عنوان مقاله [English]
Evaluating ecological potential means giving value to each unit of land. It is estimating ecological capability for specified landuse. The land is a very sensitive source. If there is a development out of power, many damages will come to the land. Land use planning is a science that specified the optimized use of land based on ecological and socioeconomic characteristics. In fact, it is very important to first consider the potential of the land before any exploitation. That is, destruction is prevented by evaluation.
In many parts of Iran, the selection and management of land use (development, especially) is done regardless of land capability that it causes disinvestment and reducing the environmental capacity. Firoozabad city is one of the cities of Fars province. Firoozabad Township with the center of Firoozabad city, with an area of 3559 square kilometers, is dedicated to 2.9 percent of the total soil area of Fars province. This city is placed in the range of 53 degrees 31 minutes east longitude and 29 degrees 15 minutes north latitude. The heights of this Township are mainly observed in the northwest and southeast. The average height for this city is about 1600 m. The average rainfall of Firoozabad city during the years 71-81 was 743.1 mm per year and the highest average rainfall was 153.6 mm in December. A large part of Firoozabad Township has a temperate or mild and humid climate and parts of this Township which is close to Bushehr province, in terms of climate are in the dry climate group.
This study's main goal is to evaluate the ecological potential of Firoozabad Township for urban development landuse using GIS. To assess the ecological potential of urban development landuse, we used the current methods in our country such as the Makhdom model (This model is based on the logic And and Or), Maximum limitation model (Boolean logic), Arithmetic mean model, EMOLUP (Eco-Socioeconomic Model of Land Use Planning) method or geometric mean model and the calibration of geometric mean or EMOLUP (with changed numerical limit for classification class of 3 in this area from 0.5-1.5 to 0.5-1.62), simple weight arithmetic mean based on criteria and simple weight arithmetic mean based on indicator and Arithmetic mean (based on criteria and indicator) with considering of limiting factor and calibration of these methods. The research method in this study is "descriptive-analytical". For analyzing data, the softwares of EXCEL 2010, ENVI 4.7, and ArcGIS 9.3 were used. Different data like physiographic, climatic, soil, geological, vegetation and water criteria were used to evaluate the ecological potential of urban development landuse in Firoozabad Twonship. The criteria also included several indicators. The total number of indicators was 16. In this study, the highest number of indicators was related to soil criteria and the lowest number of indicators was related to vegetation and water criteria. The proposed model for urban and industrial development is classified into 3 classes. class 1: suitable; class 2: moderately suitable; class 3: poor and none suitable.
The results of the tests showed that the best ecological potential assessment model for urban development landuse among all models in this research in Firoozabad Township was the EMOLUP model and the calibration of EMOLUP model. For accuracy assessment 4 indics including the overall accuracy and kappa coefficient and intra-class coefficient and average accuracy were used. The results all of the accuracy evaluation indices (especially overall accuracy) showed that the highest value for the EMOLUP and its calibration. The EMOLUP method has the best function and calculation among the others models in this region. It should be noted that arithmetic means based on the criteria and indicator and weighted arithmetic mean methods based on the criteria and indicator, are the lowest accuracy of existing methods. In fact, they had poor performance in the region. Makhdoum Model showed the lowest Kappa coefficient in this study. Makhdoum Model and maximum limitation model had the lowest intra-class coefficient in this reigon. In general, the Makhdoum model has been a weak model for assessment in this area of urban development landuse and this model is not recommended. After the EMOLUP model, Arithmetic's calibration means with considering of limiting factor based on the criteria and indicator showed the highest rate of accuracy indicators. The values of intra-class coefficient and average accuracy indices in arithmetic's calibration means with considering of limiting factor based on the criteria were higher than this model without any calibration in this region. It was concluded that the arithmetic's calibration means with considering of limiting factor based on the criteria is more accurate. The arithmetic mean method as an optimistic model, the dominant of the region (Firoozabad Township) goes toward good, and proper classes and in the methods of Boolean logic (Makhdoum model and maximum limit model) with an inappropriate parameter, dominant of the region goes towards inappropriate classes. The end result was that the geometric mean model showed a much more logical classification among all the models.
Therefore, the EMOLUP model with calibration showed the best position in terms of performance and accuracy than other models in the Firoozabad Twonship. Comparing the results of this study were similar to the results of research of Masoudi and Asadifard (2015) in Firoozabad Twonship for ecotourism landuse and similar to the results of research of Asadifard and Masoudi research (2019) in Firoozabad Twonship for commercial forestry and protection forestry landuse and similar to the results of research of Jokar and Masoudi (2015) in the Twonship of Jahrom for urban development landuse. Finally, considering the climate and weather conditions of Firoozabad Township, EMOLUP model or geometric mean with calibration of this model is proposed for the urban development landuse. Therfore, this proposed model should be tested in all regions of the country with different climates and its results should be carefully examined. In this case, this model can be offered for the whole country.
All faculty members of Universities in our country and all administrative agencies in Firozabad, Shiraz, Isfahan, Ahwaz city, and Mr. Jokar, Mrs. Alie and Mrs. Mehrabi great appreciation and thanks.