Details zur Publikation

Kategorie Textpublikation
Referenztyp Zeitschriften
DOI 10.5194/hess-23-4707-2019
Lizenz creative commons licence
Titel (primär) Reliable reference for the methane concentrations in Lake Kivu at the beginning of industrial exploitation
Autor Boehrer, B.; von Tümpling, W. ORCID logo ; Mugisha, A.; Rogemont, C.; Umutoni, A.
Quelle Hydrology and Earth System Sciences
Erscheinungsjahr 2019
Department SEEFO; FLOEK
Band/Volume 23
Heft 11
Seite von 4707
Seite bis 4716
Sprache englisch
Supplements https://www.hydrol-earth-syst-sci.net/23/4707/2019/hess-23-4707-2019-supplement.zip
Abstract Dissolved methane in Lake Kivu (East Africa) represents a precious energy deposit for the neighbouring countries, but the high gas loads have also been perceived as a threat by the local population. This is especially the case with respect to potential changes to the lake's stratification during planned industrial exploitation. Both of the above-mentioned issues require accurate and reliable measurements of dissolved gases and temporal changes to take responsible action. Previous data were unable to satisfactorily fulfil these requirements. Prior to our measurements, there was considerable disagreement about prognosticated new formation of methane. We show how measurement accuracy could be significantly improved by implementing equipment that is especially designed and modified for the complex gas conditions in Lake Kivu. Samples were taken from depths of 150 to 430 m to more reliably and more accurately determine the amount of dissolved methane and dissolved carbon dioxide. Beyond the provision of gas concentration profiles at the beginning of exploitation, this investigation can also potentially provide methods to survey the further evolution of gases over time. The use of gas-tight sampling bags produced highly reliable and accurate measurements. Our measurements confirmed the huge amount of stored methane, but clearly did not support the current belief of a significant recharge beyond diffusive loss. Direct measurements with a custom-made gas pressure sensor indicated no imminent danger due to limnic eruptions. However, a further survey of gas pressures is mandatory to detect changing conditions. Using sampling bags and a gas pressure sensor, we introduced reliable and highly accurate measurement approaches for the survey of the further development of gas concentrations. This equipment requires little effort with respect to calibration, which makes it suitable for use in the remote areas of Africa.
dauerhafte UFZ-Verlinkung https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=22437
Boehrer, B., von Tümpling, W., Mugisha, A., Rogemont, C., Umutoni, A. (2019):
Reliable reference for the methane concentrations in Lake Kivu at the beginning of industrial exploitation
Hydrol. Earth Syst. Sci. 23 (11), 4707 - 4716 10.5194/hess-23-4707-2019