Document Type

Thesis - University Access Only

Award Date

2006

Degree Name

Master of Science (MS)

Department / School

Agricultural and Biosystems Engineering

Abstract

Tile drains are increasingly used in South Dakota to drain the excess water from the soil and to allow timely field operations. The computer model DRAINMOD has been widely used for water table simulations and making subsurface drainage decisions. DRAINMOD was developed for pattern drainage system but in South Dakota, tiles are mostly laid out in an irregular or random pattern. Model results were compared to data from 2005 to test DRAINMOD performance for an irregular drainage system in South Dakota. The simulations were run for water table depths and surface flow using the freezing and thawing option and without using this option. The results indicated that the DRAINMOD was able to simulate the water table depths and subsurface flow for both freezing and non-freezing options for irregular drainage tile system. The absolute deviations and standard errors were less than 15 cm for water table simulations. The absolute deviations and standard errors were less than 20 m3/d for subsurface flow simulations. An ultrasonic sensor, model MINI-A was tested for its ability to measure the water table elevations. The range of sensor was from 0.3 to 12.2 m. The accuracy of the sensors was ±13.09 %. The sensors had very high precision with standard deviation and coefficient of variation of 0.006 m and 0.81 % respectively. The sensors were sensitive to variations of 9.5 mm depth of water.

Library of Congress Subject Headings

DRAINMOD

Drainage -- South Dakota -- Computer simulation

Drift -- South Dakota

Format

application/pdf

Number of Pages

114

Publisher

South Dakota State University

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