福建省蒸发量变化趋势及其敏感性分析

Analysis on the trend and sensitivity of evaporation in Fujian Province

基于福建省气象站1998-2017年的蒸发皿蒸发量(简称蒸发量)观测资料,通过线性倾向估计、Sen′s斜率估计、相关性分析以及Sobol′s敏感性分析方法,分析蒸发量的季节、年际和空间变化特征及其敏感因子.结果表明:福建省近20年的蒸发量呈下降趋势,其速率为4.99 mm·a-1,以秋季下降最快,夏季次之;蒸发量地域分布不均,总体上呈现东南多、西北少的分布格局;Sobol′s敏感性分析和相关系数分析结果表明,蒸发量的主要敏感因子为平均风速和相对湿度,次要敏感因子分别为春季最高温度、夏季太阳辐射、秋季太阳辐射、冬季最低温度;蒸发量与平均风速呈显著正相关,与相对湿度呈显著负相关,它们均是影响福建省蒸发量的主要因子.其中内陆地区蒸发量的主要敏感因子为相对湿度,沿海地区蒸发量的主要敏感因子为平均风速.

Based on data estimated by pan evaporation method at Fujian Meteorological Station during 1998-2017, seasonal, interannual and spatial variation characteristics of evaporation and sensitive factors were interpreted by linear tendency estimation, Sen′s slope estimation, correlation analysis and Sobol′s sensitivity analysis. The results showed that the evaporation of Fujian Province decreased at a rate of 4.99 mm·a-1 in the past 2 decades, which was the fastest in autumn and followed by summer. The evaporation was unevenly distributed, generally higher in the southeast region and lower in the northwest. Sobol′s sensitivity analysis revealed that wind speed and relative humidity were the dominant sensitive factors concerning evaporation, with the secondary sensitivity factors being highest temperature for spring, solar radiation for summer and autumn, and lowest temperature for winter, respectively. The evaporation was positively correlated with average wind speed, and negatively correlated with relative humidity, and these 2 were the main parameters affecting the evaporation of Fujian. Geographically, the main sensitive factor of evaporation for inland area was relative humidity, while it was average wind speed for coastal area.