时    间：2025年 10 月13 日（星期一 ）  

地    点：地理资源所A901

报 告 人：Roohollah Noori 教授（10:30—12:00）

报告题目：Environmental controls on the conversion of nutrients to chlorophyll in global lakes 

报告人简介：

    Dr. Roohollah Noori received his PhD's degree in Environmental Engineering from the University of Tehran, Iran, in 2012. In 2014, he joined University of Tehran, where he currently specializes in freshwater pollution caused by both natural (e.g., geogenic drivers) and anthropogenic sources (e.g., land-use/cover changes) at local, regional, and global scales. He employs a wide range of methods, including physically-based models, data-driven approaches, satellite and airborne imagery, reanalysis and gridded data, in-situ observations, and socioeconomic datasets, to address the pollution and restoration of aquatic ecosystems. He is also a senior scientist in the United Nations University Institute for Water, Environment and Health (UNU-INWEH), specializing in Environmental Pollution and Hydro-Informatics. 

Anthropogenic inputs of nitrogen and phosphorus to lakes have increased worldwide, causing phytoplankton chlorophyll concentrations to increase at many sites, with negative implications for biodiversity and human usage of lake resources. However, the conversion of nutrients to chlorophyll varies among lakes, hindering effective management actions to improve water quality. Here, using a rich global dataset, we explore how the relationship between chlorophyll-a (Chla) and nitrogen and phosphorus and inferred nutrient limitation is modified by climate, catchment, hydrology and lake characteristics. Phosphorus was the dominant control in oligotrophic/mesotrophic lakes, both nitrogen and phosphorus co-limitations were dominant in (hyper)eutrophic lakes, apart from hypereutrophic shallow lakes, where nitrogen was the main limiting factor. A generalized additive model of Chla vs nutrients identified a sigmoidal-type relationship with clear breakpoints between Chla and nutrients in all depth-dependent lake categories, except for nitrogen in shallow lakes. The model revealed that Secchi depth, as the predominant factor explaining the residuals, followed by the lake thermal region, elevation, and maximum depth. Lake shoreline slope, hydraulic retention time, mean depth, shoreline length, and watershed area were also statistically significant drivers for deep lakes. Surface area was only significant in shallow lakes, as it directly affects surface heating and surface contact with the wind,resulting in non-significant impact of thermal region in shallow lakes. These findings provide new insights into the response of global lake eutrophication and its main drivers,which could assist lake managers and policy-makers in mitigating widespread lake eutrophication.