Physical Geography Research
Year:2019 | Volume:51 | Issue:1 |Papers Count:16

Introduction Large severe floods can have enormous influence on the fluvial system in comparison with the floods with lower magnitude and more frequencies. This work addresses the geomorphic response of mountainous rivers to extreme floods to explore the relationships between morphological changes and controlling factors. In October 2015, following the occurrence of a sudden extreme rainfall, a large and devastating flood occurred in Ilam province. The flood caused major changes in the morphology of Ilam's rivers. The rate of channel expansion is various in different sections of the studied rivers. Thus, we can examine the influential and controlling factors that led to diversity of river behavior. The hypothesis of this research is that explanation of geomorphic effects requires models that include other variables, e. g., lateral confinement, degree of sediment, besides hydraulic related variables (cross-sectional or unit stream power). The main purpose of this research is to explore the relationship between channel widening and arrange of controlling factors. We have addressed channel width (i. e: pre-or post-flood width) to calculate unit stream power in order to have a better explanation of channel response? Since few studies have been done in this field, this research was conducted with the aim of investigating the factors controlling the response of Mountain Rivers to extreme flood events in upstream of Ilam dam. Materials and methods The research has examined three tributaries of the Konjancham River (upstream of Ilam dam) whose catchments were affected by an extreme flood on 7th October, 2015. An integrated approach was taken to study this flood, including (i) Analysis of channel width changes by comparing aerial photographs before and after the flood, (ii) Estimation of peak discharges in studied reaches, and (iii) Determining the degree of sedimentation in studied reaches. Delineation of spatial units was carried out according to the approach proposed by Rinaldi et al. (2013), which is a modification of the approach by Brierley and Fryirs (2005). According to the approach, stream sectors were defined as macro reaches having similar characteristics in terms of lateral confinement, while the reaches are homogeneous in terms of channel morphology (channel pattern, width, and slope) and hydrology. We have used the reach scale (reach length was commonly from 200 to 1300 m) for an overall assessment of magnitude of channel changes and for a preliminary investigation of controlling factors. The dominant process observed in the study reaches was channel widening, which was analyzed by comparing aerial photographs taken before and after the flood. To assess the changes in channel width, channel banks, and islands, these features were digitized on pre-and post-flood orthophotos. The channel width was calculated by dividing channel area by the length of the reach, and changes in channel width were expressed as a width ratio (ratio of channel width after the flood to channel width before that flood). The estimation of peak discharges has been used to calculate cross-sectional stream power and unit stream power. The last part of the methodological section deals with statistical analysis carried out to explain channel response to the flood event by exploring the relationships between the changes in channel width and controlling factors. Results and discussion The relationships between the degree of channel widening and possible controlling factors were explored using multiple regression analysis. The analysis was carried out for the widening (width ratio) at reach scale. The entire data set includes 38 reaches. We analyzed seven controlling variables including confinement index, percentage of reach length with artificial structures, degree of sedimentation, channel slope, cross-sectional stream power, and unit stream power using pre-flood and post-flood channel width. Each regression model included only three to four variables. Each model included only one of the variables expressing potential or flood flow energy, e. g., channel slope, cross-sectional stream power, unit stream power. All four multiple regression models turned out to be significant (p< 0. 001) and gave high coefficients of multiple determinations. The values of R2and adjusted R2 are ranged between 0. 73 and 0. 8 and between 0. 69 and 0. 77, respectively. The best model embraced unit stream power calculated based on pre flood channel width and confinement index as explanatory variables. Conclusion The results confirmed the main hypothesis of this work that hydraulic variables alone are not sufficient to explain channel response to an extreme flood event. The inclusion of other factors, specifically lateral confinement, degree of sedimentation, and percentage of reach length with artificial structures can lead to satisfactory models explaining the observed variability in the degree of channel widening. These results suggest that the widening process is essentially controlled by two factors: flood power and valley confinement. Flood duration exceeding a critical threshold was not included in our analysis, but it is a variable that very likely would increase the robustness of regression models in these reaches. The analysis carried out in the three subcatchments of the Konjancham River basin showed that unit stream power calculated based on pre-flood channel width has stronger relations with channel widening in comparison with that based on post-flood channel width and cross-sectional stream power. Because peak discharge was used for stream power calculation, we are aware that neither pre-flood nor post-flood channel width is actually appropriate for the estimation of unit stream power, as the most appropriate would be the (unknown) width at the flood-peak time. The pre-flood width has stronger relations with the degree of channel widening (width ratio). This could suggest the width changes occurred after the flood peak.

