مریم سادات میرعابدینی

Ectopic pregnancy (EP) occurs in 1.5-2% of all pregnancies and it is the important cause of maternal mortality in the first trimester. The aim of this study was to evaluate EP risk factors in Kowsar hospital in Qazvin.

In this case-control study, 200 pregnant women with sonographic and pathological diagnoses of ectopic pregnancy in Qazvin Kowsar hospital in 2017 were assigned to the case group and 200 pregnant women with no delivery problems were assigned to the control group. The sampling method in this study was based on complete enumeration. All demographic and midwifery data were extracted from the records in the hospital archive. Data were analyzed by t-test, chi-square, and logistic regression in SPSS software version 22. P<0.05 was considered significant.

The mean age of the study population was 30.45±6.51. About 41.8% of the mothers underwent medical treatment with methotrexate, 56.6% of them underwent salpingectomy and 1.5% of them were discharged with personal consent. There was a significant relationship between the incidence of the ectopic pregnancy and using contraception, previous abortion, using in vitro fertilization, congenital diseases, infertility problems, previous pelvic inflammatory disease, previous EP, previous surgical history and hypothyroidism (P<0.05).

The present study also showed that EP was more likely to occur in patients with history of EP, abortion, PID, surgical procedures, infertility and hypothyroidism. Therefore, it is recommended that women should undergo health care before pregnancy and further studies are required to provide solutions to reduce the cases of EP.

Landslides are natural events that one or more factors can effect in its occurrence that each of them plays a special role in this field. The hazard assessments of this phenomenon are a complicated problem due to the interference of the effective factors in its occurrence. The uncertainty that is due to ambiguous conditions of geology characteristics, hydrology, tectonics, land cover, rain, erosion, temperature fluctuations in the slope instability demonstrate the benefit of accurate methods in the study of slope instability. Since the prediction of the landslide occurrence is out of the power of current knowledge, identifying sensitive areas to landslide and ranking it can protect us from landslide dangers. According to preliminary estimates, annually 140 million dollar financial damages inflict by landslides over the country, while the loss of unrecoverable natural resources is not counted. In general, the ultimate goal of studying landslides can be found the ways that to reduce damages caused by them. Therefore, it is necessary to prepare the landslide hazard map.
The main goal of this research is landslide hazard zonation of Ziarat watershed using Dempster-Shafer. For this purpose, 13 modeling approach (using all factors and eliminating of individual factors) to prepare the hazard maps have used. Ultimately, the accuracy of the model has been evaluated using receiver operating characteristic (ROC) curves. The study area is one of the most prone areas to the landslide in the Golestan region. Sensitive lithology units, high diversity of topography and land-use changes have increased landslide susceptibility in this area. Therefore, investigation of effective factors in landslide occurrence and providing zonation maps to take management action in this area is necessary.
Material and The study area is located in northern Iran, Golestan province. The Ziyarat watershed with an area of about 7800 hectares lies between longitudes 54º 10ʹ 13ʺE and 54º 23ʹ 55ʺE, and latitudes of 36º 36ʹ 58ʺN and 36º 46ʹ 11ʺN. At first, extensive field observations of the study area and aerial photos in 1:25000 scales have been used. So, a total of 50 sliding points are recognized and inventory map is produced (dependent variables). Then, 70% of total points (35 points) have considered for hazard zonation maps and 30% (15 points) for model validation.
In this research, twelve factors affecting (independent variables) landslide occurrence to provide hazard maps were applied. These factors include land-use, soil texture, geology, rainfall, slope, aspect, altitude, distance from faults, roads and rivers, stream power index (SPI) and plan curvature (CP). These factors can be divided into three broad categories which are topographical, geological and environmental conditioning parameters. The maps of these 12 factors have been produced using basis maps (DEM and Geology maps) in GIS software. The amount of Landslide density in each factor class have calculated from a combination of independent and dependent variables, and rating of classes have done based on Dempster-Shafer equations. Finally, the Landslide hazard zoning map has drawn from the summation of weighting maps in Arc GIS with 13 approaches. In this map, Value of each pixel is calculated by summing weight of all factors in that pixel. The pixel values are categorized based on natural breaks classifier into very low, low, medium, high and very high hazard zones. Then, an accuracy of zoning map has been evaluated by ROC.
The result of effecting factors on landslide classification shows that Mobarak formation, forest and agriculture land use, areas with low distance from road and rivers, low altitudes, rainfall buffer of 550-650 mm, northwest aspect, clay-loam soil texture, areas with high stream power index, high slope amplitude and area with fault density lower than 2 km/km2 contain the most susceptibility to landslide. The result of model validation using ROC demonstrates that with eliminating lithology factor Dempster-Shafer model with 92.9% accuracy is located in the great class. Also, the model accuracy shows that with eliminating rain and altitude factors the model accuracy is decreased to 73.8% and 80.4%, respectively. So, these two factors were identified as the most effective factors in the occurrence of the landslide in the studied area. Based on the landslide zoning hazard map of the Ziarat watershed and landslide points (15 points) that are considered for model validation the 20, 40, 26.67, 13.33 and zero percent of landslides is situated in the very high, high, moderate, low and very low hazard classes.
In this research, susceptible areas to landslide in the Ziarat watershed have been mapped with the Dempster-Shafer model. For this purpose, 13 modeling approach to prepare the hazard maps have been used. The following conclusions are obtained from this study.
- The rain and altitude factors were identified as the most effective factors in the occurrence of landslide in the Ziarat watershed.
- Based on the landslide zoning hazard map of the Ziarat watershed 60 percent of landslides is situated in the very high to high hazard classes.
- The produced landslide hazard map is useful for planners and engineers to reorganize the areas which are susceptible for landslide hazard, and offer appropriate methods for hazard reduction and management.

