مجله پژوهش های دانش زمین
پیاپی 41 (بهار 1399)

The purpose of this study is to apply remote sensing technique to extract lineaments in the Saqqez-Baneh shear zone. In this study, lineaments were extracted in three manual, automatic and semi-automatic methods and their density and direction as well as their relationship with gold mineralization were investigated.

One of the most extensive Cretaceous and Paleogene deposits in Zagros are the marine sediments of the Gurpi Formation, they were first identified in the Zagros based on stratigraphy and paleontology. One of the most important researches that can be done given this formation in Zagros, is determining the exact boundaries, by calcareous nannofossil assemblages. At the Anar anticline section, the Gurpi Formation with 163 m thickness was selected which mainly consists of shale, silty shale and plagic limestone.

Formation and rocks of Kuhrang salt dome in Zagros zone, Chaharmahal Va Bakhtiari province, are equivalent to the same units in the Hormuz Formation of Persian Gulf. Evaporate basins of Late Precambrian – Early Cambrian resulted in the deposition of Hormuz and similar series (Arian and Noroozpour, 2015; Motiei, 2001). The basins were formed due to the extensional tectonic phase, as a continental rift, in the continental crust of Iran and neighboring countries occurred during Infracambrian (Nabavi, 1976; Stöcklin, 1968; Berberian and King, 1981). Acidic and mostly alkaline magmatism is dominated in the rifts resulting from the extensional phase (Berberian and King, 1981).Magmas of the continental rifts mainly have alkaline nature and they are rich volatile material (e.g. halogens and CO2) and LILE (Lithophile large ion elements), indicating they are driven from enriched sources of the mantle (Wilson, 1989; Bailey, 1983). In the continental rift regions, the lavas mostly form during the fractional crystallization of basaltic magmas which are contaminated by the variant degree of crustal sources (Wilson, 1989).The aim of the paper is the determination of geochemical characters, tectonic setting and source of the doleritic rocks of Kuhrang salt dome by using whole-rock analyses.

After field sampling and microscopic studies, 8 fresh samples were analyzed for whole-rock geochemical determination by ICP-ES and ICP-MS methods in ACME lab (Vancouver, Canada).

The igneous rocks of Kuhrang salt dome display the including textures (intergranular and sometimes ophitic). Their mineralogy consists of plagioclase, pyroxene, amphibole, titanite and leucoxene. Compositionally, the rocks have 47.02-48.10 %wt. of SiO2. Therefore they plot in field of basic igneous rocks. The rocks display variable contents of K2O (3.34-4.28 wt.%), medium values of Na2O (1.11-2.37 wt.%), MgO (5.21-6.29 wt.%) and Fe2O3*(3.93-4.60 wt.%).In the Zr/TiO2-Nb/Y diagram (Winchester and Floyd, 1977), the studied rocks are plotted in basalt field and have sub-alkaline nature. Also, the samples display tholeiitic nature on the Ce/Yb-Ta/Yb diagram (Pearce, 1982). The chondrite normalized REE patterns show low enrichment in the LREEs relative to HREEs, which confirm E-MORB nature for their origin. Geochemical diagrams (e.g. Zr/Y-Zr (Pearce and Norry, 1979); Zr/4-Y-2 Nb (Meschede, 1986); Zr/117-Th- Nb/16 (Wood, 1980); Ti-Zr (Pearce, 1982)) show that the rocks have occurred in tectonic setting of intracontinental rift. TiO2 concentrations (2.38-2.48 wt.%) are relatively high in the rocks suggesting asthenospheric mantle (enrichment mantle) as their source. Moreover, flat patterns in HREEs (TbN/YbN= 1.58-1.74) and CaO/Al2O3 ratios (0.48-0.66) demonstrate spinel-mantle sources rather than garnet ones. Enrichment of Ba, Rb, K and K2O>Na2O and Rb/Sr-Ba/Rb diagram (Furman and Graham, 1999) reveal a mantle source involvement of phlogopite (Rosenthal et al., 2009).

Basic magma of Kuhrang salt dome doleritic rocks, show sub-alkaline nature (tholeiite) with various K2O contents. It has been formed in tectonic setting of intra- continental rift due to low partial melting of phlogopite spinel lherzolite of asthenospheric mantle.

The Oxfordian – Kimmeridgian rocks of the Ravar series and the Bido Formation with the age of Upper Jurassic, are distributed in the south of Tabas Block. The most important diagenetic processes in the studied thin sections are namely hematitization, micritization, dolomitization, cementation, evaporite nodules and compaction. Interpretation of paragenetic sequences of studied samples show the effect of different processes in the marine, meteoric and burial diagenetic environments. Major and minor elements and comparison with previous studies, indicate that aragonite was an original carbonate mineralogy for the Upper Jurassic carbonate rocks in the Ravar area. Low Sr / Mn and Sr/ Ca versus Mn show higher alteration in the studied samples which mainly show an open diagenetic system with high water- rock interaction.

After field observations, 78 samples of carbonate rocks were selected from four geological sections of north of Lakar- Kuh -1, 2, Horjond, Baghamshah, and Khorand. After microscopic observations, 21 carbonate samples from studied intervals were selected for elemental investigations in the geochemistry lab of the Shahid Beheshti University. In order to determine original carbonate mineralogy, these data were compared with Mozduran Formation carbonates, Gordon warm water tropical limestones of Tasmania, the Ilam, Fahliyan Formations and Qaleh- Dokhtar carbonates with original aragonite mineralogy. Low Sr/Mn ratio show high water – rock interaction.

Activity of microscopic organisms in these environments is associated with micritization in the lagoon environments. Bladed cement forms in the marine environments and equant, blocky and drusy calcite cements are formed in meteoric and mainly in burial environments. With increasing depth of burial, chemical compaction has formed dissolution seams and stylolite. Hemititization and dolomitization processes are formed in the late diagenetic stages.
Geochemistry of major elements (Na, Sr, and Mn) such as high Sr/Na ratio with the average of > 2 show aragonite was an original carbonate mineralogy. High Mn values suggest the effect of meteoric diagenesis on the studied samples. Higher Sr values in some of the samples may indicate original aragonite mineralogy and low impact of diagenetic processes. The high Sr/Ca and Mn variations in the studied carbonates represent the effect of meteoric diagenesis in closed and open diagenetic systems.

Sr/Mn versus Mn variations in samples fall within and very close to aragonite field of the Mozduran Formation due to higher impact of meteorite diagenesis. This probably shows the effect of meteoric diagenesis with higher water - rock interaction (W/R) in an open diagenetic system. Relatively low Sr/Mn values show an open diagenetic system for studied carbonate samples. The Sr/Ca ratio in the studied carbonates show a relatively open diagenetic system with high water- rock interaction.

The Ab-Bagh Zn-Pb deposit is located in the southeastern part of the Malayer-Esfahan metallogenic belt (MEMB). A large number of Zn-Pb deposits in the MEMB (approximately 170 deposits), are hosted by early Cretaceous carbonate rocks, and few of them are hosted by Jurassic detrital and organic matter-rich sedimentary rocks. In this study, we present the results obtained from fieldwork, ore and host rock petrographic studies, main oxides, trace and rare earth elements analysis and chemistry of sulfide minerals.

This study focused on the geochemistry of both of the two ore-bearing horizons that constitute the Ab-Bagh deposit (12 samples). Trace and rare earth elements analysis were conducted using an Agilent 7500ce ICP-MS instrument, Zn and Pb were analyzed via ICP-OES and main oxides were determined via XRF in the IGME central laboratory, Barcelona, Spain. To determine chemistry of sulfide minerals, four polished thin sections were studied using EPMA in IGME central laboratory.

