Abstract:
The settlements existed before the creation of irrigation works, fulfilled
their requirements of water through natural resources which were arranged
according to the natural landscape settings. Anuradhapura old Yodha Ela
coming under this study and well before its creation, the settlements spread
in the Kala Oya Valley upper lands, fulfilled their water requirements
through cascade systems right from the early historical period. According
to the sloping of the terrain from the uppermost lands up to the lowermost
lands, the cascade is a system made up of a network of village tanks.
The problem of this research study is to establish as to why Yodha Ela
was constructed later on through this zone although the Kala Oya valley
uppermost lands received water from the cascade. The objective of
the research study, is to examine the cascade which existed before the
construction of the Yodha Ela, and the environmental and physiological
factors that caused their structural changes. In order to justify the
research objective, and during the data collection, GPS, study of aerial
photographs, drawing up of plans, earth coring methods, and during data
analysis the use of GIS, examination of soil profiles, calculation of the
mean sea levels, and the like research methodologies were followed.
As the result of this research, establishment of the spread of the village
tanks in this zonal area before construction of the Yodha Ela, physical
grouping of the cascade, establishment of the topographical landscape
pattern of the cascade system, to build up the case that Yodha Ela is a
facilitating component of the cascade systems, and the establishment of
the functionality of the Yodha Ela and the cascade, was done. Even though
in the previous researches, the originating water resources of the cascade
system was done, their functionality, and classification of topographical
patterns have not been done. But the manner in which the activities of
the cascade changed with the early historic irrigation works have not
been covered those previous studies. In this research, the structural
pattern of cascade as an early water management methodology of the
zonal area through which the Yodha Ela flowed and an understanding
of the topographical landscape pattern accordingly, variations in the
climatic factors, population density, agricultural works, and changes due
to the variations in those factors, through the cascade and as a facilitating
component the construction of the Yodha Ela during the early historic
period, and parallel to those water management methodologies, migration
of settlements from the uppermost to the lowermost zonal areas, which
factors were established in this research study.
