In GharehAghaj basin drought has the most profound effect on the way of living and regional economy. Drought Hazard by nature is a result of interrelated parameters concerned. The objective of this paper presents a mo...In GharehAghaj basin drought has the most profound effect on the way of living and regional economy. Drought Hazard by nature is a result of interrelated parameters concerned. The objective of this paper presents a model to assess hazard of drought using the Geographical Information System (GIS). The data analyzed have been gathered from the records, reports and maps published by the governmental offices of Iran. Various drought hazard indicators have different severity classification in different models. The drought hazard indicator maps take into account the meteorological, hydrological, physical and socioeconomic characteristics that related to drought hazard. Each of the hazard indicator maps and also final hazard map are classified into 4 hazard classes of drought: mild, moderate, severe and very severe. The final hazard classes were defined on the basis of hazard scores arrived at by assigning the appropriate attributes to the indicators and the final hazard map was prepared by overlaying different hazard indicator maps in the GIS, deploying the new model. The final Hazard Map shows that moderate hazard areas (89.87% of the basin) are much widespread than areas under severe hazard (10.13% of the basin) which are observed in the Southeast of the region.展开更多
Land use planning is one of the basic principles of sustainable development in a region and in a country.The main objective of this paper is to test a new model of land use planning in order to evaluate ecological sui...Land use planning is one of the basic principles of sustainable development in a region and in a country.The main objective of this paper is to test a new model of land use planning in order to evaluate ecological suitability and prioritize different land uses in Jahrom County placed in Fars Province,Iran.Hence two main steps were prepared for the new model of Eco-Socioeconomic Model of Land Use Planning(EMOLUP).Step 1 includes ecological capability evaluation of different land uses including forest,rangeland,agriculture,conservation,and development.This step is composed of the geometric mean method instead of the Boolean method;and step 2 includes land use planning and prioritizing for the various uses mentioned above.This step is composed of intersecting ecological capability maps and land use planning,based on two scenarios(economic and social).It was compared with qualitative and current quantitative methods.Also,current land use is employed for calibrating and modifying the models.The results of ecological suitability evaluation showed that the EMOLUP model has more accuracy in the process of comparison than other current methods.Accordingly,revised method using the geometric mean(with overall accuracy>72 and kappa index>0.55 for all land uses and rangeland with overall accuracy=32 and kappa index=0.02)is better than Boolean models,and the method of the calibrated geometric mean(with overall accuracy>87 and kappa index>0.73 for all land uses)is the best among different used models.It should be noted that the arithmetic mean has the lowest accuracy(with overall accuracy<45 and kappa index<0.24 for all land uses).Also,the results of prioritizing and land use planning showed that the quantitative method with two socio-economic scenarios(result based on average of EPM erosion model=0.3 that means 30%of modification in whole study area land uses)is the best method for land use planning in the study area.展开更多
The entire land of Southern Iran faces problems arising out of various types of land degradation of which vegetation degradation forms one of the major types. The Qareh Aghaj basin（1 265 000 ha）,which covers the upp...The entire land of Southern Iran faces problems arising out of various types of land degradation of which vegetation degradation forms one of the major types. The Qareh Aghaj basin（1 265 000 ha）,which covers the upper reaches of Mond River,has been chosen for a test risk assessment of this type. The different kinds of data for indicators of vegetation degradation were gathered from the records and published reports of the governmental offices of Iran. A new model has been developed for assessing the risk of vegetation degradation. Taking into consideration nine indicators of vegetation degradation the model identifies areas with ＂Potential Risk＂（risky zones） and areas of ＂Actual Risk＂ as well as projects the probability of the worse degradation in future. The preparation of risk maps based on the GIS analysis of these indicators will be helpful for prioritizing the areas to initiate remedial measures. By fixing the thresholds of severity classes of the nine indicators a hazard map for each indicator was first prepared in GIS. The risk classes were defined on the basis of risk scores arrived at by assigning the appropriate attributes to the indicators and the risk map was prepared by overlaying nine hazard maps in the GIS. Areas under actual risk have been found to be widespread（78%） in the basin and when the risk map classified into subclasses of potential risk with different probability levels the model projects a statistical picture of the risk of vegetation degradation.展开更多
Today,the world’s population is rising dramatically,and in line with this increase in the population of food and agricultural products,there must be an increasing in the number of problems associated with this proces...Today,the world’s population is rising dramatically,and in line with this increase in the population of food and agricultural products,there must be an increasing in the number of problems associated with this process of agricultural land.Then it is necessary to use the maximum potential of this lands that product maximum yield without any damage.To reach this objective,land suitability evaluation is the most important way that can reach human to this objective.The main objective of this research was to compare different irrigation methods based on a parametric evaluation system in an area of 221402 ha in the Khosouyeh Subbasin of the Fars province,in the south of Iran.After preparing land unit map,37 points were selected for sampling.Soil properties were evaluated and analyzed.Suitability maps for drop and gravity irrigation were generated using GIS technique.The results revealed land suitability of 98.42%of the case study was classified as permanently not suitable(N2)and 1.52%currently not suitable(N1)for gravity irrigation.On the other hand,land suitability of 77.73%of the case study was classified as permanently not suitability(N2),6.05%currently not suitable(N1),12.43%marginally suitable(S3)and 3.79%moderately suitable(S2)for drop irrigation.The limiting factors for both kinds of drop and gravity irrigation are soil depth and slope of land.展开更多
文摘In GharehAghaj basin drought has the most profound effect on the way of living and regional economy. Drought Hazard by nature is a result of interrelated parameters concerned. The objective of this paper presents a model to assess hazard of drought using the Geographical Information System (GIS). The data analyzed have been gathered from the records, reports and maps published by the governmental offices of Iran. Various drought hazard indicators have different severity classification in different models. The drought hazard indicator maps take into account the meteorological, hydrological, physical and socioeconomic characteristics that related to drought hazard. Each of the hazard indicator maps and also final hazard map are classified into 4 hazard classes of drought: mild, moderate, severe and very severe. The final hazard classes were defined on the basis of hazard scores arrived at by assigning the appropriate attributes to the indicators and the final hazard map was prepared by overlaying different hazard indicator maps in the GIS, deploying the new model. The final Hazard Map shows that moderate hazard areas (89.87% of the basin) are much widespread than areas under severe hazard (10.13% of the basin) which are observed in the Southeast of the region.
