额济纳三角洲日尺度水面蒸发与潜水蒸发同步观测与定量研究

Water surface evaporation and groundwater evaporation are two important processes of the water transformation and energy cycle in nature. They are natural consumption terms of runoff water resources and important part in the natural ecology water consumption in the arid region as well. To quantify and acquire the water surface and groundwater evaporation accurately together with their temporal and spatial variations are the foundation of sustainable water resources management and ecological conservation in the arid region. In this project, the Ejina delta which is in the lower reaches of the second largest inland river basin in the northwest arid region is chosen as the study area. Simultaneous in situ experiments will be conducted to observe the water surface evaporation intensity of the lake, the water table and related environmental elements. Daily water surface evaporation and groundwater evaporation intensities are quantified. Relationships between these two kinds of evaporations are analyzed. The water surface evaporation and groundwater evaporation intensities measured in different time scales (hourly, daily, monthly and seasonly) together with the effects of main environmental elements on them are studied. Empirical equations are derived to estimate the water surface evaporation and groundwater evaporation respectively..The research will deepen the studies of the water resources assessment, ecological water requirement and evaporation paradox. Evaporation from natural water body which hasn't been measured yet in the study area can well represent regional potential evaporation. A 30-minute time interval surface water measured data series can be used for supplementing the direct-measured water surface evaporation database of the arid region in the world, and also for the verification of evaporation estimated through remote sensing method.

水面蒸发和潜水蒸发是自然界水、热循环的核心环节，也是干旱区水资源自然消耗的重要方式；准确认识水面和潜水蒸发规律，是干旱区水资源可持续管理和生态保护的基础，迄今为止有关干旱区水面与潜水蒸发的详细过程、强度和影响因素等仍不清楚。本项目拟选择西北干旱区第二大内陆河黑河下游的额济纳三角洲为研究区，开展湖泊水面蒸发、戈壁带与河岸带地下水位动态以及相关环境要素的原位同步连续观测，获取高时间分辨率（30 min）的基础数据序列，精确定量逐日水面蒸发与潜水蒸发强度，并分析两者之间的协同变化关系；探讨不同时间尺度（日、月、季）水面蒸发与潜水蒸发的变化过程，定量辨识主要环境因素对其影响程度，并分别建立适用于研究区日尺度水面蒸发与潜水蒸发的经验公式。研究成果将有助于深化干旱区水资源评价、生态需水和蒸发悖论等科学研究，同时弥补研究区大气蒸发能力数据的空白，并可为遥感估算区域蒸发提供连续真值检验。

水面蒸发和潜水蒸发是自然界水、热循环的核心环节，也是干旱区水资源自然消耗的主要方式；准确认识水面和潜水蒸发规律，是生态水文过程研究和干旱区生态保育、水资源可持续管理的基础。然而干旱区水面与潜水实际蒸发过程的详细信息相对缺乏。本项目选择了位于我国西北干旱区黑河下游的额济纳三角洲，通过自行设计的基于开放型浮船的漂浮式水面蒸发平台进行了东居延海湖泊水面蒸发原位观测；并通过布设地下水位动态观测井开展了三角洲河岸带和戈壁带的地下水位动态的同步观测；辅以气象、土壤、植被等环境要素的观测，获取了项目执行期2013-2016年非结冰期高时间分辨率（30min）的湖水位与潜水位变动的基础数据序列及相关环境要素数据；通过实测与模拟定量了逐日的湖泊水面蒸发与河岸带、戈壁带的潜水蒸发强度；辨识了影响蒸发的主要因子，建立了日尺度水面蒸发经验公式，发展完善了基于地下水位波动特征的河岸带日与季节尺度的潜水蒸发计算公式；详细分析了水面蒸发和潜水蒸发变化特征；此外还延伸开展了基于水热平衡与遥感对区域潜在蒸散发与实际蒸散时空变异特征的评估。.本项目获取了第一手高时频湖泊水面与潜水位变动的同步连续数据及相关环境数据，为深入认识干旱区蒸发过程提供了极为宝贵的实测数据；基于观测定量给出的高时间频率的水面和潜水蒸发速率是干旱区生态水文过程研究的基础；建立的日尺度湖水面蒸发经验公式、发展完善的基于地下水位波动的潜水蒸发公式，以及在此基础上获得的日、植物生长季和年尺度上的蒸发特征值，为深化生态需水研究和遥感估算区域实际蒸发的连续地面真值检验奠定了基础。.项目执行期间正式发表学术论文13篇，其中SCI论文6篇，三篇发表在国际水文水资源TOP期刊WRR, JH, HESS上；CSCD论文2篇，国际会议论文3篇，中文编著会议论文2篇。博士学位论文1篇。自行设计的湖面观测设备获得了实用新型专利证书。.项目对照计划要求完成了预期研究内容，达到了预期目标。