Ore-bearing horizons of the Ab-Bagh deposit are hosted in the late Jurassic-early Cretaceous clastic-carbonate sequence. The northeast-trending, steeply southeast-dipping rocks have been subdivided into five units. Based on position, there are two zinc- and lead-bearing stratigraphic ore horizons. Ore horizon 1 is hosted by late Jurassic-early Cretaceous black shale and siltstone. The wedge-shaped ore body is located close to a synsedimentary fault. Petrographic studies indicate that mineralization comprises three sulfide ore facies: stockwork, bedded and massive ore facies. Ore horizon 2 occurs in early Cretaceous carbonates and comprises of massive ore facies that are concordant with host rock layering; it is also underlain by stockwork facies. Textures include framboidal, laminated, breccia, replacement, massive and vein-veinlet.Due to alternating pulses of hydrothermal fluid (zone refining process), temperature and redox condition changes, SEDEX deposits are chemically zoned. Based on geochemical studies, metal zoning patterns are well developed in the Ab-bagh SEDEX type Zn-Pb deposit. Both vertical and horizontal zonation is present in this deposit. In SEDEX deposits, moving outward from the stockwork facies, ore bearing horizons display decreasing Zn/Ba, Zn/Mn, Zn/Fe, Pb/Zn, Pb/Fe, Pb/Ag, and Cu/ZnþPb ratios, reflecting the oxidation control on mineralogy and the temperature dependent solubility of the base metals.Vertical and horizontal chemical zonation is well developed in ore horizon 1 of Ab-Bagh deposit, in a way that Pb/Ag increase from base to top and Cu/(Zn+Pb) and Pb/(Zn+Pb) increase from top to base in massive ore facies. Also, horizontally, Zn/Al2O3, S/Al2O3 and Cu decrease and Ba increases from massive to bedded ore facies. There is a significant positive correlation between Cd/Zn, Co/Zn and Ag/Pb in sulphide ores from ore horizon 1. REE content of massive sulphide ore is very low, however, REE content of bedded ore is more than the massive and stockwork ore facies. Fe and Cd content of sphalerite increases from margins to center, which reflects drop in temperature of ore-forming fluid over time. Also geochemical features of sphalerite and pyrite suggest that they are formed in anoxic environment.

The Ab-Bagh Zn-Pb deposit is hosted by Late Jurassic-Early Cretaceous black shales and Early Cretaceous limestone. The deposit consists of two horizons of Zn-Pb sulfide and oxide lenses situated at the different stratigraphic levels, each with an associated stringer vein zone. Vertical and horizontal chemical zonation is well developed in ore horizon 1 of Ab-Bagh deposit. Lateral zonation away from the center of fluid discharge is controlled mostly by zone refining in the vent complex and is typically accompanied by a decrease in the thickness of the stratiform body.

Chah-gabri copper deposit is located 90km south of Damghan at Semnan province, in the northeast part of Central Iran at a structural zone bottom of the Turud_Chah Shirin volcanic-sedimentary strip. This strip is eastern-western, in the form of a cross between two faults of Trood in the south and Anjilu in the north. Trend of all units are northwest – southeast) N65̊w (parallel to the zone. Copper mineralization in this area is vein-veinlets and open space fillings along the fracture and faults are composed of lava and tuff units. Minerals host rocks are mainly volcanic lava containers such as basalt andesite, andesite, trachy andesite and less sedimentary pyroclastic. The main minerals forming the deposit include sulfides (Chalcopyrite, pyrite, chalcocite and coveline), carbonate (malachite), iron oxides (hematite, goethite and limonite), and gangue minerals (Calcite, Quartz). Ore mineral textures include: vein-veinlets, open space filling, replacement and disseminated textures.

Study area is located in Semnan province, 90 km south of Damghan city, in geographical coordinates 54° 20´ to 54° 26´ northeast longitude and 35°17´ to 35 ° 23´ north latitude. During several stages of field visit, based on lithology and mineralogical diversity, 58 samples of rock and ore were taken with their geographical coordinates. Of these, 22 are thin sections, 14 are polished sections and 8 are thin - polished sections. Eventually they were prepared and studied. Overall, they were analyzed in the laboratories of Iran Minerals Research and Processing Center (IMIDRO) in which, 4 samples were studied by X-ray diffraction method (XRD), 7 by x-ray fluorescence (XRF) and 8 by ICP- MS method.

The results of geological, mineralogical, structural and textural studies of minerals show that much of the Copper mineralization is in the form of open space filling. Among the host rock components, units with a combination of andesite, basalt andesite and trachy andesite have been observed. Copper mineralization in this area is in the form of chalcopyrite, chalcocite, covolite and natural copper. It also occurs in the form of malachite on surface outcrops. In the study of fluid inclusion, temperature was175 to 200 degrees Celsius, salinity was 4 to 10.5 wt.% equivalent to NaCl and density was 0.9 to 1 g / cm3, which were determined to indicate the epithermal range.

Considering all field and laboratory evidence including host rock composition, texture and mineralization, zones alterations, major and associated metal elements, paragenetic sequence, the geochemistry and thermometry of fluid interconnects. Chahgabri copper deposit is in good compatibility with Manto type deposits, but due to vein ore mineralization, it can be classified as low sulfide vein epithermal hydrothermal deposits.

