| 其他摘要 | Shaanxi Province locates in the hinterland of China. There are four climate types
which are arid, semi-arid, semi-humid and humid climate from the north to the south
territory. And the Yellow River and the Yangtze River has pass through Shaanxi Province.
From north to south, Shaanxi Province can be divided into three natural areas by Beishan
and Qinling mountains as northern Shaanxi, Guanzhong, southern Shaanxi, and northern
Shaanxi region. For a more comprehensive and true reflection of the surface water quality
in Shaanxi province, three major rivers of Wei River, Yan River and Han River were
selected as study objects to character the water quality of Yellow River and the Yangtze
River in the province. The Statistical Yearbook and Environmental Statistical Yearbook of
Shaanxi Province from 2001 to 2010, and also the monitoring data of water quality in the
three rivers of Shaanxi Provincial. Referencing to the national ground water quality
standards （GB3838-2002）, and basing on the evaluation indexes of dissolved oxygen
（DO）, COD MN , BOD 5 , NH 3 -N, volatile phenol, oil and COD, the water pollution process
and control of the 13 sections in Wei River Basin, of the 5 sections in Yan River Basin, and
of 9 sections in Han River Basin were systematically evaluated. In the view of water
pollution, the paper analyzes the historical changes in the quality of the three rivers, and
investigates the source of pollution in the three rivers, and discusses ways to solve these
problems, thus to put forward the practical countermeasures for the water pollution. The
main conclusions are as follows.
（1） The water quality of the three typical river water bodies showed obvious
temporal and spatial characteristics. From 2001 to 2010, the quality of the three typical
rivers improved significantly. From 2001 to 2010, the cross-sections of the 27 monitoring
sections in I ~ Ⅲ water quality were increased from 11 to 18, the increasing proportion
was 66.7%. And theⅤ water quality was 9, accounting for 33.0%. On the spatial scale, the
pollution of the three typical rivers showed a large difference from north to south. The Wei
River in the north of the Qinling Mountains was seriously polluted. In comparing, the Yan
River was slightly polluted and thewater quality in Han River in the south of the Qinling
Mountains wasexcellentfor ten years.
（2） The organic pollution were the mainly pollution of the three typical river. The concentration of petroleum, ammonia nitrogen, BOD 5 , DO and potassium permanganate in
the Wei River Basin decreased significantly; and the concentration of COD and petroleum
pollution factor in the Yan River Basin decreased significantly from 2001 to 2010. The
HanRiver Basin was mainly composed of ammonia nitrogen Pollution-based, and also
showing a downward trend.
（3） The regression analysis among pollution factors and runoff and sediment
transport in the three river shows that there is a close relationship between water pollution
and river runoff. There was a significant positive correlation between DO concentration
and runoff in the Wei River. Yet the concentration of ammonia nitrogen was negatively
correlated with the annual runoff. In the Yan River Basin, the BOD 5 concentration was
negatively correlated with the annual runoff. The significant negative correlation between
NH 3 -N and annual runoff indicated that river runoff directly affected the concentration of
river pollution. There was a negative correlation between the runoff and concentration of
potassium permanganate in the HanRiver, but the correlation index was not obvious.
Moreover, the annual sediment load and the concentration of COD MN were positively
correlated.
（4） The river pollution in different regions of Shaanxi Province shows different
characteristics. The water pollutants in the Han River Basin in southern Shaanxi are mainly
derived from agricultural non-point source pollution, so to improve the agricultural model
and structure of the basin, and control the fertilizeramount arethe main measures to
enhance the water quality ofHan River.The pollutants are complicated and diverse in the
Wei River locating in the Guanzhong area. On the one hand, it is necessary to control the
amount of fertilizer in the process of agricultural cultivation. On the other hand, it is
necessary to control the discharge of various types of municipal sewage in the region.
ForYan River locating in northern Shaanxi province, developing ecological agriculture and
Preventing soil erosion is an effective measure to improve its water quality.
Key words: Water quality; assessment; Pollution control; Ecological type area; Shaanxi |
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