| WohuShan Reservoir in southern of Jinan is one of the most important drinking watersources of Jinan, its surrounding plays an important role in security of water supply.JinYangchuan and JinYunchuan River are two catchments in the upper reaches of this reservoir.Study on nitrogen compositions, temporal and spatial distribution, nutrients pollution andinfluence factors of the rivers are great significance for making an objective evaluation andreasonable development, protecting the surface water environment and making full use of itsresource.Samples were collected for laboratory analysis in JinYangchuan and JinYunchuan Riverfor December2010（low water period in winter）, May2011（water rising period in spring）,August2011（high water level period in summer） and October2011（water falling period inautumn）. August2011, an incubation of five weeks for soil samples in the river coast was usedto analyze the nitrogen mineralization characteristic, meanwhile, determining main physicaland chemical properties of soil. Conclusions are as follows:1.During December2010to October2011, the surface temperature of JinYangchuan andJinYunchuan River changed between0.5to28.5℃, seasonal variation was: winter low, summerhigh; PH changed from7.67to8.13, it showed different seasonal variation when positionchanged; dissolved oxygen changed from6.95to15.67mg·L-1，seasonal variation was: winterhigh, summer low; which was opposite to temperature variation; electric conductivity changedfrom427to660μs·cm-1, and the overall level of JinYunchuan River was higher thanJinYangchuan River; the concentration of the major anion（F-、Cl-、SO42-）in the rivers werekept in a low level, which came up to standard demanded by Ⅲwater of《surface waterenvironment quality standards》（GB3838-2002） and which were lower than the standard limitsof centralized drinking water.2. The JinYangchuan River section: TN concentration was3.09-11.19mg·L-1, nitratenitrogen was2.48-9.98mg·L-1, accounting for74.0-96.3percent of the total nitrogen; ammonianitrogen concentration was0.0628-0.5259mg·L-1, accounting for0.7-5.6percent of the totalnitrogen. The JinYunchuan River section: TN concentration was3.28-11.89mg·L-1, nitratenitrogen was1.47-11.47mg·L-1, accounting for44.8-97.5percent of the total nitrogen; ammonia nitrogen concentration was0.1295-0.9533mg·L-1, accounting for1.1-29.1percent ofthe total nitrogen. In the space, the nitrogen contents of upstream section were the highest in therivers, nitrate nitrogen was the main stable nitrogen form.3. The correlation analysis between rainfall and nitrogen concentration of two rivers that,there were all negative correlation between the two factors, in addition to the rainfall waspositively related to ammonia concentration in the water of JinYunchuan River. These resultsshowed that the amount of precipitation had a little attention to decrease nitrogenconcentrations. Riparian soil nitrogen mineralization and loss affected the increase nitratecontent to some extent.4. The increase of ammonia concentration was closely related to the sewage disposal ofcoastal tourism in JinYangchuan River, it was point source pollution; the high ammoniaconcentration was caused by farmland fertilization and drainage in JinYunchuan River. Thespatial and temporal variations characteristics of nitrate was similar to that of total nitrogenwith the highest in winter, higher in autumn and summer and lower in spring, the concentrationof dry season were greater than in flood period. Analysis of reasons: plankton growthreproduction consumed large amounts of nitrate, and the dilution effect of the wet periodprecipitation also caused the decrease of water nitrate concentration in spring and summer;large amounts of nitrogen oxides compounds which are produced by the combustion of coal, oil,natural gas and other matters could form nitrates through chemical action. They may fall toriver, eventually lead to the increase of nitrate of water baby in winter. |
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