جستجوی مقالات مرتبط با کلیدواژه « Index Overlay » در نشریات گروه « جغرافیا »

Pre-crisis management planning is a matter of paramount importance which nowadays, urban managers have to deal with, especially in the filed of crisis management. In this research, finding locations for multi-purpose crisis management stations in regions 1, 4 and 10 of Tabriz municipality has been studied. At first step, the parameters affecting the selection of locations have been investigated. After gathering and preparing the layers, raster maps were obtained and subsequently, parameter weighing was done throughout the AHP process using Expertchoice software. At next step, data layers were combined together based on IO Boolean and Fuzzy models and the results were utilized to present some locations as desired onse, Due to the Geographic Information System in solving complex problems of urban and ease of analysis and spatial analysis , the ability of the system to prepare , collate and analyze the layers have been applied . The results obtained from this study, the southern part of the region which was set four as the best urban spaces such as green spaces, educational, sportive and etc, and better access conditions for the establishment of these bases is to have the highest priority and the best places for locating the base of the parks Amir Kabir, Anna, Tawhid and Jihad area around the field to 22 Bahman and a few other points is evaluated

To reduce the city's vulnerability to crises such as earthquakes, floods and other natural disasters and abnormal only pay attention to the safety and strength of the building and construction engineering principles, is not enough. But also it is necessary for crisis management as one of the management levels urban affairs is entered. The location finds meaning in the framework of land use and in fact, is practical for Principles and scientific selection place for target land use, It is essential to taken an effective step in order to control and checkrein the crisis with the emphasis on the establishment and juxtaposition of urban land uses. Therefore, this study aimed at locating crisis management support base of Shahr-e Babak, to provide the optimal location pattern of crisis management support base. For this purpose have been invented advanced tools and techniques to become in the service more efficient of urban planning. Therefore, this study aimed at locating crisis management support base of Shahr-e Babak, to provide the optimal location pattern of crisis management support base using Analytical Hierarchy Process (AHP) for weighting criteria, overlay index (IO) to integrate layers and Geographic Information Systems (GIS). In terms of target, this research is practical and research methodology is descriptive-analytical and experimental research. Criteria used include efficiency, adaptability, safety and environmental characteristics Shahr-e-Babak. General results of this research show that 16.9% of Shahr-e-Babak land include totally inappropriate land to build a crisis management support base, 41.17 % is poor appropriate, 18.6 % is with quality neutral, 21.2 % is comparatively appropriate and 1.6 % of the land allocated to totally appropriate. Also suggested map locating also said Babak crisis management support base and the necessary land use the adjacent in Suggestion land use map.

The hospital is an important element of the new public health. The health of a population requires access to medical and hospital services as well as preventive care and a healthy environment. Site selection of urban public facilities is one of the most important goals of urban planning. Planners help increase the welfare of citizens by means of allocation of urban lands to various necessary urban land uses and facilities, by reducing unnecessary commuting and providing a healthy environment. The main objective of this study is the evaluation of site selection models of hospitals in Tabriz city considering quantitative and qualitative criteria in 3 levels of compatibility, desirability and capacity matrixes. Employing 13 indices and using the ArcGIS 9.2, Idrisi Andes, Index Overlay and AHP implications, site selection of hospitals in Tabriz city has been reexamined. The existing sites and spatial patterns of hospitals have been analyzed. Findings reveal that there has been insufficiency in the number of hospitals and hospital beds in some cases.

Drought is a severe dilemma which influences different aspects of mankind’s life. Drought has a negative impact on economy, environment and agricultural sector and cause heavy damage and losses in many parts of the world. Therefore the quantitative estimation and prediction of drought phenomena has become an important issue for policy makers and the scientific community. In the last three decades, remote sensing has provided a useful tool for drought monitoring and a variety of remotely sensed drought indices based on vegetation indices, land surface temperature (LST) and albedo, have been developed. The main objective of this study was drought riskzonation in Sheitoor basin located in Yazd province by using satellite, climatology and environmental data. The data used in this research consist of ALOS (AVNIR) image collected on 18th July 2009, topographical maps (scale: 1/25000), rainfall, temperature and evaporation data which were obtained from meteorological stations.The Sheitoor basin is located in the central part of Iran. It covers a total area of 416 km2. The altitude varies in the region between 1844 and 2989 meters. Average annual rainfall in the study area is 171 mm and average annual temperature is 14 °C. Based on the Dumarten's climate classification method, the climate of study area is cold arid.At first, the ALOS image was processed to obtain the TOA radiance using gains provided in header file. Next the FLAASH algorithm was used to remove the influence of atmosphere and also for conversion of the TOA spectral radiance into ground reflectance. The image was registered to UTM Zone 40 (WGS 84) coordinates using 1:25000 scale digital maps, 17 control points, a polynomial (degree 2) equation and the nearest neighbor resampling method. In the next step, effective parameters on drought including environmental factors (slope, aspect, height, land cover/use, stream density and vegetation fraction) and also climatic data (temperature, rainfall and evaporation) were mapped in GIS environment. The land cover/use map was extracted from satellite data using supervised classification algorithm. Vegetation fraction was also extracted from image using MSAVI1 index. The other parameters such as height, slope and aspect were produced using topographical maps (scale: 1/25000). Data standardization is a basic task in data analysis when several incomparable criteria are involved. To make comparable various data layers, the data layers which effect on drought were standardized using linear fuzzy. For example, drought severity decrease with an increase in altitude and areas having more height are less sensitive to drought, so maximum and minimum altitude were converted to 0 and 1.The AHP method was used to identify the weight of each parameter. Results of weighted layers showed maximum weight for land cover/use parameter due to the human intervention in natural ecosystems. Next, Index overlay and various fuzzy logic operators (Fuzzy Sum, Fuzzy product, Fuzzy OR, Fuzzy and) were used to model the drought risk.Drought change land cover, soil moisture and surface roughness, it also influences the exchange of energy and water between the vegetation, soil and the air. Thus, it may affect surface radiation, heat and water balance by changing surface biophysical factors such as the VI, albedo and LST. In general, with the development of a drought, the NDVI decreases, the albedo and surface temperature increase and the soil moisture decrease, provided that other factors are stable. Combinations of these parameters may provide a useful tool for better understanding of the spatio-temporal patterns of drought. Most of the drought indices presented in the last decades are based on the above-mentioned parameters (especially NDVI, LST and Albedo). The retrieval of the surface albedo and the LST contains uncertainties rooted in the atmospheric correction of satellite data, decomposition of mixed pixel information, bidirectional reflectance distribution function (BRDF) modeling and the spectral remedy by a narrowband to broadband conversion. As a consequence, the final error associated with the extraction and quantifying of drought information would be magnified. On the other hand, calculating these indices need time series of satellite data which increase the time and the cost of processing. In Ghulam et al., 2007, the MPDI as a real time index for drought monitoring based on vegetation fraction and soil moisture is presented. This index only needs one image to be calculated. In the present study, results assessed using MPDI. Final results indicated that the index overlay method can signify high-risk areas more accurately (R2=0.81) than the fuzzy operators.