Seepage rate estimation from total channel control data during periods of shut down: preliminary data quality assessment. Case study: Coleambally irrigation system

摘要

In recent years, major south-eastern Australian irrigation companies have invested heavily in modernization which includes installation of automatic control structures with remote monitoring, the so called total channel control technology (TCC). Main objectives of using TCC technology are to supply water near-on-demand and to control channel water levels. TCC includes supervisory control and data acquisition (SCADA) technology which will result in production of integrated databases based on real time measurements of the whole system. This data has the potential to be used to identify sections of channel with high rates of seepage or leakage. Pondage tests are acknowledged as the best direct method for seepage measurement, and the recorded water level data from automated systems during periods of gate closure can be treated as pondage test data. The purpose of this paper is to report on a preliminary quality analysis of such data during periods of shut down in the system in order to investigate the feasibility of using such data in seepage rate estimation. Coleambally irrigation district in southern NSW was chosen as the case study it being one of the first automated irrigation districts in the world and having three years of historical data. The analysis was done for all pondage conditions during the 2010 irrigation season and based on criteria requirements, accepted samples were categorized in different groups. The analysis showed that out of the total number of 1073 possible pondage conditions, 51% of them met the 70% criteria requirements and can be used for the purposes of this study. Examples of some individual periods of ponding are provided. Furthermore, it is concluded that TCC data is suitable for seepage and water loss analysis.