3.4 Local Environmental Knowledge
The DEM image generated considerable interest amongst participants. The
first step was to orientate the image to local landmarks, to enable
those present to identify their own land on the DEM and situate their
understanding of the real world three-dimensional landscape within the
context of the two dimensional aerial view. Once done, participants used
the infographic tool to begin relating their understanding of water flow
across their own land, and its associated connection to gullying
downslope. This was the first time that local participants could see
‘from above’ how the complexity of landscape topography played a
critical role in whether specific mitigation actions would have the
planned effect:
VLG1: In order to fill gullies and look as what we see from the
map, we have to plant grasses as it looks down there. This erosion
occurs because when the rainwater flows from the upslope it lacks
barriers which protect soil from being washed away. So now as the water
flows downslope it erodes soil and leave cracks on land surface. All we
have to do is plant grasses and trees.
Although initial discussions centred primarily on how hydrological
processes had created rapid overland flow leading to severe erosion and
gullying downslope; the focus rapidly shifted towards the physical
drivers (lack of effective terracing in upland farms to slow overland
flow; lack of trees and vegetation upslope) and associated
socio-economic drivers (lack of conservation agriculture knowledge,
skills or resources; lack of compliance) as this participant notes:
VLG8: Some of people living uphill there haven’t terraced their
farms and when it rains water flows through their farms till down here.Facilitator: Why is it that some haven’t terraced their farms.
Have they not been told or it’s just that they don’t want? VLG4: It’s because of ignorance because everyone has got their own
knowledge and understanding. You can find someone lacks even the basic
knowledge of doing something in order to prevent soil erosion.
Further discussion highlighted a particular issue on land outside of
private ownership, where less effort was made on soil erosion
mitigation, and where water was directed towards, to avoid eroding
private land. This resulted in faster flow along cattle trackways and
paths which were located on common areas. In order to deal with this
specific issue, participants identified areas on the map which could be
zoned as priority areas to plant trees and shrubs in order to mitigate
and slow hydrological flow. The DEM played a critical role in enabling
participants to identify the areas for actions likely to have most
impact in slowing flow based on their overview of the topography; and
supported a much more focussed debate regarding the specific actions
(tree-planting; terracing; education) needed to suit the differing soil
types in each area:
VLG6: First of all, the places you see are fields that people grow
crops. Although people farm, there is a difference in soil between one
zone and another. Where you see there is erosion is the newly cultivated
farming area and the other side which is uneroded it’s uncultivated
area. And areas you see as eroded are cultivated areas. Erosion takes
place downstream there. But what causes erosion downstream is the
difference in soil between down here and up there. Therefore, as water
flows from upstream it doesn’t erode as it does down here.
Using the DEM, participants also reflected on the relative success of
the demonstration plots set up with the community during the original
Jali Ardhi project. These areas highlighted the close coupling between
institutional factors, such as the commitment of village leadership to
maintain these areas as livestock exclusion zones. As a result of that
commitment, gullies in the excluded zones had begun to show significant
vegetation growth, with the resulting reduction in hydrological flow
across this lower-level topography, as this participant noted:
VLG2: Another lesson, you might for example set aside an area for
3 years without livestock getting in. […] For example, down
there you can see we have set an area and prevent cattle from getting in
and we have seen changes as gullies are now filling up. The best
practice therefore is to set an area and leave it for a while without
allowing cattle in so as to allow grasses grow and reduce speed of water
flow.
The community-led outcome of this workshop was a commitment to deliver a
tree and shrub planting programme, with specific species and planting
locations selected by community members. In order to facilitate this
next step, a community tree committee was set up, led by the Village
Leader, with externally-provided practical training and support in
planting techniques and ongoing maintenance. This programme was
delivered during the short rainy season in December 2019 to allow the
trees to use rain for survival.