L. J. Pozzo-Pirotta, J. Montes-Pérez, S. Sammartino, R. Marcé, B. Obrador, C. Escot, I. Reyes, E. Moreno-Ostos
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引用次数: 2
Abstract
Carbon dioxide emission from drawdown areas of a Mediterranean reservoir Sediment beds from drawdown areas of reservoirs constitute a relevant hotspot for carbon dioxide (CO2) emission to the atmosphere. This CO2 source is especially relevant in the case of Mediterranean reservoirs, where hydrological variability favors the exposure of large sediment areas to air. In spite of this, the role of dry sediments as CO2 emitters has been typically neglected in lakes and reservoirs greenhouse gas emission assessments, and there is also a lack of research on the spatial variability of CO2 fluxes from drawdown sediments. In this study we contribute to this knowledge by combining drone-based aero-photogrammetry techniques with in situ infrarred gas analyzer measurements to assess the magnitude and spatial variability of CO2 fluxes from the drawdown area of a Mediterranean reservoir (El Gergal, Southwestern Spain) during one dry season. Our results show that during survey dry sediments in El Gergal were a relevant net CO2 source to the atmosphere, with a mean emission of 0.36 ± 0.38 g CO2 m-2 h-1. In addition, CO2 fluxes from El Gergal drawdown depict a marked spatial variability, with maximum values measured in areas influenced by river or intermittent streams discharges. Distance to the shore, sediment particle size, pH and temperature also have a significant effect on CO2 emissions from the reservoir dry banks. The expected strengthening of droughts intensity and frequency in the Mediterranean region could enhance the role of exposed sediments from the drawdown of reservoirs as CO2 source to the atmosphere.
地中海水库水位下降区域的二氧化碳排放水库水位下降区的沉积物床是向大气排放二氧化碳的相关热点。这种二氧化碳来源在地中海水库的情况下尤其重要,那里的水文变化有利于大型沉积物区域暴露在空气中。尽管如此,在湖泊和水库的温室气体排放评估中,干沉积物作为二氧化碳排放者的作用通常被忽视,而且也缺乏对下降沉积物中二氧化碳通量的空间变异性的研究。在这项研究中,我们将基于无人机的航空摄影测量技术与现场红外气体分析仪测量相结合,以评估一个旱季地中海水库(西班牙西南部El Gergal)水位下降区二氧化碳通量的大小和空间变异性,从而为这一知识做出贡献。我们的结果表明,在调查过程中,El Gergal的干燥沉积物是大气中相关的净CO2源,平均排放量为0.36±0.38 g CO2 m-2 h-1。此外,El Gergal水位下降产生的CO2通量具有显著的空间变异性,在受河流或间歇性溪流排放影响的地区测得的最大值。到海岸的距离、沉积物颗粒大小、pH值和温度也对水库干岸的CO2排放有显著影响。地中海地区干旱强度和频率的预期增强可能会增强水库水位下降后暴露的沉积物作为大气中二氧化碳来源的作用。
期刊介绍:
Limnetica publishes original research articles on the ecology of inland waters. The scope of Limnetica includes the ecology of rivers, lakes, reservoirs, coastal lagoons and wetlands, as well as biogeochemistry, paleolimnology, development of new methodologies, taxonomy, biogeography and any aspect of theoretical and applied continental aquatic ecology such as management and conservation, impact assessment, ecotoxicology and pollution. Limnetica will accept for its publication scientific articles presenting advances in knowledge or technological development, as well as as papers derived from new practical approaches on the topics covered by the journal.