Introduction Coastal sand dunes are one of the important morphological landforms of coastal areas. These hills have been developed by interactions of sea waves, sea currents, winds and sediment materials on the coast. The sand dunes can protect the coast against waves and erosion. Thus, it is essential to protect these hills using management measures. The study area of this research is located between the Sirik port and the port of Ziarat, in the southeast part of Hormozgan province. Since the construction of new docks in recent years has led to changes in the coast of this region, so awareness of the vulnerability of the coastal hills can be effective in managing and protecting them. The purpose of this study is to assess vulnerability of the sand dunes by model DVI (Dune Vulnerability Index). A checklist is usually employed to evaluate the vulnerability index. In this research, effective factors in coastal sand dunes, geomorphologic conditions of sand dunes, marine factors, wind processes, vegetation, effects of human activities and management factors were evaluated using the checklist. Materials and methods In this study, the data from Google Earth, Landsat, and aerial photos, and questionnaires and field observations were used to complete the checklist. The steps to complete the checklist are as follows: in the first step, the value range for the quantitative variables was determined on the basis of the available structured checklists. Partial vulnerability indices are geomorphological condition (GC), marine influence (MI), aeolian influence (AI), vegetation condition (VC) and anthropogenic effects (AE). The indices were calculated as the ratio between the summations of given variable ranks within each variable class (PVi) and the total maximum possible rank within the class. A total DVI was calculated as the average of the five partial vulnerability indices (PV). The Protection Measure index (PM) was calculated separately from other factors. Lastly, the residual value as the difference between DVI and PM (DVI-PM) has been calculated to describe the stability of the dune system. According to the studies by Davis (1995), to calculate the vulnerability index (VI), the calculation of the partial Vulnerability Index is not done and the vulnerability score from the division of the total variables obtained from all the group of variables, based on the maximum total sum of the concessions of the entire group of variables. This is obtained for each site. Results and discussion Partial Vulnerability (PV), for geomorphologic agent is above 0. 75 in all sites. The degree of vulnerability is very severe because of characteristics of the sand dunes of the region with fine-to-good sorting on the slopes over 30 degrees. The vulnerability to wind processes in all areas is above 0. 5 and this shows high sensitivity of this factor. One of the reasons for vulnerability of the dunes to the wind processes is the small average diameter of coastal sediments in this area. The fine sands here are exposed to retrogressive waves and are more sensitive to erosion, so beaches with fine sand grains have less resistance to erosion. The low vegetation of the dunes in this part of the sea, in the distance between the hills and relatively high percentage of uncovered areas are other factors of high sensitivity of dunes to wind processes. The degree of vulnerability to vegetation condition is very severe in sites 4, 5 and 6, and is low in enclosures 1, 2 and 3. The vegetation condition was compared with 1966 aerial photos and satellite imagery from 2000 to 2016. This implies an increase in vegetation in 1966 and 2000, due to planting and plant care by government office like office of natural resource in Hormozgan. The level of vulnerability to the human factors of sites 1 and 2 is moderate and in the other sites it is negligible. With the use of aerial photographs and satellite imagery, during the years mentioned above, the roads in this area have been increased and in some areas the roads cross the dunes. During these years, some parts of the dunes have been cleared for construction. In addition, the construction of three new wharfs in 3 Sirik (2007), Ziarat (2012) and Taheroi port (2013) has also been associated with shore changes. According to the field observations and the results of the questionnaires (interviews with local people and experts), it can be asserted that no management action such as specifying buffer areas for access restrictions has been taken to protect the beaches. The only protective measure is the planting of seedlings in sites 1, 2 and 3 through natural resources organization. Coclusion The overall values of DVI in all areas were moderate. Among the investigated factors, the morphological condition of sand dunes and the wind processes have the highest influence on the vulnerability of the dunes. The results for the DVI-PM index indicate that all sites need quick management. Based on the obtained equilibrium index, there is no equilibrium between vulnerability and dune management in any of the sites. This indicated the lack of management or inadequacy. One of the reasons for lack of management or efficent management is that there is no a certain organization responsible for these kinds of protection measures. Comparison of the two methods for calculation of vulnerability, DiPanjun (2014) and the Davis (1995) method), shows that the severity of the vulnerability of the sites is moderate in both methods. There is no difference between the qualitive results obtained in the two methods.

Introduction Climate change in recent years has led to changes in atmospheric patterns and the appearance of climatic anomalies in most parts of the world. Earth’ s climate is a complex dynamic system that involves hydrosphere, cryosphere, biosphere and lithosphere. If any of these system changes, other systems will quickly or slowly align themselves with it, and the outcome of this coordination also affects the system initiated the change. Eventually, an endless chain of links is created between these systems. The interaction between these four systems is responsible for the concern of weather and climate scientists in recent years and propounded the term of "climate change". The result of global warming is climate change. The process of climate change, especially temperature changes, is one of the most important discussions in the field of environmental sciences. Many of our age-old problems, such as floods, storms, droughts, changes in atmospheric patterns, and so on, are rooted in climate change, especially in air temperature increasing. This study aimed to investigate the effect of global warming on subtropical high pressure behavior. Data and Methodology In order to investigate the effect of global warming on the subtropical high pressure behavior, the following steps have been taken. In the first step, maximum daily temperature data of 49 synoptic stations during the period from 1977 to 2016 were used to study the frequency of temperature higher than percentile 95 in each year. Regarding the frequency of temperature higher than percentile 95, this trend has been dramatically has been rose in 1996, so this year has been set as the border between the two pre-warming and post-warming periods. In the second stage, given that global warming is expected to increase these extreme temperature, frequency of temperature higher than percentile 95 was investigated in both periods. In the third stage, changes in the behavior of subtropical high-pressure in terms of height and spatial extent were determined based on 500-hPa geopotential data, derived from European Center for Medium – Range Weather Forecasts (ECMWF). Finally, to prove the existing relationship between the data, the 500-hPa geopotential height anomalies were plotted over the two periods and analyzed to determine that what changes occured in height of the middle level. Result and Discussion By examining the results, it was found that the long-term average of core height of the