Structural Control on the Salmas Geothermal Region, Northwest Iran, from Fractal Analysis and Paleostress Data

The Salmas geothermal field is located in NW Iran. Subduction of Neo-Tethys oceanic crust beneath the Iranian microcontinent caused to propagation of the magmatic-Arc. Fractures and faults in the convergent zone have created path-ways for the circulation of geothermal fluid. Fracture concentration in the Salmas geothermal field has been characterized using of the fractal method and creation of a fracture density map that shows the highest concentration in the central part of the study area. The permeability of fractures has been evaluated by analyzing their orientation in respect to the paleostress axes. Also, the fractal analyzing result indicates the maximum fractal dimension (1.96) is around the thermal spring outlet. Paleostress analyzing revealed that in the central part of the study area, σ1 axes orientation is S90°W/10° and the σ2 dip is near to the vertical in this stress field, where strike slip faults can be propagated. In the SE part near the recharge of the thermal springs, the σ3 plunge increases to 70? and σ1 orientation is N15°E/20°, in this local tectonic regime thrust fault developed. Fractures have an important role in the circulation of fluid and the fractal dimension increases near the thermal springs in the Salmas geothermal field. Regarding the paleostress data fracture with N-S direction such as the F1 fault zone (parallel to the σ1 axes), a suitable pathway for deep circulation of geothermal fluid flow has been created.     

CAD Tool Simulates and Evaluates GPS Receiver Designs

A new computer-aided design (CAD) program called Falcon 3.0 has been created to simulate and evaluate receiver designs. This CAD tool aims to solve tasks at the design stage of navigation receivers that operate with signals from Navigational Satellite Time and Ranging (NAVSTAR) and Global Navigational Satellite System (GLONASS). Specific tasks include: · Defining the receiver frequency plan (frequencies of oscillators and filters that guarantee accuracy of the receiver) · Specifying parameters for the digital processing of received signal · Computing interpath and interchannel biases · Computing statistical characteristics of correlation signals I, Q, dl, and dQ · Calculating noise and multipath errors of measurements · Determeining energy losses This CAD tool has been used in the design of receivers such as Javad Positioning Systems (JPS) Legacy, Regency, Odyssey, and Eurocard and in the prediction of their accuracy. It has been shown that experimental and predicted data agree well. ? 2000 John Wiley & Sons, Inc.     

Determination of Salinity in Fluid Inclusions with Laser Raman Spectroscopy Technique

ＩＮＴＲＯＤＵＣＴＩＯＮＬａｓｅｒＲａｍａｎｍｉｃｒｏｐｒｏｂｅｈａｓｂｅｅｎｆｏｕｎｄｉｎｍａｎｙｇｅｏｌｏｇｉｃａｌａｐｐｌｉｃａｔｉｏｎｓ (Ｓｈｏｖａｌｅｔａｌ.,1995 ;ＭｃＭｉｌｌａｎａｎｄＨｏｆｍｅｉｓｔｅｒ,1988;ＭｃＭｉｌｌａｎ ,1984;Ｄｕｂｅｓｓｙｅｔａｌ.,1982 ;Ｇｒｉｆｆｉｔｈ ,1975 )ａｎｄａｓａｎｏｎ ｄｅｓｔｒｕｃｔｉｖｅａｎｄｉｎｓｉｔｕｔｅｃｈｎｉｑｕｅ,ｉｔｈａｓｈａｄａｔｒｅｍｅｎｄｏｕｓｉｍｐａｃｔｏｎｄｅｖｅｌｏｐｍｅｎｔｏｆｆｌｕｉｄｉｎｃｌｕｓｉｏｎｃｏｍｐｏｓｉ…     

The application of multiple linear regression method in reference evapotranspiration trend calculation

Trend analysis of reference evapotranspiration (ET₀), as a key factor in irrigation programming, has an important role in water resources management. Many parameters affect ET₀ and their variations can change its values. In this paper, the effect of temporal variation of meteorological variables including wind speed, temperature, solar radiation and saturation vapor pressure deficit on temporal variations of ET₀ was analyzed. Trend analysis of ET₀ and its more effective meteorological parameters was accomplished in 30 synoptic stations which are located in Iran using Spearman’s Rho test. The multiple linear regressions were also used to determine the relationship between ET₀ trend and the trend of its more effective parameters. Increasing and decreasing trends in ET₀ were obtained at annual and seasonal scales. Many studied stations which had decreasing trend in the annual and seasonal periods have been located in the arid climates while all stations which have been located in humid and very-humid climates, had an increasing trend in annual and seasonal periods. The trend results in studied variables showed that annual and seasonal values of wind speed, temperature and saturation vapor pressure deficit decrease however the values of solar radiation increases in most studied stations. Multiple linear regressions results demonstrated that ET₀ trend can be calculated by the trend of two more effective variables including wind speed and saturation vapor pressure deficit.     

