Researchers:
- Andrew H. Marshall in association with Can-Ag Enterprises, Guelph, Ontario
Executive Summary
Evaluation Summary
(Tech. Transfer Report Summaries)
View / Download Final Report [2270 KB pdf]
Associated SWEEP/LSP Research
Completed: May, 1992
Key Words:
clay soils, model, phosphorus,
land planing
The land planing studies, which were
carried out by Can-Ag Enterprises Limited, were mathematically modelled
using a modified version of the Chemicals, Runoff and Erosion from Agricultural
Management Systems (CREAMS, Ver. 1.7) model. This modelling assignment focused
on the first phase of model application, the prediction of overland flow
episodes, and was based on a procedure which encompassed five areas of model
development and application. These areas included problem identification,
stated objective, development of method, results and evaluation of results.
Based on this procedure, 116 out of
130 observed episodes of overland flow were predicted for the twelve fields
in the land planing studies for the time period from April '89 to September
'90. In addition, 38 predictions were made which could not be explained,
i.e. the failure of monitoring equipment. These results were dependent on
a number of factors including the proximity of an agricultural field to
precipitation measurement as well as the seasonal variation in infiltration
characteristics of heavy clay soils.
The predictions of overland flow episodes
resulted from a novel approach of applying the CREAMS Ver. 1.7 model to
agricultural fields across seasons. This approach provided a solid basis
for the next phase of modelling application: an emphasis on the prediction
of flow quantities and sediment and phosphorus concentrations and loadings.
The framework for such an emphasis could easily be patterned on the framework
developed in this assignment, the first phase of model application.
(From Technology Transfer Report Summaries - A. Hayes, L. Cruickshank,
Co-Chairs)
The modelling was done using data from
sites monitored in the SWEEP project, Land Reshaping of Lowland Clay Soils.
A modified version of the field scale model for Chemicals, Runoff, and Erosion
from Agricultural Management Systems (CREAMS) was used. The objective of
the study was to develop a method of estimating the empirical values for
the field parameters used by the model and evaluate its ability to predict
occurrences of surface runoff and subsurface drainage flows.
The analysis was completed on field
data for surface runoff events only. The Land Reshaping project did not
measure tile flow; therefore, that component could not be incorporated into
the model. The success of the model was based on its ability to predict
an event occurrence. The analysis did not evaluate the model's ability to
quantify runoff volume of each event. An adaptation was incorporated in
the model to allow for a seasonal variation in the hydraulic conductivity
parameter.
The model successfully predicted the
occurrence of 116 out of 130 observed events of overland flow. The model
did not find any difference in the event occurrence between planed and unplaned
fields. From the measured data of overland run-off for a five month period,
the unplaned fields showed a lower amount of run-off than planed fields.
Comments:
The project successfully completed
its main objective of predicting overland flow events. This report would
be of little interest to anyone who does not understand modelling.
Future Research: ( )
indicates reviewers suggestion for priority, A - high, C - low.
(C) The model should be further evaluated quantitatively making use of
the parameter selection technique developed. At the same time, the phosphorous
loss component of the model should be evaluated using this modified technique.
Created: 05-28-1996
Last Revised:
Thursday, May 19, 2011 03:37:58 PM
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