Direct assimilation of measured soil water content in Root Zone Water Quality Model calibration for deficit‐irrigated maize

2020 ◽  
Vol 112 (2) ◽  
pp. 844-860
Author(s):  
M. W. Sima ◽  
Q. X. Fang ◽  
Z. Qi ◽  
Q. Yu
2006 ◽  
Vol 86 (4) ◽  
pp. 675-690 ◽  
Author(s):  
E. Mapfumo ◽  
D S Chanasyk ◽  
C. L.A. Chaikowsky

A study was conducted at Syncrude Canada Ltd., Alberta, to evaluate the simulation of soil volumetric water content from the reclaimed slopes of the Southwest Sand Storage Facility using the Root Zone Water Quality Model (RZWQM). Soil water content measurements were conducted every 2 wk using a neutron moisture meter in 2001 (dry year) and 2002 (wet year). Two types of calibration and evaluation were performed: first, calibration using 2001 weather data (dry year) and evaluation using 2002 weather data (wet year) (herein referred to as method 1); second, calibration using 2002 weather data (wet year) and evaluation using 2001 weather data (dry year) herein referred to as (method 2). Results from the method 1 calibration for each tube indicated modeling efficiencies (EF) between −0.27 and 0.90, coefficients of determination (r2) between 0.13 and 0.97, and deviation (D, as %) of simulated from measured values of less than 5%. The model evaluation by tube location following method 1 calibration indicated EF values between −3.80 and 0.56, whereas r2 values ranged between 0.08 and 0.82. Although five out of eight tubes had D values > 5%, all except for one tube had D values < 20%. Method 2 calibration results for each tube indicated EF values of −0.34 to 0.85, r2 values of 0.07 to 0.85 and all D values < 5%. Results of the method 2 model evaluation by tube location indicated EF values of −10.15 to 0.75 (overall EF = −0.84), r2 values of 0.04 to 0.96 (overall r2 = 0.39) and D values of 2.6 to 48.6% (overall D = 19.8). Method 2 model evaluation results indicated EF values of −1.69, −3.85 and −0.01, for depths of 15, 25 and 35 cm, respectively. The D values were 27, 20 and 13%, respectively. Graphical displays indicated that during the evaluation process, the model generally tended to slightly under-estimate the wetter moisture conditions, regardless of whether data for a wet year or a dry year were used during the calibration process. Key words: Modeling, calibration method, soil water, land reclamation


1993 ◽  
Vol 36 (2) ◽  
pp. 369-380 ◽  
Author(s):  
L. R. Ahuja ◽  
D. G. DeCoursey ◽  
B. B. Barnes ◽  
K. W. Rojas

2004 ◽  
Vol 60 (3) ◽  
pp. 205-221 ◽  
Author(s):  
Robert W Malone ◽  
Lajpat R Ahuja ◽  
Liwang Ma ◽  
R Don Wauchope ◽  
Qingli Ma ◽  
...  

1995 ◽  
Author(s):  
◽  
Youxiu Hua

The objective of this study is to evaluate the effects of variable cracking on the transportation of agricultural chemicals at the Missouri MSEA site using the Root Zone Water Quality Model (The version of the RZWQM used in this thesis is version 3.0). To reach this goal, the following tasks have to be conducted: (1) revising the RZWQM to accommodate variable cracks; (2) calibrating the RZWQM to the Missouri MSEA site' , (3) quantifying cracking at the Missouri MSEA site; (4) using the cracking data in the RZWQM; (5) predicting the effects of cracking on water content, nitrate-nitrogen, atrazine and alachlor transport by using the revised RZWQM; and, (6) analyzing the simulation results.||Evaluation of effects of variable cracking on the transportation of agricultural chemicals at the Missouri Management System Evaluation Area site using the Root Zone Water Quality Model.


1999 ◽  
Vol 91 (2) ◽  
pp. 220-227 ◽  
Author(s):  
Feliks M. Landa ◽  
Norman R. Fausey ◽  
Sue E. Nokes ◽  
Jonathan D. Hanson

1995 ◽  
Vol 38 (1) ◽  
pp. 75-83 ◽  
Author(s):  
K. E. Johnsen ◽  
H. H. Liu ◽  
J. H. Dane ◽  
L. R. Ahuja ◽  
S. R. Workman

Sign in / Sign up

Export Citation Format

Share Document