Application of grey system GM(1,N) model to predicting spring flow

In China, carbonate rocks outcrop widely at the surface or exit at shallow depths below the surface covering 1.3 million km(2) or one-seventh of the country's territory. The major karst areas in China are located in densely populated and economically important regions, moreover, almost one-quarter of the total water resources of China is of the karstic origin. The management and development of the karst areas thus form important sectors of the economy. As a representative of karst springs in North China, the Liulin Springs were selected as our study area. We constructed a predictive model of spring flow using the grey system GM (1, N) model to describe the quantitative relation between spring flow and precipitation and to forecast spring flow of different parts of Liulin Springs in the year 2006-2008. The success of this application demonstrates that grey system theory provides an important alternative tool to identify the degrees of karstification, and can simulate karst hydrological processes for a karstic aquifer.