Characteristics, sources, and distribution of microplastics in sediments and their potential ecological risks: A case study in a typical urban river of China

Journal of environmental chemical engineering, Journal Year: 2024, Volume and Issue: unknown, P. 114575 - 114575

Published: Oct. 1, 2024

Language: Английский

How Hydrological Extremes Affect the Chlorophyll-a Concentration in Inland Water in Jiujiang City, China: Evidence from Satellite Remote Sensing

ISPRS International Journal of Geo-Information, Journal Year: 2025, Volume and Issue: 14(2), P. 85 - 85

Published: Feb. 15, 2025

From 2020 to 2022, hydrological extremes such as severe floods and droughts occurred successively in Jiujiang city, Poyang Lake Basin, posing a threat regional water quality safety. The chlorophyll-a (Chl-a) concentration is key indicator of river eutrophication. Until now, there has been lack empirical research exploring the Chl-a trend inland context extremes. In this study, Sentinel-2 satellite remote sensing data sourced from Google Earth Engine (GEE) cloud platform, along with hourly collected monitoring stations Jiangxi Province, China, are utilized develop quantitative inversion model for concentration. concentrations various types were estimated each quarter spatiotemporal distribution was analyzed. main findings follows: (1) validated via situ measurements, coefficient determination 0.563; (2) spatial estimates revealed slight increasing trend, by 0.1193 μg/L closely aligning monitoring-station data; (3) an extreme drought 2022 led less bodies, consequently, displayed significant upward especially Lake, where mean increased approximately 1 Q1 Q2 2022. These seasonal changes waters events, thus providing valuable information sustainable management city.

Language: Английский

Analytical study on plastic loosening zone of weak surrounding rocks tunnel in high cold areas

River, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 8, 2024

Abstract The analysis of plastic loosening zone tunnels with cold condition, high in situ stress, and weak stratum is the key scientific problem tunnel construction areas. Based on unified strength theory considering coupling effect stress low‐temperature field, analytical model surrounding rocks was proposed, influence laws physical parameters (initial ground freezing temperature, excavation radius, intermediate principal stress) explored. results illustrate that: (1) low temperature fields, in‐situ has a more significant radius rocks, showing nonlinear correlation. When small, field obvious. (2) increases synchronously gradually decreases increase stress. (3) greater difference stability response to positively correlated coefficient (4) In actual project, proposed can well describe mechanical behavior deformation characteristics environment, applicability. research are expected provide theoretical basis for study

Language: Английский