Introduction

Wetlands play a pivotal role in supporting extensive food webs and biodiversity. These fragile ecosystems being the interface between terrestrial and aquatic ecosystems, function as kidneys of landscape as it helps in the removal of contaminants. They are biologically rich, productive and support people’s livelihood through provision of fish, fodder, etc. They are susceptible to small changes and have become endangered ecosystems in rapidly urbanizing landscapes. India, with highly diverse physiography, monsoon climate with extremes of temporal and spatial variability, and high biotic diversity, is gifted with numerous and equally diverse inland and coastal wetlands (Ramachandra 2001; 2005). These wetlands cover a wide range of ecosystem types and support a rich diversity of flora and fauna (Mitsch and Gosselink 2000; Prasad 2002). It is estimated that fresh water ecosystems support about 20 per cent of the known biodiversity in India (Deepa and Ramachandra 1999; Ramachandra and Solanki 2007). India has a total of 67,492 wetlands, covering about 4.1 million hectares. Out of which, natural wetlands accounted to 2,715, covering about 1.5 million hectares and 65,254 man-made wetlands, occupying about 2.6 million hectares (Ramachandra 2005). Wetlands in India are increasingly facing several anthropogenic pressures due to rapid urbanization consequent to globalization and opening up Indian markets. Unplanned urbanization has led to large scale land use/land cover changes posing threat to the sustainability of wetland resources. Expansion of urban centers, agricultural and industrial settlements, have altered hydrological regime and also has contaminated numerous water bodies (Krishne and Sridhara 2007). Rapid urbanization and economic developments have extensively impacted wetlands and has transformed them to other land uses for short term economic gains (Gopal 2013). The anthropogenic activities, like unplanned urban and agricultural development, industries, road construction, impoundments, resource extraction, and dredge disposal had transformed the wetlands leading to economic and ecological losses (Ramachandra 2005). Wetlands have been relegated into sinks of domestic sewage and industrial effluents which have threaten the existence of dependent biota. Heavy loads of nutrients have paved the way for many invasive exotic species affecting the native species and altered the community composition. This necessitates regular monitoring to evolve appropriate management strategies to maintain ecological health of wetlands. The assessment of nutrient enrichment and ecological health of wetlands is a complex process because large no of interrelated variables are involved including both physico-chemical and biological factors (Ignatiades et al. 1985; Vollenweider et al. 1992). Principal Component Analysis (PCA) and Cluster Analysis (CA) helps in the evaluation of environmental data. These techniques helps in reducing dimensions of the data and new variables are uncorrelated (Sharma 1996; Kazi et al. 2009; Najar and Khan 2012). These techniques helped in prioritizing wetlands based on environmental parameters.

OBJECTIVES
The objective of this study was to characterize urban wetlands through physico-chemical monitoring of selected lakes and identification of possible factors affecting water quality in wetlands.