Vulnerability mapping of shallow groundwater aquifer using SINTACS model in the Jordan Valley area, Jordan

Jordan Valley is one of the important areas in Jordan that involves dense agricultural activities, which depend on groundwater resources. The groundwater is exploited from an unconfined shallow aquifer which is mainly composed of alluvial deposits. In the vicinity of the Kafrein and South Shunah, the shallow aquifer shows signs of contamination from a wide variety of non-point sources. In this study, a vulnerability map was created as a tool to determine areas where groundwater is most vulnerable to contamination. One of the most widely used groundwater vulnerability mapping methods is SINTACS, which is a point count system model for the assessment of groundwater pollution hazards. SINTACS model is an adaptation for Mediterranean conditions of the well-known DRASTIC model. The model takes into account several environmental factors: these include topography, hydrology, geology, hydrogeology, and pedology. Spatial knowledge of all these factors and their mutual relationships is needed in order to properly model aquifer vulnerability using this model. Geographic information system was used to express each of SINTACS parameters as a spatial thematic layer with a specific weight and score. The final SINTACS thematic layer (intrinsic vulnerability index) was produced by taking the summation of each score parameter multiplied by its specific weight. The resultant SINTACS vulnerability map of the study area indicates that the highest potential sites for contamination are along the area between Er Ramah and Kafrein area. To the north of the study area there is a small, circular area which shows fairly high potential. Elsewhere, very low to low SINTACS index values are observed, indicating areas of low vulnerability potential.     

Structural and geomorphological aspects of the Kat landslides (Tokat—Turkey) and susceptibility mapping by means of GIS

Kat County, which is located in a slope of hilly region and constructed in the side of a mountain along the North Anatolian Fault Zone, is frequently subject to landslides. The slides occur during periods of heavy rainfall, and these events cause destruction to property, roads, agricultural lands and buildings. In the last few decades, a lot of houses and buildings have been damaged and destroyed. Settlement areas have remained evacuated for a long time. The slope instabilities in the study area are a complex landslide extending from north to south containing a lot of landslides. Field investigations, interpretation of aerial photography, analyses of geological data and laboratory tests suggest that some factors have acted together on the slopes to cause the sliding. In the wet season, the slopes became saturated. As the saturation of the earth material on the slope causesa rise in water pressure, the shear strength (resisting forces) decreases and the weight (driving forces) increases; thus, the net effect was to lower the safety factor. Previous failures have affected the rock mass, leading to the presence of already sheared surfaces at residual strengths. The relation between the joint planes and the instability of the slope in the study area was discussed and it was found that the potential slope instabilities are mainly in the directions of NW–SE, NE–SW and N–S. The landslide susceptibility map obtained by using the geographical information system showed that a large area is susceptible and prone to landslides in the northern part of the study area.An erratum to this article can be found at     

Two-dimensional nonlinear site response analysis of Adapazarı plain and predictions inferred from aftershocks of the Kocaeli earthquake of 17 August 1999

The objective of this study is to investigate the effects of local site conditions in the Adapazarı plain crossing the severely damaged central part of Sakarya during the 17th August earthquake. A two-dimensional model has been used to obtain the free-field motions in the valley and on surface formations. A preliminary geotechnical profile model developed from available but limited soil data was checked using recordings of some specific locations where a strong ground motion accelerometer array was in operation after the main earthquake. The range of validity of the model was assessed and modifications were made to compare with the actual recorded motions. The purpose of building such a model, which was used to study the aftershocks in Adapazarı, is to provide an improved database to be used for the design of structures in the city. This study also attempts to provide greater insight into the local site response phenomena through the use of a two-dimensional nonlinear analysis. Simulated site responses are in global agreement with the recorded data. In general agreement between the amplification functions of the computed and recorded data is satisfactory for the frequencies of engineering interest. Alluvial sites show amplification factors in the range of 4–6 in the frequencies between 0.6 and 2 Hz. A relatively shallow alluvial station, HASTAHANE, experienced considerable amplification for small aftershocks and deamplification for the strongest aftershock in frequencies between 0.5 and 2 Hz. Another station, TOYOTA, with significant deamplification characteristics and a clearly observed peak response frequency shift at the soil resonant frequency may have experienced soil shear failure during the strongest aftershock. Other alluvial stations, SEKER and GENC, show deamplification characteristics at 0.55 and at around 1 Hz. with the peak frequency shifts during the magnitude 5.8 aftershock. In general, site responses are larger in the alluvial basin for all aftershocks except the magnitude 5.8 event.     

Simulation of land use dynamics and impact on land surface temperature using satellite data

GeoJournal - Increasing of global average surface temperature naturally leading to major problems as global warming, which has typically attracted the interest of multinational organizations, civil...     

