An Analysis of Internal Geophysical Factors for the Evolution of The Micro-Irrigation System; (Based on the Dry Zone in Sri Lanka)

Abstract

Considering the technical and structural preparation of affairs in micro-irrigation, a study can be carried out itself on its evolution. The evolution of irrigation affairs from the beginning of the early historic stage to the historic stage can be authenticated by observing both the creative environment and its physical environment. But there is a vacuum in the field of research between the periods from prehistoric to the early historic stage. The intention of this dissertation is to disclose the internal geophysical variables that affected the evolution of irrigation affairs during the periods from prehistoric to the early historic stage. The fact that water is being contained in tanks that were formed according to a network between the early historic stage and the aforementioned tanks were free of the network between the period from prehistoric to the early historic stage is being discussed here as the research problem. The research area is selected as the upper valley of the border between Kala Wewa and Thissa Wewa and the lower valley of Malwathu Oya. The Coring and analysis of the soil sample method, studying contour maps and layers of the cross section in the test pit, utilizing the GIS technology and analyzing the soil particles were applied as the research method. Research results were attesting the prehistoric settlements and affairs in the micro-irrigation of those areas, constructing the connection between the underground water circulation and internal geophysical facts, classification of micro water resources and confirming the primitive industrial affairs. The conceptual frame of the research is noted as the period of prehistory stage settlements and it is clearly identified that the root cause for the migration from upper layers to lower layers is the failure of water circulation between groundwater and agricultural lands.