Diagnostic Analysis of Canal Irrigation System

Diagnosis of health (problems and their causes) of an irrigated agriculture system is the first step in seeking improvement in the operation and maintenance of the irrigation system. The objectives of this chapter are to increase our understanding of an irrigated agriculture system as it operates, recognizing its strengths (good features/values/benefits), as well as its constraints, and gain knowledge of field procedures for identifying the major constraints related to the main conveyance, on-farm, cropping, and socioeconomic subsystems that limit agricultural production. Reconnaissance survey is explained to understand the system as it presently operates. The reconnaissance help in designing detailed field surveys and experiments. Based on experience in supervising field-based diagnostic studies of minor canals of the Upper Ganga Canal system, the steps involved in planning and conducting a field study are discussed. A detailed list of surveys and experiments during the field study is given for each subsystem. A typical list of equipment required for the field study and some important Do’s and Don’ts are indicated. Emphasis of a field study is not on the results of experiments or surveys but on generating meaningful information for analysis. Analysis should provide answers to checklist questions related to crop yield, utilization of irrigation potential, water availability at the head of the canal, water delivery above and below outlets, economic effectiveness, etc. A case study illustrates a diagnostic field study of the cropping subsystem and economic subsystem. Two minor (tank) irrigation projects (Khairana and Hinauta) in the Sagar district of Madhya Pradesh state in India are selected to illustrate the procedure for the diagnosis of these subsystems.