subtropical high pressure during the second period (1996-1997) has increased by 10 meters relative to the first period (1996-2016). Given the frequency of the thresholds of percentile 95 of the second period, it can be said that most stations have experienced extreme temperatures, so it can be said that global warming has been proven. It can be said that during the current period, a temperature of 40° C is a normal temperature. Therefore, due to the mutual and direct relationship between temperature and height of the atmosphere, it can be said that the reason for increasing the height of the core of the subtropical high pressure is the increase of temperature in the lower layers of the atmosphere. When the temperature increases in the layers near the land surface, thermal low pressure on the land surface and the dynamical high pressure resulting from the subtropical high pressure subsidence and some systems, including Monsoon, are created and for every 1000 meters, while increasing power, it increases air temperature by 6˚ C. Thus, the core height of the subtropical high pressure is increased and the maximum temperatures are recorded, especially during the warm months. Pearson correlations also indicate a very strong and positive correlation between the core height of the subtropical high pressure and the maximum temperature in the both periods. Conclusion The results of the analysis of the maximum temperature data showed that during the first period, the temperature reached 30. 5 ° C in percentile 95 while during the second period with 1˚ C increase it reached 40. 5˚ C. It can be said that in the first period of global warming we did not have much intensity in our country, but in the second period temperature reached its maximum and the effect of this warming is seen in the recorded temperature. In other words, global warming has been proven and the frequency of temperatures above 40. 5 ˚ C has become prevalent in most stations. Spatial analysis of the core of subtropical high pressure indicates that its highest height in the first period over Iran is 5910 m which affect fewer stations. But in the second period, the core height of subtropical high pressure is 5940 meters, which, in comparison with the first period, shows increase in both height and extent resulted in higher temperature. It was found that the long-term average height of the subtropical high pressure core during the second period (1996-1997) has increased by 10 meters relative to the first period (1996-2016). Given the frequency of the thresholds of percentile 95 of the second period, it can be said that most stations have experienced extreme temperatures, so it can be said that global warming has been proven. In other words, during the current period, the temperature of 40 degrees is a normal temperature.

1. Introduction Land use has always been one of the most important indicators that humans through its have been influenced their environment. Nowadays, processed mining and related operations are parts of activities that have potential to harm the environment. Mining is in direct contact with nature and the environment, so this will have important effect on the environment. The negative effects of mining activities on changes in surface biophysical parameters such as greenness, brightness, wetness and land surface temperature (LST) depend on the type of minerals, location of the area, extraction method and other factors. Remote sensing technology provides useful information to understand temporal and spatial changes of land use/cover and land development processes. Sungun is a large porphyry copper mine and extraction method of this mine is open pit mining. The important environmental pollutions in this method of mining are land and landscape degradation, mass production of waste mineral extraction and loss of vegetation covers. Due to Sungun copper mine geographic location which it’ s adjacent to the Arasbaran forests and Dezmar protected area, the activities of this mine are environmental impact of great environmental importance. The objective of the present study is integrating reflective and thermal remote sensing capabilities to analyze and monitor changes in the surface biophysical parameters of the Sungun copper mine region caused by mineral activities over the past three decades. 2. Data and methods In the current study, the reflective and thermal bands of satellite images acquired by Landsat 4, 5, 7, and 8 have been used to calculate the LST and biophysical parameters. Also, the water vapor products (MOD07) and the LST products (MOD11) of MODIS sensor of TERRA satellite, the air temperature data measured at the meteorological stations and ground data have been used. In the first step, using reflective bands set of Landsat images, the land use change trends in the study area for the period 1989 to 2017 were extracted and analyzed. Satellite images classified based on maximum likelihood classifier. The cross tab model was used to study land use changes trend. In the second step, the changes in biophysical parameters such as greenness, brightness and wetness caused by mineral activities have been investigated. In order to model the surface biophysical parameters of brightness, greenness and wetness for the period from 1989 to 2017, Albedo, NDVI and NDWI parameters were used, respectively. In the third step, by integrating the reflective and thermal remote sensing capabilities, the LST maps are extracted from different years and the trend of LST changes due to land use changes in different time periods has been investigated. For LST retrieval, a single-channel (SC) algorithm was applied. Finally, the zonal analysis has been used to analyze the trend of LST changes caused by land use changes in the studied are. 3. Results and Discussion Over the past two decades, with the increase in the activities of Sungun mine, the area of this land use has increased dramatically. The results indicate that the area of the mine class will increase from 13. 41 ha in 1993 to 621. 54 ha in 2017. During the same period, as a result of the expansion and development of mineral activities, the area of the forests decreased from 995. 94 to 594. 27 ha. In the period under study, 2295 ha of forest area has changed to mine land use. Also, more than 2632 ha of pasture land has become mine land. The results demonstrate that during the period of 1989 to 2017, the mean values of Albedo, NDVI and NDWI parameters increased, decreased and increased, respectively. The mean of surface albedo values for the study area has been increased from 0. 17 in 1989 to 0. 25 in 2017. Also, the mean value of the NDVI index has been decreased by almost 0. 09 during the period from 1989 to 2017. The major reason for a decrease in NDVI mean values is the reduction of the forest lands and the conversion of them into the mine and pasture lands in past years. In all dates, the lowest and highest LST mean were related to forest and bare land classes, respectively. In these years, the mean value of LST of the forest is, on average, 6. 36 ° C below the mean value of the LST of the mine land use. The results revealed that land use changes from forest to mine, pasture to mine, forest to pasture, forest to bare land and pasture to bare land have changed the LST 5. 8,-0. 1,-1. 4,-1. 6, 3. 3, and 0. 9 ° C, respectively. 4. Conclusions One of the most important negative impacts of human activities is the change in the surface biophysical parameters. Changing the earth's surface biophysical parameters causes a change in many processes and natural cycles of the earth, including the energy billing cycle. The results of this study are a major warning to environmental authorities to provide appropriate plans and solutions to reduce the negative effects of Sungun copper mineral activities. Also, the results of the study indicate the usefulness and efficiency of the integration of reflective and thermal remote sensing capabilities for monitoring and managing various human, environmental and natural phenomena.

