The purpose of this study is to evaluate changes in the land cover in the southeastern section of the central higlands of Madagascar. Landsat imagery, TM and ETM+, have been analyzed and classified according to the major land cover types. Two multi-temporal datasets are compared for change detection between the year 1994 and 1999. Due to the steep mountainous terrain of the surrounding region, evaluation data have been used to assist with visual interpretation of land cover types. The analytical outputs of this study will consist of 2 thematic maps that classify the major land types (1994 and 1999), a change detection image, shaded relief, and a 3-D terrain map of the selected area of interest. This study provides valuable information about the fragile nature of this area and other areas with similar characteristics, quantitative results regarding the amount of landscape change, and insight into the need for subsequent studies.

One of the most polluted areas in Alexandria coastal water is El-Mex Bay, which receive more than 90% of Alexandria domestic waster, in addition to agricultural and industrial wastes. There is, therefore, an urgent need to monitor these outfall areas to ensure that there is an acceptable degree of dispersion and dilution of sewage at sites of both existing and proposed outfalls. Historical data from hydrological observations and meteorological records were used to simulate the water circulation in the El-Mex bay. While current observations and satellite images were used to validate the model. The numerical simulation was performed by the Princeton ocean model (POM) with a resolution of about 0.125 minute (about 200 m in X-direction and 255 m in Y- direction). To test the sensitivity of the model simulation. The results were compared with current measurements taken in the same period. The comparison showed good agreement between the observed and simulated current. The results of the model simulation were discussed in the light of the indications in the light of the indications form satellite images taken at different periods for El-Mex region. The results show that the main sewage water impact area varies to great extends depending on the outlet location, the weather conditions and discharge rate. In general, the huge amount of polluted water discharged in El-Mex Bay via El-Umoum drain were distributed along the coasts of Alexandria during the predominate westerly wind regime. While, the Northerly and north easterly winds caused an accumulation of waste water inside the bay.

In this paper, a proposed system for tracing water body edges has been designed and implemented based on modifying Canny’s edge detector. This modification is based on the insertion of procedural rules having the characteristics of water, which is the feature to be exclusively distinguished. The spectral characteristics of the extracted water feature in different recorded wavelength bands have been used in the designed rules. This work consists of four stages. The first is detecting boundaries between objects suing Canny’s method which extracts all possible boundaries in the image representing all features governed by the selected thresholds. The second is developing a set of rules to remove all edges except those of the pertinent selected feature (water body). In this step, the process depends on prior information about the pattern of spectral response of water (reflectance values) in the selected Landsat-TM bands 2, 4 and 7. The third stage is developing and applying a thinning technique based on the edge direction information. In the fourth stage, a tracing process has been developed, which includes rules designed for connecting relevant edges. Such rules have considered the following parameters; the terminals of each edge distance between edges and the directionality of each edges. This procedure has been applied to Landsat satellite –TM data of a test sample image containing an open area of River Nile and its branches forming islands, demonstrating the condition of changing the tracing direction. Results of applying the proposed system have been successful in automatically delineating the main river stream features.

The red Sea coastal zone is characterized by the presence of highly sensitive and fragile biological natural resources and habitats. Due to the unplanned touristic activities, the Red Sea coastal zone is subjected to a serious environmental deterioration, El-Gona coastal area is located at the northern part of the Red Sea western coast. It is characterized by an extensive tidal flat and mangrove forest, and important extensive coral reefs and seagrass mats host its aquatic environment. Also, it is characterized by a wide coastal plain and sabkha habitat. This harmonious natural setting has been dramatically deteriorated and some were demolished due to the extensive construction works of El-Gona resort LANDSAT-TM scenes before and after touristic development are used for the execution of this study . They are used to detect, analyze and assess the environmental deterioration due to the rapid and unplanned touristic development Land use / land cover maps produced from multi –date (1984 and 1998) LANDSAT data. Different changes of the environmentally sensitive habitats and natural resources are detected. Also, the various anthropogenic features are interpreted from a recent high-resolution satellite image (IKONOS) . The GIS tool is used to integrate the results of the applied digital image processing techniques and the field measurement data, with different digital maps such as those depicting topography and geology, to assess the environmental deterioration in the study area. Results indicate a serious deterioration on different land-use /land –cover classes of the study. The total area of the changed land-use / land cover classes from 1984 to 1998 is calculated by (7.16) km2. The changed areas are concentrated around the shoreline. The reef flat, coastal sabkha and coral reef ecosystems are the most affected and deteriorated natural resources and habitats at the study area , Also, the anthropogenic modifications in the reef flat, in terms of landfill and excavation , may lead to increase of the erosion processes in and nearby El-Gona Shoreline .Recommendations are indicated that the environmental legislations must be enforced and Environmental Sensitivity. Index maps should be produced for the entire Egyptian coastal zones.

