Use of remote sensing, spatial and geophysical modeling, and real recharging capabilities to identify suitable areas for groundwater exploitation in dry coastal areas.

Accurate identification of groundwater potential areas in arid regions is an important task for groundwater management and sustainability. As a result, this study used the innovative integration of remote sensing (RS), geographic information system (GIS), watershed modeling system (WMS), geophysical survey, and water mass balance equation to identify potential groundwater areas in the W. Dara, Eastern Desert, Egypt. A weighted spatial probability model (WSPM) of groundwater potential based on eight regulatory factors was implemented within ArcGIS software. Drainage density (DD), precipitation (P), net groundwater recharge (NGR), terrain slope (TS), lineament density (LD), lithologic group (LG), water quality (TDS), and depth to groundwater level (DGW) are the aspects considered. The Analytical hierarchy process (AHP) method was used to assign weights to these parameters, and their accuracy was estimated using the consistency ratio (CR). The resulting groundwater potential map classified W. Dara study area into five categories, ranging from very low to very high potential. A geophysical survey, in the form of Vertical Electrical Sounding (VES) and Transient Electromagnetic (TEM), was conducted along W. Dara to validate the results of the WSPM, which identified areas of high groundwater potential. The 1D inversion of VES/TEM shows that the central and western parts of W. Dara are considered the most promising areas for groundwater occurrence, and are located in areas of high and very high potential classes derived from WSPM. Moreover, the results of VES and TEM surveys showed that the proposed aquifers (Nubian Sandstone, Miocene, and Quaternary) in the study area are horizontally and vertically connected through a set of normal faults traversing NW-SE. Ten sites have been proposed for drilling additional exploitative wells in W. Dara area based on the WSPM and geophysical survey with the aim of sustainable development. Thus, the integrated techniques applied in this study proved effective in accurately determining the development strategy for arid and semi-arid coastal areas, especially those that suffer from scarcity of rainfall and increased agricultural reclamation requirements in remote areas.

A Hazard Assessment Method for Waterworks Systems Operating in Self-Government Units.

Informing users of waterworks systems about the quality of tap water is an obligatory trend. It should be accompanied by studies on the influence of the risk of threats on public health. Waterworks systems, being included in a critical infrastructure of the city, should be subject to special protection in this respect. In the paper, the authors' method of assessing threats to people and property from waterworks systems functioning in self-government units (SGUs), is proposed. Four categories of factors affecting the risk of threat to tap water consumers were assumed: the frequency or the probability of exposure-P, financial losses-C, damages to peoples' health-HL, the degree of the security-S. Based on this, a four-parametric risk matrix was developed. It was assumed that risk is a function of the parameters mentioned above: r = f(P, C, HL, S). For every parameter the five-parametric weight scale was assumed. An example of applying the method is presented. The proposed method should be an important element of water safety plans. It can also be adopted for other municipal systems subject to SGU.