Introduction Understanding of climate parameters and their effects on crop growth is one of the most important agricultural issues. The purpose of this recognition is to increase crop yield and thereby increase production. The position of Iran and its natural geographic features have led to a variety of climate and seasonal variations. These variations in each season has created different conditions for agricultural products. Among the climatic elements, the amount and temporal distribution of rainfall and temperature fluctuations in different stages of crop growth have the greatest impact on the yield of agricultural products, especially rain-fed wheat cultivation. In the growth stages of each crop, especially in rain-fed agriculture, the planting date and the first effective rainfall are an important environmental-managerial factor in production. The main goal of current study was to investigate the relationship of synoptic patterns of effective precipitation with planting date and yield of rain-fed wheat in Kermanshah County. Materials and Methods In this study, data from growth stages (phenology) of wheat, Azar-2 variety, and precipitation of the agrometeorological research station of Sararood, Kermanshah were used from 2004-2005 to 20015-2016. In the next step, the data of geopotential heights, wind speed and direction and specific humidity from 850 and 500 hPa levels were taken from NCEP / NCAR reanalysis dataset. The planting date of rain-fed wheat has been calculated based on 2 methods. In the first method, the starting dates for the first effective rainfall were determined. Accordingly, the date of cultivation was when the total precipitation of 5 mm within one or two consecutive days occurred and after that, the precipitation occurred by 10 days. The second method was to determine the planting date on the basis of climatic data of sowing and germination dates recorded in Sararood agrometeorological research station during the years of study. The effective rainfall was defined as 5 mm rain to wet 5 cm of soil depth for a soil with loamy. Moreover, the staring date of sowing wheat was calculated according to Weibull formula with a 75-percent probability of success. In the following, taking into account the first days of precipitation and based on the number of rainy days, the synoptic patterns of the occurrence of effective rainfall have been derived using a correlation-based method. Results and Discussion According to the results, suitable dates for Rain-fed wheat cultivation in Kermanshah Province were from Aban 3(October 25) to Aban 15 (November 5). In this research, by determining the threshold of correlation coefficient (0. 57), 4 general synoptic patterns were found. The features of each pattern were as follows: pattern 1 had the highest share in severe rainfall. This pattern in the pre-germination stage (sowing) had the highest frequency in the occurrence of effective rainfall of 5 mm and more. Pattern 2 was in contrast with Pattern 1, and it was most frequent occurrence in rainfall. Patterns 3 and 4 had characteristics such as limited rainy days and extreme daily rainfall. In addition, synoptic patterns of effective precipitation more than 5 mm were minor trough, Mediterranean trough, Omega Block and cut-off low. The results of synoptic studies of atmospheric patterns also showed that the northern seas of Indian Ocean (Red and Arabian Seas) are the main sources of moisture for all synoptic patterns. Conclusion The main goal of current study was to investigate the relationship of synoptic patterns of effective precipitation with planting date and yield of rain-fed wheat in Kermanshah County. The effective precipitation from synoptic patterns 2, 3 and 4 provided conducive conditions for germination of plant in the next priority after the first pattern. The results indicated that the lowest wheat yield as compared to average yield (2113 kilograms per hectare) occurred in the years with the forth precipitation pattern. On the other hand, the highest wheat yield observed when the synoptic patterns of 2nd and 3rd were occurred simultaneously within a year. For example, the years of 2006-2007, 2014-2015 and 2015-2016 had wheat yield of 2888, 2486 and 2700 kilograms per hectare, respectively. Moreover, the effect of synoptic patterns on planting date showed that the commencement of first effective rainfall with patterns 1, 2, 3 and 4 delayed germination stage with an average of 4, 10, 3 and 5 days, respectively. In conclusion, it should be noted that to take more precise results, it is reasonable to work with long-period data.

