A STUDY OF WATER DISTRIBUTION SYSTEMS FOR IRRIGATION WITH SPECIAL REFERENCE TO AREAS OF HIGH BUT ERRATIC RAINFALL

Abstract

The aim of irrigation distribution systems should be to achieve the .highest uniform distribution of the irrigation water applied to the field. The design of any of the irrigation systems in areas of high but erratic rainfall should have the basic irrigation requirements estimated conservatively on dry year conditions. Under actual operating conditions, crop water demand for the particular period will be related to the prevail-ing agro-climatic conditions, which should not necessarily be related in any manner to the average or other characteristics determined from analysis of past statistics. This, being a matter of water management, is beyond the scope of this dissertation. However, it is recommended that reference be made from the existing detailed literature on the subject. This dissertation has been undertaken in an attempt to show how irrigation distribution systems can be developed. It shows how the different irrigation systems can be designed to obtain high distribution efficiency (or uniformity coefficient) of irrigation water in surface sprinkler or drip irrigation methods based on soil infiltration rates, stream sizes, soil water holding capacities, advance of the water front and the duration of irrigation. The author wishes to egress his deep sense of gratitude to Dr. P. P. Sehgal, Director Refresher Courses, University of Roorkee for his valuable guidance, keen interest and encouragement throughout the preparation of this dissertation. iv to Thanks also go/the staff of the Water Resources Development Training Centre, University of Roorkee9 for their limitless guidance and assistance in one uay or another9 and to those organisations Whose published research has made this study possible. Finally, thanks are also due to the Indian and Kenyan Governments to have offered the opportunity to carry out this study.