Subsurface dams can limit saltwater intrusion and support groundwater abstraction from coastal aquifers. However, structural fractures may reduce their performance, and their effect on safe abstraction is not fully understood. This study used a two-dimensional, steady-state SEAWAT model to evaluate abstraction from a well located landward of a fractured concrete underground dam. Safe abstraction was defined as the maximum pumping rate at which salinity at the well screen remains stable at 1
Urbanisation increases surface runoff and recurrent flooding in cities, mainly by reducing infiltration capacity and shortening times of concentration. Rainwater harvesting tanks can store water to mitigate peak flows from urban development and support sustainable planning for new buildings. This study presents a hydrological routing approach for rainwater harvesting tanks, solved using the Rosenbrock method, combined with Monte Carlo analysis to generate a sufficiently large, representative set of hydrological scenarios. Based on these simulations, we developed multiple machine learning (ML) models to provide a simplified, efficient predictive framework. A total of 200 scenarios were generated using Latin Hypercube Sampling by varying key input parameters, including rainfall intensity, pipe length, internal pipe diameter, and tank surface area. In total, 28 ML regression models were evaluated to estimate peak outflow discharge. The Cubic Support Vector Machine (SVM) exhibited the best performance, achieving coefficients of determination ( R^2 ) of 0.984 and 0.985 for the validation and testing stages, respectively. Sensitivity analysis revealed that the internal pipe diameter is the most influential parameter controlling peak discharge. The proposed methodology offers a computationally efficient, reliable tool for predicting the hydraulic performance of rainwater harvesting tanks, supporting decision-making for urban planners and local authorities in flood mitigation strategies.
The study presents an experimental–numerical study of rock-filled concrete (RFC) columns incorporating variable rock sizes and volumetric contents under eccentric compression loading. The matrix was made of self-compacting concrete (SCC) of grade C30, and rectangular precast columns (300, 250, 1200 mm) were manufactured, having rock inclusions fitted in low-stress zones. Three rock volumetric fractions (35, 45, and 55
Egypt has one of the tightest water budgets in the world, while its farmland has been divided into ever-smaller holdings for a century. This paper connects these two issues by pairing a structured literature review with a transparent sensitivity analysis based on Egyptian census data and Nile Delta field studies. It asks how holding size and tenure affect irrigation water application, and how much of the excess consolidation might recover. Holdings rose from about 1.2 million in 1929 to 4.44 million in 2010, while the total holding area grew by only 31
This study evaluates land-use change and its modeled hydrological response in the study area, which covers 731.41 km2 of the Genfel watershed. The watershed ranges in altitude from 1764 to 3065 m a.m.l and its mean precipitation and temperature are approximately 597.9 mm and 18.8 °C, respectively. The Soil and Water Assessment Tool (SWAT) model was used to simulate watershed hydrological processes, while multi-temporal Landsat imagery from 1987, 2002, and 2017 was classified using supervised classification to assess land-use/land-cover changes. The SWAT model showed limited performance during calibration and validation, particularly at the monthly time step. For daily calibration, the coefficient of determination (R2) and Nash–Sutcliffe (ENS) were 0.5111 and 0.16, respectively, whereas monthly calibration produced R2 and NSE values of 0.6428 and −0.23, respectively. Daily validation yielded R2 and NSE values of 0.5147 and 0.16, respectively, while monthly validation yielded R2 and NSE values of 0.6133 and −0.05, respectively. These results indicate substantial uncertainty in the simulated hydrological responses and therefore require cautious interpretation. Land-use change showed a substantial increase in cultivation from 36.525
