1. Continuous Daily – one storm per day, 1-1000 years. Can be observed or generated data.

2. Continuous Breakpoint – detailed storm intensities, several storms per day, 1-1000 years. Observed data.

3. Single Storm Daily – One designed storm.

4. Single Storm Breakpoint – detailed storm intensities for one day. Observed data.

Separate program from WEPP.

Generates daily WEPP climate inputs.

Inputs to CLIGEN developed from long term climate statistics (30+ years).

Output from CLIGEN is not observed data, it is generated data.

Can generate from 1-1000 years of data to run WEPP.

Can generate many years of data

Gives a good representation of expected precipitation.

Can be applied to areas where not all WEPP climate parameters are available.

Good for long term averages, return periods.

Version 4.3 – Original implementation, has several bugs, kept for historical purposes.

Version 5.3 – Improvements in generated data. Recommended version to use.

Accepts a file of monthly long term statistics.

For the US there are about 2600 stations based on data to about 1992.

About 100 files were developed for China by using some observed data and matching to “similar” locations in the US.

New CLIGEN input files can be developed using observed data.

Intensity parameters are often interpolated, weakest point of data.

For each day the following are generated: ◦ Precipitation (mm) ◦ Storm duration (hours) ◦ Time to Peak Intensity (factor duration) ◦ Intensity Peak (factor of average intensity) ◦ Maximum Temperature(C) ◦ Minimum Temperature (C) ◦ Solar Radiation (Langleys/Day) ◦ Wind Velocity(m/s) ◦ Wind Direction ◦ Dew Point (C)

2 5 1 35.8 3.39 0.07 14.01 27.1 10.6 461. 6.8 206. 10.4

3 5 1 4.4 1.15 0.08 8.43 28.7 6.9 673. 4.9 117. -1.1

4 5 1 1.6 3.67 0.07 10.76 30.2 9.0 458. 6.2 28. -0.3

5 5 1 15.5 6.12 0.63 8.92 23.2 14.3 388. 5.6 317. 18.7

6 5 1 0.0 0.00 0.00 0.00 15.6 1.3 396. 4.2 163. -8.5

Day

Month

Year

Precipitation (mm)

Duration (h)

Time to Peak Intensity

Intensity Peak

Maximum Temperature (C)

Minimum Temperature (C)

Solar Radiation (Langley/Day)

Wind Velocity (m/s)

Wind Direction (Degree)

Dew Point (C)

TIME

RA

TE

Ip Peak intensity/avg intensity

Average rainfall intensity=Total precipitation/duration

Time of peak intensity-Tp

Time varying intensity-exponentially increases from time zero to peak, and decreases from peak to end of duration

Duration

WEPP uses the storm amount, duration, peak intensity and time to peak to create the storm.

Internally produces a series of duration and amount intervals that represent the storm.

Internally same as breakpoint.

Storm intervals of durations and amounts are input from observed data.

For each day the following are needed: ◦ Number of breakpoints ◦ For each breakpoint: Time (hours and fraction of hour)

Cumulative Precipitation (mm)

◦ Maximum Temperature(C) ◦ Minimum Temperature (C) ◦ Solar Radiation (Langleys/Day) ◦ Wind Velocity(m/s) ◦ Wind Direction ◦ Dew Point (C)

27 5 1986 13 25.00 12.00 481.7 1.50 112.5 16.5

02.40 0.000

02.65 1.000

02.85 1.200

03.00 1.200

03.15 1.400

04.55 1.400

04.70 3.100

04.75 3.600

04.93 7.500

05.16 7.900

05.35 8.300

09.41 8.300

09.50 22.100

Number of Breakpoints

Maximum Temperature (C)

Minimum Temperature (C)

Solar Radiation (Langley/Day)

Wind Velocity (m/s)

Wind Direction (Degree)

Dew Point (C)

Cumulative Precipitation (mm)

Time in hours and fraction of hour

Contains one day in the climate file.

Only WEPP initial conditions are used from management file.

Format is the same as continuous breakpoint file but only one day is defined

Format is the same as continuous daily cligen format but only one day is defined.

Only WEPP initial conditions are used from management file.

WEPP produces a hydrograph found in the main output file:

rainfall amount 152.40 (mm)

rainfall duration 120.00 (min)

normalized peak intensity 1.01

normalized time to peak 0.20

rainfall

time intensity

(min) (mm/hr)

----------------------------------------------------

0.00 75.82

12.06 76.58

24.00 76.87

35.90 76.68

47.82 76.49

59.78 76.30

71.76 76.11

83.78 75.92

95.82 75.73

107.89 75.54

120.00 0.00