The purpose of this work is to evaluate the spatial and seasonal variability of water quality from the Mopanshan Reservoir, which is a typical reservoir in the northern cold regions of China. The results indicate that preventive or remediation actions are necessary to improve its water quality. Water samples were collected between 2012 and 2013 at five sampling stations at the Mopanshan Reservoir, and analyzed for CODMn and total nitrogen (TN). SPSS software was used to carry out analysis of variance and correlation analysis. Spatially, CODMn and TN exhibited a rather small distinction in the horizontal direction, but there was a significant difference regarding TN in the vertical orientation. The concentration of TN also increased with the increase of sampling depth. Seasonally, the concentration of CODMn and TN showed a pronounced seasonal pattern and was divided into four periods. CODMn reached a maximum in September and was at a minimum in June. And TN reached a maximum in June and was at a minimum in November or December. The use of correlation analysis shows that the regular variations of TN was primarily affected by temperature. The main form of nitrogen in the Mopanshan Reservoir is NO3-N, and the change of TN is consistent with that of NO3-N. By Pearson correlation coefficient, the seasonal variability of CODMn correlated to changes in the reservoir's water level. The results showed that the concentration of TN exceeded the guideline values in most months and CODMn was slightly over the standard limit. Thus, it is urgent to develop preventive actions and a remediation processes to improve the water quality in this reservoir.
- reservoir in cold region
- seasonal variability
- spatial variability
- First received 13 December 2015.
- Accepted in revised form 4 July 2016.
- © IWA Publishing 2016