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| Titel |
Temporal and spatial changes of water quality and management strategies of Dianchi Lake in southwest China |
| VerfasserIn |
T. Zhang, W. H. Zeng, S. R. Wang, Z. K. Ni |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1027-5606
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| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 18, no. 4 ; Nr. 18, no. 4 (2014-04-23), S.1493-1502 |
| Datensatznummer |
250120338
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| Publikation (Nr.) |
 copernicus.org/hess-18-1493-2014.pdf |
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| Zusammenfassung |
| Temporal and spatial changes to the water quality of Dianchi Lake in
southwest China were investigated using monthly monitoring data from 2005 to
2012. Dianchi Lake is divided into two parts, Caohai Lake and Waihai Lake,
by a man-made dike. Caohai Lake lies at the north of Dianchi Lake, while
Waihai Lake is the main water body of Dianchi Lake and accounts for 96.7%
of the whole area of the lake. Based on the analysis of total phosphorus
(TP), total nitrogen (TN), and chlorophyll a (Chl a) concentrations, it was
determined that, in Caohai Lake, the annual concentrations of these
variables ranged from 0.19–1.46 mg L−1, 6.11–16.79 mg L−1, 0.06–0.14 mg L−1,
respectively. In addition, the annual concentrations of TP, TN and Chl a in
Waihai Lake ranged between 0.13 and 0.20 mg L−1, 1.82 and 3.01 mg L−1, and 0.04 and 0.09 mg L−1,
respectively. Cluster analysis (CA) classified the 10 monitoring sites into
two clusters (cluster A and cluster B) based on similarities of water
quality characteristics. Our data revealed that the current status of water
quality within Caohai Lake was much worse than that of Waihai Lake. Water
quality was seriously degraded during the economic boom near the period of
the "Eleventh Five-Year Plan" (2005–2010), and gradually improved from
2010 to 2012 because of the "standard emission directive to industry". The
main factors that influenced the spatial and temporal changes to water
quality were natural factors including lake evolution and regional
characteristic as well as human factors such as pollution load into the lake
and management strategies that were already adopted. Some activities and
regulations were implemented to enhance the lake environment by controlling
wastewater emissions and establishing regulations to protect the lakes in
the Yunnan Province. However, problems with institutional fragmentation
(horizontal and vertical), simple treatment methods, low-intensity
investment in pollution control, and lack of meaningful endogenous pollution
control strategies were still present in the lake management strategy. To
solve these problems, suitable control measures are needed, especially
considering the current old-age status of Dianchi Lake. The fundamental
improvement of the water quality within Caohai Lake was dependent on the
measures taken in the upper reaches of the Caohai Watershed, including
further recovery of submerged plants, resource utilization by floating
plants and the reinforcement of sediment disposal. Management strategies for
endogenous pollution in Waihai Lake were mainly dependent on restocking
algae-eating fish and the ecological restoration of macrophytes. In this
way, the swamping trend and the ageing process that is occurring in Dianchi
Lake can be stunted. And the management strategies would be a contribution
to the management of water conflicts between mankind and ecosystems in similar
lakes. |
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