CSI:Limnology | cross-scale interactions in freshwater landscapes


LAke multi-scaled GeOSpatial & temporal database

LAGOS is a multi-scale spatial/temporal database of lake chemistry and landscape characteristics for thousands of lakes in a 17 state study region in the Upper Midwest, North Central, and North Eastern U.S. When complete, it is estimated that LAGOS will consist of nearly 15,000 lakes > 4 ha in surface area with lake chemistry data (LAGOSlimno) and with landscape data including delineated watersheds and multi-scale landscape characterizations (LAGOSgeo). In addition, all of the remaining 40,000 lakes > 4 ha in the entire study area will also have all landscape characterizations calculated so that a complete census of lakes will be created for the landscape data that are included in LAGOSgeo. The two components of the LAGOS database (LAGOSlimno and LAGOSgeo) represent an effort to create one of the largest known spatially-explicit lake water chemistry and landscape database at a sub-continental scale. The characterization of lake and landscape features has been done using standardized methods and the best available geospatial data that are nationally available to ensure consistency. The majority of the water quality data that have been incorporated into the LAGOS database originated from state, federal, tribal, university, or citizen programs. In particular, the majority of the database is derived from state and tribal natural resource agencies that are responsible for sampling lakes for nutrients in response to requirements from the Clean Water Act, many of which have been required to operate under a Quality Assurance Project Plan. In addition to these governmental sources, we also include data from individual university researchers, consulting agencies, and citizen monitoring programs for which sufficient quality control have been conducted.


For each dataset that is incorporated into the LAGOSlimno database, an individual metadata file is created using the EML metadata standard and Morpho software (http://www.dataone.org/software-tools/morpho ; Michener et al. 1997; Michener and Brunt 2000). These metadata files contain detailed information describing the data content, context, quality, structure and accessibility. We aim to provide metadata of sufficient detail so that future users can evaluate the data quality of each individual data value. We will also create metadata for the spatially explicit components of the database (i.e. LAGOSgeo) using appropriate metadata standards and formats i.e. EML & FGDC (Federal Geographic Data Committee). Once data have been loaded into the LAGOS database, we will conduct QA/QC procedures to ensure usability of the database such as: ensuring that methods across programs are comparable, checking methodological inconsistencies such as minimum detection limits, and checking for outliers. A description of our QA/QC procedures will be incorporated into the LAGOS metadata. Because this database is a compilation of many existing sources of data, we are using extensive documentation at every step of our data loading and transformation procedures (as well information about the procedures of the original source program from which the data were obtained) to ensure the reliability and consistency of the data. This focus on documentation will ensure that the database is useful and of research grade quality for years to come, leveraging the large investment of time and resources we have expended in its development and the original collection of the data it comprises. We have also strived to achieve reproducibility through the extensive use of documentation to facilitate the addition of new data in future years using our repeatable and standardized data loading and transformation procedures, thus allowing the lineage of each individual data value to be traced from sample collection in the field to ultimate publication within the database (i.e., ensuring data 'provenance' [Michener & Jones 2012]).

Source: 1:24,000 National Hydrography Dataset

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