Changes effective components in peak rainfall Iran. Introduction Since the spatial and temporal distribution of rainfall in Iran is influenced by the distribution of global circulation systems, the slightest change in its pattern is the severe weather abnormalities. Therefore, spatial and temporal abnormalities of rainfall and extreme changes in rainfall intensity and differences in precipitation types are one of the main characteristics of Iranian rainfall. Climate change is one of the problems of human society and is a threat to the planet Earth. The increase in the temperature of the earth has caused profound and extensive changes in the Earth's climate, causing changes in the time and place of precipitation, which has caused a lot of damage, especially in the last decade. The purpose of this study was to identify and study the changes in the heavy rainfall component of Iran in relation to changes in the systems middle tropospheric. Materials and methods First, the daily rainfall data of 53 synoptic stations were received from the country's Meteorological Organization from 1984 to 2013. The cluster analysis and zoning were done using Euclidean distance method and Ward's method was used. For zoning based on cluster analysis, seven variables of rainy day (one day, two consecutive days, three consecutive days, four consecutive days, five consecutive days, six consecutive days and seven days of continuous rainfall) were used. The final result was the division of the country into 3 regions according to the number of days. In the following, data from the upper atmosphere levels were used to investigate changes in the mechanisms of rainfall formation. Includes discovery data of geopotential heights, u wind, v wind, omega, level, 500 hpa, and specific humidity level 700 at daily average and 1 * 1 degrees from the European Center for Medium Term Forecast ( ECMWF) received. The statistical period of study was divided into two periods of 15 years (first study period 1984-1998 and second study period 1999-2013), The peak days for each area were determined in each of the two time periods. And for each time period The peak of rainfall was 5 days. Then, the synoptic parameters were analyzed and compared in each study period. Discussion In area 1 in the second study period, the range of trough decreased and the depth of trough increased. The central core of geo potential heights in the first time period is greater than the second period of study, in other words, the core in the first period is 5400 geo potential meters, which in the second interval decreased to 5350 geo potential meters. In area 2, in the second period of studies, the high elevation in the convergence region of the Arabian Sea is more shallow and in a more inappropriate position than the first pattern. In area 3, in the second study period, northwest of Iran is located behind the trough, and cold weather is falling and the rainfall in this part of the area is low. In 3 areas, in the second period of studies, the amount of moisture has decreased and caused the rainfall of the second interval to decrease compared to the first interval. Conclusions In the second period of studies (1999-2013), the range of trough has decreased and the depth of trough has increased. The Omega component study showed that in the second study period, the mean omega-negative peak of the peak days of the target area was reduced. The Omega component study showed that in the second study period, the mean omega-negative in the target area was reduced. It was also found that the direction of the wind streams in the second period was reduced due to the flow Linear more of the amount of precipitation. The amount of moisture in the second period of study has also decreased and has caused the second period rainfall to decrease over the first period. In the study of the synoptic components of area two, it was found that in the second period of studies (1999-2013), located on the convergence area of the Arabian Sea, is more shallow and in a more inappropriate position than the first pattern. And caused the maximum moisture content to fall to 5 grams per kilogram. In the study of the synoptic components of the third region, it was found that in the second study period, the study area, especially the northeast of the country, is somewhat ahead of the trough, and the average annual precipitation in this part of the area is increasing in the second period. And the northwest of Iran is located behind the trough and the cold weather has fallen. The rainfall in this part of the area has decreased. Keywords: Zoning, mechanism of precipitation. Middle troposphere, Iran.

Introduction The relationship between form and process in geomorphology is very important. By changing the process, the forms will be changed and new processes will be created in the form of new forms (Gurabi & Emami, 2017. p: 75). Sea level changes mainly include tidal variations and changes due to atmospheric factors. Tidal flows are also affected by coastal washing during their daily advancement and retreat on tidal slopes and tidal zones. The formation of many coastal geomorphologic forms is the result of their involvement. (Nohegar & Hosseinzadeh, 2011. P: 131). Climatic factors cause short time fluctuations and tidal cycles and long term fluctuations in medium level of sea (Yamani & MohammadNejad, 2012: p: 87). Torabi Azad and Honarmand (2016) performed a concise investigation about sea level changes in Banda Abbas and Booshehr Stations in a period of 11 years (2000 to 2010) and analyzed and computed barometric effects, wind force and temperature on the sea level mean. The results showed that sea level mean in these stations has incremental trend by 5 cm and 4 cm respectively in the mentioned seaports. Akbari et al (2017) In order to investigate and analyze important tidal components in a vast area including Persian Gulf, Hormuz Strait, Oman sea and Arab sea applied 3D FVCOM Model. The results of this research shows that there is four kinds of tides in Persian Gulf including Daily, semi-Daily, daily compounded and semi-daily compounded tides and on the other regions there is just semi-daily compounded ides. The research aims on investigating the effects of climate change parameters (temperature, pressure, and wind rate) on the sea level fluctuations in an annual, seasonal and monthly changes and 20-year period in northern coasts of Oman Sea and also its physical justifications. Matarials and methods Research domain from geographical networking point of view, Jask port has longitude and latitude of 570 46' in east and 250 40' in north respectively to Gowatre Bay and in the terminal point of southeast of Iran and southwest of Pakistan has longitude and latitude of 570 46' in east and 250 10' in north respectively. Through calculating mean sea level from tide gauges datum belonged to IOC (Intergovernmental Oceanographic Commission) in the stations of hydrography of Jask and Chabhar ports during 1997 to 2016. Tide gauges for mentioned stations during 24 hours presented 1440 datum. In fact they registered sea level in every minutes. Data presented in every minute through averaging changed firstly into hourly data then into daily and finally into monthly data. In order to compute data based on monthly averages, the tidal effect should be deleted and computed into level fragment that means sea level minus tidal effect. According to the presented information in meteorological organization since 1997 to 2016, data about pressure, temperature and wind force were used in research stations as monthly means and the diagrams used monthly, seasonal and yearly means. In this