不同浮动覆盖条件下水面蒸发消减效果及节水效益研究

Water Surface Evaporation Reduction Effect Under Different Floating Cover Conditions and Water Saving Benefits Under Different Floating Cover Conditions

为探究不同浮动覆盖条件下水面蒸发消减效果及节水效益,以PE瓶、HDPE球、塑膜板为供试材料,设置3种不同水面覆盖率,在宁夏中部干旱带开展连续2个年度非冰期大型蒸发池试验,对比分析不同覆盖材料和覆盖率的蒸发消率、水面温度、水质变化、节水成本及效益。结果表明:覆盖材料的蒸发消减率4-6月呈趋于升高,7-10月趋于降低;同等条件下HDPE球3种覆盖率的非冰期蒸发消减率分别为42.14%、56.56%、70.15%,明显高于PE瓶和塑膜板;随着材料覆盖率增加,水体升温较为明显,且塑膜板对水温影响最大,HDPE球次之,PE瓶最小;覆盖水体中未发现毒害物质,水质稳定趋好;相同覆盖率下,HDPE球节水成本最低,塑膜板最高,相同覆盖材料下,50%覆盖率的最低,75%覆盖率的最高;3种材料消减水面蒸发直接效益均为负值,但考虑间接效益的情况下,采用HDPE球覆盖1万m^(2)的水面,寿命期50%、75%、90%覆盖率可分别实现25.94万元、27.41万元、36.60万元的正收益。综合节水效果、节水成本和效益,HDPE球是可供干旱地区选用的消减水面蒸发节水材料。

In order to investigate the effect of water surface evaporation abatement and water saving benefits under different floating coverage conditions,PE bottles,HDPE balls,and plastic film panels were used as test materials,and three different water surface coverage rates were set to carry out two consecutive annual non-glacial large-scale evaporation pool tests in the central arid zone of Ningxia,to comparatively analyze the evaporation abatement rates,water surface temperatures,changes in water quality,and water-saving costs and benefits of different covering materials and coverage rates.The results show that:the evaporation abatement rate of covering materials tends to increase from April to June,and tends to decrease from July to October;under the same conditions,the evaporation rate of the three types of cover of HDPE balls is 42.14%,56.56%,70.15%,which is significantly higher than that of PE bottles and plastic film panels;with the increase of the coverage rate of the material,the water body warms up more obviously,and plastic film panels have the greatest impact on water temperature,followed by HDPE balls,and PE bottles;no toxic substances were found in the covered water body and the water quality is stable and getting better.Under the same coverage,the water saving cost of HDPE balls is the lowest,and that of plastic film plates is the highest:with the same coverage material,50%coverage is the lowest,75%coverage is the highest;the value of direct benefits of the three materials to eliminate water surface evaporation is negative,but taking into account the indirect benefits of the case,if HDPE balls are used to cover 10000 m^(2) of water surface,the lifetime coverage rates of 50%,75%,and 90%can realize positive benefits of 259400 yuan,274100 yuan,and 360600 yuan,respectively.After a comprehensive consideration of water-saving effect,water-saving costs and benefits,HDPE ball is identified as the water-saving material that can be used to reduce water surface evaporation in arid areas.