Multi-prong model approach for ground water to alleviate drought in Sri Lanka

摘要

Mathematical models describe Hydrologic problems. Ground water potential in the sedimentary rock of Sri Lanka has been reported (Basnayake 1989) However there was a variation in the ground water hydrology of the region. The study area was located at a latitude of 79° 05' and altitude of 7° 06' and the farmers were experiencing crop failure under rain fed situation due to drought. The spatial distribution of ground water was investigated using the Kriging technique which employed interpolation technique to estimate the ground water available for supplementary irrigation.Variogram obtained for the water depth distribution was described by the equation y=0.129-0.054x-0.0047x2 +0.000lx3. Variation in the depth to water table of the shallow well in the study area was described by the equation y=1/(90.28005-0.0045).Contour diagram for the parameters considered above gave the real picture of the hydrology of the region.Draw down and discharge pattern observed from pumping test for the monitored wells gave real picture of the available ground water in the study area. Transmissivities and specific yield showed regions having adequate water for irrigation.It was concluded that the above mentioned approaches were useful in describing spatial temporal distribution of ground water.