Volume 12 ,2009

The study area was selected to represent the sediments of paleodrainage delta in the Western Desert of Egypt, covering about 15615653 feddans (6561199 hectares). The data of Landsat Enhanced Thematic Mapper (ETM) of 2002 were used for delineating the physiographic units to be a base for the soil taxonomic units (all are hyperthermic). These taxonomic units were potentially evaluated for barley and wheat (grain crops), alfalfa (fodder crop), maize, sun flower and olives (oil seed crops). The illustrated flow of the paleodrainage delta starts from the south as undulating delta apex, which most probably was deposited by the paleodrainage from Eastern Desert through the different rock structures. This apex includes soils of Calcic Petrogypsids loamy skeletal, gypsic; Typic Clacigypsids, loamy skeletal, gypsic and Typic Calcigypsids, sandy skeletal, mixed. The unit is profitable for drip irrigated olives as moderately to marginally suitable and for quarrying Oligocene gravel. Gently undulating inter delta includes sediments that was most probably received by reworking and outwashing the slopes of delta apex in relatively more recent fluvial eras. The soils are Typic Calcigypsids, fine loamy, mixed; Typic Calcigypsids, loamy skeletal, mixed and Typic Calcigypsids, sandy, mixed. This unit is profitable for drip irrigated olives as highly suitable and sprinkly irrigated alfalfa, maize and sun flower as marginally suitable. Gently undulating to almost flat inter delta is most probably received its sediments from the southern physiographic units by the paleodrainage erosion. The soils are Leptic Haplogypsids, fine loamy, mixed and Leptic Haplogypsid, sandy, mixed. This unit is profitable for drip irrigated olives as moderately suitable. In the middle front of this unit, a township is proposed to be constructed "Al Qattara Town". Flat depressed pro delta includes interfered sediments of different paleodrainage eras being received medium soil matrix over relatively old sediments of weathered gypsifreous clays (shales). The soils are Leptic Haplogypsids, fine loamy, mixed, which can be utilized for drip irrigated olives as highly suitable and sprinkly irrigated alfalfa, barley, maize, sun flower and wheat, as marginally suitable. This unit can be used for quarrying Miocene clays (shales) as well as for constructing compounds for producing evaporites, distilled water and fish preserving manufactories as resources from the detectable Al Qattara Lake. Water logged and submerged pro delta composed of poorly drained soils partly submerged by brackish lake or covered by wind-blown sands. This unit (-65 to -134 bsl) includes soils of Gypsic Aquisalids, fine loamy, mixed. It is highly recommended to be filled with sea water for a massive hydroelectric project as well as creating extra water resources and enhancing the local climate. Aeolian deposits were most probably the resultant of depositing sand over the paleodrainage lines, having soils of Typic Torripsamments, mixed (calcareous). This unit can be utilized for drip irrigated olives as moderately suitable and for sprinkly irrigated alfalfa, sun flower and maize as marginally suitable.

Remote sensing hyperspectral data has many applications especially in the field of earth sciences. Hyperspectral sensors capture the detailed spectral signatures that uniquely characterize a great number of diverse surface materials. Classification, clustering, and visualization of these very high-dimensional signatures need untraditional methods. Different approaches for spectral image interpretation have been studied using Artificial Neural Networks (ANNs) and Support Vector Machines (SVM) to meet the challenge of high-dimensionality.

The study used SVMs for geological mapping of hyperspectral imagery at Abu Zenima area, western Sinai, Egypt, the hyperspectral data has been captured in 2003 by Hyperion instrument on the USGS Earth Observing (EO-1) satellite. Precisely, the study compares between the use of SVMs and a neural network built on the concept of SVMs, this network uses the Kernel-Adatron algorithm with the Gaussian kernel for the process of training. The SVMs also uses the Gaussian kernel with different bandwidths to enhance the performance of the interpretation process; the results are compared in details.

