No abstract

Acacia trees in Sinai desert are suffering population decline. This study aims to explore this assumption and to determine the effects of grazing and urbanization on size structure of Acacia tortilis subsp. raddiana along a gradient of water availability in Wadi Feiran basin, South Sinai, Egypt. Size structure of 289 Acacia trees in thirteen isolated populations was analysed. Catchment area and lineament density as water availability indicators were calculated. Effects of grazing and urbanization on Acacia populations were evaluated. A strong positive correlation was recognized between tree height, crown diameter and trunk circumference. Acacia tree density and crown diameter are positively correlated with water availability indicators. Population structure of A. tortilis is characterized by absence of juveniles, clear reduction in numbers of small and large categories and increasing in medium categories. This pattern indicates very low recruitment and high mortality of small and large trees. The variation in water availability may have considerable effects on the structure of A. tortilis. Overgrazing, cutting and urbanization are the main causes of population decline of Acacia in Sinai desert. In addition, drought conditions and bruchid seed beetles aggravate the anthropogenic effect on recruitment of Acacia in South Sinai.

Sinai Peninsula has fascinating geologic setting and is displaying a diversity of structural lineaments that have greatly influenced the distribution of natural resources and hazards. Shaded relief images derived from SRTM-DEM mosaics were used for the identification, extraction, and mapping of these structural lineaments. Statistical parameters particularly, azimuth frequency, lineament intersection, lengths, and density distribution were analyzed using SPSS software. Two additional new statistical indices; Lineament Relative Abundance Index (LRAI) and Lineament Majority-Minority Index (LMMI) were applied. Moreover, the distribution of the different statistical parameters was illustrated as contour maps through GIS environment. Basically, two dominant clusters; NW-SE and NNE-SSW trends were detected. These trends are related to major fracture systems that are characterized by extensive mean lengths and high proportion values. Furthermore, the northern and central parts of Sinai Peninsula have lower density and intersection of structural lineaments that gradually increase towards the southern part. However, the northern part of Sinai displays wider areas of majority zones than the southern part. This could be attributed to the lower density of lineaments and little tendency for multiple lineament populations. The majority zones are usually associated with NE and NW-SE in the northern part of Sinai, whereas the majority zones are of less abundance in the central and southern parts of Sinai due to the multiple orientations of lineament populations which reduce the tendency for majority. Eventually, the results of the present work could be applicable in the different geologic and environmental aspects that are based on a good understanding of the genetic and spatial relationships of fracture systems. These aspects encompass geodynamics, exploration for mineralization and groundwater, in addition to the mitigation of natural hazards such as flush flooding and earthquakes.

No abstract

No abstract

Paleo and recent earthquakes have been recorded in Wadi Hagul area and its environs, which have left behind geologic structures of deformation preserved in exposed sedimentary rocks. To evaluate such deformation and surface break, different techniques and data types are used compromising image processing techniques, Geographic Information Systems (GIS), seismicity data, as well as, field investigation. The field investigation clarified that the study area is enriched with soft-sediment deformation structures encompassing two types of geologic structures; brittle and viscoplastic structures. The analysis of the various types of data elucidate that, the earthquakes of Wadi Hagul are frequently distributed at an average depth ranging from (1 to 35 km) within the top of the Earth’s crust which are mainly controlled by existing Hagul fault zone. The study gives new insight for a better understanding of the seismic activity in the study area which helps in the seismic hazard assessmen

No abstract

The pieces of information that are being collected from regions of disaster is critical as the rapid deployment of the first responders rely on them. Another critical part of that deployment is the acquisition of different types of information (visual, sounds, and others). Even with that information the rescuing teams still face the difficult task of rescuing humans under debris. Some of the constraints that make this task harder are the wrecked building’s unknown structure, time limitation, the difficulty to collect information under the debris and more. An important issue is the accurate collection of information beneath destroyed structures and the 3D representation of the space and the correct location of the human subject under the debris. This paper deals with the design and the capabilities of a ground bio-inspired micro-robot, called Tzitziki, capable to select visual and audio information beneath destroyed buildings and locate human subjects in areas (like deep underground cavities), the reconstruction of the underground cavities and the synergistic collaboration of drones, micro-robots and human first responders. Illustrative examples are provided proving the concept.