Publications

Zhao, L; Song, CC; Fang, C; Xu, YP; Xin, ZH; Liu, ZH; Zhang, C (2023). Spatiotemporal variation of long-term surface and vertical suspended particulate matter in the Liaohe estuary, China. ECOLOGICAL INDICATORS, 151, 110288.

Abstract
The estuary and its nearshore waters are of great ecological value. As one of the important water quality eval-uation indicators, suspended particulate matter (SPM) is also relevant to the ecology of the estuary. However, the current research on SPM of surface water is quite well established. It is urgent to study the vertical distribution of SPM due to its significance for further studies of biogeochemical processes in the water column. This study developed remote estimation model of SPM for five different depth water layers in the Liaohe estuary based on in situ Rrs(lambda) data and support vector regression (SVR) methods, and the model performed well (RMSE = 24.32 mg/ L, MAPE = 26.11%, MAE = 18.37 mg/L, N = 115). After applying the model to 10,090 MODIS images collected in 2000-2021, results show that: (1) Vertical distribution of SPM concentration in the Liaohe estuary could be divided into three types: top-down decreasing type (Type I), uniform type (Type II) and top-down increasing type (Type III). (2) Seasonal distribution of SPM concentration in the Liaohe estuary is: medium in spring (76.30 +/- 10.34 mg/L), low in summer (61.80 +/- 6.98 mg/L) and high in autumn (82.28 +/- 19.12 mg/L). There is a sig-nificant decreasing trend of SPM from 2000 to 2021 (p < 0.01). (3) Meteorological factors (wind speed and precipitation), water depth, human reforestation and reclamation activities are closely related to SPM concentration.

DOI:
10.1016/j.ecolind.2023.110288

ISSN:
1872-7034