Modeling Social and Environmental Systems

GG/EE 550

Lab Exercise #2

The Snow-white Products Company releases at 2 a.m. each day 200 m3 of a pollutant into Mystic River. There are 3 segments to the river at which its pollution levels are measured. The rivers flow rate in sections 1 and 2 are 1,000 and 1,200 m3 per minute, respectively. The volumes of water in those sections are 14,000 and 16,000 m3, respectively. After the second section, a tributary enters the Mystic River, effectively doubling the volume of water, while maintaining its flow rate at 1,200 m3 per minute. The concentration of chlorine in section 3 is measured just after the tributary enters the Mystic River (hint: use the last section of chapter 4 as a guide). Please use arrays.

(a)       Plot the chlorine concentrations at each segment of the Mystic River over the course of a day.

(b)       What is the pollution concentration in segment 3 at 1 p.m. in the afternoon?

(c)        How do the results change if the pollutant degrades at a rate of 5% per hour?

(d)       Assume a second company adds gradually throughout the day 200 m3 of the same pollutant to the second section of the river. How should that company time its release so that it does not "disturb" the temporal patterns of pollution concentration readings taken in section 3 (thus giving the impression all pollution comes from Snow-white Paper Company)?