Head-on collision of electron acoustic solitary waves in a plasma with nonextensive hot electrons

The head-on collision between two electron-acoustic solitary waves (EASWs) in an unmagnetized plasma is investigated, including a cold electrons fluid, hot electrons, obeying a nonextensive distribution and stationary ions. By using the extended Poincaré-Lighthill–Kuo (PLK) perturbation method, the analytical phase shifts following the head-on collision are derived. The effects of the ratio of the number density of hot electrons to the number density of cold electrons α, and the nonextensive parameter q on the phase shifts are studied. It is found that q and the hot-to-cold electron density ratio significantly modify the phase shifts.     

Isolation and submerged culture biomass production of the arid land cyanobacteria <Emphasis Type="Italic">Microcoleus</Emphasis> spp., an investigation on its utilization for biological soil crust restoration

Biological soil crust (BSC) restoration could effectively contribute in reducing several adverse environmental impacts such as soil erodibility. The usefulness of the microorganism constituent of the arid land (e.g., desert land cyanobacteria Microcoleus) for the BSC restoration has already been introduced, not only by laboratory studies but also by many other field investigations. In order to isolate the soil cyanobacteria with a potential to support BSC succession, soil samples from the southwestern dry lands in Iran were taken, soils serial dilution was prepared and submerged, and streaking-plate methods were applied. The newly isolated native cyanobacterium was identified as the Microcoleus on the genus level following the standard references. The isolated cyanobacterium was cultured phototrophically using five different media consisting of BBM, BG-11, F/2, Jourdan, and artificial wastewater submerged batch. Microcoleus spp. was found in all sites soil samples. The maximum biomass was achieved in the Jourdan submerged culture medium with an amount of 0.88 g/L. The cell density in this culture medium was increased up to 20 times of the initial cell density during 7 days of the cultivation. The specific biomass growth rate was calculated to be in a range of 0.03–0.057 per day. The preliminary experiments and reported restoration activities of Microcoleus submerged cultures were shown to have the potential for providing the soil with the inoculant for the restoration of the degraded arid lands such as Middle East region.     

Using Dempster–Shafer theory to model earthquake events

Natural Hazards - In this study, Dempster–Shafer theory (DST) is integrated into a geographic information system to model vulnerability of the land surface to earthquake events in...     

Environmental Hydrogeochemistry Characteristics,Controlling Factors and Groundwater Quality Assessment in Herat City,West Afghanistan

Water Resources - Water in Central Asia is a precious resource in the semiarid and arid environments in which people live in the region. Understanding the groundwater quality is important as it is...     

The Role of Ex-Post and Ex-Ante Integrated Assessment Frameworks in Conceptualization of the Modeling Process in the Context of Integrated Water Resources Management

Water Resources - Reconnaissance and conceptualization of the system are the first steps to perform an integrated assessment study and step towards sustainability. This paper focuses on the...     

Regionalization of potential evapotranspiration using a modified region of influence

Theoretical and Applied Climatology - This study examined the effect of different attributes on regionalization of potential evapotranspiration (ETp) in Urmia Lake Basin (ULB), Iran, using the...     

The role of meteorological forcing and snow model complexity in winter glacier mass balance estimation,Columbia River basin,Canada

Glaciers are commonly located in mountainous terrain subject to highly variable meteorological conditions. High resolution meteorological (HRM) data simulated by atmospheric models can complement meteorological station observations in order to assess changes in glacier energy fluxes and mass balance. We examine the performance of two snow models, SnowModel and Alpine3D, forced by different meteorological data for winter mass balance simulations at four glaciers in the Canadian portion of the Columbia Basin. The Weather Research and Forecasting model (WRF) with resolution of 1 km and the North American Land Data Assimilation System with ~12 km resolution, provide HRM data for the two snow models. Evaluation is based on the ability of the snow models to simulate snow depth at both point locations (automated snow weather stations) and over the entire glacier surface (airborne LiDAR [Light Detection and Ranging] surveys) during the 2015/2016 winter accumulation. When forced with HRM data, both models can reproduce snow depth to within ±15% of observed values. Both models underestimate winter mass balance when forced by HRM data. When driven with WRF data, SnowModel underestimates winter mass balance integrated over the glacier area by 1 and 10%, whilst Alpine3D underestimates winter mass balance by 12 and 22% compared with LiDAR and stake measurements, respectively. The overall results show that SnowModel forced by WRF simulated winter mass balance the best.     

Deformation analysis of the Lake Urmia causeway (LUC) embankments in northwest Iran: insights from multi-sensor interferometry synthetic aperture radar (InSAR) data and finite element modeling (FEM)

This paper presents deformation analysis of Lake Urmia causeway (LUC) embankments in northwest Iran using observations from interferometry synthetic aperture radar (InSAR) and finite element model (FEM) simulation. 58 SAR images including 10 ALOS, 30 Envisat and 18 TerraSAR-X are used to assess settlement of the embankments during 2003–2013. The interferometric dataset includes 140 differential interferograms which are processed using InSAR time series technique of small baseline subset approach. The results show a clear indication of large deformation on the embankments with peak amplitude of \(>\) 50 mm/year in 2003–2010, increasing to \(>\!\!80\)  mm/year in 2012–2013 in the line of sight (LOS) direction from ground to the satellite. 2D decomposition of InSAR observations from Envisat and ALOS satellites that overlap in the years 2007–2010 shows that the rate of the vertical settlement and horizontal motion is not uniform along the embankments; Both eastern and western embankments show significant vertical motion, while horizontal motion plays a more significant role in eastern embankment than western embankment. The InSAR results are then used to simulate deformation using FEM at two cross-sections at the distance of 4 and 9 km from the most western edge of the LUC for which detailed stratigraphy data are available. Results suggest that consolidation due to dissipation of excess pore pressure in embankments can satisfactory predict settlement of the LUC embankments. Our numerical modeling indicates that nearly half of the consolidation since the construction time of the causeway 30 years ago has been done.