| In northern China, karst groundwater cycles in relatively isolated units and has formed a series of water resource systems on different scales. This paper deals emphatically with problems of two aspects. First, starting with the basic concept, the authors divided the karst groundwater in northern China into 119 systems. These systems are characterized by high openness, vulnerable environmental quality, large dimensions, numerous water resource elements, complex conversion relations of the water resource elements and “water-coal coexistence”. Second, according to the superimposition relationship of geological structures and fluid fields, the authors grouped the 119 systems into 5 different framework models and described their respective distinct characteristics in distribution, development scale, cycling and enrichment regulations, fluid field patterns and main hydrogeological envi-ronments. |