Exploration on the preparation of sponge city system plan in mountainous, hilly, and river valley regions — Taking Nanlin Area of Nanping City, Fujian Province as an example

Taking the construction of sponge cities in the Nanlin area of Nanping City, Fujian Province, a typical mountainous, hilly, and valley region as an example, that systematically examines the issues and needs related to the integration of mountains and waters into the city, the risk of waterlogging, and urban development. Based on goal oriented and problem oriented approaches, a sponge city plan for the area is constructed, which includes "source emission reduction, rainwater pipes and channels, and drainage and risk elimination". Referring to the principle of terraced fields, a three-level rainwater management and control system of "mountain, city, water" is established to achieve a 30-year standard for waterlogging prevention and control in the area.