Observed changes in relative humidity and dew point temperature in coastal regions of Iran   总被引：2，自引：0，他引：2  

P. Hosseinzadeh Talaee  A. A. Sabziparvar  Hossein Tabari 《Theoretical and Applied Climatology》2012,110(3):385-393

The analysis of trends in hydroclimatic parameters and assessment of their statistical significance have recently received a great concern to clarify whether or not there is an obvious climate change. In the current study, parametric linear regression and nonparametric Mann?CKendall tests were applied for detecting annual and seasonal trends in the relative humidity (RH) and dew point temperature (T _dew) time series at ten coastal weather stations in Iran during 1966?C2005. The serial structure of the data was considered, and the significant serial correlations were eliminated using the trend-free pre-whitening method. The results showed that annual RH increased by 1.03 and 0.28?%/decade at the northern and southern coastal regions of the country, respectively, while annual T _dew increased by 0.29 and 0.15°C per decade at the northern and southern regions, respectively. The significant trends were frequent in the T _dew series, but they were observed only at 2 out of the 50 RH series. The results showed that the difference between the results of the parametric and nonparametric tests was small, although the parametric test detected larger significant trends in the RH and T _dew time series. Furthermore, the differences between the results of the trend tests were not related to the normality of the statistical distribution.  相似文献   

Application of integrated geoelectrical methods in Khenadarreh (Arak,Iran) graphite deposit exploration     

Hamidreza Ramazi  Mohammad Reza Hossein Nejad  Aenollah Azizzadeh Firoozi 《Journal of the Geological Society of India》2009,74(2):260-266

This paper is devoted to application of SP, resistivity and mise-a-la-masse method in Khenadarreh (Arak, Iran) graphite deposit exploration. Mise-a-la-masse method is one of the main geophysical exploration methods used to investigate conductive bodies with outcrops on the surface or in exploratory pits. By integrating mise-a-la-masse results with other geoelectrical methods, such as self-potential and resistivity surveys, useful results can be acquired. Powerful survey design, data processing and interpretation methods can make geoelectrical surveying results more reliable. Here, we applied integrated geoelectrical methods to explore the Khenadarreh-bala graphite deposit in the Sarband region of the Markazi province, Iran. We present a new and simple method for processing and interpreting mise-a-la-masse data, which corrects for the effect of distance from the current electrode in the conductive body. After correction, the residual potential values corresponded with the SP results and the apparent resistivity pseudosections. The geophysical results were confirmed by drill holes in the study area.  相似文献   

Biostratigraphy and Sequence Stratigraphy of the Tarbur Formation (Maastrichtian) from Iranian Zagros Foreland Basin, Southwest of Iran     

Hossein GHANBARLOO  Amrollah SAFARI  Hossein VAZIRI-MOGHADDAM 《《地质学报》英文版》2022,96(1):147-166

Shallow carbonate deposits(Tarbur Formation)were formed in the Zagros foreland basin with dynamic tectonics during the Maastrichtian age.From the viewpoint of reconstruction of depositional conditions in these deposits,studies of biostratigraphy,microfacies,microtaphofacies,and sequence stratigraphy were performed in a single area at Tang-e Shabi Khoon,northwest of Zagros.Based on the identification of two assemblage zones consisting of benthic foraminifera in these strata,the formation was deposited during the middle to late Maastrichtian.The number of cycles in test size and type of coiling in Loftusia decreased from the study area toward the northwest of the Neotethys basin.The input of clastic sediments affected the distribution of Loftusia and rudists in the study area.Nine microfacies,six microtaphofacies,and one terrigenous facies(shale)were identified based on the sedimentary features.These deposits of the middle-late Maastrichtian were deposited on a homoclinal carbonate ramp.The platform can be divided into restricted and semi-restricted lagoon,shoal,and open marine environments.In the study area,the deposits of the Tarbur Formation were deposited during four third-order depositional sequences.Local fault activities affected the formation of depositional sequences in the study area.  相似文献   

Numerical Modeling of Tropical Cyclone-Induced Storm Surge in the Gulf of Oman Using a Storm Surge–Wave–Tide Coupled Model     

Siahsarani  Amir  Karami Khaniki  Ali  Aliakbari Bidokhti  Abbas-Ali  Azadi  Majid 《Ocean Science Journal》2021,56(3):225-240

Ocean Science Journal - A storm surge is a complex phenomenon in which current, tide, and waves interact with each other. Even if the wind is the main force of driving the surge, waves and tide are...  相似文献   

Novel Hybrid Integration Approach of Bagging-Based Fisher’s Linear Discriminant Function for Groundwater Potential Analysis     

Chen  Wei  Pradhan  Biswajeet  Li  Shaojun  Shahabi  Himan  Rizeei  Hossein Mojaddadi  Hou  Enke  Wang  Shengquan 《Natural Resources Research》2019,28(4):1239-1258

Natural Resources Research - Groundwater is a vital water source in the rural and urban areas of developing and developed nations. In this study, a novel hybrid integration approach of...  相似文献   

Modeling and assessing the effects of land use changes on runoff generation with the CLUE-s and WetSpa models     

Mohammady  Majid  Moradi  Hamid Reza  Zeinivand  Hossein  Temme  A.J.A.M.  Yazdani  Mohammad Reza  Pourghasemi  Hamid Reza 《Theoretical and Applied Climatology》2018,133(1-2):459-471

Theoretical and Applied Climatology - Land use change is an important determinant of hydrological processes and is known to affect hydrological parameters such as runoff volume, flood frequency,...  相似文献   

An integrated object-based image analysis and CA-Markov model approach for modeling land use/land cover trends in the Sarab plain     

Amin Naboureh  Mohammad Hossein Rezaei Moghaddam  Bakhtiar Feizizadeh  Thomas Blaschke 《Arabian Journal of Geosciences》2017,10(12):259

The present paper is an attempt to integrate a semi-automated object-based image analysis (OBIA) classification framework and a cellular automata-Markov model to study land use/land cover (LULC) changes. Land use maps for the Sarab plain in Iran for the years 2000, 2006, and 2014 were created from Landsat satellite data, by applying an OBIA classification using the normalized difference vegetation index, salinity index, moisture stress index, soil-adjusted vegetation index, and elevation and slope indicators. The classifications yielded overall accuracies of 91, 93, and 94% for 2000, 2006, and 2014, respectively. Finally, using the transition matrix, the spatial distribution of land use was simulated for 2020. The results of the study revealed that the number of orchards with irrigated agriculture and dry-farm agriculture in the Sarab plain is increasing, while the amount of bare land is decreasing. The results of this research are of great importance for regional authorities and decision makers in strategic land use planning.  相似文献   

Paleoenvironment of geomorphic surfaces of an alluvial fan in the eastern Isfahan,Iran, in the light of micromorphology and clay mineralogy     

Omid Bayat  Hamidreza Karimzadeh  Alireza Karimi  Mostafa Karimian Eghbal  Hossein Khademi 《Arabian Journal of Geosciences》2017,10(4):91

Alluvial fans are one of the most important landforms in geomorphological and paloenvironmental studies. The objective of this study was the application of clay mineral assemblages and micromorphological properties of the studied paleosols in the geomorphic surfaces of an alluvial fan in the eastern Isfahan as proxies for paleoenvironmental and paleoclimatic changes. Micromorphology, X-ray diffraction, and scanning electron microscopy approaches were used to study the representative pedons. The results indicated that the illuviation process in the calcareous soils of the arid regions of the eastern Isfahan was probably in response to Quaternary moist conditions. There was no significant difference between clay coating properties of the studied relict and buried paleosols. Clay mineralogical study suggested that kaolinite and illite were inherited from the parent materials, while smectite and palygorskite were formed in the soil environment. Paleoargillic horizon was characterized by smectite and calcic (especially the calcrete) horizons were dominated by palygorskite. Palygorskite was accumulated by both neoformation and illuviation processes. High clay content, high intensity of smectite peak, and activity of the illuviation process in paleoargillic horizon demonstrated the seasonality of climate (rainfall) even in the moist periods of Quaternary in Central Iran. Clay mineralogical assemblages suggested a trend of increasing environmental aridity in the study area. This study, therefore, highlighted the role of clay mineralogical investigations in arid lands’ geomorphological and paleoenvironmental researches.  相似文献   

3D geomechanical modeling and estimating the compaction and subsidence of Fahlian reservoir formation (X-field in SW of Iran)     

Ali Ranjbar  Hossein Hassani  Kourosh Shahriar 《Arabian Journal of Geosciences》2017,10(5):116

A geomechanical model can reveal the mechanical behavior of rocks and be used to manage the reservoir programs in a better mode. Fluid pressure will be reduced during hydrocarbon production from a reservoir. This reduction of pressure will increase the effective stress due to overburden sediments and will cause porous media compaction and surface subsidence. In some oil fields, the compacting reservoir can support oil and gas production. However, the phenomena can also cause the loss of wells and reduced production and also cause irreparable damage to the surface structures and affect the surrounding environment. For a detailed study of the geomechanical behavior of a hydrocarbon field, a 3D numerical model to describe the reservoir geomechanical characteristics is essential. During this study, using available data and information, a coupled fluid flow-geomechanic model of Fahlian reservoir formation in X-field in SW of Iran was constructed to estimate the amount of land subsidence. According to the prepared model, in this field, the maximum amount of the vertical stress is 110 MPa and the maximum amount of the horizontal stress is 94 MPa. At last, this model is used for the prediction of reservoir compaction and subsidence of the surface. The maximum value of estimated ground subsidence in the study equals to 29 mm. It is considered that according to the obtained values of horizontal and vertical movement in the wall of different wells, those movements are not problematic for casing and well production and also the surrounding environment.  相似文献   

Experimental study of headcut erosion in cohesive soils under different consolidation types and hydraulic parameters   总被引：2，自引：0，他引：2  

Hossein Babazadeh  Masoumeh Ashourian  Mahmood Shafai-Bajestan 《Environmental Earth Sciences》2017,76(12):438

Headcut is a change in stream channel elevation, where there is concentrated flow. Most of the past studies focus on non-cohesive soils, although many problems on the streams occur because of cohesive beds and banks. In this study, eight samples of cohesive soils, with a different composition of silt and clay, for different waterfall heights and flow velocity under long- and short-term natural consolidation conditions were tested. In one of the tests, a sand layer was settled on the headcut bed to investigate its impact on headcut erosion. By increasing clay content, the headcut will remain vertical as it moves backward. Result showed that the effect of clay content reduction was more noticeable under the long-term consolidation condition. In general, the effect of clay percentage variation on the measured parameters is much higher than the effects of waterfall height or flow velocity, and the effect of consolidation type and adding a sand layer on the measured values is much higher than the effect of clay percentage variation on the waterfall height and flow velocity.  相似文献