Forecasting Hechi Water Consumption In Middle Range By Grey Forecast Method

Urban water consumption forecasting is the basis of the rational exploitation,management,water pollution control,integrated using and programming in water resource. By forecasting the scope and the development trend of water consumption in city planning term,the appropriate water consumption can be guaranteed and saving water can be to the great limit. Through accurate water consumption forecasting,the investment in water supply can be more reasonable. It can be good to the planning of water supply system and the optimizing,rebuilding in pipe network. It can be good to assign water quantity appropriately by different district and can be the basis of water production in different water plant,then can reduce the cost of water supply. The rational water consumption forecasting can also instruct the whole city layout and can be useful to water pollution defend and control.The core of water consumption forecasting is the technique of forecasting, or the mathematical model of forecasting. With the development of modern science technology, a lot of water consumption forecasting methods have emerged, ranging from the classic index method,yearly increasing rate method,regressive analyze method and time series method,to the newly-emerged neural network method and grey-forecasting method, which all have their own characteristics and application fields. Grey-forecasting method, especially GM (1,1) model, is a comparatively new and widely used forecasting technique in the middle-long range of water consumption forecasting.Associating with the situation of Hechi city,several forecasting methods are applied in the middle range of water consumption forecasting in this paper. The application of grey forecasting theory and the improved,combination grey model are analyzed deeply. The results show that forecasting water consumption with grey theory is better than other forecasting methods,the residual GM(1,1)model and the improved new information model are better than the basic GM(1,1)model,and the combination grey model of two has the best forecasting precision.The combination grey model based on the residual GM(1,1)model and the improved new information model used in forecasting the middle range urban water consumption is a new point in this paper. It extends the application scope of the basic GM(1,1)model and greatly enhances the forecasting precision.