U.S.-Egypt Cooperative Research: Influence of Structures on Drainage Patterns in the Tushka Region, Southwest Egypt

项目描述：本项目支持波士顿大学遥感中心Cordula Robinson博士和埃及开罗国家研究中心Hesham El-Kaliouby博士的合作研究。在这项研究中，pi将使用一种新的方法，利用星载雷达和热成像，GIS和地球物理技术来分析结构对排水的影响；查明地下水补给的结构，以及地下水驻留或传输的结构；在埃及西南部图什卡运河以南的北纬22至23度和东经30.5至31.5度之间的区域，确定地下水积累增强的位置。研究区位于努比亚含水层系统之下，该系统被认为是无约束的，地下水存在于砂岩中，砂岩不整合地覆盖在基岩上，并被第四纪沉积物覆盖。然而，含水层不是均匀的，而是具有可变的性质，因为存在的地下水取决于：1)过去地质时期的补给；2)压裂，在岩石中引入了次生孔隙，增加了储层容量。为了描述这种变化，将使用地理信息系统（GIS）数据库中的星载雷达和热图像以及数字高程模型（dem）推导近地表河流特征和相关结构特征的空间组织。这些矢量层将与DEM相结合，以获得进一步的水文形态参数和已定义流域的水文特性，并确定需要实地调查的结构。为此目的，地球物理剖面将用于提供有关断层的地下分布和相对含水量以及含水层深度的信息。使用地理信息系统可以很容易地解决必要的比例转换问题。该合作项目源于2003年12月在开罗举行的由美国国家科学基金会支持的关于“评估和管理埃及地表水和地下水”的研讨会。知识优势：为满足本提案的目标而建立的RS和GIS流程流程，以及先进的地球物理剖面技术的可用性，将允许对理论推论进行经验检验。数据库的创建和使用的数据集的相关性确保了对研究区域的排水系统、结构控制和地下水分布的新的和改进的理解。该方法是创新的，并且可以访问所需的所有数据集，使项目的目标可以实现。更广泛的活动：结果将确定结构如何影响研究区域内无限制的努比亚含水层的排水模式和地下水分布；因此，可以确定在这项试验性研究中设计的方法是否可以适用于大撒哈拉的其他地区。了解构造环境和断层的潜在分布，对该地区的建设发展也很重要。孔隙流体压力增大的断层地震易损性增大；因此，必须在建筑发展规划中加以标记。研究结果将发表在同行评议的科学期刊上，新的数据库将在波士顿大学的互联网上提供。该项目得到了美国-埃及联合基金项目的支持，该项目向两国的科学家和工程师提供赠款，以开展这些合作活动。

0513379RobinsonDescription: This project supports a collaborative research between Dr. Cordula Robinson, Center for Remote Sensing, Boston University, Boston and Dr. Hesham El-Kaliouby, National Research Center (NRC), Cairo, Egypt. In this research the PIs will use a new approach utilizing space-borne radar and thermal imagery, GIS and geophysical techniques to: analyze the influence of structures on drainage; identify those structures recharged by groundwater, and in which groundwater resides or is transmitted; and determine locations with enhanced groundwater accumulation, in the area between 22 to 23 degree N and 30.5 to 31.5 degree E, south of the Tushka canal in southwest Egypt. The study area is underlain by the Nubian aquifer system that is considered to be unconfined whereby groundwater resides in sandstone rocks that unconformably overlie basement rocks and are covered by Quaternary deposits. The aquifer, however, is not homogeneous, but has a variable nature in that the groundwater present depends on: 1) recharge in the geologic past; and 2) fracturing, which introduced secondary porosity into the rocks and increased their storage capacity. To characterize this variability, the spatial organization of near-surface fluvial features and associated structural features will be derived using space-borne radar and thermal images and Digital Elevation Models (DEMs) in a Geographical Information System (GIS) database. These vector layers will be combined with a DEM to obtain further hydro-morphological parameters and hydrological properties for the defined drainage basins, and to identify those structures requiring field investigation. Geophysical profiling will be used to this end to provide information about the subsurface distribution and relative water content of the faults, as well as aquifer depth. The use of a GIS will allow the necessary scale transformations to be easily resolved. The collaborative project resulted from an NSF-supported workshop held in Cairo, in December 2003, on "Assessing and Managing Surface and Groundwater in Egypt".The Intellectual Merit: The RS and GIS process-flow routine established to meet the objectives of this proposal, and the availability of advanced geophysical profiling techniques, will allow the theoretical deductions made to be tested empirically. The creation of the database and the correlation of the datasets to be used ensure a new and improved understanding of the drainage systems, structural controls, and groundwater distributions in the study area. The approach is innovative and access to all the datasets required makes the goals of the project achievable.The Broader Activities: Results will establish how structures influence drainage patterns and groundwater distributions in the unconfined Nubian aquifer for the study area; thus, it can be determined if the method devised in this pilot study can be applied to other areas in the Great Sahara. Understanding the structural setting and the potential distribution of faults that received most recharge is also significant in building development that is anticipated for this area. Faults with increased pore fluid pressure have increased seismic vulnerability; thus, must be flagged in building development plans. Results will be published in peer-reviewed scientific journals, and the new database will be made available over the Internet at BU. This project is being supported under the US-Egypt Joint Fund Program, which provides grants to scientists and engineers in both countries to carry out these cooperative activities.