University of Hormozgan
Environmental Erosion Research Journal
2251-7812
2717-3968
4
1
2014
5
1
Identification of the Best Infiltration Model in Order to Investigation of Spatial Variability of Infiltration Parameters (Case Study: Darabkola River Basin)
1
16
FA
ebrahim_omidvar@yahoo.com
Y
ataollah.kavian@yahoo.com
N
solaimani2001@yahoo.co.uk
N
Infiltration is the process of water penetration from the ground surface into the soil and is an important process in the hydrological cycle by which surface runoff and groundwater recharge can be linked. Over the years, the importance of the infiltration process resulted in the development of several simplified analytical models for predicting infiltration. These infiltration models range from entirely empirical to physically based models. The most serious problem associated with infiltration modelling of a catchment is how to express the spatial soil variability. In the present study, various infiltration models were fitted to the observed infiltration data of 27 double ring infiltrometer tests and the best-fit infiltration model for Darabkola watershed was identified and evaluated. In addition, the spatial variability of the selected infiltration model parameters was analyzed using the geostatistical techniques. Results showed that among of four models, the Green - Ampt model could determine the infiltration rate with smallest values of RMSE. Hence, saturated hydraulic conductivity parameter (KS) and suction head at the wetting front (Sw) were estimated for all the test points. Evaluation of spatial variability of these parameters indicated that parameters KS and Sw had the spatial dependencies of 0.49 and 0.25 respectively, showing medium spatial dependencies of both parameters. Also, investigation of interpolation parameter maps showed that in the upland with forest land use, relative to other areas in the watershed, the saturated hydraulic conductivity (KS) and suction head at the wetting front (Sw) have larger (1.57-2.69 cm/hr) and smaller values (12.12-1737 cm), respectively.
Infiltration, Green - Ampt Model, Geostatistic, Darabkola River basin
http://magazine.hormozgan.ac.ir/article-1-215-en.html
http://magazine.hormozgan.ac.ir/article-1-215-en.pdf
University of Hormozgan
Environmental Erosion Research Journal
2251-7812
2717-3968
4
1
2014
5
1
Assessment of the important Factors on Gully Erosion in Arid and Semi-arid Region in Ilam Province
17
28
FA
Javad
Mirzaei
Ilam University
mirzaei.javad@gmail.com
Y
Farhad
Nourmohammadi
Lorestan University
Fnoormohamadi@gmail.com
N
ali
yousefi
Ilam University
yousefia38@yahoo.com
N
Infiltration is the process of water penetration from the ground surface into the soil and is an important process in the hydrological cycle by which surface runoff and groundwater recharge can be linked. Over the years, the importance of the infiltration process resulted in the development of several simplified analytical models for predicting infiltration. These infiltration models range from entirely empirical to physically based models. The most serious problem associated with infiltration modelling of a catchment is how to express the spatial soil variability. In the present study, various infiltration models were fitted to the observed infiltration data of 27 double ring infiltrometer tests and the best-fit infiltration model for Darabkola watershed was identified and evaluated. In addition, the spatial variability of the selected infiltration model parameters was analyzed using the geostatistical techniques. Results showed that among of four models, the Green - Ampt model could determine the infiltration rate with smallest values of RMSE. Hence, saturated hydraulic conductivity parameter (KS) and suction head at the wetting front (Sw) were estimated for all the test points. Evaluation of spatial variability of these parameters indicated that parameters KS and Sw had the spatial dependencies of 0.49 and 0.25 respectively, showing medium spatial dependencies of both parameters. Also, investigation of interpolation parameter maps showed that in the upland with forest land use, relative to other areas in the watershed, the saturated hydraulic conductivity (KS) and suction head at the wetting front (Sw) have larger (1.57-2.69 cm/hr) and smaller values (12.12-1737 cm), respectively.
