Time-Series Analysis of Surface-Water Quality in Xiong'an New Area, 2016–2019.

The Xiong'an New Area was established by the Chinese government on 1 April 2017 as a new district in the Hebei Province, and soon after its establishment, investigations on the waterbodies of the district began to initiate governance. In this study, data from 105 Sentinel-2 cloudless images for the period April 2016–September 2019 were analysed to understand the changes in the concentrations of chlorophyll-a and water turbidity in surface waterbodies of the Xiong'an New Area. The results suggest that (1) the water quality shows an overall improving trend owing to surface-water pollution control measures by the Chinese government in the region; (2) the turbidity of the surface waterbody declined gradually particularly after the spring of 2017; (3) the concentration of chlorophyll-a shows a weak decreasing trend, with a low value in spring and a high value in summer with a four-year average of 31.3 μg/L; and (4) by comparing the results of the water quality of two ponds inside and outside the Lake Baiyangdian and the overall water quality of Xiong'an New Area, the changes in turbidity and chlorophyll-a concentration during the study period were consistent. [ABSTRACT FROM AUTHOR]