Study On Composite Systems Analysis Of Urban Multi-source Water Resources And Reasonable Allocation

Water, a necessary and vital natural resource, is physical basic to the human survival and to the development of economy and society. With increasing of population, developing of socioeconomic and advancing of people's living standard, an acuity conflict between limited water resources supply and increasing water demand is coming into being, and it is especially prominent during urban development. Water resources shortage, water pollution, and water waste are the primary causes, which form the conflict between urban water supply and demand. However, urban water resource is directly related with the existence and prosperity of city, and it directly restricts and affects urban construction and development of economy. Urban water resource is important and precious resource to city, it plays a significant role. How to resolve the water problem during urban development is related with urban modernization construction and sustainability development. Water affairs are not only technology activities, and also not only economy activities, but connected with nature, society and interweave into a unity. Water resource, society, economy and environment, which mutual promoting, restricting and action, come into being a complex system. It is important guidance for promoting harmony among human, water resource, economy society and environment to study relationship between water resource and society, economy, environment and allocation of multi-source water among multi-user in city detailedly. Therefore, in this paper, from the characteristics of urban water resources and water users, urban water consumption forecast and modeling, simulation of composite system dynamics of water resource-society-economy-environment, reasonable allocation of urban multi-source water for multi-user and the analysis of harmony and evolvement of water resources composite system are studied. The main contents are as follows:(1) Urban water resource and analysis of its demand. After detailed analysis of the characteristics of urban multi-source water and multi-user, the forecast of urban water consumption has been studied. Owing to the influence of economy, population, living standard and so on, the urban water consumption has certain grey characteristics. In this paper, the genetic algorithm is adopted and combined with the multi-variable grey model (MGM (1, n)), and a Multi-variable model (MGM (1, n, q)) based on Genetic Algorithm has been established, which has been applied to forecast Dalian city urban water consumption. (2) Study on water resources composite system dynamics simulation. Through the relationship of mutual restricting, promoting, coupling and action among water resource, society, economy, and environment, a complex system (named as water resources composite system) has been formed. Due to the characteristics of non-linear, multivariable, information feedback and temporal dynamic, the system dynamics is suit to study the structure of complex system. In this paper, using the method of system dynamics, a water resource composite system dynamics model in Dalian city has been established, which to study system simulation.(3) Reasonable allocation of multi-source water for multi-user based on water quality and quantity. Water quality and quantity are all the basic factors of water resources. According to idea of water supply based on water quality, the system structure frame of urban water resources of multi-source water for multi-user is built, and at the same time a reasonable allocation model of multi-source water for multi-user is developed based on harmony of resource, environment and economy. The Step method is adopted to solve the multi-objective model. This model has been applied to the reasonable allocation of multi-source water for multi-user of Dalian city in 2010, 2015 and 2020.(4) Analysis of harmony and evolvement of water resources composite system. As an opening complex system, influenced by the disturbing from outside and fluctuating from inside, water resources composite system have an evolvement and changing process. The "entropy" is a measurement to systemic confusion extent. In this paper, the harmony exponent of system is combined with information entropy to judge the systemic evolvement direction. This method has been applied to analysis of harmony and evolvement of water resources composite system in Dalian city.In the last part, the whole paper is summarized and some promising issues are discussed.