Abstract:
Springs are classified based on their genesis into depression spring, contact spring, overflow spring and fault spring, etc. Based on the depth of groundwater circulation (or the position of groundwater flow), springs can be classified into the spring of surficial groundwater circulation, the spring of shallow groundwater circulation and the spring of deep groundwater circulation. A spring is referred to as the spring of shallow groundwater circulation when its orifice is still lower than the deepest position of groundwater flow in the subsurface. The spring of shallow groundwater circulation does not occur in the lowest topography. After receiving recharge from infiltration of precipitation, groundwater flows from high position to low position as a result of gravity. Groundwater flow path for this kind of springs is short and the groundwater residence time is not long. Springs of shallow groundwater circulation are generally ambient springs and fresh water springs (also saline springs or salty springs), and most of them are perennial springs and parts of them are seasonal springs or temporary springs. The Beiliaoling Northern Slope spring in Guangxi and the Shundangjing salty spring in Yunnan are typical springs of shallow groundwater circulation.