基于太湖流域及周边气象站1957—2009年气象数据,采用Mann-Kendall和小波分析方法,分析其平均气温、极端最高和最低气温、降水量、最大日降水量及径流量的变化趋势和周期特征,并对流域径流量的变化及与降水量的耦合关系等进行分析。结果表明:太湖流域在过去50多年整体呈增温增湿的趋势;靠近大城市的站点气温升温趋势明显高于其他站点;流域夏季的极端高温事件有增强的趋势;流域年降水量呈不显著的增加趋势,而最大日降水量却呈显著的增加趋势,从一定程度上反映出流域内极端降水有增强的趋势;降水量和径流量的变化趋势较为一致,都呈不显著的增加趋势,且两者增加幅度基本相当;流域各要素存在约4 a的显著振荡周期和8 a的不显著振荡周期。
Trend and periodicity of mean air temperature, maximum air temperature, minimum air temperature, maximum daily precipitation, precipitation, and runoff over the Taihu Lake Basin, which is one of the most developed regions in China, were analyzed in this study. The non-parametric Mann-Kendall test and Morlet wavelet were used to detect trends and periodicity of major hydro-climatic variables respectively. Results showed that air temperature experienced an increasing trend, while precipitation and runoff exhibited a decreasing trend during the past 50 years. Air temperature of stations located near big cities showed much greater increasing trends than that in other stations, which might be due to urban heat island effect. Maximum air temperature in summer, a season with the highest air temperature in a year, showed much greater increasing trends than mean and minimum air temperature. It was included that extreme higher air temperature events in summer exhibited an increasing trend during the past 50 years. Although annual precipitation in the basin exhibited an insignificant increasing trend, maximum daily precipitation did show an increasing trend which is significant at 95% confidence level. It indicated that extreme higher precipitation events (storms) also experienced an increasing trend in the past. Trends of runoff were similar with that of precipitation. Both of runoff and precipitation showed insignificant increasing trends, and magnitude of these trends was with little difference. There existed significant periods of about 4 years and insignificant periods of about 8 years for all six hydro-climatic variables at 95% confidence level, included mean air temperature, maximum air temperature, minimum air temperature, maximum daily precipitation, precipitation, and runoff over the Taihu Lake Basin.
[1] 施雅风,朱季文,谢志仁,等.长江三角洲及毗连地区海平面上升影响预测与防治对策[J].中国科学D 辑,2000,30(3):225-232.
[2] 黄俊雄,徐宗学.太湖流域1954—2006 年气候变化及其演变趋势[J].长江流域资源与环境,2009,18(1):33-40.[HUANG Jun-xiong, XU Zong-xue. Spatial-temporal characteristics of long-term trend for climate change in the Taihu Basin during 1954-2006. Resources and Environment in the Yangtze Basin,2009,18(1):33-40.]
[3] 尹义星,许有鹏,陈莹.太湖最高水位及其与气候变化、人类活动的关系[J].长江流域资源与环境,2009,18(7):609-614.
[4] 商兆堂,任健,秦铭荣,等.气候变化与太湖蓝藻暴发的关系[J].生态学杂志,2010,29(1):55-61.
[5] 王成林,潘维玉,韩月琪,等.全球气候变化对太湖蓝藻水华发展演变的影响[J].中国环境科学,2010,30(6):822-828.
[6] 尹义星,许有鹏,陈莹.1950—2003年太湖流域洪旱灾害变化与东亚夏季风的关系[J].冰川冻土,2010,32(2):381-388.
[7] 高俊峰.太湖流域土地利用变化及洪涝灾害响应[J].自然资源学报,2002,17(2):150-156.
[8] 万荣荣,杨桂山.流域土地利用/覆被对洪峰的影响研究——以太湖上游西苕溪流域为例[J].自然资源学报,2009,24(2): 318-327.
[9] 李恒鹏,杨桂山,金洋.太湖流域土地利用变化的水文响应模拟[J].湖泊科学,2007,19(5):537-543.
[10] 张兴榆,黄贤金,赵小风,等.环太湖地区土地利用变化对植被碳储量的影响[J].自然资源学报,2009,24(8):1343-1353.
[11] Hirsch R M, Slack J R. A nonparametric trend test for seasonal data with serial dependence [J]. Water Resources Research,1984, 20(6):727-732.
[12] Lettenmaier D P, Wood E F, Wallis J R. Hydro-climatological trends in the continental United States: 1948-88 [J]. Journal of Climate, 1994,7:586-607.
[13] Burn D H. Hydrologic effects of climatic change in West Central Canada [J]. Journal of Hydrology,1994,160: 53-70.
[14] Gan T Y. Hydroclimatic trends and possible climatic warming in the Canadian Prairies [J]. Water Resources Research,1998, 34(11): 3009-3015.
[15] Yue S, Pilon P, Phinney B. Canadian streamflow trend detection: Impacts of serial and cross-correlation [J]. Hydrological sciences journal, 2003, 48(1): 51-63.
[16] Fu G B, Chen S L, Liu C M, et al. Hydro-climatic trends of the Yellow River Basin for the last several decades [J]. Climatic Change, 2004, 65: 149-178.
[17] Xu Z X, Li J Y, Liu C M. Long-term trend analysis for major climate variables in the Yellow River Basin [J]. Hydrological Processes, 2007, 21: 1935-1948.
[18] Hamed K H. Trend detection in hydrologic data: The Mann-Kendall trend test under the scaling hypothesis [J]. Journal of hydrology, 2008, 349: 350-363.
[19] Xu Z X, Liu Z F, Fu G B, et al. Trends of major hydroclimatic variables in the Tarim River Basin during the past 50 years [J]. Journal of Arid Environment, 2010, 74: 256-267.
[20] Torrence C, Compo G P. A practical guide to wavelet analysis [J]. Bulletin of the American Meteorological Society,1998,79: 61-78.
