Finding the Forest in the Trees The Challenge of Combining Diverse Environmental Data (1995) / Chapter Skim
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2 Impact Assessment Project for Drought Early Warning in the Sahel
2 Impact Assessment Project for Drought Early Warning in the Sahel
Pages 18-29
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From page 18... ...
As the United States sought to define meaningful ways to respond to the plight of and requests for technical assistance from the drought-affected sub-Saharan nations, one of the proposals that emerged was to use Earth observation (remote sensing) systems to provide regular sequential data about the crop growth conditions in the region (Salby et al., 1991~.
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From page 19... ...
The major question posed by this proposal was whether data from Earth observation satellites could be combined with sparse data from other sources to design a system and methodology for credible crop modeling and yield predictions in this environment. Several U.S.
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From page 20... ...
The historical data were obtained from the NOAA National Climatic Data Center, from site visits to the subSaharan region, or through correspondence with local meteorologists or other scientists. For historical precipitation data, the available dates and quality of data varied by country.
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From page 21... ...
This information was used in confirming a planting date and various stages of crop production in order to mesh precipitation values with crop growth. The committee was informed through its briefings that the methodology used to generate these values was proprietary to the EarthSat Corporation and not available to anyone else, including the NOAA staff, though the planting dates did correspond to values estimated by using data from other sources.
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From page 22... ...
Other changes were in response to difficulties encountered in obtaining desirable ground observations at the time they would have been most useful for real-time modeling of precipitation and yield predictions. If such a project were initiated today, the management and operations plan obviously would include much improved data acquisition, analysis, and communications systems.
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From page 23... ...
The NOAA satellite data are archived at the National Climatic Data Center. Because different components of the project data reside in different locations, it is unclear how any subsequent crop modeling projects or activities might have access to and benefit from the data acquired during this project.
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From page 24... ...
In this region the beginning of the rainy season, if it begins at all, varies greatly, and the entire season is generally of short duration. Knowing the crop calendar and following the precipitation events throughout the stages of growth and development of the grain crops are an essential part of conducting a credible crop yield prediction program, which can be modified as environmental and growth conditions change with advancing maturity of the crop.
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From page 25... ...
Accommodation of Users' Needs for Crop Yield Estimates Officials of USAID appeared to be satisfied with the results of the yield predictions, and so the members of the committee were left to wonder why the NOAA project was terminated.
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From page 26... ...
It is unlikely that an alternative modeling procedure would have alleviated these budgetary concerns. Interfacing of Disparate Databases As discussed above, the broad range of data used in the NOAA project included historical precipitation data used to establish normal ranges, satellite data to predict current rainfall, a mix of satellite-generated vegetation data, and historical and current yield data that came from several sources, including the countries surveyed.
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From page 27... ...
Institutional constraints in many cases can be related to the fact that in some countries there is no clear-cut boundary or definition of the appropriate government agency to be assigned responsibility for collaborating in a project on crop modeling. Further, once an agency has been assigned responsibility, the identification of personnel with the special knowledge and skills essential to the project may prove to be difficult.
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From page 28... ...
Many of these countries did not have adequate technology, logistical support, and trained personnel to provide essential data. There were substantial efforts at quality control through collaboration with participating government agencies, often with a less than desired degree of satisfaction.
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From page 29... ...
1987. Final Report: Panel on the National Oceanic and Atmospheric Administration Climate Impact Assessment Program for Africa.
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