Analysis of crop indicators

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Spatial analyses of crop development stage of winter wheat on June 10th 2011 (dekad 16).
Average temperature around flowering of winter wheat, starting 10 day's before until 10 day's after flowering (crop development stage = 100).

Crop indicators and yield forecasts are produced with 10-day intervals. They presented as 25x25 km grid cells or administrative regions. Crop indicators can be presented as departures from normal (other years or long term average), expressed in relative terms or absolute values. Assessments of the dates of occurrence of specific phenological stages are likely to be imprecise and probably only suitable to be expressed in relative terms such as departures from normal or ‘very late, late, normal, etc.’ (Vossen and Rijks, 1995).

Marsop Viewers

The Marsop Viewers are developed to analyse the available datasets. The analyst version has full functionality and can access all datasets. The web version serves the 'outside' world with a selection of datasets and limited functionality. The data can be analysed in spatial (maps) and temporal resolution (graps). Data are available from 1975 onward.

Indicators available for administrative regions

  • Potential above ground biomass
  • Water limited above ground biomass
  • Potential storage organs biomass
  • Water limited storage organs biomass
  • Potential Leaf Area Index
  • Water limited Leaf Area Index
  • Total water requirement
  • Total water consumption
  • Relative soil moisture
  • Crop development stage

Indicators available at 25x25 km grid resolution

On a 25x25 km grid resolution the above mentioned indicators are extended with indicators that are used for generating risk maps of critical crop development stages (such as sowing, flowering, ripening and maturity). Some of these indicators combine a critical crop development stage with extreme weather events.

Available indicators:

  • All above indicators
  • Precocity
  • Number of heat waves around crop development stage
  • Longest heat wave period around crop development stage
  • Rainfall around crop development stage
  • Rainfall around sowing
  • Daily temperature around crop development stage
  • Minimum temperature around crop development stage
  • Maximum temperature around crop development stage
  • Temperature around sowing

The indicators that combine a crop development stage with an extreme weather event are calculated on-the-fly in the viewers. First a crop development stage is selected. For each gridcell the date is retrieved on which this crop development stage is reached. This can be a different date for each gridcell! Subsequently for each gridcell the weather data are collected in a time window around this date. The user can define the time window by offset and duration.

The indicators 'around sowing' are treated differently because crop development stage is stored between emergence (value 0) and harvest (200). These indicators use a crop and grid cell specific fixed sowing that is stored in table JSOW.

Frost risk maps

Two types of frost risk maps are generated. Maps that are based on meteorological criteria only and maps showing the hardening index or frost induced reduction of leaf area index (for winter wheat crops).

In the first approach maps display the simultaneous occurrence of minimum temperature below -8°C and snow layer thinner than 1 cm, or the occurrence of minimum temperatures below -18°C combined with a snow layer thinner than 10 cm. In the second approach the physiological status of the plant is taken into consideration (see Integration of CGMS DBs and CERES-Wheat).