# Quick review of remote sensing, Introduction to remote sensing by xdu18397

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```									 Quick review of remote sensing,
Introduction to remote sensing in
hydrology, hydrological cycle and
energy balance

Lecture 1

1/16/2009
1.
Hydrologic
cycle

All units in the picture above are 1012 m3.
http://www.globalchange.umich.edu/globalchange1/current/labs/water_cycle/water_cycle.html

• Identify the reservoirs of the hydrological cycle
• Hydrological processes (flux) connecting the reservoirs

• Write the water balance equations for ocean, atmosphere, and land.
Reservoirs

http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/hyd/bdgt.rxml
Percent of    Percent of    Residence
Volume (km3)
total       freshwater    time (yr)
Water in Land Areas:   47,971,710     3.5
Lakes:
Fresh          91,000         0.007        0.26           (All surface
Saline         85,400         0.006                       water:)
4.0
Rivers                 2,120          0.0002       0.006
Marshes                11,470         0.0008       0.03
Soil moisture          16,500         0.0012       0.05
Groundwater:                                                      (All subsurface
water:)
Fresh         10,530,000     0.76         30.1           20,000
Saline        12,870,000     0.93
Biological Water       1,120          0.0001       0.003
Icecaps and glaciers 24,364,100       1.76         69.6
Atmosphere             12,900         0.001        0.04           0.02
Oceans                 1,338,000,000 96.5                         2,650
Total                  1,385,984,610 100           100
Hornberger et al., 1998
Water Balance Equation

where: M = mass within the control volume [M]; t = time [T]; I' =
mass inflow rate [M T-1]; and O' = mass outflow rate [M T-1].

where: V = volume of water within the control volume [L3]; I =
volume inflow rate [L3 T-1]; and O = volume outflow rate [L3 T-1].
where: V = average volume of water stored, and assumed to be
constant; P = average precipitation rate; rsi = average surface
water inflow rate; rgi= average groundwater inflow rate; rso=
average surface water outflow rate; rgo= average groundwater
outflow rate; and et = average evapotranspiration rate. All terms
in the equation have dimensions of volume per time [L3 T-1].
What drives the hydrologic cycle?
2. Energy Balance

http://geography.otago.ac.nz/Courses/283_389/Resources/palaeo/GlobalEnergyBalance.html

•Write the energy balance equations for the earth

http://www.physicalgeography.net/fundamentals/7i.html
Campbell and Norman, 1998

http://www.physicalgeography.net/fundamentals/7i.html

•Write the energy balance equations for the earth surface
Campbell and Norman, 1998
Discussion

• What determine incident short-wave radiation
on the earth surface?
– Solar constant: Describes the Solar Radiation that falls on an
area above the atmosphere at a vertical angle: s = 1.37 kW / m².

– others

• What control out-going long-wave radiation
from the earth surface?
Describe the patterns, and
Explain…

Find the difference
between the two

http://www.agu.org/eos_elec/95206e.html
How is the Hydrological Cycle driven?
3. Atmospheric circulations

If no earth rotation                          With earth rotation

http://ess.geology.ufl.edu/ess/Notes/AtmosphericCirculation/atmosphere.html
http://www.blueplanetbiomes.org/climate.htm
4. Oceanic circulations

http://www.uwsp.edu/geo/faculty/ritter/images/maps/ocean_currents.jpg
Hydrologic Information System to the State
in (Near) Real Time Via Internet

Products:
- Rainfall
- Snow cover
- Runoff
- River flow
- Recharge
- ET
-Soil Moisture
-LULC
-VI

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