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ThesisItem Open Access Simulation studies on different design parameters of spurs (Groynes)(Department of Land and Water Resources and Conservation Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1995) Roy, Mathew; KAU; Xavior Jacob, KThe Use of spurs as river training measure has proved to be an effective means of protecting river bank and their design requires indepth knowledge about its parameters related to the solution of a specific river training problem. To analyse various design parameters of spurs, a simulation study was conducted at KERI,Peechi. Characteristics such as flow pattern, velocity distribution and scour pattern was analysed for different spur lengths 25 cm, 35 cm, 45 cm and 55 cm, spur angles 900, 1000, 1100 and 1200, spur spacings 2L, 3L, 4L and 5L and for discharge rates 14.14 1ps, 28.28 1 ps and 42.42 1 ps. Single spur and multiple spur scheme were tested on rigid as well as mobile bed condition. The analysis of the obtained flow pattern, velocity distribution and scour pattern reveals that the specified design parameters have a significant effect on flow diversion, length of bank protected, maximum scour depth at the spur nose, percentage increase in velocity at opposite bank etc. The analysis of the present study also led to conclusion that L/B ratio of 0.19, spure angle of 900 was the best combination for single spur study and the same with a spacing of 5L was most effective for multiple spur scheme.ThesisItem Open Access Effect of different types of mulches on growth and yield of drip irrigated vegetables(Department of Land and Water Resources and Conservation Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1997) Gilsha Bai, E B; KAU; Jobi V PaulThe present project was to study the effect of drip irrigation along with two colours of plastic mulching on the growth and yield of summer season vegetable. Two types of irrigation methods, drip and surface, and two colours of plastic mulches, black and transparent, were used in the experiment. Three levels of irrigation water, v, 0.8V and 0.6V volume, were applied in drip treatments. Mulches increased the soil temperature. High soil temperature was developed under transparent mulch compared to black mulch. Black mulch increased the soil temperature in the root zone by 3 to 4°C compared to non-mulched plots. This increase in soil temperature under the black mulch was advantageous to the crop. Presence of mulch sheet over the soil reduced the evaporation from the soil. Hence, moisture depleted from the non-mulched plots were more than mulched plots. Water saving obtained by the use of plastic mulch was about 30 to 35% in the different treatments. Black mulched and non-mulched treatments did not show significant difference in the plant height. Maximum plant height was observed in the non-mulched drip irrigated treatment with O. BV volume of water. Maximum plant spread was observed in the surface irrigated black mulch treatment. Surface irrigated treatments gave more plant spread than drip irrigated treatments. Use of mulch sheets reduced the weed growth in the field. Practically, there was no need of weeding from the plastic mulched plots. Earlier flowering and maturity of fruits were observed in the mulched plots. All treatments with black mulch increased the yield compared to the control. Treatment with black mulch and drip irrigation with O.BV volume of water gave 76.5% more yield than the control. Most of the treatments with transparent mulch reduced the yield. This reduction in yield was due to the high soil temperature developed under the transparent mulch. Yield was increased with the soil temperature upto an optimal level of about 46°C and then decreased with the increase in soil temperature. In drip method O.BV volume of irrigation water level was the best. It gave highest yield and growth in mulched as well as non-mulched treatments. Drip irrigation along with mulching in summer vegetable can reduce the cost of cultivation through efficient water management. Also the area of cultivation can be increased with the available water in the water scarce areas.ThesisItem Open Access Monthly water balance model for lateritic hill slope- a case study(Department of Land and Water Resources and Conservation Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1996) Beena, Thomas; KAU; Noble, AbrahamThe groundwater balance of K. C. A. E .T. Campus, Tavanur, Kerala has been studied and a deterministic model has been developed for the prediction of depth to water table in this hill slope based on Darcy’s equation. The input data required are the precipitation, evapotranspiration, specific yield, initial water table, elevation of the points under consideration and the distance between the points. The weekly precipitation and evapotranspiration were calculated and from this the recharge to groundwater was estimated. The groundwater recharge was taking place only during the southwest monsoon season. The change in storage divided by the hydraulic gradient for a period without rainfall i.e., from 01 December 1994 to 16 February 1995 were determined. Using these values and other inputs in the model, the depth to water table for a period from 26 May 1994 to 25 May 1995 were estimated from the model. These values were compared with the observed values for the same period. It was found that the estimated values give a reasonable estimate of the depth to water table in the study area. This model can be used to predict the changes expecting in the water level in a particular region. The model has several areas of application in the fields of groundwater resource development and irrigation. The infiltration characteristics of the selected area was evaluated and observed that the infiltration rate was increasing towards the higher elevation. The model was simulated for different percentages of effective rainfall and found that, at 50 per cent it accounts as groundwater recharge and the rest as surface runoff.