Eutrophication in a Chinese Context: Understanding Various Physical and Socio-Economic Aspects

Abstract

Eutrophication is now a ubiquitous water quality impairment in China. The first step toward restoration of eutrophicated water bodies is a marked reduction of nutrient loadings in their drainage basins. However, the combination of a number of physical and socio-economic factors is now producing compounded increases in nutrient loads while the nutrient assimilation capacities of natural systems are decreasing. Meanwhile, most of the lakes in densely populated part of China are shallow and very susceptible to anthropogenic alteration. Therefore, in spite of ascending efforts in eutrophication control upward trends of algal blooms in both fresh and coastal waters have been observed for the past two decades. Huge knowledge gap exists in our understanding of the sources and pathways of nutrient losses to aquatic ecosystems. Successful water quality restoration of China's eutrophic waters relies not only on more resource input but also more emphasis on basic, integrated, and management-oriented research.

Changes in river water temperature between 1980 and 2012 in Yongan watershed, eastern China: Magnitude, drivers and models

“…1). The Yongan River is the third largest river of Zhejiang Province and flows into Taizhou Estuary and the East China Sea, a coastal area that commonly experiences hypoxia (Li et al, 2007;Gao and Zhang, 2010). The river drains 2474 km 2 and has an average water depth of 5.42 m and discharge of 72.9 m 3 s À1 at the downstream BZA sampling site (Fig.…”

“…Examining long-term river water temperature trends is especially important for watersheds in eastern China that have experienced rapid economic development, human population expansion, and urbanization, as well as significant climate change since the 1980s Chen et al, 2014). For coastal waters along the East China Sea, serious algal blooms and persistent hypoxia have been widely reported in recent decades (Li et al, 2007;Gao and Zhang, 2010). From the perspective of future global warming and increased human activities, higher temperature of water from upstream rivers has the potential to greatly aggravate eutrophication (including harmful algal blooms) and hypoxia of downstream coastal waters.…”

Agricultural Non-Point Source Pollution in China: Causes and Mitigation Measures

“…1) (SEPA 2000(SEPA -2008. Lake eutrophication has been showing a rapidly increasing trend since 2000, with serious algal bloom crisis in Dianchi Lake in 2001 and in Taihu Lake in 2007 (Qin et al 2007;Gao and Zhang 2010). Nitrogen concentrations in large rivers, especially the Yangtze and Yellow river, have been increasing in recent years (Li et al 2007;Yu et al 2010).…”

Evaluating anthropogenic N inputs to diverse lake basins: A case study of three Chinese lakes

“…For larger lakes over 10 km 2 in area, freshwater lakes make up 35 % of the total lake area, and have an average depth of approximately 2 m. Before the 1980s, most freshwater lakes had relatively good water quality and were eligible for drinking (Le et al 2010). However, since China's rapid economic development in the 1980s, human-induced nutrient inputs have increased substantially (Han et al 2013(Han et al , 2014, and a majority of freshwater lakes have experienced a substantial reduction in water quality and ecosystem functionality (Gao and Zhang 2010;Liu et al 2012). One common problem for most lakes is elevated levels of total nitrogen (TN), total phosphorus (TP), and other organic pollutant concentrations, which are mainly caused by expanding populations and agricultural fertilizer inputs (Le et al 2010).…”