Figure 1
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Data sources:
Data was provided from National Environmental Monitoring Department of the Ministry of Ecology and Natural Resources under the ENI SEIS II East project activities
Note: the data series are calculated as the average of annual mean concentrations of phosphate (mg P/l) (top) nitrate (mg NO3-N/l) (bottom) for river monitoring sites in the whole of Azerbaijan (left) and in different regions (right) for the period 2001-2017. Lakes; the data series are calculated as the average of annual mean concentrations of phosphate (mg P/l) (left) nitrate (mg NO3-N/l) (right) for lake/reservoir monitoring sites in Azerbaijan for the period 2001-2017. The number of monitoring sites is 8 for both determinants.
There is a tendency of decrease in the average river phosphate concentration for the whole country since 2012. However, the average concentration was still more than the double at the end of the time series compared to the start. The concentrations in Gazakh-Ganja and in particular in Shirvan increased markedly from 2009 to 2011. In Gazakh-Ganja the concentrations continued to increase steadily also after this. A slower, but steady increase is also seen for the Guba-Khachmaz region.
Average river nitrate concentrations decreased strongly over the studied time period, and in particular from 2011 onwards, reaching very low average levels from 2014 onwards. The time series pattern was fairly similar between the different regions, but at the beginning of the time series the nitrate concentration was higher in Gazakh-Ganja and Shirvan than in Guba-Khachmaz and Lankaran-Astara. The highest levels were observed in Nakchivan, but this region was only represented by one monitoring site.
Lake and reservoir phosphate concentrations showed a strong increase and a subsequent decrease starting in 2009. The concentration level has increased over the time period as a whole, with the values at the end being around 1.5 times higher than at the beginning of the time series.
For nitrate, the concentration pattern for lakes and reservoirs was opposite of that seen for rivers, with lowest concentrations at the start of the time series. The average concentration increased abruptly somewhat before the increase seen for lakes but has more than halved since 2009. Still the current levels are about four times higher than at the beginning of the time series.