FACTOR ANALYSIS OF WATER QUALITY DATA : A CASE STUDY

Abstract

River water is frequently used for drinking, irrigation, industrial supplies, agriculture, fisheries, and power development. Rivers are also sinks for different types of industrial wastes and sewage. Therefore, the quality of river water depends upon the catchment characteristics, land use in catchment area and the last but not the least on the quality and quantity of effluent disposed off in the river by different industries and towns. It is not possible to keep the water bodies pristine or of uniform quality throughout the entire stretch. However, it is necessary that various stretches of the rivers are maintained at characteristics quality level which can sustain the respective uses of the stretches. To assess the quality status of any river, continuous monitoring round the year is required. After completion of any such monitoring programme enormous amount of data is generated which needs to be analysed. The assessment of the various stretches of river is difficult in view of unavailability of any method or tool. In past certain methods had been applied very marginally. In the present work an effort has been made to illustrate the potential of Factor Analysis in analysing water quality data of river Hindon. The river was monitored under the project "Water Quality Monitoring of River Hindon under GAP Phase II" sponsored by Ministry of Environment & Forests. Data from five sampling stations namely Maheshpur, Barnawa, Daruheda, Mohan Nagar and Noida collected over a period of three years (December 1993 - October 1996) has been considered for analysis. A computer program in FORTRAN 77 was used to analyse water quality data in two phases. In the first phase 21 parameters at each station were analysed and different number factors were retained. Similarly, in the second phase analysis was carried out using 9 parameters. Results were interpreted keeping various sources and interactions in mind. Key observations recorded are : (i) Cd is generally associated with organics (i.e. COD). (ii) Ni and Cr always appear in combination except at Maheshpur (iii) Water quality at Daruheda is represented by the water quality of Upper Ganga Canal (iv) Water hyacinth at Mohan Nagar affects the water in terms of suspended solids (v) COD exhibits high variability at Noida. The analysis reveals the fate and source of pollutants. Factor Analysis appears to have potential for its application in the analysis of water quality data.