Gully Erosion, Environmental Factors, Chemical Factors, Ilam Province
http://magazine.hormozgan.ac.ir/article-1-39-en.html
http://magazine.hormozgan.ac.ir/article-1-39-en.pdf
University of Hormozgan
Environmental Erosion Research Journal
2251-7812
2717-3968
4
1
2014
5
1
Study the Relationship between Digital Number Values from ETM+ Satellite Images and Soil Organic Matter Using Artificial Neural Network and Regression Models
29
38
FA
elham
noshadi
Tarbiat Modares University
noshadi@modares.ac.ir
N
Hossein Ali
Bahrami
Tarbiat Modares University
bahramih@modares.ac.ir
Y
Seyyed Kazem
Alavipanah
Tehran University
salavip@ut.ac.ir
N
Soil organic carbon (SOC) content plays a key role in soil biological, chemical and physical behavior and knowledge about its state and distribution is essential for the effective and sustainable use of soil. Laboratory measurements of SOC are costly and time consuming and have not the possibility to extend the results to similar areas. Recently, the use of remote sensing data for evaluation of SOC as a simple, rapid, inexpensive and even accurate have attracted the attention of researchers. The aim of this study was to evaluate the efficiency and accuracy of ETM+ satellite images for estimating SOC using artificial neural network and regression models. In this way, the digital number values in different bands of ETM+ satellite images have been used. Both regression and neural networks were used to develop the models between organic carbon measured in the laboratory and satellite data. Finally the accuracy of these models was evaluated with R2 and RMSE indices. The statistical analysis shows that these models was fitted using digital number values in the visible and mid- infrared bands of satellite images have the highest coefficients of determination. Moreover, the neural network models have the higher accuracy and .less error than regression models.
Soil Organic Carbon, Remote Sensing, Digital Number Reflectance, Artificial Neural Networks, Regression Models
http://magazine.hormozgan.ac.ir/article-1-135-en.html
http://magazine.hormozgan.ac.ir/article-1-135-en.pdf
University of Hormozgan
Environmental Erosion Research Journal
2251-7812
2717-3968
4
1
2014
5
1
Synoptic Analysis of Extreme Dust Storms in Kermanshah
39
49
FA
hmousavi15@kashanu.ac.ir
Y
sajad_khamooshi@yahoo.com
N
ehsantamasoki@yahoo.com
N
Dust storms are one of damaging climatic phenomena on the synoptic maps that are affected from the elements of pressure, cloudiness, precipitation, relative humidity, wind, temperature, and evaporation. According to Kermanshah province is one of the areas that is affected by the storms, the aim of this study is synoptic analysis of extreme dust storms in Kermanshah Station in 54-year period (1951-2005). First, the number of extreme dust days was identified according to the horizontal visibility index of 100 meters or less. Then, for recognition of transporting atmospheric system of dust, the synoptic patterns of sea level pressure, 500 hPa geopotential, wind direction, omega, surface temperature and profile of subtropical Jetstream from 1000 to 100 hPa were plotted using climate data of upper and middle atmosphere. The results show that the isoheight lines of 500 hPa geopotential have the west - east orientation in both days, and are condensed in the study area. The SLP maps represent the high pressure systems in the West (Iraq, Syria, Europe and Africa) and low pressure systems in the East (Eastern neighbors) that are the cause of western winds and dust storms. Sea level winds are the northern and western winds in both days. Center of Subtropical Jetstream has been formed in the levels higher than 400 hPa. Its tongues have arrived to the ground surface, and have developed in the latitudes of 50 to 65 degrees. Isothermal maps have a similar pattern in both days, and lines 30 to 36˚C have expanded on Iraq, Syria and Iran. Also, Omega maps indicate the descending motions of the air that increases the dust in the study area.
