根据1964—2013年汉江生态经济带气象站点的逐日观测数据,通过气候斜向率、Kriging插值法、M-K突变检验、小波分析等手段分别对各干湿要素进行趋势、空间、突变、周期分析。结果显示:该区域总体上经历了由湿变干的过程,年降水量、潜在蒸散量、干湿指数、水分盈亏量均呈线性下降趋势,突变分别发生于2005,1972,2006,2005年前后,且存在5,15,25 a左右时间尺度的干湿周期;该区域分为湿润、半湿润地区,各干湿气候要素在空间上基本呈 “山区少、平原多”沿汉江自东南向西北逐渐变干的格局。综上,受多因素的影响,汉江中下游流域干湿气候空间分布相对复杂并逐渐变干,这种趋势已经凸显,应予以必要的重视,并采取科学可行的防旱减灾措施应对干湿气候变化。

According to the daily observation data of meteorological stations in the Hanjiang river ecological economic region from 1964 to 2013, we analyzed the trends, spatial changes, abrupt changes and cycles of dry-wet climate factors through climate inclination rate, Kriging interpolation, M-K mutation test, and wavelet analysis. Results suggest that the study region generally experienced a change from wet to dry. Annual precipitation, potential evapotranspiration, dry-wet index and water deficit all displayed a linear downward trend, with their sudden changes happened in 2005, 1972, 2006, and 2005, respectively. The dry-wet cycle is 5-year, 15-year and 25-year in time scale. Moreover, the study region can be roughly divided into humid and semi-humid regions, and each dry-wet climate factor presents a trend of “small in mountainous area and large in plain area” in space, which gradually becomes dry along the Hanjiang river from the southeast to the northwest. In conclusion, the dry-wet climate in the Hanjiang river basin is relatively complex and has gradually become dry. We should pay necessary attention to it and take scientific and feasible drought-resisting measures in response to dry-wet climate change.