CIVE 321 - Assignment 1

CIV E 321 – Principles of Environmental Modeling and Risk Homework Assignment #1 Due Tue, Feb 03, 2023, at 11:59:59 PM 1 Instructions: You are allowed to use Excel Question 1 Siwa Lake in the western desert of Egypt (Figure 1) has been undergoing an unprecedented increase in water level from one year to the next. This increase has been causing losses to productive agricultural lands, and flooding to critical infrastructure and roads thus increasing the risk of loss of lives of residents (Figures 2 to 5). This increase has been attributed to the excess inflow from the drainage of the nearby agricultural lands and uncontrolled flows from nearby groundwater wells. The lake loses water through evaporation only. Due to the seasonal fluctuation of the water levels across months as determined by telemetry installed in the lake (Figure 6), the surface area of the lake changes from one month to the other (Table 1). It is required to estimate the total incoming flow to the lake to investigate measures to ration the inflow and prevent any potential flooding of the lake in the future. Note that the salinity of the water in the lake is extremely high – approximately 210 ppt (part per thousand) [ seawater salinity is 35 ppt]. This hypersaline water is known to evaporate at much lower rates than freshwater. A reduction factor of 0.72 can be used for hypersaline water. The available inputs are shown in Table 1. Table 2 has the readings of the water telemetry measurements shown in Figure 6. It is required to: 1. Estimate the monthly inflow rate in m 3 per month. 2. Plot the cumulative inflow in m3 with the cumulative evaporation in m 3 on the same figure. Figure 1. Siwa Lake and surrounding agricultural areas that drain to the lake.

CIV E 321 – Principles of Environmental Modeling and Risk Homework Assignment #1 Due Tue, Feb 03, 2023, at 11:59:59 PM 2 Figure 2. Submerged agricultural areas with hypersaline water (M. Ammar, 2021) Figure 3. Submerged agricultural areas with hypersaline water (M. Ammar, 2021)

CIV E 321 – Principles of Environmental Modeling and Risk Homework Assignment #1 Due Tue, Feb 03, 2023, at 11:59:59 PM 3 Figure 4. Submerged agricultural areas with hypersaline water (M. Ammar, 2021) Figure 5. Dead palm trees due to submergence of surrounding areas with hypersaline water from Siwa Lake (M. Ammar, 2021)

CIV E 321 – Principles of Environmental Modeling and Risk Homework Assignment #1 Due Tue, Feb 03, 2023, at 11:59:59 PM 4 Figure 6. Recorded hourly water levels from telemetry for Siwa Lake. The blue line represents the daily averaged and smoothed water levels. Table 1. Input data Month Area (hectare) Daily freshwater evaporation rate (mm/day) Jan 2906 2.9 Feb 2978 4.0 Mar 3016 5.2 Apr 2958 6.7 May 2925 8.5 Jun 2903 8.8 Jul 2895 9.2 Aug 2886 9.0 Sep 2872 7.6 Oct 2833 5.8 Nov 2905 3.8 Dec 2944 3.0 Table 2. Water levels over the year 2020 Date Water level (telemetry reading) 01-01-20 -16.09 01-02-20 -15.92 01-03-20 -15.82 01-04-20 -15.79 01-05-20 -15.80 01-06-20 -15.92 01-07-20 -16.04 01-08-20 -16.12 01-09-20 -16.20 01-10-20 -16.26 01-11-20 -16.24 01-12-20 -16.12 01-01-21 -15.96 L

Q1. SampahonS AS: p.*-*-E-) AS = Roui + Rin - E · g I salinity trap so mm/dul -> ms/day Areax days in a month AS RM - E · = 4Ah ms month mmaracnectar one seA-A nec, Holume change: AxAH(hee.) x orome Thectare = 10000mZ - Sample Calculations; 3 AH = 0.17 January: volume change = Area > AH = 2906ha x 0.17m x 0000m2 A S = 4940200m3 Evaporation Rat E = 0.72 +2.9m x 2906Ax 000m2 x Eldays a m day E = 1880995.68 m3