The Neural Network was trained with four data sets , the first consists of 11310 samples, gives recognition rate of 84%, the second has 22620 samples, recognition rate was 91.5%; the third has 33930 samples, recognition rate was 94.6%; finally the fourth has 45240 samples, recognition rate of 99.2%. The previous results fall in comparison with the results of SVMs which use two algorithms for training the first is the one against one algorithm which gave a recognition rate of 84% for the first data set, a recognition rate of 76.9% for the second data set, a recognition rate of 95.2% for the third one and 98.5% for the fourth one. and the other is one against many algorithms which gave a recognition rate of 84% for the first data set, a recognition rate of 72.3% for the first data set, recognition rate of 94.6% for the second one and 98.5% for the third one.

Single crop coefficient factor (Kc) is an essential component for crop water allocation for efficient irrigation scheduling and irrigation water management. Kc is basically defined as the ratio of actual evapotranspiration and grass/alfalfa reference evapotranspiration, and always measured by lysimeter in localized area in the field, which then generalized on the whole irrigated land. The lack of precise information about the crop coefficient particularly in our country together with both small sized fields and heterogeneity of agricultural crops calls for developing a new methodology for computing a real time crop coefficient from remotely sensed data. This paper discusses the methodology developed for obtaining a real time single crop coefficient from Landsat Satellite ETM+7 imageries. The methodology was applied and optimized on one irrigation field with two different dates and crop cover in the northern Delta of Egypt.

Hazard assessment studies are necessary to identify the investigated area along Qena-Safaga road, between km 20 – km 30 from Qena City, where extensive damage has constantly been reported. This damage includes asphalt road, breaking of the potable water pipeline, tilting of tower line and telephone poles, as well as of Safaga-Abu Tartur railroad. These types of damage result from tectonic activity around the Qena-Safaga district. The structural and seismic maps are used to interpret and evaluate the deep-seated structures and the tectonic setting of the study area. Strong ground motion is the most important phenomenon of natural hazard. It has an effect on the nature, human life and man- made structures. Geographic Information Systems (GIS) and Remote Sensing are useful tools in disaster management for the study area. These automated tools are used for the storage, analysis and visualization all geological and geophysical data of the investigated area to the decision support. Also, by using the Landsat image acquired in 2001 and aerial photograph dated 1955 reveals that the spatial deformation of the recent surface features has been estimated during 46 years.

Flash flood hazard of Wadi Aday threaten human activities in an important urban area of Muscat City, the capital of Sultanate of Oman. To evaluate and mitigate these floods; remote sensing (IKONOS images), topographic and cadastral maps, data of rainfall, floods and other data sources have been used under a GIS environment and manipulated. The study determined the areas under the flood risk, and clarified the risk class and degree for each of human activities object in the lower part of Wadi Aday. In order to mitigate the flood hazards, and to utilize the floods water in such extreme hot desert; the study suggested: establishing two dams and artificial channel added to some methods that reduce the erosion on canyon reach road.

In the current study we proposed a new band ratio combination by using Landsat Enhanced Thematic Mapper (ETM+) image. The new proposed band ratio has been tested for its effectiveness in four regions in the study area. This proposed band ratio (5/3, 3/1, 7/5 in RGB respectively) with the help of supervised classification technique succeeded in discrimination of different types of rock units. The results revealed that by using the proposed band ratio, it was so effective to discriminate different granitic phases (Kadabora region); serpentinites from metasediments and sheared granites (El Mayite region); mollase type Hammamat sediments from metavolcanics and metasediments (Wadi El-Miyah region); and serpentinites from metavolcanics (El-Baramiya region). The results demonstrate the accuracy and suitability of using this band ratio as a powerful tool in lithological mapping and the data was verified by field investigation and previous studies.

Practical and economical constraints prompt the need of obtaining lithological and structural information for development of desert areas with reduced field effort. The fusion of multi-sensor satellite data is an effective mean of exploiting the complimentary nature of different data types. This technique allows fusion of spectral-spectral information of multi-source data with high accuracy.