Upper Cretaceous period can be considered as the peak of diapirism movements in Zagros sedimentary basin (Bosak et al, 1998). After sedimentation of Hormoz salt series, these salts were rising up towards the surface during the Lower Paleozoic (Jahani et al, 2009).  In this study, Cenomanian-Santonian strata in Fars area that consist of Bangestan group (NE-SW trend), have been studied based on effect of local and regional diapirism on these strata.

One hundred and sixty samples from two stratigraphic sections (upper part of Kajdumi Formation, Sarvak Formation and lower part of Gurpi Formation) in Darmadan anticline (Near salt dome and far from it) have been studied. All samples shave been stained with alizarin red-s to enhance differentiation of calcite from dolomite (Dickson, 1966). In petrographic studies, skeletal and non-skeletal allochem percentages have been accounted based on Tucker (1991) and Flugel (2010). Identification of microfacies based on Embry and Clovan (1971) and clastisity index based on Carrozi (1989) have been carried out.

Eight microfacies related to the open marine, shoal, lagoon and tidal flat sedimentary environment areas have been identified:Open marine facies:MF1- Pelagic Foraminifera Glauconitic Wackestone/Packstone MF2- Bioclast Wackestone. MF3- Fine grained Bioclast Packstone MF4- Intraclast Wackestone MF5- Echinoderm and Rudist debris Packstone to Rudstone Shoal microfacies:MF6- Rudist Grainstone Lagoon microfacies:MF7- Orbitolinids Wackestone/Packstone Tidal flat microfacies:MF8- Sandy Mudstone Sedimentary environment Based on lateral and vertical facies changes, marginal carbonate shelf can be proposed as the sedimentary environment for these strata. In this case, sedimentation has happened in deep, outer shelf, middle shelf and inner shelf areas. Moving towards salt dome, facies change to shoal, lagoon and intertidal shallow facies. This can be due to diapirism movements in the area. Due to upward salt dome movement, some evaporitic clasts have been transported to the sedimentary environment (Giles and Lawton, 2002); this can be observed more in near salt dome sections. Diagenetic process in two sections In areas far from salt dome section, there are some diagenetic processes such as: micritization, cementation (equant), bioturbation and, glaconitization processes, but close to salt dome sections, we can see more diagenetic processes such as: cementation (syntaxial), physical and chemical compactions (stylolite), silicification, dolomitization and hematitization. This fact shows that there are more diagenetic processes in near salt dome sections which can be related to the diapirism movement in this area.

Based on petrographic studies, eight microfacies related to the carbonate shelf (from open marine to tidal flat) have been identified. Dolomitization, silicification and cementation (anhydrite and dolomite) processes had happened because of supersaturated fluids (high mg) in this area. Some diagenetic processes such as hematitization and physical and chemical compaction have increased once moving towards the salt dome. Comparing two sections to each other based on petrography, microfacies, diagenesis, energy index allochems, siliciclastic particles, gypsum and anhydrite cements, dolomite, etc. show us that diapirism had happened as a syn-sedimentation and post-sedimentation process.

Land degradation is a global challenge that results in reduced soil fertility and eventually becomes one of the major environmental issues worldwide. The issue of land use and land cover changes by mankind is one of the most important factors of environmental change at the local and global scale which has significant implications for ecosystem health, water quality and sustainable land management (Foley et al., 2005; Lubchenco, 1998). The problem of land degradation in the Ilam province is affected by a combination of natural and anthropogenic factors, including deforestation, drought, overgrazing, intensive agriculture, increased sediment performance due to soil erosion, evaporation, dam construction and drought. These environmental problems are ultimately linked to changes in land cover and land use. Therefore, it is important to consider land cover and land-use changes to monitor environmental changes and sustainable resource management plans for fragile ecosystems such as Ilam province and provide results to area managers and planners for restoration and prevention.

In this study, we used MODIS Terra Satellite Land Cover Products (MCD12Q1) to study the monitoring of land cover changes in the Ilam province for the period of 2001 to 2013. All data for the study area were mosaicked and sampled with the UTM Global Coordinate System, using the nearest neighbor sampling method. Then they were Geo-referenced and finally, on Gis-Envi software correction operations (geometric, radiometric and atmospheric) were run and then the study area was clipped. The method initially classified the images into 17 classes and then calculated the number of pixels (zeros up to 255) of each class for the duration of 13 years and mapped the trends and percentages of changes occurring to each class.

