WSP06419

• File Number: 8276.150
• Description: Grand Valley Unit - Colorado River Basin Salinity Project
• State: CO
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 7/1/1982
• Title: Monitoring and Evaluation Plan -- Colorado River Basin Salinity Control Program for Grand Valley Unit and Uinta Basin Unit, Utah -- PART I
• Water Supply Pro - Doc Type: Report/Study

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'-:1' Some of the advantages and disadvantages for each soil monitoring method are:
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Hethod

Advant~

1. Feel and
appearance

1. Low equipment cost
2. Moderate la"or requirement
3. Relatively rapid method
4. Very simple

2. Gravimetric

1. Direct method
2. ~09t accurate
3. Moderately simple
4. Overall equipment cost
rela ti vely low

3. Neutron Moisture 1. Rapid measurements
logging 2. An in-situ method
(neutron probe) 3. Succesfve measurements
are obtained in the same
profile
4. Overall labor requirement low
5. High degree of accuracy
6 _ Simple

Field Irrigation Evaluation

Disadv~ntag~

1. Poor accuracy
2. Destructive metho~-
additional samples cannot be
obtained 1n same site
3. Indirect method

1. Large number of samples
2. Expensive where large number
of samples required
3. High labor requirement
4. Destructive method
5. Relatively slow method

1. Overall equipment cost high
2. An indirect methoi-requires
calibration at each soil moisture
site using gravimetric method
3. Requires installation of access tubes
4. Requires licensing;

Evaluation of farm irrigation systems will in general be conducted according to

procedure given in National Irrigation Guide Notices No.1, No.2, and No.3.

Some modifications of the procedure is required to account for deep percolation,

changes in procedure for evaluating semicontrolled flood:lng (border), and type

of equipment used in collecting data. Modification of procedure would be made

prior to start of a monitoring program. Adequate data w:l11 be collected to

determine the amount water infiltrated into the soil. All part of the

evaluation, rainfall data will be collected at each evaluation site.

Climatic Data

Special climatic data is needed in the case where daily erop evapotranspiration

(ET) is computed. To compute ET, the Modified Penman method will be used. The

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