Conventional tourism is a growing industry in the U.A.E and the number of tourists visiting the country is escalating over the last few years, political stability, free-market economy, superb infrastructure and friendly attitude are the main assets. Beside conventional tourism, fascinating geological environments and spectacular landforms can add to the breadth of tourism. The main landforms of the country are: desert plains, sand dune fields, mountains, coastal zones and islands. Most of the population inhabits the desert plains and the coastal fringes. The main towns and most of the agricultural lands are located in these areas. Historically, an elaborated system of surface connected subterranean irrigation canals is known in the region (Aflai). These are remarkably efficient, and traditional farmers mastered their construction. They should be considered as a tourist attraction, the sand dune fields of the U.A.E, are world reknown for their awesomeness and variety. They include longitudinal, transverse, barchan and star types. The giant dunes of Liwa Oasis, A-Rub’a Al-Khali (Empty Quarter) and the interdune farms (Mahader) are quite unique. The eastern mountains in Al – Fujira Emirate are characterized by a set of rock units known as the amphibolites sequence “which was originally formed at and below the bottom of the ocean and then moved landwards to occupy its present place through dynamic earth processes some 58 million year ago. These mountains attract scientists from allover the world to study. The rocks are colorful and develop deeply incised canyons. Because of the relatively high annual rainfall, plenty of oases, farm plots and even springs do occur and add to the contrast of colors in the region. Jabal hafit stands some 1100 m above sea level near Al-Ain. This and the historical oases of Al-Ain, Hilly and Burami represent special attractions. Several of the Emirates islands are geologically unique, being cored (centered) by salt mountains (plugs) that came to surface some millions of years ago through melting of salt –Bearing (evaporate) rocks (Horomoz complex) several thousand feet deep. They are commonly fringed by low – lying lands and beautiful coastal zones these and the coastal belt of the main land are quite scenic. Coral reefs commonly develop in the shallow waters of the Arabin Gulf. The eastern coast is rather rocky but spacious sandy beaches are locally present. The coastal areas of the U.A. E are being subjected to various types and degrees of development activities. Some however, are still pristine. sabkhas and mangroves are well represented . Interest should be extended to historical and archeological sites. Desert and marine sports should be promoted and taken advantage of. These include mountains and dune climbing, sand and water skiing, hunting and fishing, camel, horse, motor cycle and car (off- road vehicle) racing

The Kalabsha fault, south of Aswan, is one of many E-W oriented faults, which exist in Egypt. Movement on this fault was responsible for the November 14, 1981 earthquake (5.6 M) in the south-eastern part of the Western Desert. Detailed structural field mapping of a 30-km long segment of this fault, from Gebal Marawa in the east to Wadi Kalabsha in the west, was carried out using conventional aerial photographs, Landsat Enhanced Thematic Mapper (ETM+) images and Shuttle Imaging Radar (SIR) C/X Synthetic Aperture Radar (SAR) as base maps. The study indicates that the Kalabsha fault extends for ca. 260 km west of the Nile and can also be traced for 20 km to the east of the Nile before it dies out. The studied part of the fault shows that the Kalabsha fault is not a single continuous fracture, but is composed of several segments having right stepping en -echelon arrangement. Kinematic indicators (e.g. slickensides, minor folds, faults) indicate a major dextral strike-slip movement and a subordinate northward dipslip movement. The same result was also obtained from the fault plane solution of the 14th of November 1981 earth quake. Rocks between the ends of en echelon fault segments are forming sag synclines. Irregularity of the fault line produces releasing and constraining bends. Rocks adjacent to the releasing bends are deformed into rhomb-shaped grabens and left-stepping en echelon minor faults. The rocks between these minor faults are deformed by relay ramps. On the other hand, rocks adjacent to the constraining bends are deformed by push-up anticlines whose cores expose Precambrian granites. The Kalabsha fault is post Early Eocene in age as it affects Cretaceous, Paleocene and Lower Eocene rocks. Quaternary wadis and tufa deposits are also offset by the fault. Quaternary terraces and sand sheets along the trace of the fault show open fractures filled with wind-blown sand indicating recent seismic activity due to reactivation of the fault. These criteria indicating that although the Aswan High Dam reservoir may have contributed to the seismicity of the area, it is not the only reason for the earthquake recurrence. It is argued that the seismic activity of the Kalabsha fault is due to the present day plate configuration and stress distribution related to the Red Sea opening.

