实际蒸发量

利用长江流域115个气象站点1961-2000年的观测数据，计算了各站点的参照蒸发量和实际蒸发量，并进行了20cm蒸发皿蒸发量、参照蒸发量和实际蒸发量时空变化趋势分析。

Based on the measuring data from 115 meteorological stations between 1961 and 2000 in the Yangtze River Basin , pan evaporation ( PE ), reference evapotranspiration ( ETr ) and actual evapotranspiration ( ETa ) as well as their trends are calculated and analyzed .

利用气象资料计算陆面实际蒸发量

The approaches to calculate actual regional evaporation by means of meteorological data

它在顶极植被净第一性生产量与实际蒸发量之间有一个有效的对数关系。

It has an effective , logarithmic relationship between net primary production of climax vegetation and evapotranspiration .

长江流域净辐射和实际蒸发量变化呈高度正相关关系，二者年际、季节变化趋势一致，地表净辐射的下降变化对长江流域实际蒸发量的减少产生了极其重要的影响。

Variation relationship of net radiation and actual evapotranspiration show highly significant positive correlation , and their changing trend are consistent .

所以，近地面风速的下降对长江流域实际蒸发量的减少未产生显著影响。

So , wind speed decreasing does not have a significant impact on the actual evapotranspiration changing over the Yangtze River basin .

上游地区实际蒸发量的年际、季节下降变化趋势均比中下游地区明显。

The decreasing trend of inter-annual variability and seasonal variability about actual evapotranspiration in the upper reach is more significant than the decreasing trend in the mid-lower reaches .

长江流域年实际蒸发量的减少主要是由于春、夏、秋三季实际蒸发量下降所致，其中春季实际蒸发量减少幅度最大。

Decreasing of annual actual evapotranspiration is mainly due to decreasing of actual evapotranspiration in spring , summer , autumn , while decreasing level of actual evapotranspiration is also the largest amount in spring .

地面实际蒸发量的高峰不是在春季而是在雨季7、8、9三个月，蒸发强度和表土含水量成直线正相关。

The amount of peak evaporation in surface is not in spring but in July , August , September in the rainy season . Also , there was a linear correlation between surface water content and evaporation strength ;

以实际蒸发蒸腾量、有效降雨量和土壤贮水量来预报未来灌水时间。

It is based on actual evapo-transpiration capacity , effective rainfall and water reserve of soil to forecast irrigation time .