الفهرس 
CHAPTER I INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Knowing the spatio-temporal characteristics of water storage changes is essential for Nasser Lake, which is dealing with a variety of water management issues brought on by anthropogenic influences as well as climate and seismological variability. In addition, the lack of in situ measurements of soil moisture and groundwater, along with inherent ”scale limitations” of conventional methods employed in hydrological characterization, are making it more difficult to determine the distribution of water resources in the area.
Therefore, the main goal of this study is to use remotely sensed and model data across Nasser Lake to (i) evaluate the effectiveness of models and remotely sensed data in simulating the distribution of water resources in un-gauged desert regions around Nasser Lake, (ii) analyze the inter-annual and seasonal variability as well as changes in total water storage (TWS) over Nasser Lake, and (iii) comprehend the connection between TWS fluctuations and anomalies in soil moisture over the studied region.
(iv) understand the relationship between TWS changes and seismicity around Nasser lake.
(v) Identify fault systems responsible for seismic activities with particular attention to the Mafid fault due to its recent activity and significant location.
The following data were used in this study; monthly gravity field data from the Gravity Recovery and Climate Experiment (GRACE) mission, soil moisture from the Global Land Data Assimilation System (GLDAS) model and seismic data of the Aswan from 2000 till 2021 after the Egyptian National Seismological Network (ENSN). Our investigation covers a period of 19 years from 2002 to 2021.
The results of the study show that the main source of recharge is Nasser Lake, and the mass movement is large and rapid (tens of mm/year along the preferred paths); this is consistent with phase patterns observed during the dry period. Groundwater from Nasser Lake flows quickly and abundantly to the southern region. The observed increase in must be connected to an increase in surface and/or groundwater storage.
Lake level during the recharge period was high (6.2 metres) versus the depletion period (4.6 metres), an increase of 26%, so the observed increase in must be connected to an increase in surface and/or groundwater storage.
The results of the study show that the western part and the north- western region around Nasser Lake experienced increase in TWS water between 2002–2021, whereas all the other regions lost water during the study period.
Most of the seismic activity in Aswan looks to be concentrated where the north-south fault system and the east-west trend intersect.
Comparison the hydrological pattern with the number of the recorded events, shows that the highest recorded number of events correlated well with highest discrepancies between surface and underground water pattern.
This study aims to define structures below the surface of the Mafid Area by using gravity data interpretation. Estimates were made for the contact density contrast and the gravity sources’ depths. The source depths and contact locations were estimated using the Euler deconvolution method. Structures with shallow and deep seats were also assessed using power spectrum analysis. The structure at a shallow depth was between 0.032 km and 0.437 km.
Euler deconvolution map locates the causative bodies and determines its depth from the observation level. However, the structural index = 0. 0 gives the best solution and such map displays the causative bodies’s depths ranges of less than 40 m (from the observed level) to more than 450 m of the mapped area.
Multiple faults affect the region that most trends in the E-W, NNW-SSE, NW-SE, NE-SW, and NNE-SSW directions, according to the structural map that has been interpreted. Two-dimensional gravity modelling shows that the depth of crystalline rocks (Basement rocks) ranges from 22 to 697 meters. Three-dimensional gravity modelling shows that the depth of crystalline rocks (Basement rocks) ranges from 139.2 to 587.5 m.