scholarly journals Ecological space zoning based on lake ecosystem health maintenance: taking the Hongfeng Lake basin as example

2021 ◽  
Vol 41 (7) ◽  
Author(s):  
蒋啸,周旭,肖杨,罗雪,杨大方 JIANG Xiao
Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2493 ◽  
Author(s):  
Meena Kumari Kolli ◽  
Christian Opp ◽  
Daniel Karthe ◽  
Michael Groll

India’s largest freshwater ecosystem of the Kolleru Lake has experienced severe threats by land-use changes, including the construction of illegal fishponds around the lake area over the past five decades. Despite efforts to protect and restore the lake and its riparian zones, environmental pressures have increased over time. The present study provides a synthesis of human activities through major land-use changes around Kolleru Lake both before and after restoration measures. For this purpose, archives of all Landsat imageries from the last three decades were used to detect land cover changes. Using the Google Earth Engine cloud platform, three different land-use scenarios were classified for the year before restoration (1999), for 2008 immediately after the restoration, and for 2018, i.e., the current situation of the lake one decade afterward. Additionally, the NDVI (Normalized Difference Vegetation Index) and NDWI (Normalized Difference Water Index) indices were used to identify land cover dynamics. The results show that the restoration was successful; consequently, after a decade, the lake was transformed into the previous state of restoration (i.e., 1999 situation). In 1999, 29.7% of the Kolleru Lake ecosystem was occupied by fishponds, and, after a decade of sustainable restoration, 27.7% of the area was fishponds, almost reaching the extent of the 1999 situation. On the one hand, aquaculture is one of the most promising sources of income, but there is also limited awareness of its negative environmental impacts among local residents. On the other hand, political commitment to protect the lake is weak, and integrated approaches considering all stakeholders are lacking. Nevertheless, alterations of land and water use, increasing nutrient concentrations, and sediment inputs from the lake basin have reached a level at which they threaten the biodiversity and functionality of India’s largest wetland ecosystem to the degree that immediate action is necessary to prevent irreversible degradation.


2016 ◽  
Vol 36 (5) ◽  
Author(s):  
蔡琨 CAI Kun ◽  
秦春燕 QIN Chunyan ◽  
李继影 LI Jiying ◽  
张咏 ZHANG Yong ◽  
牛志春 NIU Zhichun ◽  
...  

Author(s):  
Robert B. Richardson ◽  
Murari Suvedi

Fisheries in Cambodia play an important role in supporting household food security and livelihoods throughout the country. Inland fisheries production is largely dependent on numerous ecosystem services, particularly the flood waters of the Tonle Sap Lake basin, which has been degraded from increased fishing pressure because of population growth and a rising demand for fish. To address the dual problem of food insecurity and overfishing, an integrated food security and climate change program involved the promotion of small-scale aquaculture through semi-intensive pond management. The objective of this study is to examine perceptions of small-scale aquaculture by participants in this program in order to assess the potential for aquaculture to contribute to household food security and conservation of the Tonle Sap Lake ecosystem. Focus group discussions and a household survey were conducted among current and previous fish farmers. Results demonstrate that most farmers continue to practice small-scale aquaculture as a means to supplement household food availability and income. Numerous barriers to adoption of small-scale aquaculture were identified, including access to water, prices of commercial fish feed, selling price of fish in markets, and concerns about profitability. Seasonal water scarcity is the most prominent challenge in promoting aquaculture technologies, so aquaculture development should be expanded in areas where there are abundant supplies of water, or where use of water storage techniques are feasible. Aquaculture technology appears to have the potential to contribute to food security, nutrition, and household income, and the expansion of the practice of small-scale aquaculture has the potential to reduce fishing pressure on the wild fisheries of the Tonle Sap Lake.


2012 ◽  
Vol 518-523 ◽  
pp. 4510-4520
Author(s):  
Hong Shuai ◽  
Jing Bao Li ◽  
Si Min Xu ◽  
Yu Dan Li

The lake basin morphology is closely related to the health level of the lake system function. It is the prerequisite and fundamental to evaluate whether the lake ecosystem and service function are healthy or not. According to historical documents, maps, water and sediment data from 1986 to 2010, the author evaluated the health of the lake basin morphology on the typical years by using the catastrophe progression method and by selecting 8 indicators which includes the exposed frequency of bottomland, hydrodynamic conditions and geometry form of the lake basin.The results showed that: ① The East Dongting Lake has a relatively good health status ( the average of membership grade is 0.7486), but with high fluctuations (0.6775 ~ 0.7965); then followed by South Dongting Lake, (0.7311); the worst is West Dongting Lake (0.7269) while it has a minimum fluctuation of health relative membership degree (0.7026 ~ 0.7487);② In the last 20 years, the health standard of the Morphological Structure of Dongting Lake Basin has shown an tendency of "firstly get worse then improved" . It had the lowest healthy membership grade in 1998(0.6912), and the highest value in 2004(0.7711), the values of the remaining typical years are in between. They constitute a sufficient support to claim that the implementation of "4350" project, and the construction and impounding of the Three Gorges reservoir dam are so effective in improving the lake basin morphology toward the more healthy developing direction.


2012 ◽  
Vol 178-181 ◽  
pp. 304-308 ◽  
Author(s):  
Wei Guo Chen

The properties of urban lake ecosystem considered, the index system for its health assessment is built with the pressure-state-response model framework put forward by Organization for Economic Co-operation and Development. The comprehensive index weights are determined with improved analytic hierarchy process and entropy value method. The model based on fuzzy optimum selection theory is used to assess health state of urban lake ecosystem. The application of this model in Lake Dongchang is given as an example. The states of its ecosystem health are assessed. The results conform basically to the reality.


2009 ◽  
Vol 9 (6) ◽  
pp. 1234-1247 ◽  
Author(s):  
Douglas D. Kane ◽  
Steven I. Gordon ◽  
Mohiuddin Munawar ◽  
Murray N. Charlton ◽  
David A. Culver

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