|Book Group Author:||NA|
Competition for water among many users such as industries and domestic water is reducing the amount allocated for agricultural use (irrigation). In addition, water is being contaminated and the quality is deteriorating, while the world population is increasing rapidly. Under these circumstances, it is essential to increase the productivity of water in agriculture, the largest single user of water. To utilize water effectively, farmers and decision makers need reliable studies based on information. Optimization technique is a promising approach to increase the productivity of water and stabilizing farmers' incomes. Tank irrigation systems are found in the northern part of Thailand and the southern parts of India and Sri Lanka. They are well suited to small-scale irrigation projects due to the low cost of construction and maintenance. The investment in small scale-irrigation systems such as small tanks from farmers, government and other donors is reportedly high. In the North Central Province (NCP) of Sri Lanka, tanks (small water reservoirs) provide the main water resource. There are more than 12 000 tanks in NCP. In some cases, the tanks are connected and consist of a continuous system (referred to as "Tank Cascade System (TCS)"). Others function independently. Generally, NCP farmers do not have sufficient rainfall in the dry (Yala) season. During these months, rainfall events tend to be of high intensity and sporadically distributed. Farmers need additional water to obtain adequate yields. This report focuses on the optimal water management of a tank cascade system (TCS), mainly in the dry (Yala) season. During the wet season (Maha), farmers usually have enough rainfall to cultivate rice, the main and staple crop, while, in the dry season, their rice crop sometimes fails due to water shortage. The primary objective of this report is to investigate the potential of optimization of water management and the introduction of OFC (Other Field Crops) for crop diversification to raise productivity and stabilize farmers' incomes even during the dry season. In this study, a procedure was developed for determining a cropping strategy to cope with the variations in annual rainfall and surface water inflows in the Meegassagama command area through the use of an optimization model.
|Pages:||77 - 86|
|Journal:||JIRCAS International Symposium Series|
agriculture, cropping systems, development projects,diversification, irrigation, irrigation systems, irrigation water,optimization, rain, reservoirs, rice, seasonal variation, simulationmodels, surface water, tanks, water management, water pollution, waterquality, water requirements, water use efficiency, India, Sri Lanka,Thailand, Oryza, Oryza sativa, Poaceae, Cyperales, monocotyledons,angiosperms, Spermatophyta, plants, eukaryotes, Oryza, South Asia, Asia,Developing Countries, Commonwealth of Nations, South East Asia, ASEANCountries, Ceylon, paddy, rainfall, seasonal changes, seasonalfluctuations, storage tanks, water composition and quality, waterresource management, watering, Pollution and Degradation (PP600),Mathematics and Statistics (ZZ100), Field Crops (FF005) (New March2000), Plant Production (FF100), Plant Cropping Systems (FF150), SoilWater Management (Irrigation and Drainage) (JJ800) (Revised June 2002)[formerly Soil Water Management], Water Resources (PP200)