生态环境部发布10月及1-10月全国地表水空气质量报告探索自然低碳环保小技巧

生态环境部发布：2020年10月及1-10月全国地表水、空气质量报告，探索自然低碳环保小技巧

一、地表水

（一）总体情况

在2020年的10月份，1940个国家地表水考核断面中，水质优良（Ⅰ-Ⅲ类）比例上升至83.3%，同比增长了7.5个百分点；劣Ⅴ类断面比例下降到0.8%，同比下降了2.1个百分点。主要污染指标包括化学需氧量、总磷和高锰酸盐指数。图1展示了2020年10月全国地表水的分类比例。

对于1-10月份的情况，也有相似的趋势发生。在这期间，有1940个国家地表水考核断面，其中-water quality classification-ratio-increased-to 81.8%, with an increase of 6.4 percentage points compared to the previous year; and the proportion of poor V-class water bodies decreased to 0.8%, with a decrease of 2.4 percentage points compared to the previous year.

The main pollutants were still chemical oxygen demand, total phosphorus, and permanganate index.

（二）主要江河水质状况

In October 2020, the water quality in seven major river basins and northwest rivers was better than before, with a ratio of I-III class water bodies reaching 86.7% and a ratio of V-class water bodies decreasing to 0.4%. The main pollutants included chemical oxygen demand, permanganate index, and total phosphorus.

For January to October in that year, similar improvements were seen in these areas: I-III class water body ratios reached 85.6% while V-class ratios decreased to only 0.4%.

（三）重要湖（库）水质状况及营养状态

In October 2020, among the monitored lakes (including reservoirs), there were fewer lakes classified as V-grade (with poor quality) - at just over five percent - while those classified as I-III grade had increased by about twelve percentage points compared to last year's data.

As for nutrients' status in these lakes during this period:

Three out of six hundred seventy-three monitored lakes showed medium-level eutrophication.

Twenty-eight out of one hundred ten monitored lakes exhibited light eutrophication.

The remaining fifty-six showed no signs or levels below light eutrophication.

One lake experienced heavy pollution but no significant changes occurred otherwise during this time frame.

During January through October,

Sixty-two out of one hundred ten monitored lakes displayed medium-level eutrophication,

Twenty-five exhibited light-level eutrophication,

And three experienced heavy pollution;

Forty-four remained unaffected or showed low levels below light eutrophication.

Notably:

Tahoe Lake was found moderately polluted with slight nutrient enrichment,

Pat Lake moderately polluted but less so due mainly due its high concentration levels,

Erhai Lake also displayed moderate pollution primarily caused by nitrogen dioxide emissions from local industries within close proximity around it where nearby agricultural practices contributed little towards any noticeable change observed here on site since then onwards until now when comparing between two different years' results given below:

* Year One: Tahoe's average dissolved oxygen content fell slightly more dramatically down into deeper depths along its shoreline area after being exposed longer duration under warmer temperatures which led me suspecting if might have been affected indirectly perhaps through some kind unknown factors not yet fully understood but suspected could be related somehow connected possibly linked via atmospheric conditions such as humidity level variation maybe? Or perhaps something else entirely different altogether?!