In the present study, fusion of SPOT and ASTER data was applied to test the potentiality of this technique in mapping geological formations and structural lineaments in Wadi Ghoweiba area, to the west of the northwestern tip of the Gulf of Suez, Egypt. ASTER data is characterized by a wide range of spectral bands (14 bands), while SPOT panchromatic data is characterized by high (10 meters) spatial resolution.

Based on spectral characteristic analysis (SCA) of the 3 VNIR and the 6 SWIR bands of ASTER data, two false-color band-ratio images (1/3, 2/5, and 4/ 9) and (1/5, 8/9, and 4/6) in R, G, B were produced for better lithological discrimination. SPOT panchromatic image data was fused with ASTER band- ratio images data using principal component (PC) and color normalization or Brovey transformation techniques. The fused images proved to be excellent for lithological discrimination.

ASTER data includes bands 3N (Nadir) and 3B (Backward) that are acquired in the spectral range of near infrared region allowing extraction of digital elevation model (DEM). Three-dimensional perspective views were generated by draping SPOT-ASTER ratio fused images over ASTER DEM. This technique was used to enhance morphologically-defined structures.

The fused images and the 3D perspective views were interpreted to produce a photogeological-structural map that was verified using the available geological maps and subsequent field check. The produced photogeological map indicates that fusion of SPOT and ASTER ratio image's data is a reliable technique for geological mapping especially in remote and inaccessible areas.

Gabal Qattar area is located in the north Eastern Desert of Egypt between Latitudes 26° 52 ́ and 27° 08 ́ N, and Longitudes 33° 13 ́ and 33° 25 ́ E. The exposed rock units, there, from the oldest to the youngest, are metavolcanics; granodiorites- diorite complex; Hammamat sediments and younger granites. Most of the area is densely traversed by felsic and mafic dykes.

The Qattarian younger granites are divided into seven granitic areas according to their spectral characters to facilitate the studying and delineating physical characteristic differences between these areas, as well as to throw a light about the best conditions of exploration for radioactive mineralizations. This study is based on brightness Digital Number values (DNs) of the granitic areas, predominant trends and densities of the structural lineaments, shape and type of weathering products. Three areas of these seven younger granite areas form Gabal (G.) Qattar, and designated Gr1, Gr3 and Gr4, where the other granite areas which form the G. Um Dissi (Gr2), G. Thelma (Gr5), G. Abu Samyuk (Gr6) and G. Ayn Al Ruwayshed (Gr7). Photogeologically, these seven granite areas show some differences in shape, texture, predominant trends and densities of structural lineaments and ability of weathering.

This study shows that the seven granite areas could be gathered into three main groups according to their DNs values of Landsat ETM+ spectral bands especially of band 5, where these three main groups representing different, and mainly coincide with the three granite phases previously delineated according to chronological field relation, petrographic and geochemical studies.

The Gr1 area contains all uranium occurrences from locations I to V. This area is characterized by semi circular shape of NW trend, massive appearance with high relief peaks, and high fracture density, where the N55 ̊E, N5 ̊E, N45 ̊E and N45 ̊W are the predominant trends. Some of the N55 ̊ E fractures form shear zone along the contact with Hammamat sediments. This granitic area displays taffoni weathering with highest clay minerals content in its weathered surfaces. It shows the highest brightness value (DN), especially in band 5 reaching about 152, due to the highest felsic minerals and the lowest ferromagnesian minerals contents relative to the other granite areas. Also, the high fractures density of the Gr1 area acted as good channels for the hydrothermal ascending fluids and the percolating meteoric water, that leached uranium mineralization and redeposited it in the shear zones especially at sites of intersection of the main fractures. These characteristic features of the Gr1 area may be responsible for the presence of uranium mineralizations.

