Comparison of different lining materials for field channels based on seepage characteristics

Abstract

Agricultural productivity is based on the availability of required at proper time. As water is becoming a limited resources its effective utilization is important. The water resources which could be tapped for irrigation are very limited and its conservation is very important. Also, the losses in a new canal are very great in initial stages. But they slowly diminish in time due to saturation of the surrounding soil and due to stanching of banks and canal section by deposition of silt from canal water. The other factors affecting the transit losses are nature of soil, its condition and size of the canal, depth of water, temperature and position of sub soil water level. The study entitled “Comparison of different lining materials for field channels based on the seepage characteristics” was aimed to assess the seepage characteristics of locally available low cost lining materials such as coir geotextile, gunny cloth, and plastic sack which were used to line the earthern channels. The study was conducted at instructional farm of KCAET; Tavanur in the month of September 2013 to January 2014.The experiment set up consists of four treatments including one control and five replications. The plot is of 30 12 m size and four channels of trapezoidal cross section with dimensions bottom width of 0.8m, depth of 0.7m and a side slope of 1:1⁄2 were constructed. The textural analysis revealed that soil type in the area is sandy loam in nature. For coir geotextile lined channel, variation in seepage rate was observed less compared to other treatments, and reduces with time and ceases to a constant rate. The maximum moisture content observed for coir geo-textile and plastic sheet material was at 40cm horizontal distance and 60cm vertical distance. But for gunny cloth lined channel and in control, the maximum moisture content was observed at 60 cm vertical and horizontal distances. This implies that the seepage (lateral movement of water) is less in coir geo-textile and plastic sheet material compared to gunny cloth and control channel. The contour maps also show that there is a uniform distribution of moisture in coir geo-textile, followed by gunny cloth. The vegetation in the coir geo-textile channel after 3 months of construction is 12.75×10 -2 /cm 2 . This implies that the channel will act as a vegetated water way after a long time of running.