Abstract: On the basis of systematically checking up nearly ten years observation data of 11 water temperature observation wells in the Capital Circle, the behaviors of well water temperature are divided into several types, such as perennial tendency, annual, monthly and daily behaviors. The mechanisms and characteristics of these behaviors are then analyzed. The perennial tendency can be sub divided into smooth, ascending, descending, fluctuate and composite subtypes; the annual behaviors can be sub divided into smooth-stepwise, ascending, descending and fluctuate subtypes; the monthly behaviors can be sub divided into smooth, smooth-stepwise, smooth-fluctuate, descending-fluctuate, ascending fluctuate and composite subtypes; the daily behaviors are mostly fluctuate types, but 5 wells have tidal effects and most wells posses stepwise or pulsed changes. Up to now, the main factors that have been found to have influence on the behaviors of water temperature include the infiltration recharge of atmospheric water, lateral recharge of groundwater, groundwater exploration in adjacent area, and water turbulence in the observation wells, etc. In addition, the instability of observation instruments has great impact on water temperature behaviors. After the normal behaviors are recognized and all kinds of interference factors are eliminated, water temperatures are found to have good reflection on seismic event. Relatively distinct short imminent term anomalies have been found before some moderate-strong earthquakes, and remarkable co seismic anomalies can be recognized while distant strong earthquakes occur. Moreover, some pre seismic anomalies are also identified before the occurrence of a few distant strong earthquakes. Therefore, the further study on the behaviors of water temperature, and the elimination of all kinds of interference factors including stepwise or pulsed variation caused by the instability of observation instruments, will remarkably enhance the capacity and effectiveness of the reflection of water temperature behavior on seismic event. This will also help to improve the capability of short imminent term earthquake predication in our country.

Key words: water temperature, types of behaviors, mechanisms, Capital Circle

摘要： 在系统清理首都圈地区11口高精度水温度观测井近10年的观测资料的基础上,归纳出井水温度动态的多年趋势、年、月、日动态类型,并对其成因与特征进行分析。多年动态类型可归纳为平稳型、上升型、下降型、起伏型与复合型;年动态类型可归纳为平稳-阶变型、上升型、下降型、起伏型;月动态类型可归纳为平稳型、平稳-阶变型、平稳-起伏型、下降-起伏型、上升-起伏型与复合型;日动态多为随机起伏型,但在5口井发现有水温潮汐,绝大多数井中存在阶变或脉冲等。目前发现的影响水温动态类型的因素有大气降水的渗入补给、地表水的侧向补给、邻井地下水开采及观测井内的井水扰动等,此外仪器本身的不稳定性对动态类型也产生重要影响。认识上述的正常动态类型,排除各种干扰之后,仍发现井水温度有较好的映震效应,在一些中强以上地震之前有较好的短临异常,在一些远大震之时也有显著的同震异常,在个别远大震之前发现有震前异常。因此,深入研究井水温度的动态类型,有效地排除各种干扰,包括仪器不稳定产生的阶变或脉冲等,将会显著地增强井水温度动态监测的映震效能,有助于提高中国的地震短临预测能力。

关键词: 水温, 动态类型, 成因, 首都圈