WMS:TR-20 Job Control Parameters

The Job Control parameters include all of the data necessary to run a TR-20 analysis that are not a part of a basin, reach, or reservoir. The following are the specific parameters defined as part of job control:

Precipitation

In TR20, there are two different ways to define precipitation. Precipitation is defined by selecting the Job Control command from the TR20 menu. Then, select the Define Precipitation button to define precipitation over the entire watershed. You can define precipitation by using either a standard SCS rainfall distribution or by defining a custom rainfall distribution. If a custom rainfall distribution is used, you must define a custom rainfall distribution in the XY Series Editor. If one of the standard SCS rainfall distributions are used, you can select one of the following rainfall types:

• Emergency Spillway and Freeboard
• Type I: 24 hours
• Type II: 24 hours
• Type IA: 24 hours
• Type III: 24 hours
• Type II: 48 hours

For all the standard distributions, you must define the rainfall depth. For the dimensionless distribution, you must also define the rainfall duration. You only need to define the depth and/or duration of the rainfall for a custom distribution if one of the units entered in the XY Series Editor is dimensionless.

Time Control

Main Time Increment

The computational time increment defines the length in time between hydrograph ordinates. The interval should be specified in hours.

Starting Time

The starting time of the simulation is defined in this entry. The time should be specified as floating point number of hours past midnight. For example 7:45 am would be entered as 7.75 and 1:20 p.m. as 13.33.

• Title
• Unit Hydrograph Definition
• Base Flow

Related Topics

• TR-20 Analysis
• Basin Data
• Reach Data
• Reservoir Data
• Diversion Data