Spatio-temporal Land use/cover assessment of Sub-Tropical Forests ofThatta Division
The deterioration of forests has contributed to greenhouse effect on massive scale, during last four decades and related regional climatic changes and rapid disappearance of natural landscapes left unattended will cause no sign of forests in the past. The integrated remote sensing technology applied to assess forest resources cover information regarding health and related problems and depended factors such as rural population, livestock and wildlife. The main focus of this study is to quantitatively assess deforestation to evaluate forest cover change from 1979 to 2010. The employment of space borne Landsat MSS and TM sensor (multi-spectrum sensor & thematic Mapper) technology is used to analyze forests patterns and Maximum Likelihood Algorithm is applied for quantitative assessment. This study was also conducted to carry out field survey in Thatta riverine forest from Kotri barrage to Arabian Sea and three hundred samples were collected from different locations using GPS device (global positioning system) the results of remote sensing satellite imagery helped to find out significant changes in Thatta forests cover from 1979 to 2010. The forests cover in 1979 was 35.11%, 1992 29.14%, 1998 8.10%, 2000 5.56%, 2006 2.57%, 2009 1.96%, 2009-12 3.02% and 2010 2.23% the overall change observed in forests area 89.07%. The field survey revealed that the main causes of deforestation asconstruction of dams/barrages on the upper streams to produce hydroelectric power and irrigation purpose which significantly reduction in the discharge of fresh water into the lower Indus basin. The reduction in flood caused severe erosion of the Indus Delta; the sea water has been encroached the Indus basin and livestock population increased grazing load and illegal tree cutting; these main causes directly impacted on natural sub- tropical forests and also effected rural population which depended on forests produced. All these uncontrolled situations have been creating environmental, climatically, social and economical problems direct impacted on Indus region and these changes threatening Indus Eco-region system.