Llyn y Gweision (a Welsh lake) has a surface area of 10 km2. It is fed by two rivers: the Afon Chwefru and the Nant Aeron. The Chwefru(Ich) has a catchment area of 1250 km2. The Aeron(Iae) has a catchment area of 2.400 * 106 ha. The outflow stream, the Afon Rhondda (Orh) has an average annual flow rate of 1367.6 ft3 s-1 (c.f.s). Rainfall in the region is 40.0 inches y-1, and annual evaporation from the lake surface is 8.10 * 106 m3.The equilibrium amount of water stored in the lake is 0.550 km3. Of the total amount of rainfall over the Chwefru basin, 32.0% leaves the basin as streamflow. For the Aeron basin, the annual streamflow amounts to an equivalent water depth of 33.87 mm over the whole basin. Show that for the above inputs and outputs that S = 0. If 10% of the flow from the Chwefru is diverted for municipal water supply, how much will lake level fall in one year; all else staying the same?

Question

Llyn y Gweision (a Welsh lake) has a surface area of 10 km2. It is fed by two rivers: the Afon Chwefru and the Nant Aeron. The Chwefru(Ich) has a catchment area of 1250 km2. The Aeron(Iae) has a catchment area of 2.400 * 106 ha. The outflow stream, the Afon Rhondda (Orh) has an average annual flow rate of 1367.6 ft3 s-1 (c.f.s). Rainfall in the region is 40.0 inches y-1, and annual evaporation from the lake surface is 8.10 * 106 m3.The equilibrium amount of water stored in the lake is 0.550 km3. Of the total amount of rainfall over the Chwefru basin, 32.0% leaves the basin as streamflow. For the Aeron basin, the annual streamflow amounts to an equivalent water depth of 33.87 mm over the whole basin. Show that for the above inputs and outputs that S = 0. If 10% of the flow from the Chwefru is diverted for municipal water supply, how much will lake level fall in one year; all else staying the same? 
A friendly (continuity) equation might be:

(I(Chwefru)+ I(Nant Aeron) + I(precipitation in lake) ) - (0(Rhonnda) + O(evaporation). 
) = SL

where Ii = Inputs, Oi = Outputs and S = change in storage.

Easha · Answer

i have this same assignment..and i am stuck as well...as far as i understand..u need to get each individual parts in m^3/year.

myles · Answer

which process proceds most of the oxygen in earths atmosphere phototsynthesis or transipation

what gas does photosyntheses produce carbon dioxide or oxygen

grasss-grasshopper--snake--hawk
if apart of the food web qouls mORE ARROWS POINT TOWARD OR AWAY FROM 2ND LEVEL

jim · Answer

Easha has the right idea. You need to get all the inputs and outputs into the same units.

There's water entering the lake, and there's water leaving the lake. The numbers are just given in different units, which is common in the real world!

There's nothing difficult or hard to understand about it; it's just long and tedious, and requires you to work carefully. Calculate one input at a time, converting each into some standard unit of your choice. m^3/yr will do fine.

It's a nice question in itself, neat and well-constructed, but especially clever because it contains several unusual words, which makes it easy for the teacher to Google where the question has been posted and what answers have been given online. Hi, Teacher! I admire your work. :-)