Impact of Urbanization on River Ecology – A GIS Technologies Perspective

Abstract

Malir River which is the major seasonal river of Karachi once supported the market gardening practiced in Karachi. Its valleys and plains, once comprises the cultivated lands of vegetables and fruits that fulfilled the local market demand. But with a shift in rainfall characteristics, the cultivation also started to recede slowly as many of the crops could not withstand the prolonged drought conditions and farmers were not ready to take the risks and hence abandoned cultivation. Hence, changing climate gives way to the industrialization of rapidly growing urban center which in turn inducing desertification. Since the cultivated land which is supplied with water also is helpful in evapo-transpiration leading to precipitation by taking part in the water cycle. But the whole process was disrupted by the abolition of agricultural activity in the area. The study gives a GIS (Geographical Information Sciences) perspective of Land Use/Land Cover of the southern part of Malir plain near its mouth – the Korangi and Landhi Area which were also the active flood plains of Malir during 1960s. Since the huge urbanization and population growth has led to water scarcity in the area due to the reduction of underground aquifers and the reduction of agriculture, high research efficiency can be achieved using satellite imagery and GIS.