黄土高原西部土壤蒸发实验研究

对兰州南北两山绿化区内的土壤蒸发状况，进行比较系统的试验研究。试验采用扰动土土柱内储存水分和人工模拟降雨的方法，对不覆盖/覆玉米秸秆/覆卵石三种处理的土壤蒸发情况进行了分析研究。结果表明，覆盖可有效地抑制土壤蒸发；不覆盖处理的土壤蒸发与土壤水分呈正相关，土壤水分越大，土壤表层保持湿润时间越长，蒸发量越大。在33 d的试验观测期内，三种处理的蒸发动态不同，覆盖处理的土壤蒸发过程没有集中的蒸发高峰期，而不覆盖处理的土壤蒸发过程主要集中在前10 d。土壤累计蒸发量与蒸发时间的回归分析说明，同一时间内各处理的累计蒸发量存在显著差异。

Experimental Study on Soil Moisture Evaporation in Western Loess Plateau

We have systematically studied the soil water evaporation of planted vegetation in the southern and northern mountains of Lanzhou city.In experiment,we controlled soil moisture by methods of artificial rainfall and restoring water in soil post;soil treatments included non-cover,mealie haulm cover and gravel cover. The result indicated that soil cover had significant effect on soil water evaporation.For non-cover there was positive correlation between soil water evaporation and soil moisture,that is more soil water and more soil water evaporation. The evaporation dynamic was different in the three soil treatments during the experimental observation for 33 days.The evaporation process had no concentrated fastigium of soil water evaporation in cover treatments,but in non-cover it concentrated in the first 10 days.Besides,the regression analysis on accumulative soil evaporation and lasting time showed that there were obvious difference of accumulative evaporation among various treatments.