CHANGE IN MORPHOLOGY AND ENVIRONMENT OF HUBLI- DHARWAD TWIN CITIES IN THE WAKE OF URBANIZATION – USING GEOSPATIAL TECHNIQUES

Most of the urban centers in the world are expanding to accommodate over flowing population, and this in turn is causing drastic change in the nature of the landscape of the cities. Urbanization is a process which is taking place at a drastic rate with or without proper planning strategies (Hagerstand, 1995). Unplanned expansion of cities have created unsolvable issues like conversion of agricultural lands, reclamation of water bodies, creation of slums, generation of urban solid and liquid waste etc. These issues are attracting the attention of Urban/ environmental researchers for finding appropriate measures to create a healthy environment for residents. In this direction the investigators have selected Hubli- Dharwad twin cities to study the process of urbanization and its impact on morphology and environment. In the recent past, morphology of the study region has been undergoing rapid change due to rapid growth of population and establishment of industries. This change has occurred all along the National High way, and in and around Hubli- Dharwad city for commercial, administrative and residential purposes. In the present study an attempt has been made to classify the satellite images for land use and land cover and find out the temporal variation, and an attempt is also made to understand the impact of urban changes on environment, particularly alteration in temperature and rainfall. The morphological changes have been analyzed by using LANDSAT, TM (1975 and 1989) and IRS LISS III (2011) images at different time period. The satellite images of 1975, 1989 and 2011 were analyzed to detect the temporal changes in the land use and land cover. The topographical maps (1:50,000), ARC GIS (10) and ERDAS (9.1) software packages were used to process the satellite images, generate data and preparation of final layout. The study makes use of Bands 1, 2, 3 and 4 of LANDSAT, TM and IRS LISS III data with spatial resolution of 30 M. and 23 M. respectively. It has been noticed that land use in Hubli- Dharwad city has undergone significant changes within a span of three decades. This change is due to over flowing population and establishment of industries. The changes can be mainly observed through the agricultural area and water bodies reclaimed for built up area and industrial purposes. During 1975, the study area recorded about 4,914.11 hectares of Agricultural land, and in 2011 it has decreased to 2,320.39. It is witnessed that within a span of 36 years, about 2,593.72 hectares of agricultural land decreased. It is noticed that there is a phenomenal increase in the Built up area from 1,080.94 hectares (1975) to 3,852.78 (2011). The study area was known for its water bodies and there were more than 100 small and big water bodies and these water bodies maintained healthy climate of the city and fed water for its residents and domestic animals however, due to rapid growth of urbanization these water bodies are reclaimed for residential and industrial purposes. As a result of this, hardly few water bodies are left, and a visible change in temperature and rainfall can be noticed in the twin cities. Another aspect of these changes is that the cities are facing scarcity of drinking water which was once known for surplus water supply.