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Arguments - Data Quality |
| Water |
| This study mainly uses the
detailed assessment of China's water resources and demand compiled by the United Nations
Economic and Social Commission for Asia and the Pacific (ESCAP) in 1997. The ESCAP study
basically brought together and evaluated information from two Chinese sources: |
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The assessment of national
water resources by the Nanjing Institute of Hydrology and Water Resources,
which was conducted in 1995-1996. This was a replication of an earlier study from
1981-1985 and included detailed estimates of surface and groundwater supply, as well as
water demand estimates and projections by various sectors. For its assessment, the
Institute used precipitation and runoff data collected from 9,230 meteorological stations
and 2,150 surface water flow stations between 1956 and 1979. |
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Information from the Ministry
of Geology, including regional hydrological mapping information for groundwater
(at a scale of 1:200,000), which has been collected since the 1950s. |
| We have no specific
information about the accuracy of these data sources. However, surface water estimates are
usually more accurate than groundwater assessments. First, it is difficult to know where -
and how deep - the groundwater is. Second, it is difficult to know exactly where the
groundwater comes from and where it goes. While it is certainly possible to get accurate
information for a small test area, it is extremely difficult to assess the amount of
groundwater on a macroscale. The information must be generated using indirect, model-based
methods. Therefore the groundwater estimates for China are probably rather uncertain. The
accuracy of precipitation and river flow data, on the other hand, primarily depends on the
number of data-collection stations and is probably quite high in China. |
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| Related Arguments |
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Water Resources: Trends
Impact Data Quality Prediction Error Intervention Possibilities
Intervention Costs
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Revision 2.0 (First revision published in 1999)
- Copyright © 2011 by Gerhard K. Heilig. All rights reserved. (First revision: Copyright © 1999 by IIASA.) |
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