| Abstrakt: |
Bengaluru is the fifth largest urban centre in India and one of the fastest growing cities of Asia. The city is unique with a distinction of having no perennial water resource in near vicinity. Both surface water and ground water act as the major sources of drinking water in many parts of the city. In the study, statistical analysis was accomplished to determine the ground water level, water level drop of Bengaluru metropolitan area and the major environmental factors affect the water level fluctuation. The study included 711 square kilometer BBMP area where BWSSB is supplying water through 9 divisions-North, West, South, East, North-East, South-West, Central, South-East and North-West. To meet the objectives, groundwater level (DTWL) data from 11bore wells and 64 dug wells were collected for the period 2010 to 2015 for three seasons (Pre-monsoon, Monsoon and Post-monsoon) together with the contributing factors viz; population density, altitude of a region, rainfall, municipal water supply coverage, well density etc. These factors were identified for having influence on ground water level and ground water level drop in the study area. The study gave an attempt to arrive at the predictor significance among these various contributing factors on water level and its drop. CRISP DM data mining process aided by the statistical tool (SPSS) was utilized to accomplish statistical analysis of ground water condition in the city. Present work included C5.0 algorithm which yielded best results in predicting the ground water scenario (ground water level classification and ground water level drop classification) in the entire study area. The results of statistical analysis were as follows: 1) Prediction accuracy of the ground water level classifications (good, moderate and bad) showed good accuracy in the range of 91% to 96%. 2) The prediction accuracy of ground water drops levels showed good accuracy at 83% both in moderate drop and safe drop. High drop showed around 70% accuracy. 3) Water level drop among borewells depends on Rainfall Previous, Population density, well density, K_rainfall and variation in rain fall to normal. However, the analysis showed rain fall has no immediate effect on water level fluctuation in bore wells. 4)Population density was the major factor deciding water level in bore wells whereas dug wells showed no direct correlation between ground water level & population density. Unless measures are taken to regulate population density, ground water exploitation and condition in the city will move from bad to worse inspite of the rainfall receipt by the city. Further GIS technique using Arc GIS was incorporated in the work to determine ground water condition and its availability with the help of water table movement analysis in the city. Based on the water level contours, seasonal variation of ground water levels (pre-monsoon, monsoon and post monsoon), ground water level fluctuation, progression of critical areas in terms of ground water availability were established between years 2010 and 2015. The results showed that ground water levels were receding at an alarming rate in 2015 compared to 2010. Parts of North-West, North and East were very critical zones for ground water. In addition, the paper gave an overview about the socio-economic significance of the study in Indian context. [ABSTRACT FROM AUTHOR] |
