Application of Shannon Entropy Model to Zoning of Developed Cities from Combating Desertification View (Case Study: Yazd Province)

Interoduction: Desertification is defined as land degradation in arid, semi-arid and dry sub-humid that happens as a result of various factors including climatic variations and human activities. Based on United Nations Conference of Desertification report desertification will threat more than 750 million peoples equivalent to 17.7% of the total world population living in arid area. Also in Iran 16 provinces with an area of 57.5 million ha have been located in desert conditions. Therefore, detection, control and management of desertification in a sustainable and balanced way seems essential. Necessary to achieve sustainable development is determining the degree of development of desertification criteria to provided ideal condition of appropriate framework in the distribution of facilities and services for arid land managers which can be determined and analyzed by the distance from them. This in addition to the protection of ecosystems fringe, also prevents the loss of national wealth. In the field of desert management except Sadeghiravesh researches which apply taxonomy and Morris model to study the development of regions from perspective of desertification, so far neither at international-level nor at national-level, have been conducted, and the assignment of resources and alternatives, only based on expert opinion and sometimes downward influence has been done.
It should be noted that these models have fundamental flaw while in evaluating of effective indexes, just the absolute value of each index in each region was considered and their priority relative to each other in the process of desertification was not considered which led to unrealistic results. Hence, first we decided to estimate the priority of indexes using Shannon Entropy Model, and assess the development of working units from the perspective of desertification activities.
The purpose of this study is to assess the degree of desertification development in regions, which was carried out in Yazd province by using the Shannon Entropy Model. The results of this study can be considered in planning for the sustainable development in desertification processes and the pattern of this model can be applicable in other parts of the country.
Material and The research was carried out by practical and analytical method. In this study, ten cities of Yazd province were analyzed by entropy Shannon method from viewpoint of desertification criteria development.
After determining indices (desertification activities), performance rate was determined for each index and in each city frim the relevant organization performance statistics. Data matrix was formed based on entropy model framework (Xij), and the data matrix values were normalized (Zij). In addition to estimate entropy indices (Ej) the importance of indices to each other (Wj) was determined. After determining coefficient of important indices, the final priority of strategies was obtained by multiplying normalized decision matrix component (Zij) in indices of importance (WJ); and priority coefficient matrix of units to each indices (Aij) was
formed. Finally from total row of the priority coefficient of each unit ( ∑ ij A ) , the
final priority of units was estimated.
For the ease and accuracy in analyzing the data and achieveing results based on the
relative convergence of working units from de-desertification ideal working units and
by using Arc View we attempted to prepare the map of developed cities.
With regard to the total criteria, conducted analyses and combining results, the cities of Bafgh, Ardaghan and Sadough have the most appropriate status with the degree of development of 0.7679, 0.5957 and 0.5389 respectively. The cities of Tabas, Maybod and Abarkooh with development degree of 0.4749, 0.2279 and 0.1583 were on the next level in terms of desertification development activities, while Khatam city had improper status with development degree of –o.4156 and the cities of Yazd, Taft and Mehriz together with zero preference coefficient had the most unfavorable and unstable conditions.
Achieving sustainability in the units of study needs to balance the developed area from the perspective of de-desertification which requires identifying the level of development. As in the research literature said, no systematic studies have been done and the only study was assessing the developed area by using numerical taxonomy model and Morris models. Also by considering the both; value of each index in each working unit and preference of indexes towards each other more accurate results were preferred compared to others models.According to the subjects that were discussed in brief, it is necessary to consider these three following issues; the results of the current development of de-desertification indexes, potential resources under threat of desertification and area of desert lands; for future planning and investments in order to achieve sustainable development.