125
Tecnología y Ciencias del Agua
, vol. VIII, núm. 2, marzo-abril de 2017, pp. 117-126
Wang
et al
.,
Simulation for non-point source pollution based on QUAL2E in the Jinghe River, Shaanxi Province, China
ISSN 2007-2422
•
years, NH
4
+
-N in the river mainly came from
point source discharges such as domestic sew-
age and organic waste water.
The above method yielded quite expected
results for such non-point source pollutants, as
NO
3
−
-N, and somewhat contradictory ones on
such point source pollutants, as NH
4
+
- N.
Conclusion
In this study, we proposed the combined ap-
plication of QUAL2E, a river water quality
model, and PCA and FA to study the source
apportionment of point and non-point pollutant
loads to surface water. PCA and FA were used
to evaluate pollutant sources in different river
sections in dry and wet seasons, and then the
amount of point source and non-point source
pollution was calculated by using QUAL2E.
The results of PCA and FA show that the
water pollution in the lower reaches of the
Jinghe River mainly involved nitrogen and or-
ganisms. NH
4
+
-N and NO
3
−
-N, as the nitrogen
nutrient indices, were taken as the objects, and
the QUAL2E model equation was adopted to
calculate their source-sink terms in dry and wet
seasons, respectively; the difference between
the terms in wet and dry seasons were the non-
point source loads. The calculation results for
NO
3
−
-N were reasonable, while those of NH
4
+
-N
were somewhat unexpected, but consistent with
the results of PCA and FA. NO
3
−
-N comes from
point source discharges of domestic sewage
and similar in dry seasons and from non-point
source pollution generated by precipitation in
wet seasons, whereas NH
4
+
-N was mainly dis-
charged from point sources throughout the year.
The instability of the point source discharges
caused the above deviation of the calculation
results. It is shown that application of the
QUAL2E river water quality model provides
reliable results for non-point source pollution
caused by storm runoff, but unreliable results
for point source pollution. Therefore, further
model refinement or application of newer ver-
sion QUAL2K (
, http://
/) may be expedient. In con-
trast to QUAL2E, which segments the system
into river reaches comprised of equally spaced
elements. QUAL2K uses unequally-spaced
reaches. In addition, multiple loadings and
abstractions can be input to any reach, which
may be quite instrumental for more accurate
account of the local specific features.
Acknowledgements
We would like to thank the Project of Science and Technol-
ogy of Social Development in Shaanxi Province [grant num-
ber 2016SF-411]. We would also like to express our thanks to
all helpers from the Water Environment Monitoring Center
and Reconnaissance Office of Shaanxi Provincial Hydrologic
Bureau, China for providing
in situ
survey data, without
whom this study would not be possible.
References
Azzellino, A., Salvetti, R., Vismara, R., & Bonomo, L. (2006).
Combined use of the EPA-QUAL2E simulation model
and factor analysis to assess the source apportionment of
point and nonpoint loads of nutrients to surface waters.
Science of the Total Environment
,
371
(1), 214-222.
Beck, M. B. (1987). Water quality modeling: A review of the
analysis of uncertainty.
Water Resources Research
,
23
(8),
1393-1442.
Chowdary, V., Rao, N., & Sarma, P. (2005). Decision support
framework for the assessment of non-point-source
pollution of groundwater in large irrigation projects.
Agricultural Water Management
,
75
(3), 194-225.
Feier, W., Huanchun, L., Yingxu, C., & Dong, W. (2003).
Prediction of output loading of nitrogen and phosphorus
from Qiandao Lake watershed based on AnnAGNPS
Model.
Transactions of the Chinese Society of Agricultural
Engineering
,
19
(6), 281-284.
Gao, Y., Zhu, B., Zhou, P., Zhi, Y., & Tang, J. (2008). Study
on the application AnnAGNPS and SWAT to non-point
resource pollution research: A case of Yanting agro-
ecological experimental station. Chinese Academy
of Sciences.
Journal of Shanghai Jiaotong University
(Agricultural Science)
,
6
(6), 567-572.
Geladi, P., & Kowalski, B. R. (1986). Partial least-squares
regression: A tutorial.
Analytica Chimica Acta
, 185, 1-17.
Guihong, Z., & Jiangyong, C. (2007). Simulation of
agricultural non-point pollution based on AnnAGNPS
model.
Transactions of the Chinese Society of Agricultural
Engineering
,
23
(12), 11-17.
