Evaporation from Camargos hydropower plant reservoir: water footprint characterization

ABSTRACT In recent years, a relevant debate has been raised by a question related to if the hydropower plants indeed represent a non-consumptive use of water resources. In this context, this work was developed at the Camargos Hydropower Plant reservoir, Grande river basin, southern Minas Gerais state, aiming to estimate evaporation rates, which allow the characterization of the Water Footprint in this facility, between the years of 2010 and 2014. Evaporation rates were estimated based on Linacre, Penman and Penman-Monteith methods. Regarding the distribution of evaporation throughout the year, all methods showed the same seasonal pattern, consistent with the meteorological elements behavior that influence this physical process. Although an annual average evaporation considered normal for the studied region (1329 mm) and a small reservoir area (64 km2), this hydropower plant has presented low electric energy production as it is an old facility (more than 50 years) and has low installed capacity. Therefore, Camargos Hydropower Plant has presented, by all methods, a high Water Footprint (130 m3.GJ–1 on average) compared to estimates for other hydropower plants in Brazil and worldwide.

摘要 近年来，围绕水电站是否确实属于水资源非消耗性利用方式这一问题，学界展开了相关讨论。在此背景下，本研究以米纳斯吉拉斯州南部格兰德河流域的卡马戈斯（Camargos）水电站水库为研究对象，旨在估算2010至2014年间的蒸发速率，以此表征该电站的水足迹（Water Footprint）。蒸发速率的估算采用了莱纳克（Linacre）、彭曼（Penman）以及彭曼-蒙特斯（Penman-Monteith）三种方法。就全年蒸发量分布而言，三种方法均呈现出一致的季节变化模式，且与影响该物理过程的气象要素变化特征相符。尽管研究区域的年平均蒸发量（1329毫米）与水库面积（64平方千米）均处于常规水平，但该水电站因服役时长超过50年、装机容量较低，导致电能产出偏低。因此，相较于巴西及全球其他水电站的估算值，卡马戈斯水电站的水足迹（平均为130 m3.GJ–1）在三种方法下均处于较高水平。