The spatial–temporal variation of dry and wet periods in Iran based on comparing SPI and RDI indices

Drought is a natural hazard which can cause harmful effects on water resources. To monitor drought, the use of an indicator and determination of wet and dry period trend seem to have an important role in quantifying the drought analysis. In this paper, in addition to the comparison of Reconnaissance Drought Index (RDI) and Standardized Precipitation Index (SPI), based on the most appropriate probability distribution function, it was tried to examine the trends of dry and wet periods based on the mentioned indices. Accordingly, the meteorological data of 30 synoptic stations in Iran (1960–2014) was used and the trend was analyzed using the Mann–Kendall test by eliminating the effect of any significant autocorrelation coefficients at 95% confidence level (modified Mann–Kendall). Comparing results between the time series of RDI and SPI drought indices based on statistical indicators (RMSE?<?0.434, R²?>?0.819 and T-statistic?<?0.419) in all studied stations revealed that the behavior of the two indices was roughly the same and the difference between them was not significant. The trend analysis results of RDI and SPI indices based on modified Mann–Kendall test showed that the variation of dry and wet periods was decreasing in most of the studied stations (five cases were significant). In addition, the results of the trend line slope of dry and wet periods related to the drought indices in the studied area indicated that the slope was negative for SPI and RDI indices in 70% and 50% of stations, respectively.     

An Integrated Water Resources Management Considering Agricultural Demands and the Assessment of Different Scenarios in Hirmand Catchment,Iran

Water Resources - The lack of water resources as a critical substance and the increase of water demands and also the complexity of water resources management issues are made the integrated water...     

An empirical model for salinity intrusion in alluvial estuaries

The main parameters that affect the salinity intrusion in estuaries are their geometric, hydrologic and hydrodynamic characteristics. The recognition of effective parameters and understanding their roles in the salinity intrusion are required for estuarine water management. In this study, the governing equations of the salinity intrusion processes were scaled to derive the effective dimensionless parameters. Then, a previously verified model, CE-QUAL-W2, was utilized as a virtual laboratory to investigate the effects of different governing parameters on the salinity intrusion. Analysis of the results showed that logarithmic functions can be used to describe the effect of dimensionless parameters obtained by scaling of governing equations. Finally, a formula was suggested to predict the salinity intrusion length based on geometrical and hydrodynamic characteristics of alluvial estuaries.     

Determination of Storage Coefficients During Pumping and Recovery

An aquifer test is used mostly to determine the storage coefficient and transmissivity. Although residual drawdown data are widely used in estimating the transmissivity of aquifers, the estimation of storage coefficients with recovery data is controversial. Some researchers have proposed methods to estimate storage coefficients with recovery data by assuming equality of storage coefficients for the recovery and pumping periods (S = S′). The aim of this study is to determine storage coefficients without such an assumption, that is, S≠S′. The method is a modified version of Banton‐Bangoy's method without considering drawdown data due to pumping. Drawdown is plotted vs. the logarithmic ratio (t′/t) or time since pumping stopped to the duration of pumping and the ratio of storage coefficient during recovery to the storage coefficient from the pumping period (S′/S). The method is verified with one case study and two synthetic examples. Thus, it is possible to determine storage coefficient of pumping period accurately without any data from pumping period by recovery data.     

Assessment of a spatial multi-criteria evaluation to site selection underground dams in the Alborz Province,Iran

Most part of Iran is arid and semi-arid; thus in most parts of the region, groundwater is the only source of water. This research presents a method based on a spatial multi-criterion evaluation (SMCE) for designing possible sites of underground dams and ranks them according to their suitability. The method was tested for siting underground dams in the Alborz Province, Iran. At first, screening algorithm was applied using exclusionary criteria, and thirty-one potential areas were recognized in the study area. In the next step, a suitable gorge or valley was recognized using the combination of basic maps and extensive field surveys (long axis of tank level) in each potential area. Subsequently, the analytical hierarchy process was used as a powerful tool for decision-making in the SMCE in order to evaluate different criteria for underground dam sites. SMCE techniques were then applied to combine the criteria, and obtain a suitability map in the study area. These sites were then compared and ranked according to their main criteria such as water, storage, axis and socio-economics. All these criteria were assessed through geographical information system modelling. This method shows passable results and could be used for site selection of underground dams in other regions of Iran.