theo brandsma knmi, the netherlands
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Theo Brandsma KNMI, the Netherlands. Daily Indonesian rainfall in the 1879–1916 period. International workshop on the digitization of historical climate data the new SACA&D databases and climate analysis in the Asian region Citeko, Bogor, Indonesia, 2-5 April 2012. Background. - PowerPoint PPT PresentationTRANSCRIPT
Theo BrandsmaKNMI, the Netherlands
International workshop on the digitization of historical climate data
the new SACA&D databases and climate analysis in the Asian region
Citeko, Bogor, Indonesia, 2-5 April 2012
Daily Indonesian rainfall in the 1879–1916 period
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1. Obtaining knowledge of the rainfall climate in Indonesia 2. Design of irrigation systems3. Planning of agricultural crops4. Planning of infrastructural works like railways
Reasons for setting op a rainfall network
Background
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Growth of the network
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Growth of the network
Number of stations with daily rainfall (1879-1916)
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Distribution of the stations in 1879 (124 stations)
Growth of the network
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Distribution of the stations in 1900 (225 stations)
Growth of the network
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Standardization
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Standardization
Rain gauge
1. Rim at 1.2 m above ground level
2. Diameter of 12 cm3. Vessel containing 275 mm
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Standardization
Regulation examples
1. Following the orders of the director of the Batavia observatory concerning the positioning of the rain gauge
2. Measuring of rainfall each morning at 6, 7, 8, or 9 local time and assigning it to the day of measurement on specially prepared measurement forms
3. Rounding the measurements to whole mm 4. Sending two duplicates of the daily measurements to
Batavia/Jakarta right after the end of a month by two subsequent postal deliveries (and keeping the original for another six months)
5. Publishing monthly summaries in the Javasche Courant en the daily values in the annual rainfall books (by the director)
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Digitization and quality control
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Digitization and quality control
Example from the yearbooks
1.Scanning2.OCR3.Quality control4.Database
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― means no rain n.w. means not measured * means multi-day amount† means measuring period not exactly 24 hoursw.o. means incomplete measurement, monthly totals could not be calculated
Possible codes
Digitization and quality control
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Digitization and quality control
Example page
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Final goal: to import the 1879-1916 daily rainfall series in SACA&D
Digitization and quality control
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1. Extreme-value analysis 2. Studies of climate change and variability 3. Validation of climate models
Possible applications of the dataset
Applications
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