Changes in perturbation-correlation moving-window two-dimensional correlation spectroscopy of dissolved organic matter induced by dam regulation in a river-type reservoir

<b>Background: </b>Water levels in reservoirs are regulated by dams and thus affects the fate of dissolved organic matter(DOM). For more effective water management and natural watershed conservation, the correlation between dam regulation and DOM changes urgently needs to be explained. According to the regulation rules of Shuikou Reservoir dam, the monitoring times were determined to be September 2021, November 2021, January 2022 and May 2022, and the sampling sites covered Shili'an, Yangkeng, Liujia Bridge, Youxi reservoir entrance (downstream), Gutian Huangtian, Gutian Huangtian (downstream), Bay mouth, Xiongjiang River in Minqing, and Front of Shuikou Reservoir dam. Basic water quality parameters, such as temperature, pH, dissolved oxygen (DO), dissolved total nitrogen (DTN), total phosphorus (TP), dissolved organic carbon (DOC), NH₄⁺, NO₃^-, turbidity, conductivity (us), as well as the components and concentrations of DOM, were collected at the time and space defined above.<b>Methods: </b>In this study, in-situ monitoring, field sampling, perturbation-correlation moving-window two-dimensional (PCMW2D) correlation spectroscopy technology and statistical methods were used orderly.<b>Technique</b><b>: </b>Perturbation-correlation moving-window two-dimensional (PCMW2D) correlation spectroscopy technology was employed to analyze the DOM fluorescence components. Mantel tests were used to statistically evaluate the relationships between DOM fluorescence components and water quality parameters, as well as indicators of organic pollutants.