Seismicity pattern studies are one of the effective tools in the interpretation of variation in seismic sequence. The study of variations of seismicity parameters as a function of time indicates that the temporal distribution of events is not uniform, and these parameters can give quantitative information about the seismic patterns of different regions. In this research, to investigate temporal variations of seismicity pattern in the Zagros fold and thrust belt, the Schreider algorithm is applied. This algorithm that introduced by Schreider (1990) to detect seismic quiescence has been used in different parts of the world. For this purpose, four earthquakes with Mw≥6 that have recently been occurred in Zagros have been studied. At first, a complete catalogue from the period of 2000 to 2017 within a circular area has been selected. Then, the catalogues are homogenized to ML and the Minimum magnitude of completeness are computed (Mc=3.4). To perform Schreider algorithm, the time between consecutive earthquakes ( ) should be calculated. The smoothness procedure is used to evaluate a convolution function of . The smoothness of this function is done by Gaussian function. In the R radius, smoothness parameter (s) has controlled the extent of surrounding earthquakes to detect smooth values. The kth seismic event is related with the temporal convolution T(k) that decrease and increase indicate seismic activity or low seismic activity, respectively. The numbers of earthquakes that are located in the nearest distance to main shock determine the l parameter. The value of l is determined when the function f(n,s) is approximately zero. Therefore, the function T(k) depends on the s and l parameters. To investigate temporal variations of seismicity, in addition to the temporal convolution (T(k)) plot the magnitude-time, number-time and space-time plots have drawn. The results show that before the 2006 Silakhor and 2014 Mormori earthquakes, both of which occurred in the north part of Zagros, the precursory doughnut pattern is seen. Several years before the 2013 Dashti and 2005 Qeshm earthquakes, both of which occurred in the south part of Zagros, the seismic quiescence is seen for which ended with the sudden occurrence of these earthquakes. The result of sensitivity analysis showed that smoothing parameters of Schreider algorithm have a significant influence on the algorithm outcomes, and these parameters should be selected with more accuracy. The results of this paper show that Schreider algorithm can demonstrate precursory seismic quiescence before the occurrence of large earthquakes due to the intelligent usage of t parameter.

Baladeh-Kojour earthquake of May 28th, 2004 is one of the largest earthquakes in vicinity of Tehran, occurred in the northern part of the Alborz range. In this research, spatial variation of fractal parameters has been studied to estimate the seismic pattern of the study area. In order to draw the spatial variation maps, b-value, correlation dimension of epicentral and temporal distribution of earthquakes, De and Dt have been calculated for the data sets of before and after the mainshock, separately. The results show that before the earthquake, these parameters have low values in the eastern side of the mainshock epicenter. It seems that these low values before the earthquake may arise due to clusters of events with larger magnitude and small events after it. Seismic rate has decreased in the surroundings of the mainshock (seismic quiescence). After the mainshock, the lowest values of b-value and Dt is seen in the epicentral and western part of the mainshock. These low values are due to aftershock clustering and stress release, took placed just after the mainshock and during the aftershock sequence. Intensity increasing is observed in the shake map of earthquake. The De parameter is low after the mainshock occurrence. Low b-value and high De indicate high level of seismic activity in the region. The obtained results show the fractal parameters sensitivity to spatial and temporal clustering of earthquakes. Therefore, these parameters can be used as an indicator for seismic precursory patterns of major earthquakes.

