Environmental Engineering Reference
In-Depth Information
needs to be de
ned (e.g. based on a principle component analysis, score), stated and
defended. The weights reflect their influential importance for the process or con-
dition an index represents. For example an index of economic resources of a
speci
c area might be calculated from different weighted data as, for instance,
number of companies, unemployment, income, expenses and ownership.
2.3.2 Point Data
Knowing and Verifying Environmental Parameters
For water-related issues, data is needed that informs about socio-economics (water
use and quality, income, health status), near-surface characteristics (soils, vadose
zone), subsurface characteristics (saturated zone), climate and land cover (vegeta-
tion, urban areas). Questionnaires, interviews and information obtained from media
and press can be used to assess socio-economic aspects such as water use, water
quality, population density, location of urban areas and political (policy), as well as
economic relationships. The mapping of objects and resources, such as the position
of a speci
c tree, river, lake, groundwater well or climate station, is useful to create
maps. Those maps can support environmental planning, decision-making, as well as
the veri
cation of system modelling results or remote sensing image analysis.
On discrete locations, environmental qualitative (e.g. concentration levels high/
low) and quantitative data (e.g. concrete concentration values) can be collected as
single samples. The data collection in developing countries can be supported by
freely available software tools such as the
, which was
designed to collect data easily based on spreadsheets from maps generated without
an internet connection or extensive GIS knowledge 3 (see Sect. 2.6.1 ). Samples for
quantitative investigations applicable in environmental risk assessments are col-
lectable from surface and subsurface water, soils, rocks, air, plants or humans.
Conventional sampling methods are time- and cost-consuming, because sampling
generally has to be carried out at a large number of locations. However, point
samples along with their corresponding laboratory analysis still provide the most
reliable source of information about the environment. This point information is
connectable to remotely sensed data visualizations, which is crucial for interpre-
tation of its image features (Sect. 2.3.3 ). Additionally, simple proxies (e.g. water
colour) or measurements (e.g. temperature, pH) can be applied to derive further data
(e.g. water pollution, eutrophication) through the application of known transfer
functions.
Recent technological development in the mobile phone sector opens the
potential for using phones as mobile sensors. There already exists several software
projects that offer freely usable (some are even open source) software tools that
allow for partly automatic (e.g. geographic position) or manually entered (e.g. name
of a lake, water quality) data collection. OpenDataKit is an example of an open
'
Water Point Mapper
'
3
For more information, visit WaterAid at http://www.waterpointmapper.org .
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