Buffalo Valley is a topographically-closed basin in central Nevada with a total

Question

Buffalo Valley is a topographically-closed basin in central Nevada with a

total area of 5,000 square miles. Given the following information: Groundwater is discharged from Buffalo Valley through evapotranspiration in thecentral lowland area, which encompasses 1 percent of the total drainage area or 50square miles. Mean annual evapotranspiration is 42 inches and includes bothgroundwater and precipitation. Mean annual precipitation on the central lowland is 6inches. Assume no surface runoff enters or leaves the central lowland area.

All groundwater recharge occurs in limestone rocks exposed in the mountain areawhere mean annual precipitation is 18 inches over an area that is 20 percent of the totalbasin area or 1,000 square miles. Mean chloride concentration in precipitation and dryfall is 0.6 milligram per liter.

Wells on the alluvial fan between the mountain area and the central lowland have amean chloride concentration of 6 milligrams per liter. Groundwater between themountain and central lowland areas has not been affected by any discharge or loss dueto evapotranspiration.

a.) Using the chloride ratio between precipitation in the mountain recharge area and thewells on the fan between the mountain area and central lowland, determine the meanannual recharge to Buffalo Valley in acre-feet per year.

b) What is the ratio of groundwater recharge to precipitation in the mountain area?

c.) Determine groundwater discharge in the central lowland area.

d.) Is groundwater beneath the valley in steady-state

Explanation / Answer

Using the chloride mass balance method R=P*Clp/ClSw

where R=recharge rate(mm/year)=?

P=precipitation in central lowland=6inch/year=152.4mm/year

Clp=chloride concentration in precipitation=0.6mg/L

Clsw=average soil concnetration below root zone=0.6

=152.4*0.6/0.6

=152.4

Groundwater recharge in the mountain area=P*Clp/CLw

P=precipitation in the mountain area=152.4mm/year

Clp=chloride concentration in precipitation=6mg/L

=152.4*6/6

=152.4

Related Questions

Navigate

• Browse (All)
• Browse B
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.