In this research, to investigate seismic pattern and precursory properties of fractal dimensions, spatial distribution and temporal variations of correlation dimensions of epicentral, De, and temporal distribution of earthquakes, Dt, before the Baladeh-Kojour earthquake have been studied. The May 28th, 2004, Baladeh-Kojour earthquake with Mb= 6.2 (ISC), which is one of the largest earthquake in the vicinity of Tehran, was occurred in the northern part of the Alborz mountain ranges. The spatial distribution maps show decreasing in De and Dt in the eastern part of the epicenter, which is observed at 2002 in the temporal variation plots. With respect to space-time plot, it seems that this decreasing caused by the earthquake clusters that were occurred between 2002 -2003. Investigation of seismic pattern based on spatial and temporal variations of fractal dimensions and space-time plot of earthquakes demonstrate doughnut pattern (some earthquake clusters and a lot of small events) and seismic quiescence before the main shock. The results indicate that fractal dimensions are sensitive to clustering in space and time. So, the spatial and temporal variations of these parameters can be used as a precursory phenomenon, which is caused by seismic activation and quiescence.

Nowadays، remote sensing is considered as an important subject in many field studies، like agronomy، hydrogeology، mineral exploration، geography and geology. This knowledge has been applied in most of the geological fields. The significant application of remote sensing is preparation of lineament maps that is an important issue in the geological studies. In the remote sensing study، geological structures (e. g. cracks، fractures، faults، shear zones and foliations) are illustrated as a lineaments (Kamali et al.; 1390،2). Therefore، tectonic and structures of different areas can be investigated with use of remote sensing techniques and providing these maps. Lack of access to some areas as well as necessity to spend a lot of money and times for studying large areas have been forced researchers to find a solution for these problems. The first remote sensing studies related to geological applications dates back to first aerial photo studies in the early 20thcentury (Koç; 2005، 6). The lithology، structures and geology units had been identified with using aerial photographs، and finally geological maps had been drawn. After the Landsat images were published in 1972، the use of remote sensing was increased in the earth studying. Recently these images are largely applied in the geological researches. Since satellite images are obtained from varying wavelength intervals of the electromagnetic spectrum، they are considered to be a better tool to discriminate the lineaments and to produce better information than conventional aerial photographs (Casas et al.; 2000، 2011). The purpose of this research is to apply the remote sensing techniques and ASTER images for lineament extraction (faults) using both visual (manual) and automated methods in the central Alborz، map faults preparation، and then comparison of these maps with geology maps and with together. Study Area: Iran is located within the Alpine–Himalayan folded belt in a zone of continental convergence between Eurasia and Arabia platforms which is mostly accommodated by shortening and strike-slip faulting in the mountain belts such as the Great Caucasus، Zagros، Alborz، KopehDagh and also the active Makransubduction zone (Javidfakhr et al.; 2011، 290). The Alborz range is an active mountain belt that surrounds the South Caspian Basin. The deformation of the Alborz is due to the northward shortening between the central Iranian block and the Eurasian plate (Vernant et al.; 2004، 179). The researches show that the present-day deformation in Alborz is characterized by range-parallel left-lateral strike-slip and thrust faults (Djamour et al.; 2010، 1). The study area is located in the northern part of the Central Alborz Mountain range between longitude of 51. 19 -52. 13 E and latitude of 36. 01 -36. 68 N. The main structures of the study area are the North Alborz and Khazar faults، which are only separate structures east of 51°30''E. The North Alborz Fault is mapped as a south-dipping thrust (Geological Survey of Iran 1991a، b، Allen et al.; 2003، 662). It changes strike at 53° E from ENE to WNW. The Khazar Faultwith a southward dip direction is the longest fault in the northern edge of the Alborz Mountains. This structure separates the Caspian Sea to the north from the Alborz Mountains in the south (Motaghi et al.; 2010، 790).

