Temporal and Spatial Variation Trend and Protection Ideas of Water Environment Quality in the Jinsha River Basin, Lijiang

The water quality and change trend of the Jinsha River Basin in Lijiang from 2011 to 2020 were analyzed using Nemero pollution index method and Spearman rank correlation coefficient method. The spatial distribution and monthly change of water quality were presented. Some suggestions on water pollution prevention and control were put forward. The results showed that from 2011 to 2020, the water quality of Lijiang section of the Jinsha River Basin has a trend of improvement. In 2019, the water quality of Lijiang section has a trend of improvement from upstream to downstream, but the change trend was not significant. In 2020, the water quality of Lijiang section has almost no change from upstream to downstream. The water quality of the river in March, August and December of 2020 was significantly higher than that of the previous month. However, the water quality became worse, showing a downward trend from April to July and September to November, and the water quality improved. The water quality was no significant correlation between the upstream section and the downstream section.