Bias correction of regional climate model simulations for the impact assessment of the climate change in Egypt.

This study projected the future temperature change for Egypt during the late of this century (2071-2100) for three representative concentration pathways (RCP2.6, RCP4.5, and RCP8.5), by correcting regional climate model (RCM) simulations of average, maximum, and minimum daily temperature with reference to observed data of 26 stations. Four commonly used methods of bias correction have been applied and evaluated: linear scaling, variance scaling, and theoretical and empirical quantile mapping. The compromise programing results of the applied evaluation criteria show that the best method is the variance scaling, and thus it was applied to transfer the correction factor to the projections. All temperature indices are expected to increase significantly under all scenarios and reach the highest record by the end of the century, i.e., the expected increase in average, maximum, and minimum temperature ranges between 4.08-7.41 °C, 4.55-7.89 °C, and 3.88-7.23 °C, respectively. The largest temperature rise will occur in the summer, with the highest increase in the maximum (minimum) temperature of 10.9 °C (10 °C) in July and August under RCP8.5. The maximum (minimum) winter temperature, on the other hand, will drop by a maximum of 2 °C (1.35 °C) under RCP2.6. The Western Desert and Upper Egypt are the regions most affected by climate change, while the northern region of Egypt is the least affected. These findings would help in impact assessment and adaptation strategies and encourage further investigation to evaluate various climate models in order to obtain a comprehensive assessment of the climate change impacts on different hydrometeorological processes in Egypt.

Surface water quality management for drinking use in El-Beheira Governorate, Egypt.

This research was initiated to assess and manage water quality status of fourteen surface drinking water intakes in El-Beheira Governorate, Egypt. The study was conducted on four main branches of water resources in the governorate. Three water quality indices (WQIs) and two multivariate statistical techniques were applied, based on the Egyptian guidelines for the Nile River. Water quality records were collected for two successive years, 2014 and 2015, and were analyzed by descriptive statistics. The results revealed the critical water quality status of the four branches at the fourteen intakes. The multivariate statistical techniques returned the critical water quality conditions to the agricultural drainage and the domestic wastewater discharges. In addition, a new software application was developed to manage WQIs calculation. An urgent water quality monitoring and assessment system should be initiated for the drinking water resources all over Egypt, based on the developed water quality assessment techniques of this study. PRACTITIONER POINTS: Three different WQIs and two different statistics tools were applied. Critical water quality status for the investigated surface drinking water intakes was reported. Agricultural drainage then domestic effluents are the main pollution sources. A new software application was developed to calculate WQIs to support decision makers.

Numerical and experimental analyses of the use of double vertical barrier walls for groundwater protection.

The groundwater contamination and its impacts on the hydrologic systems and society are critical environmental concerns in the world. This research presents insights from the numerical (SEEP/W and CTRAN/W) and the experimental (sandbox model) analyses of the use of double vertical barrier walls for groundwater protection. The main objective was to evaluate contaminant transport under the effect of several variables. The arrival time increases with increasing the distance between the pollutant source and the first wall, first wall depth of penetration, the distance between the two walls and also increases at smaller hydraulic head differences, and lower conductivities. Furthermore, using double barrier walls would significantly reduce contaminant concentration at the downstream area. This control is most significant when the depth of first wall penetration is larger than that of the second wall. Results proved consistent with several similar studies and advantageous over many of them by the integrated use of both techniques with more variable parameters evaluated. PRACTITIONER POINTS: The research will introduce insights from the effect of using double barrier walls on the hydraulic control of contaminant transport. The effect of several variables on the contaminant arrival time and concentration is investigated. Using double barrier walls has a significant impact on contamination transport through the soil. This control is most significant when the penetration depth of the first wall is larger than that of the second.