research, Meta heurestic-Algorithm (Decision Tree Algorithm) The CARD regression tree decomposition algorithm (Classification and regression tree) is used as a type of regression decision tree for prediction purposes. Different elements have been used in simulation using decision tree model. In order to verify the relationship between the final decision tree tree based on the statistical index, graphical graphs and correlation coefficients obtained from the field operation method, visual inspection, ground monitoring and verification of control points were made. Result and discussion. The decision tree model in the Jask area has three parameters: wind pressure and wind speed, and the tree has acted on the basis of these two parameters that the model did not use the temperature parameter in the decision tree and was not selected as an effective parameter Is. Also in Chabahar region, all three parameters are used in the model The above-mentioned model has a very high performance in predicting values. In most of the 12-month intervals, the model performed its predictions close to real values; in other words, the tree created using data has a good prediction process and can simulate the changes well Also, according to the above figure, the predictions were evaluated. The results indicate that this model can be predicted with high accuracy and 95% confidence level in the region data. Because the temperature parameter has not been able to predict the response variable in the decision tree, the model has been eliminated, and the final equation of Jask and Chabahar is as follows. MSL(Jask) =13. 197+5. 619 T(1. 102)-11. 092 P (0. 195)+7. 208 W(0. 71) MSL(Chabahar)= 4. 520+1. 529 T (1. 089)-1. 596 P(0. 87)+2. 776 W(0. 316) Conclusion MSL fluctuations are among the general methods of analysis; therefore, accurate prediction can provide conditions for assessing its status. The purpose of this study was to investigate the effect of data pre-processing on the performance of nonlinear decision tree model in predicting MSL in Jask and Chabahar. The results of this study in all simulations show that pressure and wind parameters are more effective in the final model, which indicates the importance of these parameters in predicting future MSL. Physically, the close relationship between wind speed and water level changes is evident with the strong positive correlation coefficient of the Jask station compared to the Chabahar station in the annual windfall of both regions. Based on the relationship between the final model derived from the decision tree tree algorithm in MSL prediction using available data, it is 95% reliable. Investigating the related geomorphologic forms in the study area, the tidal range fluctuations in the Chabahar region are 1 to 1. 5 meters, and in the Jask area more than 3 meters above the time interval are shown well in the diagrams. Therefore, in a closer examination of the processes governing the environments around the coastline, studying and monitoring the status of the tidal region and the influential climatic parameters is necessary.

Introduction Dust is one of the most important environmental events that can dramatically affect and destroy its living areas. The purpose of this study was to investigate the long-term trends in dust events and to investigate the effects of these events in the city of Ilam on the record of respiratory diseases. Materials and Methods In this regard, data on recorded events of dusty days during the 1995-2015 statistical periods was taken for two synoptic stations in Ilam and Dehloran. The relationship between time series of dust events could be detected throughout the day as TDE (Total Dust Event), in which total dust storms (including local and overflow and sandstorms and light to medium dust) are used in this research. With the fitting of a linear model at a confidence level of 0. 95 (P_value = 0. 05), the process of this time series was analyzed. In order to reveal the relationship between the time series of the annual registration of pulmonary and respiratory diseases, which were obtained from male and female patients of Shahid Mostafa Khomeini Hospital in Ilam during the statistical period of 1380-1384, two methods of Pearson correlation of matrix at confidence level of 0. 95 (P_value = 0. 05) and linear model is used at confidence level. Results and discussion The results showed that the increase of dust records in Ilam and Dehloran stations was 0. 8 and 0. 96 records per year, respectively. Correlation matrix indicates that at the confidence level, a significant direct correlation was found between the annual number of patients with pulmonary and perfused patients registered in Shahid Mostafa Khomeini Hospital in Ilam and the occurrence of a recession. In spite of the fact that in the years when the number of records of the higher gathering was recorded at two stations in Ilam and Dehloran, a record of the respiratory examination was significantly higher. Also, models based on the relationship between the number of male patient admissions and the events recorded in the two waves of two synoptic stations in Ilam and Dehloran indicate that these two models, respectively, verified 0. 79 and 0. 69, respectively, of the variability of the time series of client hospital records. In the case of women with pulmonary and respiratory diseases, the model has been fitted, which according to the number of days with dust in Ilam and Dehloran stations showed that these models could define 0. 70 and 0. 83 of the number of female patients. Conclusion The correlation matrix indicated that at the confidence level, a significant direct relationship was established between these two time series so that the number of annual records of patients with respiratory diseases recorded in Shaheed Mostafa Khomeini Hospital in Ilam during the years Which had a higher number of dusty days recorded at two stations in Ilam and Dehloran, was significantly higher. The correlation matrix indicated only the direction and severity of the relationship, so that linear regression models were used to quantify this association and to be aware of the susceptibility function of the records of patients with pulmonary and respiratory diseases. The proposed model can be meaningfully and cognitively able to model the association between dust events (as independent variables) and the records of patients with respiratory diseases (as a dependent variable). A model for recording the number of female patient records during the period 2000-2014 based on the number of dusts recorded at Ilam station has been able to justify 0. 62 times of the time records of women referring women in Shaheed Mostafa Khomeini Hospital, while The number of recorded events of the Dehloran Synoptic Station, based on the fitted model, has been able to justify about 0. 58 of these changes. The fitted models on the relationship between the number of records of hospital male patients and the recorded dust events of two synoptic stations in Ilam and Dehloran showed that these two models were 0. 79 and 0. 69, respectively, of the variability of the time series of the records of male patient clients To explain. For the total population of patients with pulmonary and respiratory diseases (without attention), the model was also fitted according to the number of days with dust in Ilam and Dehloran stations, which showed that these models also were 0. 67 and 0. 83 Describe the records of patients referring. Finally, comparing the results of this study with other researches, it was found that the results obtained in Ilam are in agreement with the results of other researchers in Kermanshah and Ahwaz.

