Coastal Ecosystem Health Assessment And Prediction Research Of Jiaozhou Bay

Jiaozhou Bay, a natural bay with exploitable functions of port, tourism, foreign trade, marine scientific research etc, plays a very important part in the economic development of Qingdao city. However, due to the strong human influences, the bay's area is continuously decreasing, the environmental quality is continuously damaged, and the biological resources has an even sharper decline. If these problems can not be resolved properly, they may pose a threat to the development of the overall Qingdao region, eventually. Case studies conducted abroad have indicated that single management method is not good enough to solve the current problems as the coastal ecosystem is a socio-economic natural complex ecosystem, with the characteristics of huge organizational structure, energy flow and dynamic flow. New management methods that could integrate multi-discipline factors such as environmental, ecological, economical, social factors and so on are needed.This dissertation explores new methods to protect the Jiaozhou Bay from the perspective of the coastal ecosystem health, the interaction of the pressure on the coastal zone, the changing process and the changing trend of the bay's health state. The study results provide basis for the coastal zone environmental management and the decision-making of the ecosystem management, and it also provides methodological basis for the maintenance and restoration of Jiaozhou Bay's health and the stability, and sustainable development of the coastal zone.The major study contents and results of this dissertation are as followed:1.Recognizing the main influential factors of the bay by analyzing the interrelationships between the environmental stress and the ecosystem's health, by analyzing the pressure of single factor and multi-factor on the Jiaozhou Bay coastal ecosystem. 2.A pressure evaluation system of Jiaozhou Bay coastal zone is established on the basis of the recognizing pressure factors, which contains economic pressures, population pressure, human activity pressure (fishing pressure, land reclamation pressure, terrigenous sewage pressure, heated discharge pressure, mariculture pressure, oil spill accident, air pollution pressure, and coastal tourism pressure) etc. Using the system, the ecosystem stress indices of the Jiaozhou Bay coastal zone were calculated from 1990 to 2005. The results showed that: (1)the ecosystem stress indices of Jiaozhou Bay have a fluctuating upward trend from 1990 to 1996; have a sustainable growing trend from 1997 to 2005; the increasing rate of the index slowed down somewhat from the year 2003, which might be a result of economic pressures changing from positive to negative. (2) The most important human activity pressure is the pollution pressure, followed by the fishing pressure. The pollution pressure has a sustainable upward trend and the fishing pressure reached its maximum value in the year 1999, and started to decrease from then on.3.A coastal ecosystem health assessment indicators system is established based on the influential factors. The system is divided into three subunits: coastal land subsystem, coastal waters subsystem and socio-economic subsystem. According to the results of the pressure assessment, the marine environmental quality indicators and the marine ecological indicators are treated as the most important indicators in the system. The system is used to assess the health state of the Jiaozhou Bay in the year 1988, 1997, and 2005. The assessment results showed that: (1) Jiaozhou bay was healthy in the year 1988, but the health evaluation index showed a sharp decline in 1997, which caused the health state of the bay changed to sub-healthy. In the year 2005, although the health state of the bay was still sub-health, the rate of decline has slowed down. (2)The socio-economic subsystem has shown a steady and healthy development; the coastal land subsystem has shown an upward trend instead of a downward trend at the beginning; the coastal waters subsystem has shown a downward trend.4.A health predicting system of Jiaozhou Bay coastal ecosystem is established based on the coastal ecosystem health assessment indicators system of the bay. The system contains four sub-models: the markov chain model, the numerical model of the marine environment, the EwE ecological model and the grey forecasting model to predict different types of indicators. The predicting results showed that: (1) in the year 2010, Jiaozhou Bay would still be sub-healthy, but would improve compared to the year 2005. (2) The improved dominant factors of Jiaozhou Bay's health from 2005 to 2010 would be: coastal land use optimization, socio-economic development and restoring fisheries resources. Meanwhile, the detrimental factors would be: land reclamation, population growth and marine environment pollution. (3) From 2010 to 2020, the improved dominant factors and the deterioration dominant factors would continue their role in the Jiaozhou Bay. The factors that dominate the health state of the Jiaozhou Bay would be marine environment pollution (4) The healthy evolution process from 1980 to 2010 can be divided into four stages: health, rapid deterioration, slow deterioration and restoration.