Session 2 : Assessing water harvesting suitability
190
GENERAL CONCLUSIONS AND CURRENT STATUS OF PILOT STUDY
The results of the study so far indicate that there is substantial potential for the assessment of
WH suitability for semi-arid areas. Any assessment methodology must be demand driven in terms
of social and environmental suitability. An appropriate logic by which to match supply and
demand is the FAO Framework for Land Evaluation. The ‘matching’ logic is similar to that by
which local people classify soil; with respect to a specific use, and in terms of requirements and
limitations for a given use. The Framework can be operationalized within an expert system,
which allows input of data from local resource experts and output--by interfacing with a GIS--in
map form, a commonly understood representation and basis for land use planning with local
people. Furthermore, GIS can be used to create scenarios with different local ‘interest groups’,
stratified into ‘Social Response Units’ using PRA tools. These concepts and techniques are
currently being explored in the study area, comparing in particular groups statified on the basis of
degree of pastoral orientation, on the hypothesis that the concept of investment in land/a fixed
location is a critical factor for predicting WH suitability. This hypothesis is derived from a study
of the experiences of three major WH projects in the area.
On the environmental side, assessment of WH suitability involves different techniques for
runoff and runon areas but the same approach in that ‘Suitability Filters’ corresponding to
progressively more precise, quantified but costly techniques are applied to the most promising
Land Units [as they are defined, on an iterative basis]. The appropriate level at which to begin
and end an investigation is determined on the basis of specified objectives and corresponding
scale, data availability and resources [Figure 1]. A clear but flexible statement of purpose from
the beginning of data collection therefore is important. For assessing runon suitability simple tests
have proven to be very promising and cost effective, and can be related to local soil knowledge
because they are primarily visual. Assessing suitability for runoff necessitates more quantitative
data and involves larger unit areas, and thus amenable to rainfall simulation and remote sensing.
Rainfall simulation has proven to be a useful and cost effective tool in this research.
Image interpretation provides a natural link to indigenous knowledge because both are
fundamentally visual phenomena and complementary to IK because the former is time static but
the latter time dynamic. Furthermore, remote sensing can potentially be used to extrapolate the
spatial validity of indigenous knowledge beyond the territorial boundaries of the group which has
acquired this knowledge through many years of trial and error. This possibility is currently being
explored.
Ultimately the degree to which suitability for WH can be assessed depends on the degree to
which a critical analysis of past experience of WH signals the key social and physical factors
which define whether and which type of WH system is feasible and beneficial and for whom and
under what circumstances. Technology is not socially neutral and thus Micro and Macro WH
have different social requirements and implications and both must be viewed in a dynamic context
of trends in the larger economic environment. The degree to which suitability can be assessed also
depends on amenability to the tools by which they are assessed; for example, Micro WH may not
be amenable to remote sensing. Thus a range of potential tools is being examined by this research
in order to assess suitability for suitablility assessment.
On the basis of an extensive general literature review of factors explaining WH adoption and
the experiences of projects in the study area, in addition to social and environmental data sets
being collected for this pilot study and by a variety of methods, the current research is attempting
to operationalize the prediction of social and environmental suitability for WH and in a manner
190
GENERAL CONCLUSIONS AND CURRENT STATUS OF PILOT STUDY
The results of the study so far indicate that there is substantial potential for the assessment of
WH suitability for semi-arid areas. Any assessment methodology must be demand driven in terms
of social and environmental suitability. An appropriate logic by which to match supply and
demand is the FAO Framework for Land Evaluation. The ‘matching’ logic is similar to that by
which local people classify soil; with respect to a specific use, and in terms of requirements and
limitations for a given use. The Framework can be operationalized within an expert system,
which allows input of data from local resource experts and output--by interfacing with a GIS--in
map form, a commonly understood representation and basis for land use planning with local
people. Furthermore, GIS can be used to create scenarios with different local ‘interest groups’,
stratified into ‘Social Response Units’ using PRA tools. These concepts and techniques are
currently being explored in the study area, comparing in particular groups statified on the basis of
degree of pastoral orientation, on the hypothesis that the concept of investment in land/a fixed
location is a critical factor for predicting WH suitability. This hypothesis is derived from a study
of the experiences of three major WH projects in the area.
On the environmental side, assessment of WH suitability involves different techniques for
runoff and runon areas but the same approach in that ‘Suitability Filters’ corresponding to
progressively more precise, quantified but costly techniques are applied to the most promising
Land Units [as they are defined, on an iterative basis]. The appropriate level at which to begin
and end an investigation is determined on the basis of specified objectives and corresponding
scale, data availability and resources [Figure 1]. A clear but flexible statement of purpose from
the beginning of data collection therefore is important. For assessing runon suitability simple tests
have proven to be very promising and cost effective, and can be related to local soil knowledge
because they are primarily visual. Assessing suitability for runoff necessitates more quantitative
data and involves larger unit areas, and thus amenable to rainfall simulation and remote sensing.
Rainfall simulation has proven to be a useful and cost effective tool in this research.
Image interpretation provides a natural link to indigenous knowledge because both are
fundamentally visual phenomena and complementary to IK because the former is time static but
the latter time dynamic. Furthermore, remote sensing can potentially be used to extrapolate the
spatial validity of indigenous knowledge beyond the territorial boundaries of the group which has
acquired this knowledge through many years of trial and error. This possibility is currently being
explored.
Ultimately the degree to which suitability for WH can be assessed depends on the degree to
which a critical analysis of past experience of WH signals the key social and physical factors
which define whether and which type of WH system is feasible and beneficial and for whom and
under what circumstances. Technology is not socially neutral and thus Micro and Macro WH
have different social requirements and implications and both must be viewed in a dynamic context
of trends in the larger economic environment. The degree to which suitability can be assessed also
depends on amenability to the tools by which they are assessed; for example, Micro WH may not
be amenable to remote sensing. Thus a range of potential tools is being examined by this research
in order to assess suitability for suitablility assessment.
On the basis of an extensive general literature review of factors explaining WH adoption and
the experiences of projects in the study area, in addition to social and environmental data sets
being collected for this pilot study and by a variety of methods, the current research is attempting
to operationalize the prediction of social and environmental suitability for WH and in a manner