Shrub forests have begun to grow in size since 2009 and their numbers appear to have increased in the coming years. Conversely, forest-savannahs and savannas in 2001-2007 had a small area (34 pixels in total) of their own, and since 2007 species of this type have become extinct and are not observed at all, in the studied level. The water levels (code zero) in the study area underwent very little change from 2001 to 2013, and only from 2004 to 2008 did the extent of the water levels show greater values than other years. The maximum amount of water in 2005 was 29 pixels (that means, 7250000 m = 500*500*29), which is mostly related to the Karkheh and several pixels of the Simare River in the south and east of the border. But water levels appear to have increased since 2013 due to the construction of several dams in the study area. Also, the levels for urban and residential areas (Code 13) from 2001 to 2013 are consistently 159 pixels per year across the study area, and we don't see any increase or decrease in it. Finally (code 7, 10, 12 and 15), respectively, each are 564.424 and 8.953 and 47.030 and 443.520 pixels for 13 years. That is %99.78 of the area covered. Among these areas, open forest shrubs with 564,424 pixels and no vegetation areas with 443,520 pixels had the highest amount of land cover (%94.5) in the area.

According to the extracted map (Map No. 2) the story lacking vegetation named Code 15 which is marked yellow in the map, is mostly located in the west and southwest of the study area, including the lowland basins, namely Western Abbas plain, Eastern Abbas plain, Chenane, Abadan, Mehran, Dehloran, Salehabad, and Sumar. In some years, due to the increasing trend of land degradation, it is advancing toward the center and east of the region. Overall, the trend of changes in the amount of no vegetation levels over the past 13 years show an increase, and this can be a concerning issue in terms of land degradation. This should be seriously taken into consideration. As the maps show, there is a decreasing inclination in the trend of open shrub forest zones during the study period as well.

Increased urbanization has led to urban poverty. In developing countries, rapid urban growth is typically greater than the capacity of local governments in providing services and infrastructure. This leads to an increase in urban poverty and inequality within the city. In recent decades, due to the significant concentration of poverty in the city, discussions and conversations about the causes and consequences of poverty have become prevalent with a renewed importance.The city of Noorabad has witnessed the formation of slum areas in some urban spaces, due to the rapid population growth over the past decades and the inability to provide proper services and facilities to citizens. In order to plan and reintegrate the situation of the poor, initially, the location and spatial distribution of poverty must be exactly identified in the city. Then with careful planning, this challenging urban problem may be solved.

The research method is based on descriptive-analytic approaches and detailed data were obtained at the level of statistical blocks of Noorabad city in 2011. Also some relevant information collected from secondary studies were used. First, the 32 indicators of urban poverty are un-scaled with fuzzy method in Excel and then, by combining the indicators, the combined indexes of urban poverty were extracted. For spatial analysis of the integrated urban poverty index, several spatial cluster analysis models such as spatial Moran spatial, local Moran statistics, hot spots, profile graphs and trend analysis in ArcGIS software were used.

The results of multi-distance spatial cluster analysis and Moran spatial autocorrelation show that amounts of the combined index of urban poverty with clustered pattern is distributed in Noorabad city. Based on the results of local Moran and hotspot methods, poverty clusters are concentrated in the northern parts of the city and rich clusters are in the southern parts. Also, based on the combined index of urban poverty, 51 percent of the population of the city are poor and very poor, and 31 percent of its population are rich and very rich, and 18 percent of its population are located in the middle income areas. Based on the profile of the combined index of urban poverty, the west and south of the city are considered to be the prosperous area and the eastern and northern parts of the city are deprived zones. The trend analysis of the combined index of urban poverty also showed that the trend in the data of the combined index of urban poverty in the east-west direction and in the north-south direction has increased significantly.

Poverty is one of the socially undesirable phenomenon that planners and policymakers are always seeking to reduce. The success of poverty alleviation programs depend on the exact identification of the phenomenon of poverty and its indicators. Urban areas are very diverse and there are significant differences in different regions and in particular urban areas. Hence, measuring urban poverty is also important in urban areas. In this research, by using available tools in Arc GIS, spatial analysis of urban poverty in the city Noorabad was performed. The results of the analyzing patterns show that the combined indexes of urban poverty have been distributed with cluster patterns across the city. According to the results of the mapped clusters, poverty clusters are concentrated in northern parts of city and rich clusters in the southern parts. Also, based on the zoning the combined index of urban poverty, 51 percent of the population of the city are poor and very poor. According to the results, it can be stated that the results of this study are based on the clustering pattern of urban poverty distribution corresponding with the results of most researches presented in the study, including Gio et al (2018), Nikpour et al (2019), Nikpour and Hasanalizadeh (2018), Farhadikhah et al (2017), Rustai et al (2016), and Movahed et al (2016).

