Urbanization Affects Aesthetic Quality of Lake

Lake Chao Hu, valuable for its aesthetic quality, attracts tourists.
 Source: <http://www.absolutechinatours.com/china-travel/Five-Great-Lakes.html>  

Lake Chao Hu, the fifth largest lake in China attracts visitors who generate financial income for the local economy.  The video below, found on Youtube, demonstrates a family enjoying their visit to this beautiful aquatic ecosystem.  

Found: http://www.youtube.com/watch?v=wkx5VsulHkk

It is clear that in its pristine form, Lake Chao Hu can develop into a spot for ecotourism.  However, the effects of eutrophication must first be combated.  

Visible algal blooms reduce the lake's aesthetic quality and lower the prospects of tourism.
Source: <http://www.chinadaily.com.cn/china/2007-06/12/content_892212_2.htm>  

One might ask oneself how the lake became so polluted.  While many factors led to the lake's detriment, urbanization is perhaps the largest factor.  Larger numbers of people, now living in urban areas near the lake, place a larger demand on the ecosystem than they did  in previous years.  It is no surprise that "with the urbanization rate increasing from 17.4% in 1978 to 44.9% in 2008," inadequately treated sewage is disposed into the lake (Zhao v).  The city's infrastructure simply cannot support all the extra waste of a population larger than the one it was designed for.  In a study, Zhang, Liang, and Wang report that "urban sewage input from local urban regions [around Lake Chao Hu are] suspected of being the major source responsible for the pollution" (362).
The link below provides a map that shows population density within China.  In comparison to other regions, the south-east region, in which Lake Chao Hu is located, has a high population density, at about 250 people per sq. meter.

http://www.atozmapsdata2.com/downloads/Regional/Modern/R-ASIA-Pop.pdf

This map shows where Lake Chao Hu is located.

Liu et al. include this map in their study "Human-induced change in sedimentary trace metals and phosphorous in Chaohu Lake, China, over the past half-millennium."  Other interesting graphs that they present show levels of heavy metals and phosphorus in the Nanfei River mouth, which deposits water right into Lake Chao Hu.

This graph shows the accumulation rates of heavy metals and  phosphorus  found in core samples the research team took in 2007 from the Nanfei River. 

These graphs show the concentration of metals and phosphorus.  Furthermore, it demonstrates that the elements have high enrichment factors.

Liu et al. state that low enrichment factors, or EFs should be between 0.8 and 1.1 (1).  The graphs (b) and (d) show that Lead, Zinc, and Phosphorus exceed this range, and pose a problem.  These nutrients enrich the lake and cause eutrophication.  Since they are found in the river mouth, it suggests that urban areas further from Lake Chao Hu are also affecting it.  Perhaps the numbers are even higher within the lake itself.  Unlike the free-flowing river, the lake cannot move and therefore has a harder time in filtering out these pollutants.  All this adds up and aggravates the process of eutrophication.  

Works Cited 

Hwang, Aaron. “5th biggest lake in China.” Online video clip. YouTube. YouTube, 13 Feb. 2008. Web. 25. Nov. 2012.

Liu, Enfeng, et al. “Human-induced change in sedimentary trace metals and phosphorus in Chaohu Lake, China, over the past half-millennium.” Journal of Paleolimnology Springer Science+Business Media (2012): 677-689. Web. 26 Nov. 2012.

Zhao, Jingzhu. “Towards Sustainable Cities in China: Analysis and Assessment of Some Chinese Cities in 2008.” SpringerBriefs in Environmental Science. (2011): v. Web. 26 Nov. 2012.

Zhang, Kai, Bo Liang, and Ji-Zhong Wang. “Tracing urban sewage pollution in Chaohu Lake (China) using linear alkylbenzenes (LABs) as a molecular marker.” Science of the Total Environment. Jan. 2012: 356-63. Science Direct. Web. 26 Nov. 2012.