摘要
研究旨在建立冷空气影响期间海水水温和溶解氧的预报方程,以期为海水养殖户做好防灾减灾气象服务。通过分析近5年宁波西沪港0.5、2.5 m深海水水温、溶解氧在11月至翌年3月的日逐时平均变化特征以及较强冷空气影响期间的变化特征,采用数理统计方法建立相应的预报方程。结果表明,溶解氧、水温的日均变化与气温的变化具有较好的相似性,前两者的变化幅度较气温平缓,日极值出现时间较气温平均滞后1~3 h。较强冷空气影响期间,水温的降温时间和最低值出现时间较气温有1~3 d的滞后性,其降幅与相对湿度、冷空气强度和过程极大风速有关,而最低值滞后时间与相对湿度和冷空气强度有关。水温与气温、相对湿度成正相关,与极大风速成负相关。伴有低温阴雨的冷空气过程易导致2.5 m溶解氧的下降,其降幅与同期气温的降幅、水汽压的增幅及前期气压的降幅有关。溶解氧与气温及本站气压成线性相关,与水汽压呈二次多项式相关。建立0.5、2.5 m深平均、最低水温预报方程以及2.5 m深平均、最低溶解氧浓度的预报方程,方程均通过α=0.01的显著性检验。0.5、2.5 m水温预报最大误差在1℃以内,平均误差在0.3℃以内。2.5 m的平均、最低溶解氧最大误差分别为0.40、0.97 mg/kg,平均误差分别为0.10、0.25 mg/kg。
The aim of this study was to establish the forecast equation of sea-water temperature and dissolved oxygen during the cold air affectingperiod,so as to provide better meteorological services of disaster prevention and reduction for the mariculture households. The diurnal variationcharacteristics of the 0.5 m-depth and 2.5 m-depth sea water temperature,and dissolved oxygen in Xihu Port of Ningbo City from November to nextMarch in recent 5 years,as well as that during the cold air affecting periods were analyzed. By using mathematical statistics methods,the correspondingforecast equations were established. The results showed that the diurnal variation of dissolved oxygen and water temperature were similar to the changeof air temperature. The variation ranges of the former two indexes were gentler than that of air temperature. The time of diurnal extremums of dissolvedoxygen and water temperature lagged by 1-3 h on average,compared with that of air temperature. During the cold air affecting periods,the time of thewater temperature decline and the minimum value lagged by 1-3 days,compared with that of air temperature,while the decline degree was related tothe relative humidity,cold air intensity and the maximum wind speed.The lag time of minimum value appearing was related to the relative humidity andcold air intensity.Water temperature was positively correlated with air temperature and relative humidity,and negatively correlated with maximum windspeed.Cold air process accompanied by low temperature and rain was easy to cause the decrease of 2.5 m dissolved oxygen,and its decline wascorrelated to the temperature decline and the vapor pressure increase in the same time period,as well as the decline of atmospheric pressure in the earlystage.Dissolved oxygen was linearly correlated with air temperature and local air pressure,and had quadratic polynomial relationship with water vaporpressure. On the basis of correlation analysis and stepwise regression analysis,the forecast equations of the 0.5 m/2.5 m mean water tempera
出处
《现代农业科技》
2017年第22期144-148,共5页
Modern Agricultural Science and Technology
基金
浙江省气象局科技项目(2016YB01)
宁波市气象局项目(NBQX2014009B)
象山县科技局项目(2014C6019)
象山县科技局项目(2016C6012)
关键词
冷空气
海水养殖
水温
溶解氧
特征分析
预报方程
cold air
mariculture
water temperature
dissolved oxygen
characteristic analysis
forecast equation
