The influence of rainfall on ground water quantity and its changes; a study in selected areas of porativupattu ds division in Batticaloa.

Abstract

Groundwater is an essential natural resource for sustaining domestic life and environment. Rapid development of agriculture, economy and increase of population growth due to the resettlement of past war recovery were caused to the water quantity. Moreover, due to uneven distribution of rainfall in both time and the space, water resources are dwindling. The study is undertaken to identifying the seasonal changes ground water especially the drinking water. Through this, the changes of water level, influence of rainfall were examined with appropriate data. Rainfall data of 146 years from the meteorological department, the formula and 5, 11 years standard deviation of moving average were used to analyze the groundwater quantity. Meteorological department’s repots, images were utilized for this study, published reports and statistical records were employed to collect as secondary data. MS Excel, GIS software were used for data analysis. Seventy domestic wells were randomly selected for the study. The different measurement tools were used to measure the well water level. The water level was measured in equal six times in one year. The results confirm that the positive and higher value of groundwater by the rainfall during Northeast monsoon period. This established with deviation of rainfall and the measured well water level. Thus, keeping the balance of tank water level, surface runoff and groundwater level, the performance of the water level could be stabilized. The development of the new tanks, its irrigation system and drinking water supply also reduce the water shortages in the study area. Temporary water retaining structures should be constructed to facilitate the infiltration. Further, rainfall water should be saved for future use. Controlling the intensive use of water pumps for drainage and making the farmers aware about the water wastage and pollution is also important for the water stability.