A Global database of methane concentrations and atmospheric fluxes for streams and rivers

This dataset, referred to as MethDB, is a collation of publicly available values of
methane (CH4) concentrations and atmospheric fluxes for world streams and rivers, along with
supporting information on location, geographic, physical, and chemical conditions of the
study sites. The data set is composed of four linked tables, corresponding to the data
sources (Papers_MethDB), the study sites (Sites_MethDB), concentrations
(Concentrations_MethDB), and influx/efflux rates (Fluxes_MethDB). Information was extracted
from journal articles, government reports, book chapters, and similar sources that were
acquired before 15 September 2015. Concentrations and fluxes were converted to a standard
unit (micromoles per liter for concentration and millimoles per square meter per day for
flux) and both the author-reported and converted data are included in the database. MethDB
was assembled as part of a larger synthesis effort on stream and river CH4 dynamics, and
assembled data were used to identify large-scale patterns and potential drivers of fluvial
CH4 and to generate an updated global-scale estimate of CH4 emissions from world rivers.

本数据集命名为MethDB，整合了全球溪流与河流公开可得的甲烷（CH4）浓度及大气通量数据，同时附带研究点位的位置、地理、物理与化学条件等辅助信息。该数据集由四张关联数据表组成，分别对应数据源表（Papers_MethDB）、研究点位表（Sites_MethDB）、浓度数据表（Concentrations_MethDB）以及流入/流出速率表（Fluxes_MethDB）。数据集信息提取自2015年9月15日前收录的期刊论文、政府报告、图书章节及其他同类文献资料。研究人员将原始浓度与通量数据统一转换为标准单位（浓度单位为微摩尔每升，通量单位为毫摩尔每平方米每天），数据库同时保留作者原始报告数据与转换后的数据。MethDB的构建是全球溪流与河流甲烷动态综合研究项目的一部分，整合后的数据集被用于识别河流甲烷的大尺度分布格局与潜在驱动因子，并生成了更新后的全球河流甲烷排放估算值。