Stochastic Dynamics Analysis Of City Daily Water Consumption System And DEA Evaluation Of Of Wastewater Treatment

In recent years along with the constantly increase of development of society econ-omy and the increase of population, the city volume of used water is constantly being enlarged, and it is stern with each passing day to be short of water. The nervous con-dition of water supply is universally appeared in most of big cities of our country, and the water resource shortage has become an important factor to confine the develop-ment of the city. Meanwhile, the water environment of city is also being aggravated, but the foul water in city is one of the major reasons of the worsen water environment. Particularly in some cities which are developing fast, almost more than half pollutants are directly put into rivers or lakes without being dealt with. These were all put for-ward the higher requirement to the used water and wastewater treatment ability. This thesis uses the theory of non-linear dynamics and constructs the model of sys-tem of city daily-water consumption to make systemic dynamic analysis. Also DEA method is applied to evaluate the running conditions of 16 wastewater plants in Tian-jin.1. A stochastic nonlinear dynamical model of city daily-water consumption was constructed, considering many factors such as economy, population, technology and environment. Based on quasi non-integrable Hamiltonian theory and Oseledec multi-plicative ergodic theory, the max Lyapunov exponent was calculated and the local sta-bility conditions had been obtained. the global stability conditions had also been ob-tained by judging the modality of the singular boundary; the stochastic Hopfbifurca-tion was analyzed from the sharp change of stable probability density, and the condi-tion of stochastic Hopf bifurcation had been discussed..2. Moreover, this thesis uses the data of 16 wastewater treatment plants of Tianjin as well as the consideration of actual condition to select 6 input indexes and 7 output indexes. According to these indexes, evaluated system is constructed. And this system is analyzed from the perspective of DEA and constructs C 2? R model. The model is calculated by using DEAP, and the final result will be found. Finally the analysis is made and uses the concept of efficiency to asset the effect of the plants and judge DEA Efficiency of Decision Making Units, giving out how to improve invest and output.