【摘要】 湿地—大气之间通过物质和能量交换并相互作用形成特有的区域小气候特征,本文采用小气候梯度观测法对比分析了2015年辽河三角洲芦苇湿地与同纬度锦州地区玉米旱地的近地层(0—30 m)小气候特征。结果表明:2015年辽河三角洲芦苇湿地年平均气温为9.91℃,比玉米旱地年平均气温低0.58℃,湿地在春季、夏季和秋季具有降温作用,冬季具有保温作用。芦苇湿地和玉米旱地年平均气温的日变化范围分别为7.50—12.92℃、6.16—15.59℃,芦苇湿地平均气温振幅和层次间气温差小于玉米旱地,玉米旱地存在明显的逆温现象;芦苇湿地年平均相对湿度为64.58%,比玉米旱地年平均相对湿度高7.97%,芦苇湿地月相对湿度主要受水文和植被蒸腾作用的综合影响,芦苇湿地和玉米旱地平均相对湿度的日变化范围分别为51.78%—74.38%、41.00%—73.00%,二者均存在逆湿现象但高度不同;芦苇湿地春季风速为玉米旱地的两倍以上,风速随高度升高呈指数增大,芦苇生长季湿地具有较高的粗糙度,随高度降低风速下降明显,挡风作用明显好于玉米旱地。太阳辐射影响地表湍流是玉米旱地风速日变化的主要影响因子,芦苇湿地风速日变化体现了海陆热力差异的特点。芦苇湿地由于地表有水层覆盖,植被蒸散能力较强,叶面积指数较高,减小近地层气温和相对湿度的变化速率,可有效降低风速,调节区域小气候的生态功能比玉米旱地强,本文研究可为辽河三角洲湿地对区域气候形成的影响及其生态环境效益评价提供参考。更多还原

【Abstract】 The interaction between wetland and atmosphere through the exchange of energy and mass forms unique regional microclimate characteristics. A comparative analysis of microclimate characteristics near the surface layer from 0 to 30 cm between Panjin reed wetland in the Liaohe River Delta and Jinzhou maize dry land located at the same latitude as at Panjin reed wetland was conducted in 2015 using the microclimate gradient method. The results showthat the mean annual air temperature of Panjin wetland is 9. 91 ℃ in 2015,which is 0. 58 ℃ lower than that of Jinzhou maize dry land. The wetland plays a cooling effect in spring,summer and autumn,and a warming effect in winter. The daily variations of mean annual air temperature at Panjin wetland and Jinzhou maize dry land range from 7. 50-12. 92 ℃ and 6. 16-15. 59 ℃,respectively. The amplitude of the mean temperature and temperature difference between the different vertical layers of the wetland are less than those of the dry land. The mean annual relative humidity at Panjin wetland is 64. 58%,which is 7. 97% higher than that of Jinzhou dry land. The monthly relative humidity of wetland is mainly affected by the hydrological factors and vegetation transpiration. The daily variations of mean annual relative humidity of wetland and dry land range from 51. 78%-74. 38% and 41. 00%-73. 00%,respectively. There are inversion humidity phenomena in both of wetland and dry land,while the occurring heights are different. The spring wind speed in Panjin wetland is 2 times higher than that in Jinzhou dry land.The wind speed of wetland increases exponentially with the height. During the growth season,Panjin reed wetland has a higher roughness. With the decrease of height,the wind speed decreases significantly. This kind of sheltering effect in wetland is much better than that in dry land. The land surface turbulent affected by the solar radiation is the main factor to influence the diurnal variation of wind speed in dry land,while that in Panjin wetland reflects the characteristics of thermal difference between land and water. Due to the water coverage on the land surface in wetland,there are higher evapotranspiration amount and leaf area index,which slows down the changing rates in temperature and relative humidity near the land surface layer,and can effectively reduce the wind speed. This kind of ecological functions to regulate the regional microclimate in wetland is better than that in dry land. This study provides a reference for the evaluation of the impact of wetland in the Liaohe River Delta on the regional climate and their ecological and environmental effects.更多还原