三江平原沼泽蒸发研究

A STUDY ON MARSH EVAPOTRANSPIRATION IN THE SANJIANG PLAIN

据1990年和1991年两年实际观测资料可以看出,沼泽蒸发一般比水面蒸发大1～2倍,沼泽植物蒸腾在沼泽蒸发中占有重要地位,沼泽植被覆盖率越高,日蒸发量越大,植被覆盖率小于10%时,沼泽蒸发与水面蒸发相差不大。最后建立了沼泽蒸发统计模型。

The Sanjiang Plain is situated in northeast China. It is one of the areas where marshes are distributed concentratedly and widely in China. Carex lasiocarpa marsh and the marsh with Carex lasiocarpa as dominative species are distributed widely. We choose Carex lasiocarpa marsh as observation object. Marsh evapotranspiration includes transpiration of marsh plants and evaporation from among plants. We used evaporimeters to observe the water level, and calculated the water level amplitude. The article, based on the observed data in 1990 and 1991, gives out the analytical results and comes out with the model of the marsh evapotranspiration. The evapotranspiration of the marsh is one or two times more than the evaporation of water surface in growing season. The larger the vegetation coverage,the greater the daily evapotranspiration. When the vegetation coverage of the marsh is less than 10%, the daily evapotranspiration of the marsh is close to the evaporation of water surface. The difference between the evapotranspiration of the marsh and the evaporation of water surface in sunny days is more than that in cloudy days. Tht model of the marsh evapotranspiration is as follows: