of dusty days in different years indicated an increasing trend from 2000 to 2018. The frequency of dusty days was higher in 2008 and 2012 compared with other years. The results also showed that the main sources of dust in the west and northwest of Iran are the desert areas of Iraq, the Arabian Peninsula, and the African Sahara. At sea level, the most important cause of dust storms in the west and northwest of Iran was the existence of a low-pressure center in Saudi Arabia and Iraq. In other words, dust storms in the west of Iran were transitional and have originated from the western neighbors of Iran (Iraq, east of Syria, and northern Saudi Arabia), where in the most severe event, the dust has spread to central Iran. At 500 mb level, the most important factor in creating dust storms in the west and northwest of Iran was the rule of the Azores sub-tropical high-pressure tongue and the location of the region below it. Due to the high pressure of the Azores on Iran, migratory cyclones and troughs due to lack of penetration into the region, had little effect on the formation of instability and dust storms, which the main reason for this phenomenon should be found in surface pressure systems. The extreme warming of the earth's surface had caused the instability of the atmosphere of Iran in summer up to a height of 2-3 km above the earth's surface. The low-pressure thermal cell was stretched from Pakistan to the south of Iran, and from there to the deserts of Saudi Arabia, Iraq and Syria on all days under study. The Iran-Pakistan low-pressure system, which appeared as a focal point in the southeast of Iran, was a low-pressure, high-suction system that created dust storms in the region.
4- Discussion & Conclusions
The results of dust storms monitoring in northwest and west of Iran using satellite images showed that remote sensing techniques due to extensive and continuous coverage in space, monitoring natural disasters and also monitoring dust storms, intensity and dynamic tracking, can play a major role in dust monitoring. The results also showed that the Aqua and Terra satellites have a high capability in detecting and tracking dust storms due to their high temporal, spatial, and spectral resolution.
 

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1- Introduction
Remote sensing and Geographic information system have the capability of detecting and/or monitoring the features of the earth’s surface using satellite images and have different radiometric, spectral, spatial, and temporal resolutions. These technologies resolutions have several advantages in order to minimize the time and cost  of extracting Land cover and Land use (LULC). In addition, the remote sensing provides important and different kinds of remote data sources to extract LULC information. Remote sensing data are widely used and applied to perform classification of LULC in the world. Remote sensing data has the ability of updating information about all of the features located on the earth’s surface. The classification of remote sensing imagery is an important method in order to determine the LULC information. Classification approaches are divided into two categories:  pixel base and objected oriented base classifiers. The present study's aims are conducting land use classification by making a comparison between different algorithms in Taham watershed in Zanjan province.
2- Methodology
In this research, Landsat8 satellite images (25 July) were used to perform preprocessing and processing steps. Geometric, radiometric and atmospheric corrections were used to eliminate the image noise. In the next step, for the existing uses in the region, first, field samples (160 educational points) were collected separately for each use in the region by using field visits and the Global Positioning System (GPS). Educational samples were divided into two categories, 70% of them were used for classification and 30% were used to accuracy of classification methods. After applying the image corrections according to the studied algorithms for each algorithm using EVVI 5.3 software and educational samples, the land use role for the study area was prepared. According to the sampling, five classes in the study area include agricultural land, rangeland, barren land, residential areas and waterbody areas. To evaluate the accuracy of the classified maps, the error matrix was calculated by using ENVI software. For this purpose, in the present study, the coefficients of Overall Accuracy, Kappa Coefficient, Producer Accuracy, User Accuracy, Commission and Omission had been used.

3- Results
The aim of this research was to classify and map land-use/land-cover of the study area using remote sensing and Geospatial Information System (GIS) techniques and includes two sections, namely Land use/Landover (LULC) classification and accuracy assessment. In this study, the supervised classification and four algorithms (including SVM, MLC, MDC and MC) were used and then five classes for the study area including agricultural land (3.26), rangeland land (89.85), residential land (0.15), waterbody (1.19) and barren lands (5.55) were extracted. Also, the results showed the SVM algorithm with overall accuracy (98.24), kappa coefficient (0.969) as the most accurate, MDC algorithm with overall accuracy (94.36) and kappa coefficient (0.9) as the last priority in this study. According to the results of Tables 2 and 3, it can be seen that the percentages related to the five land use classes (residential areas, irrigated areas, agricultural lands, rangelands and baire lands) are mostly above 90%. This indicates that a high percentage of the pixels associated with these uses are properly classified. This study also presents essential source of information whereby planners and decision makers can use to plan sustainably measures for the environment.  
4- Discussion & Conclusions
Today, the use of LULC mapping is a vital issue for collecting data in urban planning, comprehensive watershed management, identification of effective factors, and environmental monitoring. The use of remote sensing technology with different satellite images is recommended as the best strategy for preparing LULC maps. By using different systems the limitations and capabilities of these images can be identified. The purpose of this study was to generate LULC thematic maps by comparing different algorithms, using maximum likelihood, minimum distance from mean, Mahalanobis and Support vector machine in Tham watershed in Zanjan province by applying Landsat 8 images. After performing all of the necessary corrections with the steps of preprocessing, processing and analysis of satellite images, four different algorithms were used to classify the satellite images. Support vector machine algorithm with an accuracy equal to 98.24% and kappa coefficient with an accuracy equal to 0.969 has the highes accuracy among other algorithms.  Of course, the maximum likelihood algorithm with 97.45% overall accuracy and kappa coefficient equal to 0.961 have the highest accuracy in extracting land use maps and the slightest difference with the support vector machine algorithm, respectively.  In other words, it can be said that the two support vector machine algorithms and the maximum likelihood have a high level of accuracy in extracting the land user maps. The two algorithms of Mahalanobis distance and minimum distance from the mean were ranked next.