CONJUNCTIVE USE PLANNING FOR SAPON IRRIGATION PROJECT OF INDONESIA

Abstract

Natural resources are the basis for strength, growth and the very future of every nation. Water and land are the key resources and human has been pioneer in the use of these resources. Optimal use of available surface water and groundwater in any area will be provided better utilization of available resources and more benefits in the area. This study describes LP based optimization model to optimize land and water resources of'a study area for sustainable agricultural development. The combined and integrated management of surface water and groundwater .for optimal utilization of available water resources is called conjunctive use. The present study is directed to planning of surface water and groundwater resources system conjunctively to meet irrigation demand in Sapon Irrigation Project of Indonesia. The project has gross command area of 4917 ha. The irrigated area by this project is 2250 ha, and remaining the area for fulfill the crop water requirement depend on rainwater. The major portion of rainwater occurs during wet season period (i.e. November, December, January and February). In other months of the year rainfall occurs very less, which cannot fulfill the crop water requirement. Therefore shortage of rainwater during the dry season period causes a strong needs to plan and investigate the utilization of groundwater potential for agricultural purpose. At present these is no groundwater development in the command. The main aim of the present study is to arrive at an optimal cropping pattern for optimal use of land and water resources for maximization of net benefits. The " LINDO" optimization package has been used to solve linearised model and to get the optimal allocation of land and surface water and groundwater conjunctively. Model has been used for allocation of water on existing cropping pattern and proposed cropping pattern. First trial to solve the existing cropping pattern without groundwater supply and crops area constraint, and to get the optimal crop. Basis on the existing cropping pattern to solve the solve the proposed cropping pattern with groundwater supply and crop area constraint and to meet the maximum net benefits. After extensive study on different case of the proposed cropping pattern, the optimal plan giving maximum net benefits of Rs. 101,115.300 millions, utilization of surface and groundwater 4981 ha-m and 3330 ha-m respectively, whereas the optimal of land use for wet season .70% optimal area under paddy, and 10 % shift to each crop, 15t dry season 30%, 40%, and 10% optimal area under paddy, groundnut, and other each crop respectively, and 2'd dry season 40% optimal area under groundnut and 20% other each crop. So, this case is suggested to adopted and implemented for the area under study.