Page 57 - CIWA Water Data Revolution Overview Report

respondents were asked if they collected information on precipitation; surface water; vegetation
and land cover; evapotranspiration; topography; snow and ice; water quality; soil moisture;
and/or groundwater using RS. Figure 4 presents the frequency of RS data collected by the
organizations for these variables and water cycle attributes.

16
14
12
No. of Organizations 10

8

6
4
2

0

Figure 4: RS data collected by the organizations for information on specific variables and water cycle attributes.

Two-thirds of the respondents reportedly used RS to collect data on each variable and water cycle
attribute, except for soil moisture (n = 9), water quality (n = 9), and groundwater (n = 8). The
lower quantity of organizations using RS for soil moisture, water quality, and groundwater data
was expected. RS for water quality generally is limited to observation of large water bodies and
oceans, thus reducing the water resources in Africa that may benefit from using water quality-
related RS data. Sub-surface properties, such as groundwater storage or soil moisture, are also
difficult to assess using satellite-based technologies, thus reducing the utility of RS for collection
of data related to these attributes. This challenge was underscored through interviews with
organizations that reported using RS to collect groundwater information. Discussions clarified
that a majority of the respondents did not collect direct information on groundwater due to the
poor quality of available RS data pertaining to aquifer storage. One organization also described a
process for approximating fluctuations to groundwater using more reliable RS variables, such as
precipitation. Overall, precipitation is the most collected variable using RS (n = 15), followed by
using RS to characterize surface water sources (n = 14). RS data on vegetation and land cover, as
well as evapotranspiration, were also highly collected by the organizations (n = 13). No
respondents collected RS data related to snow and ice cover.

RS was reportedly collected for the purposes outlined in Figure 5. At most, three organizations
used RS for the same utility. The most reported uses of RS were for flood monitoring and early
warning; drought monitoring and forecast; basin monitoring and planning; and water allocation

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