Dust, Extreme Days, Synoptic Analysis, Kermanshah
http://magazine.hormozgan.ac.ir/article-1-216-en.html
http://magazine.hormozgan.ac.ir/article-1-216-en.pdf
University of Hormozgan
Environmental Erosion Research Journal
2251-7812
2717-3968
4
1
2014
5
1
Determining the Factors affecting on the geometry of Gully Erosion (Case study: Darrehshahr, Ilam)
50
61
FA
Ghobad
Rostamizad
Tehran University
gh_rostamizad@ut.ac.ir
Y
Ali
salajeghe
Tehran University
salajegh@ut.ac.ir
N
Ali Akbar
Nazari Samani
Tehran University
aknazari@ut.ac.ir
N
jamal
ghodousi
Soil and Water Conservation Center
jamal_go@yahoo.com
N
One of the types of water erosion and land degradation which causes imbalance in the area of natural resources and agricultural land and gives heavy losses, is the gully erosion phenomenon. To control this phenomenon, It is important to understand the influence factors on the geometry specification. Land degradation, a broken ecological balance of the land and landscape and risk of falling at biological resources in these areas, among other things, the study of the gully, is inevitable and necessary especially in the Darrehshahr township. In this regard, Gully 36 number were selected in Darrehshahr area in the Ilam province. To this end, were identified environmental factors, Physical - Chemical Soil properties, cover and hydrological properties of gullies tested using aerial photography, the digital maps and field operations. Results of statistical analysis using multiple regression (stepwise method) revealed that length of gully with upstream area of the gully, top and bottom width and cross section of the Gully with basin elongation, deep gully with basin elongation and slope curvature, high of head Gully with local slope of the gully and steep walls of gully with percentage cover have a significant relationship. So could be concluded that characteristics of geometry gully in the study area would be a function of the upstream, basin elongation, curvature slope, and local slope of the gully head and the percentage of canopy cover catchment area of gully.
Gully Erosion, Geometric Properties, Stepwise Method, Multivariate Regression, Watershed
http://magazine.hormozgan.ac.ir/article-1-99-en.html
http://magazine.hormozgan.ac.ir/article-1-99-en.pdf
University of Hormozgan
Environmental Erosion Research Journal
2251-7812
2717-3968
4
1
2014
5
1
Analysis of Sand Masses Morphogenetic in Makran Coastal Plain
62
78
FA
Siavosh
Shayan
Dept. of Natural Geography, University of Tarbiat Modares
shayan@modares.ac.ir
Y
Mohammad
Akbarian
Dept. of Natural Geography, University of Tarbiat Modares
m.akbarian@modares.ac.ir
N
Mojtaba
Yamani
Dept. of Natural Geography, University of Tehran
myamani@ut.ac.ir
N
Mohammad
Sharifikia
Dept. of Remote Sensing, University of Tarbiat Modares
sharifikia@modares.ac.ir
N
Mehran
Maghsoudi
Dept. of Natural Geography, University of Tehran
maghsoud@ut.ac.ir
N
The instability and mobility of sand dunes is a major concern of planning and management in arid coastal plains. The aim of this study is to identify morphogenetic characteristics of sand masses and their locations, as well as to identify the processes that formed and transported them in the western part of the Makran coastal plain. Research data and tools were including spatial distributions of landforms, the morphologic and stretch of sand dunes, sedimentologic characteristics including granolometric and morphoscopic indicators, the velocities and directions of winds, Geologic and topographic maps, satellite images, aerial photos and computer;#39s software including ArcGIS, WRPLOT View and Gradistat. By using data from local meteorological stations, wind characteristics were studied and wind roses were plotted, also. Maps of Aeolian landforms and general morphology of sand masses were plotted by using aerial photographs, satellite images and field controls. Elongation of sand masses was investigated, too. The results indicate that from sediment sources aspect, Coastal Plain sand masses are divided to interior sand masses that are originated from removing plain surface and coastal sand masses that are originated from tidal ranges. Also, where removal landforms are widely absent, no interior masses were formed and only coastal sand masses and barriers were formed.
Aeolian Sand, Coastal Sand, Morphogenetic, Makran Coastal Plain
http://magazine.hormozgan.ac.ir/article-1-147-en.html
http://magazine.hormozgan.ac.ir/article-1-147-en.pdf