JWSS - Journal of Water and Soil Science

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The vast and diverse rangelands of Iran require the selection of appropriate methods for grazing intensity measurement in the different vegetation types. Methods can be compared on the bases of time and budget as well as their accuracy. In this study nine methods of the utilization measurement were conducted on the E. ceratoides stands of Hanna exclosure Semirom, Isfahan province. The duncan multiple range test was used to compare mean utilization percentages obtained from the different methods, with paired cage method data was used as control group. Analytical Hierarchy Process (AHP) was also used to compare methods for accuracy, time and budget. The means from reference unite, twig length, production index, plant count and stem count methods had significant (p<0.05) differences compared with control group but were comparatively time consuming and more expensive than other methods. The height-weight method resulted in an estimate with no significant difference with the control group. This method was also fastest and least expensive among methods with the accurate results (p<0.05).

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One of the most important cost factors in forest management, which involves a great deal of investment costs, is road construction. So evaluating forest roads and determining the best one can decrease costs. The objective of this study was to evaluate forest roads using Multi Criteria Evaluation with respect to costs. In Multi Criteria Evaluation method such factors as slope, aspect and soil type were used for suitability map. Then factors were compared in pair-wise comparison in the context of a decision-making process known as the Analytical Hierarchy Process (AHP) to develop weights of map layers. To do this, the opinions of some experts were collected using questionnaires and the results were integrated and factor weights were calculated. Then weights and their factors were entered into Multi Criteria Evaluation (MCE) Module to create final suitability map (factors were standardized before combining). Total costs of each variant were extracted from suitability map. After variant costs were obtained by dividing each variant total cost by its length, unit cost of each variant was calculated. Finally, unit costs were compared and the variant with the lowest costs was determined. The results showed that the slope had the greatest weight followed by soil and aspect. Also, variant 7 had the lowest cost and variant 8 the greatest cost. AHP method has the capability of considering qualitative and quantitative criteria so it is a proper method for weighting. Also MCE method in GIS environment has the capability of combining different factors. As it requires less time and cost, also has a higher precision, it is better to use MCE method in such studies.

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Determine appropriate locations with accuracy and speed required is for Floodwater spreading very important. The main objective of this research, preparation, use and evaluation decision support systems is based on GIS and RS techniques to identify and prioritization appropriate areas Floodwater spreading in the study area. In this study area suitable for flood water spreading were selected based on major criteria four, sub criteria eight and index twentyfour. Finally five scenario will be provide and assessment (a scenario based on the relative values for the criteria four, and different scenarios four based on the obvious one of the main criteria). Comparison desirability average among the scenarios five indicate that it is Sub watershed (1) In the scenario third (infilteration preferred, water application preference and equality of all the main criteria) had a higher average desirability therefore between Sub watershed 2 in this scenario is preferred more than the other Sub. Of between the two sub watershed ivar region considering that the desirability average, sub watershed (1) and implemented of between scenarios, scenario (1) (infilteration major criteria preferred) were selected as first priority. Second priority for Floodwater spreading site selection is belong to sub watershed 2, and with scenario (1).