In this study، three data sets have been used: 1) ASTER Digital Elevation Models (DEMs) of central Alborz (between longitudes of 51. 19 -52. 13 E and latitudes of 36. 01 -36. 68 N). 2) 1:25000 contour line maps of central Alborz. 3) 1:100000 geological maps of Baladeh and Marzan AbadBefore the lineament extraction، a set of image processing techniques should be done that are including radiometric and geometric images correction and image enhancement techniques. Since the radiometric correction had been performed in the ground stations on the satellite images، this correction wasn’t necessary for our ASTER images. The geometry correction and geo-referencing have been done only on VNIR images due to be high spatial resolution. The image enhancement techniques that applied on VNIR band are including filtering (directional)، PCA (principle component analysis) and band rationing (OSAVI (Rondeaux et al.; 1996، 102)). Then، lineaments have been extracted using both visual (manual) and automated digital interpretation method.

After lineament extraction the fault maps، rose diagram، density and length-density maps have been drawn. The comparison analysis of obtained faults maps by both methods (visual and automated) with faults maps that obtained from geology maps was done in points of estimating frequency، length، direction and density of line aments. The frequency of automatically extracted lineaments (3886) are greater than the manually ones (1912). The first reason for this results is that short lineaments have been identified by the program (LINE module of PCI Geomatica)، and the second one is that this program can’t distinguish faults from other lineaments (roads، rivers، etc.). The amount of identified lineaments with filtering، PCA and band rationing are respectively 1440،411 and 57. As you see، the frequency of identified lineaments with filtering and PCA are greater than the band rationing ones. The reason is due to further lineaments enhancement using directional filters as well as 80% information in the first component of the PCA. With using band rationing some of the lineaments in the southern part of the study area which could not be recognized by directional filters and PCA have been identified. The average length of the manually extracted lineaments (2. 19 km) that are close to the geology map lineaments (1. 93) are far from the average length in the automatically extracted ones (0. 18). The maximum length of lineaments for the manually extracted (25 km) which is as long as fault lengths in the central Alborz (e. g. 150 km for Mosha fault) is 0. 36 km in the automatically ones. Orientations of lineaments for both maps are illustrated with rose diagrams. The dominant orientations for the manually extracted lineaments are in the east-west and northwest-southeast directions. These orientations are as a result of deformation in the region. Dominant deformation in Alborz is characterized by range-parallel left-lateral strike-slip and thrust faults. Deformation is due to the north–south Arabia–Eurasia convergence، and westward motion of the adjacent South Caspian relative to Iran. Roughly north–south shortening occurs on thrusts that dip inwards from the range margins (Allen et al.; 2003، 659). The density (Zakir et. al.; 1999، 1073) and length-density maps indicate increasing of lineament density in the northern parts and in east-west direction (in the direction of Khazar and North Alborz faults). This means that there is a fracture zone in the area (Sarp; 2005، 58).

In this research، lineaments (faults) of central Alborz are extracted from the ASTER images by using remote sensing techniques and both visual (manual) and automated methods. The results show that directional filters and PCA had a main role in faults identification and extraction. The reason is due to further lineaments enhancement using directional filters as well as 80% information in the first component of the PCA. Some of the lineaments in the southern part have been identified by using band rationing. The extracted lineaments are consistent with the geology maps’ faults (Saidi; andGhassemi; 1381; VahdatiDaneshmand، 1379). These images processing techniques and lineaments identification indicate that directional filters (Sarp; 2005، 43. Koçal; 2004، 15) are the most important factors for lineaments recognition in the vegetated areas. Frequency، length and orientation of the automatically extracted lineaments have no consistency with the geology maps’ faults. Since the program (PCI geomatica) can’t distinguish fault lineaments from the others، the Khazar and North Alborz faults which are the most important structure in the Alborz region have not been recognized. So، for geological researches that always have been based on field studies and require high precision، the automated method because of the low accuracy isn’t recommended. In the visual (manually) method، length، orientation، density and length density are consistent with fault’s status in central Alborz. Consequently، the best way for geological and structural studies on large areas or areas that are difficult to access، is the visual method for lineament extraction.