Gabal EL Minsherah-El Hasanah district, located in the northern Sinai of Egypt, is highly folded and deformed due to the effect of the Syrian Arc System. The exposed rock units of the area range from Lower Cretaceous sequence (Malha Formation) to Early Eocene sequence (Egma Formation).

The lithologic rock units, the structural framework and the high zones of radioactive anomalies of the study area were interpreted using the Landsat-7 ETM data and digital image processing techniques. The structural interpretation shows that the main trends of NE-SW and NW-SE normal faults are dissecting the folds of the area. These folds are mainly double plunging in the east and northeast directions and form the main heights in the study area. The faulting and folding in the area led to the disturbance and redistribution of the rock units hosting the radioactive anomalies.

The image processing of ETM data and the continuous field check and measurements of the interpreted rock units revealed that the occurrences of radioactive anomalies were recorded in three sequences of Themed, Sudr and Egma Formations. The first radioactive anomaly is recorded in gray medium thick phosphatic limestone bed in the uppermost part of the Themed Formation and ranging from 50 to 100 ppm, due to the presence of phosphatic components hosted uranium in their apatite structure. The second one is observed in the middle member of Sudr Formation and ranging from 60 to 110 ppm, due to the presence of phosphatic chertified beds. Whereas the third radioactive anomaly up to 90 ppm is recorded in the upper member of Egma Formation, due to the presence of phosphatic limestone beds.

Generally, the radioactive anomalies in the study area are mainly due to the occurrence of the phosphatic beds which contain phosphatic components hosting uranium in their apatite structure.

Gabal Halal is one of the major asymmetrical doubly- plunging anticlinal fold belts (50 Km length) related to the Syrian Arc System in northern Sinai, Egypt. The exposed rock units at Gabal Halal range from Cretaceous to Quaternary and are divided into eight formations which are from base to top: Malha, Halal, Wata, Themed, Sudr, Beida, Egma Formations and Quaternary wadi deposits. The image processing is applied using Landsat-7 satellite data to discriminate structure and lithology for defining the horizons of the radioactive anomalies of each rock unit. The extracted structural lineaments, using GeAnalyst-PCI package, from digital ETM data showed that the main structural trends are NE-SW and NW-SE normal faults which originated as extensional fractures with lateral dip-slip displacement. The axial trace of Gabal Halal fold is curved and plunging to W and SW directions, while the northeastern part (Gabal Dalfa) is plunging to NE direction. The use of remote sensing data and field radiometric measurements of each rock unit revealed the presence of three radioactive anomalies in Malha, Themed and Sudr Formations. The recorded radioactive anomalies in Malha Formation are ranging from 50 ppm to 75 ppm due to the capture of uranium by iron oxides of oolitic ironstone and iron concretions in the thick-bedded ferruginous sandstone member. The presence of radioactive anomalies up to 71 ppm in the upper unit of Themed Formation and 90 ppm in the middle member of Sudr Formations is due to the presence of phosphatic beds hosting uranium in the phosphatic components. The effect of Syrian Arc System and the structural framework of the area led to the redistribution of the rock units hosting radioactive anomalies.

A new generation of satellite data has been emerged since the launch of the Moderate Resolution Imaging Spectroradiometer (MODIS) in 1999, for monitoring land resources and terrestrial environments. Agricultural land area of Egypt in 2005 was estimated using MODIS data. Four scenes were utilized to extract the total country area. MODIS vegetation indices product (MOD13Q1) was the most suitable to extract the total gross cultivated land area of Egypt. An unsupervised classification algorithm was applied to estimate the cultivated land area, which approached 8.2 million feddans in 2005. The Nile Delta contains the majority of agricultural lands (63.2%). The Nile Valley and El-Fayoum Depression possess 33.9% and the remaining little percent (~3%) represents the scattered agricultural land along the Suez Canal, Sinai and the Western Desert. The classification accuracy of agricultural land reached 84%, revealing higher confidence of assessment. The present study asserts on the importance of using remote sensing in monitoring agricultural land resources.