Document Type : Research Paper
Authors
Abstract
This paper describes the utilization of a system dynamics model to predict the effects of vegetation-based management scenarios on structural landscape ecology in the Hablehrud River Basin. The river basin covers an area between Tehran and Semnan provinces. In this research, vegetative management scenarios include: the current condition, terracing, saxaul plantation, riparian restoration, forage growing, bunch seeding, contour furrowing, tree plantation, grazing exclusion, seeding, drill seeding, orchard development, and agroforestry. In order to predict the effects, Weighted Mean Patch Size index (WMPSI), Weighted Land Cover Area Index (WLCAI) and Riparian Proportion Index (RPI) were quantified. Additionally, the model uncertainty analysis was conducted using bootstrap method. Ecological impacts of the scenarios using aforementioned indices were predicted and the best scenarios were chosen using system dynamics. Results suggest that considering WMPSI, tree plantation and riparian restoration scenarios are the preferred scenarios. Seeding and orchard development scenarios were considered to be the best scenarios based on WLCAI. Moreover, riparian restoration and saxaul plantation were chosen as the best scenarios considering RPI. Seeding and riparian restoration scenarios obtained the highest priority considering the combination of the indices. WLCAI and RPI have the minimum and maximum uncertainty levels with respect to coefficient of variation as 0.28 and 0.45, respectively. The system dynamics models are capable of predicting the effects of various management scenarios providing the information required for decision making and management at watershed scales.
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