Global warming leads to rising ocean water levels, Destruction of pastures and environment, desertification, and an increase in extreme events such as droughts and sand storms, heat waves, storms and flooding of rivers. Wind energy is essential because it reduces greenhouse gases and global warming once compared with thermal power plants while producing a unit of energy. Wind power has been generated in 103 countries, and in 2013, about 318529 MW of electricity was generated by this method which is about 4 percent of the world's electricity, it could reach 700,000 MW in 2020. In this study, with regard to global warming and its effects on the potential of wind energy in different parts of the world, the potential for wind power was examined in the coming years.

To simulate the wind speed at Ardabil station for the 2021-2040, CGCM1 model under RCP4.5 scenario and the SDSM model were used. Subsequently, the Weibull distribution function, which suits the wind speed data, especially in the range of wind turbine speeds, was used to determine the potential of wind energy in wind turbines to generate electricity and estimate its output energy for the future climate of Ardabil station. Also wind energy was calculated for the next two decades (2021-2030 and 2030-2040).

In the base period (1992-2012) and the future (2021-2040), the average wind speed is between 3 and 5 m/s which are 3.75 and 4.34 m/s in the base period and future, respectively. Then, an increase of 1.9 m/s for the wind speed in the future (2021-2040) compared to base period may occur. The wind power density at 10m height will be 440.3 and 492.8 w/m2 in the first (2021-203) and second decades (2031-2040), respectively. The wind power density at 30m was calculated to be 500 w/m2 at the base period; but it will be more than 600 w/m2 in the future, which can generate more energy compared to the base period. The wind power density at 50 m height was calculated to be 800 w/m2 at the base period; but it will be more than 1000 w/m2 in the future. The most wind density at the height of 10m in the first and second decades of the future will be at the speed of 11.26 and 12 m/s, respectively. The speed of 11 to 17 m / s will have the highest frequency of wind speed in the future decades. The availability of wind hours will be more than 4000 hours per year. Wind will be available at Ardabil station in more than 50 percent of the year. About 3000 hours of wind speed will be more than 4 m/s which is the winding speed of turbines and in these hours, turbines will spin and generate energy.

Global warming will increase wind speed by about 14% during 2021-2040 which is suitable to provide energy from wind turbine rotation. The wind power will reach over 1000 w/m2 at a height of 50 m, which will be economically viable. Using this renewable energy can play a direct role in reducing greenhouse gas emissions.

Since geographic issues and problems have large and variable dimensions over time series, it leads to the study of a geographic field while considering a variable during the time series. In recent decades, mankind has caused changes in land and sea, which have led to increased pollution and a subsequent increase in phytoplankton numbers. For this purpose, to understand and monitor these effects, there is a need for a link between scientific work in this field and its management. To manage these regions, strict approaches, stringent measures, infrastructure compliance, and finally modelling and prediction are required. The chlorophyll-a parameter is one of the most common elements which its value and changes over time and different parts of the area are determining the conditions for biomass and the development of flora and fauna in the marine environment. It has also played an important role in administrative and management programs such as finding suitable areas for establishing fishing shelves and finding suitable locations for protecting marine areas.

The purpose of this study is to explore the procedures and trends of time series in the two sectors, including the one-year procedure (2015), in the pixel range of 3*3 in order to perform calculations of procedures and the 18- year trend. For this purpose, chlorophyll-a from the MODIS Aqua and SeaWiFS Satellite data of the Caspian Sea were collected from January 1998 to December 2015. After pre-processing and extraction of time series using the Mann-Kendall test and Thiel-Sen test, trends were determined.

The results showed that the rate of changes in 2015 for the median and linear trends are minus 0.01 and minus 0.05, respectively. Also, the average change rate for the bio-optical component of chlorophyll-a using the linear and median trend in the overall southern basin of the Caspian Sea were 0.019 and 0.0187 g /m3 in 18 years and therefore has an annually increasing rate. In general, the amount of chlorophyll-a component in the eastern parts of the Caspian Sea has a rate of 0.058, 0.22 and 0.29 mg / m3, respectively. The ρ Value is < 0.001 and 0.01 in Mann-Kendall and Contextual Mann-Kendall tests which shows a fairly similar trend, but at ρ< 0.05, a significant increase was observed in the region because the Contextual Mann-Kendall test considered the variance of neighboring pixels.

