RESEARCH ON THE FEATURES OF AQUIFER SYSTEM STRUCTURE AND SEAWATER INTRUSION IN THE COASTAL AREA, HAIKOU CITY

摘要

The aquifer system of the Haikou's coastal area is the eastern part of the Qiongbei -^sArtesian Basin. It is from the Dongzhai Harbor in the east to Macun in the west, and from Shizilu in the south to the Qiongzhou Strait in the north, with an area of 1100 km~2. In the loose layer of Tertiary System, there are 7 confined aquifers within a depth of 700 m. This paper only describes the 1st, 2nd and 3rd+4th confined aquifers, which are the main exploited layers of Haikou now. The groundwater yield in Haikou has reached 340 000 m~3 / d in the whole area and accounts for 80% of the supplying water quantity. The depression cone of confined water has formed and the area of the depression cone of the 2nd confined water is near 800 km~2. The minimum water levels in the main developing layers of the depression center in May, 1995 are: -23.48 m in the 1st confined aquifer, -39.82 m in the 2nd and -23.90 m in the 3rd respectively. The water levels have a trend of going down by 1-3m annually and the area of the depression cone enlarges gradually.