Mapping and assessment-based modeling of soil fertility differences in the central and eastern parts of the Black Sea region using GIS and geostatistical approaches

This study was carried out on arable lands of the central and eastern Black Sea regions including eight provinces (Artvin, Giresun, Gümü?hane, Ordu, Rize, Samsun, Sinop, and Trabzon). The present study aims to generate a soil fertility map for agricultural lands in the central and eastern parts of the Black Sea region. The main objective of this research is to quantify soil fertility by developing a soil fertility index (SFI) model at the regional level. The related objectives were to map the spatial distribution of soil fertility by using auxiliary variables and to model soil fertility within the study region. To accomplish this, a data set for soil fertility differences was collected and a model was developed to predict the spatial distribution of differences across the region. The study area was divided into 2.5 × 2.5-km grid squares. A total of 3400 soil samples were collected from the surface (0–20 cm) of each grid intersection point. The geostatistical method was used to generate the SFI distribution map of the study area for surface soils. Of the total study area, 93.76% had good (S1) or moderately fertile (S2) soil while 6.15% of the area had marginally fertile (S3) soil. Only a very small area (N) had low-fertility soil.     

Quantitative Control of Migration: A Geostatistical Attempt

This paper is devoted to a geostatistical attempt at modeling migration errors when localizing a reflector in the ground. Starting with a probabilistic velocity model and choosing the simple geometrical optics background for the wave propagation in such media, we give the expression of the errors. This may be quantified provided the covariance of the velocity field is known. Variance of arrival times at constant offset is related to the covariance of the velocity field at hand. A practical application is given in the same paragraph. After that we give a typical schema for migration and uncertainty modeling: starting with seismic data, we make the weak seismic inversion. We then obtain the covariance of the velocity field that we use for simulating migration errors. The main issues of this methodology are discussed in the last paragraph.     

A modified light transmission visualization method for DNAPL saturation measurements in 2-D models

In this research, a light transmission visualization (LTV) method was used to quantify dense non-aqueous phase liquids (DNAPL) saturation in two-dimensional (2-D), two fluid phase systems. The method is an expansion of earlier LTV methods and takes into account both absorption and refraction light theories. Based on this method, DNAPL and water saturations can rapidly be obtained point wise across sand-packed 2-D flow chambers without the need to develop a calibration curve. A single point calibration step is, however, needed when dyed DNAPL is used to account for the change in the transmission factor at the dyed DNAPL–water interface. The method was applied to measure, for the first time, undyed DNAPL saturation in small 2-D chambers. Known amounts of DNAPL, modeled by tetrachloroethylene (PCE), were added to the chamber and these amounts were compared to results obtained by this LTV method. Strong correlation existed between results obtained based on this method and the known PCE amounts with an R² value of 0.993. Similar experiments conducted using dyed PCE showed a stronger correlation between results obtained by this LTV method and the known amounts of dyed PCE added to the chamber with an R² value of 0.999. The method was also used to measure dyed PCE saturation in a large 2-D model following sparging experiments. Results obtained from image analyses following each sparging event were compared to results obtained by two independent techniques, namely gas chromatography–mass spectrometry (GC/MS) analyses and carbon column extraction. There was a good agreement between the results obtained by this LTV method and those obtained by the two independent techniques when experiments were carried out under stable light source conditions and errors in mass balance were minor. The method presented here can be expanded to measure fluid contents in three fluid phase systems and provide a non-destructive, non-intrusive tool to investigate changes in DNAPL architecture and flow characteristics in laboratory experiments.     

Seismic hazard map of the Middle East

The collaborative project Earthquake Model of the Middle East (EMME, 2010–2015) brought together scientists and engineers from the leading research institutions in the region and delivered state-of-the-art seismic hazard assessment covering Afghanistan, Armenia, Azerbaijan, Cyprus, Georgia, Iran, Iraq, Jordan, Lebanon, Palestine, Pakistan, Syria and Turkey. Their efforts have been materialized in the first homogenized seismic hazard model comprising earthquake catalogues, mapped active faults, strong motions databank, ground motion models and the estimated ground motion values for various intensity measure types and relevant return periods (e.g. 475–5000 years). The reference seismic hazard map of the Middle East, depicts the mean values of peak ground acceleration with a 10% chance of exceedance in 50 years, corresponding to a mean return period of 475 years. A full resolution poster is provided with this contribution.     

Analytical Modeling of Well Design in Riverbank Filtration Systems

Analytical studies for well design adjacent to river banks are the most significant practical task in cases involving the efficiency of riverbank filtration systems. In times when high pollution of river water is joined with increasing water demand, it is necessary to design pumping wells near the river that provide acceptable amounts of river water with minimum contaminant concentrations. This will guarantee the quality and safety of drinking water supplies. This article develops an analytical solution based on the Green's function approach to solve an inverse problem: based on the required level of contaminant concentration and planned pumping time period, the shortest distance to the riverbank that has the maximum percentage of river water is determined. This model is developed in a confined and homogenous aquifer that is partially penetrated by the stream due to the existence of clogging layers. Initially, the analytical results obtained at different pumping times, rates and with different values of initial concentration are checked numerically using the MODFLOW software. Generally, the distance results obtained from the proposed model are acceptable. Then, the model is validated by data related to two pumping wells located at the first riverbank filtration pilot project conducted in Malaysia.