Laoting county belongs to the warm temperate coastal semi-humid continental monsoon climate type area. Four distinct seasons, long winter, longer winter than summer, shorter spring and autumn. Spring starts from April 16, summer from June 2 1, autumn from September 1, and winter from1October 22. 165438+1entered the severe winter on October 23rd and ended on March 8th. Winter 170 days, summer 72 days, spring 66 days, autumn 5 1 day. The seasonal temperature in China is the average temperature, which is 10℃-22℃ in spring and autumn, above 22℃ in summer and below 10℃ in winter. The annual average temperature is about 65438 00℃. The average annual precipitation in Laoting County is 6 13.2mm, and the total annual precipitation is 794 million cubic meters. There are three characteristics of atmospheric precipitation in China: (1) The annual distribution of atmospheric precipitation is extremely uneven, which is characterized by drought in winter and spring and concentrated rainfall in summer and autumn. From the annual average for many years, the rainfall from June to September (flood season) is 495.7mm, accounting for 80.8% of the whole year, while the rainfall in other months is117.5mm, accounting for only 19.2% of the whole year. ⑵ The annual distribution of atmospheric precipitation changes greatly. According to the measured data of Laoting Meteorological Observatory (bureau) for 30 years, the annual precipitation is 289.8 mm-1008.2 mm, with a difference of 3.5 times. (3) Geographically, inland areas are larger than coastal areas. The annual precipitation in the lower flood area and the middle well irrigation and drainage area of Luanhe River is about 620 mm, while the annual precipitation in the coastal canal irrigation and alkali treatment area is 589.5 mm, with a difference of about 6%. Laoting County has 0/2 backbone canals/kloc-0 (excluding Luanhe River and Xiaoqing River), 7 major drainage canals 17, and the total water area 1 133 square kilometers (including 89. 1 square kilometers in Luannan County); The average annual runoff for many years is 65.438+0.2 billion cubic meters, of which 0.65438+0 billion cubic meters comes from other counties. The converted surface runoff depth is 9 1.5 mm ... The main source of groundwater recharge in Laoting County is atmospheric precipitation. The exploitable amount of shallow groundwater is/kloc-0.03 million cubic meters, and the coastal salt water is 29 million cubic meters. The exploitable amount of deep fresh water (coastal areas) is very small, which is 7.68 million cubic meters. According to the hydrogeological conditions, the groundwater in Laoting County can be divided into three areas: (1) the central area of Luanhe River impact fan, which is located in the north of Nanchangtuo, Shuangmiao and Shangjianian. There are two water-bearing formations above150m in this area, and the groundwater is extremely rich, which can be completed in 20-40m, and the water output of a single well is100t/hour.

(2) The front area of Luanhe River impact fan includes all fresh water area, phreatic water desalination area and deep fresh water gravity flow area. The whole desalination area is located in the north of Heguanying, Li Jiawan Tuo and Qi Zhuangzi. Aquifer over 200-250m in this area 15-20, cumulative thickness100-120m. The groundwater is abundant, and the well can be completed in 40-80 meters, and the water output of a single well is 80-65438/ hour. In some areas, such as a few villages in Daxianggezhuang Township and Xinzhai Town, the fluorine content of shallow groundwater exceeds the standard. Shallow water desalination area, located in Jianggezhuang, Hujiatuo, Zhaotan and north of Wharf Camp, is a transitional section of salty and fresh water. Fresh water is above 20-60m, salt water is in the middle, fresh water is in the lower part, and the salt water layer in the middle is 100- 120m thick. Most of this area is shallow wells, and there are deep wells in the west. The water output of a single well is 50 tons per hour. Fluoride exceeded the standard in some areas. The deep freshwater gravity flow area is located in Lianhuachi, Xinkai and the north of Guozhuangzi. The upper salty water body in this area is thick, and there is no fresh water in the shallow layer. /kloc-The deep groundwater below 0/00 meters flows by itself, with a well completion depth of 200 meters and a single well water output of 40 tons/hour. (3) Coastal plain area, located in the south of the above two areas, is a saline water layer100-250m below the surface. The bottom of the salty water body is shallow in the west and deep in the east, and the deep groundwater flows by itself under pressure. The depth of well completion is 200-300m, and the water output of a single well is 30 tons/hour. In some areas, such as the vicinity of Caozhuangzi, the groundwater level drops due to exploitation exceeding recharge, forming a "funnel area".