پيش بيني تغييرات احتمالي كاربري جنگل به ديم كاري با استفاده از مدلسازي احتمالاتي در حوزه آبخيز فريم صحرا- استان مازندران

Probabilistic prediction of land use change from forest to dry farming using Bayesian Theorem modeling in Farim Drainage Basin

Land use change is one of the most accelerated factors of surface and subsurface hydrological processes, soil erosion and sediment yield. The purpose of this study is distributed-probabilistic modeling of land use change from forest land to arable land using development of scenarios. At first, Land use map of three dates 1967, 1994 and 2004 were prepared using digital topographic maps and ETM+ satellite images. By means of comparison and using change detection extension of Arc/View software, change detection of these periods was obtained. Change detection analysis has shown forest and dry farming area was decreased by 375 and 1154 hectare and released and irrigated farming area was increased by 1240 and 202 hectare respectively, between 1967 to 2004. The results of T-student and Chi-square statistical analysis showed that slope angle, elevation above sea level, distance from roads and residential areas have effect on forest-dry farming transformation, significantly. The results of statistical analysis have shown that some environmental and anthropogenic factors are the effective factors of these changes. Then using Bayesian Theorem, distributed-probabilistic model of these changes was developed and overall probability of each factor was derived from single probability. Also, this model was developed in GIS using stochastic distribution in whole of Farim Drainage Basin and predicting maps of land use change from forest land to arable land were generated. The results have shown 88 hectare forest lands will be converted to dry land farming into lower slope and close to roads and residential areas.