Satellite images suffer degradations of varying origins spanning image acquisition system (sensor, scanners and electronics), atmosphere, relative motion, platform orientation and images communication and archiving system. Degradation is a complex of interaction of blurring source, distortions and noise corruption. Removal or reduction of degradations that were incurred while the digital images were being obtained will be termed as restoration. We distinguish two generally confused concepts: image enhancement and image recovery or restoration; the latter is the only one considered in this work. Image restoration is concerned with the reconstruction or estimation of an uncorrupted image from a distorted and noisy one. The restoration problem studied is formulated as follows: Given data (x, y) [image]; Determine f (x, y) [object or scene] that produced g (x, y). Algorithms for computing or getting an estimate ƒ (x, y) satisfying certain performance measure represents the focal point of this work. Several representatives for the classes of algorithms for recovering from certain impairing sources are given and an “acceptable” estimate of the object distribution function f is obtained on the basis of regularized and iterative algorithms that are truncated upon satisfying a given quality measure. It is believed and has been consistently demonstrated that iterative procedures can be especially powerful when prior knowledge about the underlying signal or image is available in the form of constraints on the allowable restorations, when the blurring function is only approximately known, and when the user elects to vary the degree of blur and noise removal with the local information content in the image. As happens in general iterative approaches, they suffer “long” time to converge (if ever) compared to non-iterative ones and may require important storage of intermediate results as penalty to their flexibility that promotes iterative algorithms as being particularly well suited to the problems of images restoration. This issue will be highlighted despite the included comparative performance of the investigated algorithm.

The aeronautical communication architecture incorporates ground, satellites and airborne infrastructures. Conventional communication system that were generally of segregated and of analog voice-based nature are moving towards an integrated data-based globalized system built upon a communication network; known as the Aeronautical Telecommunication Network (ATN). The ATN has a niche for (HF) data communication due to its beyond-line-of sight capability that remains relevant even in today’s satellite era as they offer potentially worldwide coverage (where GEO satellites couldn’t for polar regions), without using third-party equipment and without the per-minute coasts associated with satellite services. For assessing quality-of-service, lumped here in the error rate in the communicated data over the HF segment of the ATN, channel characterization models and channel simulators have to be developed and used to analyze the link performance subjected to channel impairments. HFDL is susceptible to fading, multipath effects and interference. Theoretical performance data have been derived and evaluated for the purpose of comparison with the simulated system results. Various digital carrier modulation (M-ray PSK, FSK, QAM…..etc) used for data transmission (as the main aeronautical communication approach over the ATN) have been evaluated over the HF segment of ATN subnetworks. Moreover, convolutional coding/Viterbi decoding and their impacts upon the system performance and the quality of offered services have been evaluated.

Adaptive image enhancement methods are concerned with avoidance of noise distorting and edge blurring. This paper overcomes the problem by dealing with the source image as divided regions such that each region gets a suitable processing according to its local characteristics. The proposed algorithm presented in this work is an improved version of another algorithm developed by Centeno et al (1997), and is based on segmenting images into homogeneous and non-homogeneous regions. Smoothing and sharpening operations are then applied to homogeneous and non-homogeneous regions respectively. Within a non-homogeneous area that contains a probable edge, the sharpening operation is represented by histogram analysis due to the location of the pixel to be calculated. The algorithm uses the level of significance and the window size as tuning parameters to obtain the best visual results. According to the nature of the source image, the tuning parameters’ values can be properly selected. A comparative study is introduced to evaluate the performance of the improved algorithm.