The blocks that showed a non-significant trend with the Mann-Kendall test, once the impact of neighbor pixels were considered, showed to be significant at the confidence level. Also, the different results between the OLS and Thiel-Sen procedures in the southern basin of the Caspian Sea showed that the Thiel-Sen Procedure was less than the OLS procedure for the bio-optical component.

Weak westerlies over high and mid latitudes cause cut-off low blockings (CB) and CBs create durable phenomenon such as frost waves. Iran, in the south of mid latitudes is engaged with annual spring frost waves. So far, most of the researches in Iran have been done with statistical and synoptic methods, but most of these studies, especially the synoptic ones, are case study samples. The apparent role of large-scale atmospheric systems such as cut-off low blockings in the emergence and durability of spring frost-waves, requires great research to undertaken throughout Iran and in a long period. So our goal was the study of effects of cut-off lows on frost durability over Iran.
Data and

For this purpose, the data of minimum daily temperature of 69 weather stations from March 20th 1968 to June 21st 2014 was collected from the meteorological organization of Iran. It was determined that 114 spring frosts with a duration between 3 to 25 days exist and in the next step 47 enduring ones based on tables of daily temperatures and fluctuation of their frequencies were determined. All of these 114 waves were determined based on the frost duration criteria which lasted at least two consecutive days and their spatial criteria occurrence in more than two stations. This allowed the determination of the most durable frost index wave of each year during spring. Analyzing the peak-days of all index waves, distinguished the waves affected by the cut- off low blocking system. The final synoptic patterns were designed for analysis by examining the 500 hPa maps of the distinct days.

The height contours on 500 hPa air-charts from ENCEP/ENCAR showed cut-off low blockings were dominant patterns during the peak days of the most enduring frosts (18 ones). The first results indicate that the appearance of this blocking which directs the cold air flows to Iran from high latitudes has minimized over the last three decades. Designed synoptic patterns show that during the peak days of spring, frosts affected by cut-off low blockings, appeared around Caspian Sea, especially its eastern basin and stayed for many days and then divided into two branches including the main one in northern latitudes and minor in southern ones. Although the southern branch of these winds appeared relatively weaker than the main and northern one, but its effects were cold and sub-zero airflow from the Scandinavian Basin, Eastern Europe, Caucasus Basin and the Ural Mountains towards northwest, north, and sometimes northeast of Iran, and penetrated till Central Iran. Lack of high summits and mountains, lower inclination of sunlight and proximity to the southern warm waters are factors that have moderated the violence of these flows in the southern coastal provinces and there have been no reports of temperatures of zero and below zero degrees Celsius. The results showed four factors including “the diagonal move of cut-off lows from Southern Scandinavia to Pamir Plateau” and “eastward movement of troughs from Mediterranean Basin” both at 500 hPa level and “the position of Zagros mountains” and “the entrance of cold high pressure tongues of Siberia” at the surface, caused the symmetric influence of durable frosts over west and east of Iran.

Based on this research, the decrease in the occurrence of cut-off low blockings during the last three decades in Iran can be justified by the tangible and searchable expansion of warm air territory from low latitudes to the high latitudes in Southwestern Asia.

One of the problems of the power companies in cold areas is freezing and snowfall on the transmission lines. Therefore climatic zoning of the Mazandaran province and the load conditions in accordance with requirements of the region are important for the mechanical design of the transmission lines. The correct selection of these conditions have a significant technical and economic impact on designing the project. One of the problems of a regional power company in cold, frosty and snowy areas is the wiring and shielding of power lines.Snow and ice load maps developed by the Ministry of Energy do not have the necessary efficiency and innovation anymore and were not reviewed for many newly developed urban and rural areas. Iran is divided into four regions of light, medium, heavy and super heavy in terms of weather conditions and for each of these regions, the four main and primary variables of loading, namely normal wind speed, maximum wind speed, normal ice thickness and maximum ice thickness are provided.

