Determination of controlled limit value of groundwater level depth and management practice in Xi’an, China

Based on the different types of geomorphic units in Xi'an, China, and the groundwater recharge methods of the different geomorphic units, the goal is to ensure the sustainable development and utilization of groundwater, to ensure the natural attributes and to prevent salinization. According to different rainfall conditions, the upper and lower limits of the controlled limit value of groundwater level in different regions are calculated to define the control targets of the different geomorphic units. Based on the calculated controlled limit value of groundwater level and the administrative divisions of Xi'an City, the red lines of groundwater control in each county and city are developed. Four management lines are delineated from the surface to the bottom (from top to bottom, the upper limit of groundwater depth, the upper limit of infiltration of groundwater depth, the lower limit of groundwater depth and the risk line in extremely dry years), and five management areas are delineated (from top to bottom, the prevent soli salinization area, the normal extraction area, the careful extraction area, the permit only in extreme dry years area and the prohibited extraction area) to provide technical support for groundwater management in Xi'an.