Introduction Precipitation is considered as one of the most important climate elements with high temporal-spatial variations. The variable can affect different environmental aspects represented through several different behavioral forms in extreme precipitation. Heavy and extreme rainfalls can occur in the form of flashfloods and usually in draught conditions with considerable negative consequences on human-environment. Therefore, the study of this type of precipitation in the area is an area suitable for agricultural activities. Recognition of such patterns can determine the success in environmental management as well as certainty in resources planning. There is considerable heavy and super heavy precipitation in coastal regions of Caspian Sea, Iran, especially in eastern areas. Thus, understanding the spatial auto-correlation of such a phenomenon can facilitate environmental planning and the reduction of vulnerability to increase adaptability with such a disaster...

Thunderstorm is one of the meteorological phenomena seen in most parts of the world and is a major threat to modern societies, which operates in more local-scale. This natural occurrence, despite having advantages in most cases, due to the sudden occurrence, is the most severe and destructive natural disasters in each year, and cause severe damage to different parts of economies and human casualties. Convective storms usually affect small areas than tropical cyclones. Moreover, their destructive effect is often less than the actual value. Basically, thunderstorms are in the most frequent in the warm seasons on the land surface and in the cold seasons on the oceans many factors influencing the occurrence of thunder storms, including thermodynamic and kinematic conditions of the atmosphere, topography, and surface cover, coastal configuration and atmospheric flows. Ardabil province due to its location in northwest of Iran And being in the vicinity of the Caspian Sea and Gilan province have a several extreme precipitation days in each year, which causes severe damage to the agricultural and livestock sector. In this study, daily large-scale circulation patterns are firstly characterized in the northwest area of Iran, Ardabil province, through the use of SOMs technique. Then, the potential implications of circulation types to explain variability and change of the Ardabil precipitation are also attempted. Therefore studding of this phenomena and identifying of synoptic patterns have Great importance for the region. Materials and method The observed daily extreme precipitation records over 50mm used in this study are provided by the Ardabil Meteorological Data Sharing Service System. There are 4 stations in the data sparse Ardabil but their operations started in different years (most are from January 1 in 1961) and there are missing values at some stations in the early decades during the 1961– 2016. Additionally, the daily geopotential heights at 500 hPa isobaric level (GH500) with the spatial resolution 2. 5° latitude × 2. 5° longitude based on extreme precipitation days used for circulation types are obtained from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR, . http: //www. esrl. noaagov/psd/data/grided/data. ncep. reanalysis. html reanalysis dataset to identify circulation types. Some of the circulation patterns in Ardabil area were objectively evaluated with Pettit test. Based on this method, a significant abrupt change point is detected in the series of the sum of q-error and t-error, which indicates 9 distinct circulation patterns with a 3 × 36 SOM topology can describe the changes in synoptic positions in the Ardabil area. In addition, the maps created in the Grads software are also presented. Result and discussion The large-scale circulation classification provides an ideal tool to understand the circulation dynamics and their association with local climate variability. In this study, daily circulation types are objectively studied through the use of SOM technique and are further linked to the extreme precipitation over 50 mm characteristics in the northern area of Iran, Ardabil, during the period 1961– 2016. Results show that the SOM method adopted could reasonably classify the daily geopotential height field at the 500 hPa vertical level over Ardabil province. By using an objective determining method (the Pettit test), 9 circulation types are qualified. Most of the severe precipitation patterns in Ardebil are related to the spring and April months, which is the time of the occurrence of thunderstorm in Ardebil. The 500 hpa HGT patterns during spring rainfall are associated with Omega Block, Rex Block and deep wave on Caspian Sea. This atmospheric pattern at the level of 500 Hpa has a completely baroclinic and unstable atmosphere in Ardabil which produced thunderstorm. In summer patterns, Ring Of Fire Block and Cut off Block are seen. This type of Block occurs during the summer, the conditions of high pressure system centre are very stable. Cut off Block, is a deep craft, occurs when high-altitude winds change to high latitudes and leave a low-spin (low pressure) behind them. In autumn pattern, a deep wave in the northern part of Iran and a cut off block are seen. Deep Wave, supplemented by cold weather in northern latitudes. In winter pattern is a Rex Block, which is a set of systems with a strong high stack in the vicinity of a low-altitude strong lane. Ardebil is located on the eastern side of the wave, is the location of the western winds ascent that creates barocilinc atmosphere and precipitation. In the A1 group, the highest frequency is in May with 30%, in the A2 group with 34% the highest frequency is in April and the lowest frequency is in October with 5%. In the A3 group, the frequency is 15% in February, March, April and May. Also in group B2, the frequency of April, May and August are 8%. In group B3, the highest frequency with 25% and 15% are for October and November. In the C1 group, the July-September months are over 16%. In the C2 group, January-April are 16% and 8% and in the C3 group, May, June and September are 8%. In the spring, the highest percentage of precipitation belongs to the B3 model with 45% fluctuation and the lowest amount of precipitation belongs to the A1 pattern with 20%. The patterns of A1 and C1 (45%), B1 (35%) and C3 (20%) are summer season patterns, The C1 pattern with (45%) has only some rainfall in winter. The C3 pattern has a rainfall of only 25% and 15% in spring and summer. In autumn, the patterns of A1 (28%), A2 (10%), B1 (15%) and B3 (45%) are high-end models. In winter, only A3 patterns with (35%) and B3 with (20%) are rainfall patterns.