The purpose of this study is applied and the nature and method of research is descriptive-analytical. In this study, the parameter of ice thickness with multi-year return periods, which is one of the effective loads in the loading of the power transmission lines, was evaluated using the weather data (2010 to 2018), at three mountain stations of Baladeh, Kajur and Siah Bisheh in western Mazandaran. Meteorological information is measured hourly at meteorological stations, After collecting and correcting the meteorological data, in the Excel environment and in the final worksheet, the program is written to calculate the daily, monthly, and annual ice thicknesses and to calculate the statistical parameters at a height of 35 meter (mean height of the cables). Using the Smada software, the relevant histograms are plotted.

Eventually, new nominal values were recommended with different return periods. The results showed that in the design of transmission lines with a return period of less than 50 years, Baladeh and Kojur regions are among the heavy areas. With a return period of more than 50 years these points are considered as super-heavy. With the return period of 50 to 100 years, the Kojur area is an intermediate region and a heavy region with the return period of>100 years (in accordance with the Ministerial code also known as Mashanir Code). Therefore calculated values of snow and ice loads for 10 m (less than 66 kW) and 35 m (above 220 kW) elevations were not significant, Based on the results, it is suggested that with the establishment of automatic weather stations in the area and field and laboratory studies, more detailed results will be obtained in future studies.

In this research, the ice thickness statistical parameters with multi-year return periods were evaluated, using meteorological data and simulation methods. The meteorological data was provided by Mountain Engineering Laboratory and Research Institute. Finally new nominal values were suggested after comparing them with various return periods. In the case of Baladeh, calculated values of snow load and ice for a height of 35 meters, with different return periods from 50 years onwards, the maximum amount of ice exceeds the nominal value (40) and was likely to cause damage to transmission lines. Therefore, for the design of power lines with a return period of less than 50 years, Baladeh region is one of the heavy areas and with a return period of more than 50 years, it is one of the super heavy areas.For the Siahbisheh area, the amount of snow and ice for the 50 to 100-year return period is moderate, and for return periods greater than 100 years, the heavy areas are less than the nominal average value defined in the Ministerial code(Mashanir). In the Kojour area, which according to Mashanir is a superheavey region, for return periods from 50 years onwards the maximum amount of ice thickness exceeds the Mashanir code. Therefore the probability that it could damage the transmission lines is greater than the nominal value (40). Hence, for the design of power lines with a return period of less than 50 years, the Kojour region is a heavy area and with a return period of more than 50 years, it is a heavy area.

Tourism is one of the most important accomplishments that has played a special role in the development of human activities in recent decades. As economists call it, tourism is a sort of invisible exports. In fact, tourism is considered an industry today. Jiroft County in Kerman province is no exception. It has the potential and many natural attractions. The tourism industry can be very supportive of the development of Jiroft. Achieving these advantages and requirements will not be possible until the proper planning and contexts are provided. The first step in planning for tourism development in Jiroft is identifying its strengths and bottlenecks. In this regard, the present study aims to review and analyze the most important opportunities and challenges for ecotourism development of Sardoyeh in Jiroft County. These are necessary for strategic planning process, which is an important and essential step for planning tourism development and consequently sustainable regional and national development.

This study aimed to determine the appropriate strategies for the development of tourism in Sardoyeh area of Jiroft County in order to answer the following questions: What are the potentials and limitations of rural tourism development in the region? What strategies and solutions can be identified for developing this type of tourism in the region? In this research, descriptive-analytical method and field and documentary information was used. SWOT strategic model was used to identify weaknesses, strengths, opportunities and threats. The QSPM model was used to offer the most important strategies in the field of tourism development in the Sardoyeh region. The statistical population of this research is Jiroft County and the sample population includes 25 experts related to tourism in Jiroft County.

Surveys showed that despite the great potential of Sardoyeh, there was no proper planning for the development of ecotourism in the region. Investigation of internal and external factors using SWOT model showed that although the study area has high potentials, tourism industry in the region faces serious challenges and threats. Based on the analysis, 4 conservative strategies are presented, with the first priority being "applying appropriate management practices to attract private and public funds" with the highest score based on the QSPM matrix score.

It can be concluded from the results, that decreasing internal threats and weaknesses and using existing opportunities and strengths are necessary, while external opportunities must be used to address the weaknesses. Therefore, these plans and strategies can address many of the threats and disadvantages of ecotourism development in Jiroft County, thus moving towards ecotourism development and taking an important step towards sustainable regional and national development.