Key facts on Xi'an environment in 2015     Updated: 2019-01-31

Air quality

Days above Grade II*: 251 (15 days of Grade I)

*According to the criteria of the National Environment Air Quality Standard (GB 3095-2012), the air quality is divided into six grades, in which the air pollution index is arranged in ascending order. 

Proportions of days above Grade II: 69.1%

Annual average dust fall:15.19 tons/(sq m ×30 days), 3.8% higher than previous year

Rainfall ph value:6.8

Acid rain sample: 0 

Water quality

The municipality's river water pollution alleviated, with overall pollution index dropping by 47.0% compared to the previous year.

Rivers are listed here in descending sequence according to the severity of water pollution level:

Zaohe River, Shichuan River, Xinhe River, Linhe Riverhe, Chanhe River, Juehe River, Fenghe River,  Weihe River, Jinghe River, Haohe River, Bahe River, Heihe River, Laohe River, Wangchuan River, Linghe River.

18 of the cross-sections for river water quality monitoring reached the standard, according to the criteria based on functions of water environment.

100% of drinking water source reached standard quality. 

Outdoor noise

The environmental noise maintained a stable level in 2015, except a few areas were increasingly affected by construction noise. According to the international criteria, 4 out of 5 functioning areas met the daytime noise standard, while only 1 passed the night-time noise standard.