Introduction Occurrence of weather hazards such as freezing, annually late spring frost can create much damage in agricultural section. Programming and decision making with suitable action can decrease damages resulted from weather hazards. Therefore, it is necessary to consider comprehensive and precision of this phenomenon. Nowadays, use of numerical weather prediction (NWP) models and recognition of weather hazards can prevent such damages. In the recent years, direct numerical weather prediction models can forecast near surface parameters suffering from systematic errors mainly due to the low resolution of the model topography and inaccuracies in the physical parameterization schemes incorporated in the model. On the other hand, verification is a critical component of the development and use of forecasting systems. The verification should play a major role in monitoring the quality of forecasts, providing feedback to developers and forecasters to help improve forecasts, and provide meaningful information to forecast users to apply in their decision-making processes. The purpose of this study is to evaluate the performance of the WRF model for Temperature Forecast and frosting occurrence in Zayandeh Rud Basin....

Introduction Natural hazards with their varieties and their extent of influence as repetitive and destructive phenomena have always been present through the life in the planet; they have always been a serious threat to human beings since the advent of mankind. Accordingly, it can be said that no community claims immunity from natural hazards, and humans always suffer from objective and subjective harmful effects. Natural hazards by destroying income sources, biological resources, and people activity centers (houses, workshops, farms, etc. ), increase their economic and physical harms. Related to the history of the hazards studies, the following notes could be mentioned. Materials and Methods In this research, in order to zone the flood and landslide hazards in the Alborz Province based on the used models, the indices of each model were extracted to be utilized in providing the risk map of these hazards as follows: for the landslide hazard zonation of the Alborz Province, one of the outranking methods, entitled VIKOR consensus optimization method, based on calculation of maximum utility and minimum losses was utilized and the susceptibility map of the sub-basins of the Alborz Province was prepared according to the occurrence of the landslide phenomenon. IN order to study the flood hazard of the Alborz Province, the Frequency Ratio Model (FR) was used. In order to perform these two models, it is necessary to extract the most important indices affecting the occurrence of the hazards; for this purpose, based on a deep investigation on previous studies in this field as well as the features of the study area, 9 indices were determined for landslide zoning using VIKOR-AHP compound model as follow: lithology, drainage density, soil type, precipitation, altitude, distance from the fault, land use, dip gradient, vegetation As well, for the flood zoning, using the frequency ratio model, 11 indices were applied which are: lithological factors, land use, distance from the river, soil type, dip gradient, dip direction, surface curvature map, Topographic Wetness Index (TWI), drainage density, altitude and amount of precipitation. Discussion and results In order to zone the risk of the landslide in the Alborz Province, initially nine criteria were considered regarding the basin tendency to land-sliding in sub-basins. After selecting the main criteria, in the next stage, the maps for each one of the selected criteria for weighting and evaluating sub-basins in the GIS environment were prepared and mapped. Considering the effect of the nine criteria in the occurrence of landslide (distance from fault, precipitation, vegetation, land use, soil type, lithology, height, drainage density and dip) distance from fault and vegetation criteria have a decreasing effect and the other seven criteria have an increasing effect. After preparing the selected criteria map, the significance coefficient of the mentioned criteria was determined by the AHP hierarchical algorithm, based on the importance level of the landslide occurrence and basins susceptibility to this phenomenon. In this investigation, in order to weight options based on the role of each criterion in the considered option, the definitive weighting range of one to ten is used; so that weight 1 has the least effect and weight 10 indicates the most effect in the landslide risk. After determining the importance coefficient of the criteria, weights decision matrix was prepared for the VIKOR algorithm. As it is known, nine criteria are efficacious in evaluation of the watershed basins. Table 2 shows the decision matrix based on the effective parameters in the sub-basins. After weighting and preparing the weight matrix, the matrix values were normalized. Conclusion The results of the landslide study in the Alborz Province indicates that in Taleghan and Karaj counties, the occurrence possibility of landslide is high due to the natural conditions of the region in terms of considered indices; since in these counties, the precipitation conditions are relatively good and vegetation is mainly of poor pasture type, there are no proper drainage conditions. The presence of less developed soils and almost impermeable bedrock, high altitude and relatively steep slope in these areas and the presence of frequent faults, provided the occurrence condition of landslide phenomenon. Therefore, as the output of the landslide zoning map shows, more than 60% of the area of these two counties are located in high-risk areas. Also, the natural conditions in relation to the flood risk is persistent and some indices such as susceptibility to erosion, land use, rivers distance, amount of precipitation, altitude, precipitation, slope angle and slope direction have led to the presence of possibility of flooding in the Alborz Province; consequently, due to the dominance of these indices in Taleghan, Karaj and Savojbolagh counties, the highest flood risk could be observed respectively. The situation of Taleghan and Karaj counties are more susceptible and vulnerable to geomorphic hazards; because the area percentage of the high and high risk classes in these two counties is considerable (high). On the other hand, most of the habitat areas of the Province are situated in high risk places in terms of flood and landslide hazards; it shows the necessities of more detailed planning to prevent the hazards and the related damages. In the following, in order to investigate the status of residential centers of the Alborz Province in relation to geomorphic hazards and the degree of adaptation and correct location-defining of these centers (urban and rural), a study was conducted; it indicates the establishment of most urban and rural centers in high-risk areas. For example, 52% of the Karaj County with 28% of the Province’ s area and about 2 million populations are located in very high flood and landslide risk zones; in order to reduce their probable losses, people should be aware of probable risks and necessary plans should be considered.