Mohammad Akhavan Qalibaf; Hamid Alipour; Elovsat Guliev; Marina Kurnova; Mohammad Hossein Mokhtari
Volume 6, Issue 18 , June 2019, , Pages 97-113
Abstract
Introduction The ability of a system to detect changes depends on its capacity to estimate variables on a scale. In any case, observing changes at successive times is the first step towards identifying the active processes and change forces. The assessment of land use change and land cover has been considered ...
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Introduction The ability of a system to detect changes depends on its capacity to estimate variables on a scale. In any case, observing changes at successive times is the first step towards identifying the active processes and change forces. The assessment of land use change and land cover has been considered as one of the main techniques of assessing environmental changes and has played a major role in environmental planning. Vegetation change and land use due to human activities are among important issues in regional and developmental planning. Given the advantages and capabilities of satellite data, this technology can help identify and discover these changes. Materials and methods In this research, the investigation of the land cover change of the Lake Urmia basin was based on the use of the MODIS Annual Coverage (MCD12Q1) with the HDF format and spatial resolution of 500 m. These images were categorized as Type I with 17 classes of land cover. Then, the image was taken annually by the mask region border and a geometric correction which Converted to UTM system Through entering the annual descriptive information tables into the Excel software, the change trend of land cover area was estimated between the years 2005 and 2016. Results and discussion The review of Tables 2 and 3 showed that there were significant variations in coverage over the period of 2005 to 2016. The area of the water zones had been declining since 2009. The grasslands had a relatively stable area between 2005 and 2015 and showed a decreasing trend over the last two years. Urban coverage during this period had not changed much, and the population growth seemed to be moderated by increasing urban densities. Between 2009 and 2014, water level changes were steeper than they were in previous years. In addition, since 2014, the slope had become even more intense. The area of the water zones in 2008 had a slight and noticeable decline compared to its following and preceding years. Conclusion According to the MODIS image information, the proportion of land area and water zones in 2016, compared to 2005, were respectively 1.39 and 0.69. Between 2005 and 2016, the greatest increase in the area of use was related to agricultural land and solid or dense floor coverings, respectively with an increase of 1648 and 837. The greatest reduction in the use of the area was related to water zones and desert cover, respectively with decreasing 1383 and 1159 km2. The results of the research showed that satellite images ha high potential for rapid decoupling of agricultural land, the preparation of map of different types of crops in the region, and determining under cultivation with a relatively accurate accuracy in a regional scale.
Hamed Jafarian; Abdorreza Vaezihir; Hossein Pirkharrati
Volume 5, Issue 15 , October 2018, , Pages 75-94
Abstract
Abstract
Introduction
The investigation into water resources of hard rocks and limestone, is very important because of their quality and role in the supply of the portable water. More than 10 percent of Iran is covered with hard rocks formations which increases up to 25% in the northwest of Iran. Because ...
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Abstract
Introduction
The investigation into water resources of hard rocks and limestone, is very important because of their quality and role in the supply of the portable water. More than 10 percent of Iran is covered with hard rocks formations which increases up to 25% in the northwest of Iran. Because of the high quality of hard rock and karstic aquifers and their suitable location for supplying the drinking water of rural areas, the exploration and exploitation of groundwater from these formations are of interest. In quantitative terms, while the frequency of springs in hard rocks is normally more than that of karstic aquifers, the discharge of karstic springs is normally higher. The hydrochemistry of groundwater in hard rocks and limestone is influenced by aquifer body material, groundwater flow velocity, and residential time of water in aquifer.
Methodology
The study area was located in the west of Urmia City, northwest of Iran as a part of Lake Urmia watershed. The geological units is mainly carbonate rocks (limestone and dolomite).
In order to investigate the quality of groundwater resources, 15 samples of springs were collected and analyzed for the major ions (HCO3, CL, SO4, Mg, Ca, Na, K). Other parameters such as TDS, PH and EC were also measured. Various diagrams and techniques like Durov and Gibbs diagrams, saturation index, and ion ratios were employed to determine the water type and faces and the source of ions. Also some diagrams were used to check water quality for agricultural and drinking usages.
Results and Discussion
Pie diagrams of SO4, Na, and EC showed that the basin area located in young alluviums bearing gypsum caused an increase in SO4 and EC. Marls of Miocene formation in the area also had increased the concentration of Na in some water samples
Based on the samples position in the Piper, Durov, and Gibbs diagrams, most types of groundwater was bicarbonate and calcic types.
The main factors which controled the groundwater chemistry were processes such as ion exchange (due to the presence of clay minerals), weathering, and dissolution of limestone and dolomite formations. It was also found that the watersheds of the large number of springs were located in Permian limestone and detrital Miocene units.
Wilcox diagram showed that most of the samples were in the class C2-S1, which indicated their low salinity and their appropriateness for agriculture. Schoeller diagram also showed that the groundwater region had good and acceptable quality for drinking. Saturation index survey showed a highest value of unsaturity related to dolomites for the samples which is influenced by Silvana dolomitic formation. Under saturity of samples related to gypsum, halite, and anhydrate was expected because of the absence of saline gypsiferous formations in the area.
Conclusion
The results of this research showed that the groundwater of the study area has a water with calcic and bicarbonate types with a high hydrochemical quality, which is appropriate for agriculture and drinking uses. It was also found that lithology has a major role in the hydrochemistry and quality of the groundwater. Weathering and solution of Routeh and Tertiary limestone karstic formations, and Silvana dolomitic formation have more impact on the groundwater quality of the study area. However, alluvial gypsiferous and Miocene formations with marl beds have a little impact on the quality of groundwater in the north, center and east of the area.
