Impact of New Urban Schemes on Natural streams of Karachi

Pakistani social activist, director of the Orangi Pilot Project Research and Training Institute Ms Parveen Rehman said that "Development doesn't come from concrete! It comes from human development."Landuse planning and development is one of the key feature of urban centers. This landuse planning has a direct impact on landuse patterns and eco-environmental quality of the area. Landuse planning is a systematic analysis of land suitability and its alternative use. For landuse planning the best choice of land is that which fulfills the present social need but without disturbing the environment of area. Residential development processes in the urban-rural fringe of mega cities has major environmental consequences. Karachi, Pakistan is one of fastest growing urban centers of the world, but this fast-growing population has also been associated with increasing pressure on ecosystems and their individual components. In 1993 only 08% of the city area was developed which is now 21% of the total city area. These development processes have influence on socio-economic, political and environmental situation of the city. The conversion of fertile agricultural land and natural ecosystems into built-up area bring negative ecological impacts. One recent study shows that the urbanization is also going to cause recurrent flash floods in Karachi city which will cause damages in terms of livelihood and assets. The damages by these floods is just not due to heavy rainfalls but because urban development acts as barriers to natural major stream networks and hamper the flow of rainwater to the riverbeds.This study also aims to analyze the impact of one of the well-known real state scheme "Bahria Town Karachi" on natural landcovers. Bahria town is located in the northern part of Karachi almost covering an area of 44,000 Acres. In a newspaper article urban development expert and town planner Mr. Arif Hasan reveals that according to the first master plan of Karachi (1953) the rural area around Karachi were previously reserved for agriculture and the status was unchanged in the revised plans of 1958, 1989 plan for 2000. Bahria town Karachi also responsible for displacement of villages located in the area of prior to the development of the project. About 45 goths (villages) residents were displaced. Figure 01 shows the map and list of the villages which were affected due to Bahria town. In spite of having all the controversies the new town is also responsible for deteriorating the natural landcover and natural streams bed in the area. A previous study related to blockage of stream networks in Karachi reveals that the town is encroaching the riverbeds which in turn will affect the river flow and also ground water recharge. This research aims to study the detailed impacts of Bahria town development on the natural and semi natural environment of the city. For this study Landsat ETM+ and Landsat data for the year of 2000 and 2017 were collected. Landsat is one of the satellite program providing extensive remote sensing data free of cost. Landsat data have been proved valuable for many urban related studies.