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en:concept [2019-07-14] – external edit 127.0.0.1 | en:concept [2022-11-24] (current) – external edit 127.0.0.1 | ||
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+ | ====== System Architecture ====== | ||
+ | <WRAP box> This is the technical description of HgIS. It is not very useful for users not interested in information technology. | ||
+ | The architecture of the system corresponds to a spatial business intelligence solution (GeoBI) – a combination of BI and GIS. </ | ||
+ | ===== Analysis ===== | ||
+ | The data needed to develop groundwater models are of various types. They are time-dependent and fully 3D. The source data exist in various formats as databases, data exchange formats (e.g. DBF, XML or flat files), archive data (e.g., MS Excel, or MS Word), spatial data (e.g., ESRI SHP, KML, or geodatabases). These data need to be retrieved into a single data structure to be used together. Highly structured data usually do not contain any interpretation or additional knowledge. Therefore it is necessary to store and process all types of data adequately. Some should be saved in a structured form so it can be further used (creating graphs, tables, maps, cross sections, etc.). Other data are used ad-hoc in the form it was obtained in, so it is sufficient just to be stored and accessible – e.g. in the file system. The data and processes are depicted in table 1 that stands for the data flow diagram. | ||
+ | |||
+ | //Table 1. Data flows – data sorted from structured to unstructured// | ||
+ | ^ Data source | ||
+ | | Structured and semi-structured data – observations (databases, files) | ||
+ | | Spatial interpretation of data, other geodata | ||
+ | | Documents | ||
+ | | Other files | Storage, accessibility | ||
+ | |||
+ | ===== Business Intelligence ===== | ||
+ | Groundwater information management can be described as loading of both archive and actual data (that are not modified anymore) from diverse (structured and semi-structured) sources; visualization of data in tables and graphs (downloadable in common formats as MS Word and MS Excel), data analysis, and model development. The same description corresponds to a completely different discipline – Business Intelligence (< | ||
+ | Therefore HgIS utilizes Pentaho – the < | ||
+ | |||
+ | ===== HgIS ===== | ||
+ | HgIS is an information system developed at the Technical University of Liberec in the Czech Republic. Its purpose is to load data from the available data sources of any kind, to visualize and analyze data (to support the formulation of alternative conceptual models), and to implement simple models based on the data. Table 2 shows how specific kinds of data are managed in HgIS. Although it is focused on groundwater, | ||
+ | |||
+ | //Table 2. HgIS architecture// | ||
+ | ^ Data source | ||
+ | | Observations (XML, MS Excel, flat files, SQL databases) | ||
+ | | ::: | ::: | ::: | ETL (PDI) | Complex visualization | ||
+ | | Spatial data (ESRI SHP, KML, raster images etc.) | GIS (QGIS), ETL (PDI) etc. | Spatial database (PostGIS) + georeferenced images | ||
+ | | Documents | ||
+ | | Other files | ||
+ | | ||
+ | {{schemahgis_en.png? | ||
+ | //Figure: HgIS architecture// | ||
+ | |||
+ | ===== Database – data warehouse ===== | ||
+ | It is reasonable to use an existing data model for the newly developed information system. We have reviewed available data exchange standards and data models as GWML, other application schemas of GML, INSPIRE, Hg2O, Arc Hydro Groundwater, | ||
+ | The original data model of EnviroInsite (9 tables) was extended to 36 tables because the EnviroInsite data model contains the data relevant for visualization only. The original tables were extended by additional fields and the model was further normalized.</ | ||
+ | * observation objects*, | ||
+ | * characterization of geological layers, | ||
+ | * technical construction of wells, | ||
+ | * definition of observed quantities*, | ||
+ | * action levels, | ||
+ | * definition of vertical intervals*, | ||
+ | * measurements tied to vertical intervals (e.g. chemical assays or head measurements)*, | ||
+ | * measurements tied to a specific depth (e.g. geophysical logging), | ||
+ | * sampling conditions, | ||
+ | * conversion of units (e.g. mg to g) and quantities (e.g. nitrate to nitrogen), | ||
+ | * anti-aliasing, | ||
+ | * time intervals, | ||
+ | * metadata, | ||
+ | * lookup tables etc. | ||
+ | Tables containing data noted with asterisk (*) are organized to the snowflake schema. \\ | ||
+ | We are using the [[https:// |