基金This work would not have been possible without the financial support of Shiraz University(Grant No.93GRD1M75441).
文摘Land use planning is one of the basic principles of sustainable development in a region and in a country.The main objective of this paper is to test a new model of land use planning in order to evaluate ecological suitability and prioritize different land uses in Jahrom County placed in Fars Province,Iran.Hence two main steps were prepared for the new model of Eco-Socioeconomic Model of Land Use Planning(EMOLUP).Step 1 includes ecological capability evaluation of different land uses including forest,rangeland,agriculture,conservation,and development.This step is composed of the geometric mean method instead of the Boolean method;and step 2 includes land use planning and prioritizing for the various uses mentioned above.This step is composed of intersecting ecological capability maps and land use planning,based on two scenarios(economic and social).It was compared with qualitative and current quantitative methods.Also,current land use is employed for calibrating and modifying the models.The results of ecological suitability evaluation showed that the EMOLUP model has more accuracy in the process of comparison than other current methods.Accordingly,revised method using the geometric mean(with overall accuracy>72 and kappa index>0.55 for all land uses and rangeland with overall accuracy=32 and kappa index=0.02)is better than Boolean models,and the method of the calibrated geometric mean(with overall accuracy>87 and kappa index>0.73 for all land uses)is the best among different used models.It should be noted that the arithmetic mean has the lowest accuracy(with overall accuracy<45 and kappa index<0.24 for all land uses).Also,the results of prioritizing and land use planning showed that the quantitative method with two socio-economic scenarios(result based on average of EPM erosion model=0.3 that means 30%of modification in whole study area land uses)is the best method for land use planning in the study area.
文摘The entire land of Southern Iran faces problems arising out of various types of land degradation of which vegetation degradation forms one of the major types. The Qareh Aghaj basin（1 265 000 ha）,which covers the upper reaches of Mond River,has been chosen for a test risk assessment of this type. The different kinds of data for indicators of vegetation degradation were gathered from the records and published reports of the governmental offices of Iran. A new model has been developed for assessing the risk of vegetation degradation. Taking into consideration nine indicators of vegetation degradation the model identifies areas with ＂Potential Risk＂（risky zones） and areas of ＂Actual Risk＂ as well as projects the probability of the worse degradation in future. The preparation of risk maps based on the GIS analysis of these indicators will be helpful for prioritizing the areas to initiate remedial measures. By fixing the thresholds of severity classes of the nine indicators a hazard map for each indicator was first prepared in GIS. The risk classes were defined on the basis of risk scores arrived at by assigning the appropriate attributes to the indicators and the risk map was prepared by overlaying nine hazard maps in the GIS. Areas under actual risk have been found to be widespread（78%） in the basin and when the risk map classified into subclasses of potential risk with different probability levels the model projects a statistical picture of the risk of vegetation degradation.
文摘Today,the world’s population is rising dramatically,and in line with this increase in the population of food and agricultural products,there must be an increasing in the number of problems associated with this process of agricultural land.Then it is necessary to use the maximum potential of this lands that product maximum yield without any damage.To reach this objective,land suitability evaluation is the most important way that can reach human to this objective.The main objective of this research was to compare different irrigation methods based on a parametric evaluation system in an area of 221402 ha in the Khosouyeh Subbasin of the Fars province,in the south of Iran.After preparing land unit map,37 points were selected for sampling.Soil properties were evaluated and analyzed.Suitability maps for drop and gravity irrigation were generated using GIS technique.The results revealed land suitability of 98.42%of the case study was classified as permanently not suitable(N2)and 1.52%currently not suitable(N1)for gravity irrigation.On the other hand,land suitability of 77.73%of the case study was classified as permanently not suitability(N2),6.05%currently not suitable(N1),12.43%marginally suitable(S3)and 3.79%moderately suitable(S2)for drop irrigation.The limiting factors for both kinds of drop and gravity irrigation are soil depth and slope of land.
