A STATISTICAL APPROACH FOR ESTIMATING IRRIGATION WATER USAGE IN WESTERN SAUDI-ARABIA

This paper presents a statistical practical approach to the estimation of irrigation water requirement in the western region of Saudi Arabia . The approach describes the variation in water requirements as a func tion of regional climatic parameters, types of crop grown and irrigati on techniques used. Irrigation water requirements are also calculated, for comparison purposes, by Modified Penman and Blaney-Criddle method s, taking leaching requirements and losses into consideration. It is f ound that irrigation water requirements for vegetables and perennial c rops are close to the values estimated by Blaney-Criddle method, while for fodder and cereal they are close to the values estimated by Modif ied Penman Method.