3. What is a watershed?
+
Land that drains downhill
to a body of water
waterways
4. Why it is important to determine the watershed healthiness?
Pollution of the water resources has become a serious concern over the period of
time
Healthy watersheds provide numerous social and economic benefits to local
communities
protecting them is much less expensive than restoring watersheds that have become
degraded.
5. Scope of the project
Polgolla watershed area is approximately 738 km2 and it is
delineated into fourteen sub watersheds. Among them following six
sub watersheds consider.
Pinga Oya
Meda Ela
Nanu Oya
Nillambe Oya
Atabage Oya
Kothmala Oya
Study area in polgolla watershed
6. Make an understanding on activities which affect the
watershed healthiness in polgolla watershed
Extract high priority influencing factors
Address Effectiveness of qualitative factors at sustaining
healthy watersheds
Scope of the project cnt…
7. Relationship between Quantitative and Qualitative parameters
Presence of natural
resilience features that
have positive effect on
resilience mechanism
New imports to the
system which increase
fluxes (loading) in the
environment (land/water)
Resilient infrastructure
and performance
efficiency
Introduction of new
features/ alteration of
natural systems which
have some degree of
negative impact on
resilient mechanisms
BOD
(mg/L)
DO
(mg/L)
pH
Faecal
Coliform
Nitrate
(mg/L)
Total
Phosphorous
Turbidity
(NTU)
Watershed
health
8. Objectives of the project:
Make an awareness of the potential qualitative factors which plays a
central role in healthiness of polgolla watershed
Determine relative importance of the factors using Analytic
Hierarchical Process(AHP)
Create a report based on findings by emphasizing potentials we do
have in order to improve the healthiness of the polgolla watershed
9. Identification of vital factors which affect water quality
parameters.
Data Collection of each qualitative factor for each sub watersheds
(government sources , secondary data used by other projects)
Use AHP(Analytic Hierarchical Process)for analyzing
Pair-wise comparison of alternative factors.
Pair-wise comparison for main factors.
Determine overall ranking for main factors.
Continue this process for six sub watersheds
Determine the overall healthiness in polgolla watershed
Methodology
