فصلنامه سنجش از دور و سامانه اطلاعات جغرافیایی در منابع طبیعی
سال چهارم شماره 4 (زمستان 1392)

Knowing the ratio of landuse and how this ratio change over the time is a significant factor in landuse planning and management. By knowing how landuses change over time, we can predict future changes and do preventive and appropriate actions. The aim of this study is detecting the landuse changes in the Tehran city in period of (1995-2005). Landuse maps for the mentioned years were derived from LandSat imagery and improved using AutoCAD data produced by the National Cartographic Center (NCC) and available maps. For verification produced maps, using the error matrix approach, a Kappa coefficient of 88% was achieved and after classification, change detection was carried out using comparison approach. The results of change detection with a Kappa coefficient of 91% and Cramer’s V of 88% show that the greatest increases were in built up area (4603.68 ha), parks (650.7 ha) and water level (22.32 ha) and in contrast, the greatest decreases were in open land (4561.47 ha) and vegetation cover (715.23 ha). In addition, according to the results the most changes of built up area has been occurring in the west part of Tehran.

Land surface temperature estimation in the vast area using remote sensing can be eliminated depletion of its monitoring in limited numbers of weather stations. The surface energy balance algorithm for land (SEBAL) used for estimating the temperature in most parts of the world. The aim of this research is gaining the land surface temperature and studying its relation to geographical factors like height، geographic direction، lithology and morphometric of some landforms in Taftan volcanic cone. Therefore، by using SEBAL method on ETM+ imagery in 2001 year، heat map of this area is produced. As for performing this method، the corrected thermal radiance، surface emissivity in thermal band، spectral radiance، reflectivity in each bands and surface albedo was calculated. Ridges and thalweg map is produced by studying the regional contours using topographic maps and Google Earth. On the other hand، river maps، digital elevation model، geographic direction and geology are digitized and created. Then by overlapping the mentioned maps with land surface temperature (LST) map and using zonal statistical analysis، the LST is taken in every elevation class، geographic directions، formation and special land forms. Overall، results showed that at higher levels، LST decrease and geographic directions have an important role in temperature rate of cone. The minimum average of temperature and the maximum average of temperature are seen in west direction and east direction، respectively. Furthermore، formations and land forms that have minimum and maximum temperature are located in these directions. So، by regarding temperature conditions in geographic directions and different formations، could plan for implanting compatible agricultural crops and appropriate environmental conditions.

Accordance with the importance of air pollutants and their effects on human health، assessment of air pollutant emission model''s accuracy is significant. One of the models that widely used is AERMOD which is a permanent prediction model. The purpose of this research was evaluated the accuracy of AERMOD model، with and without application of topography. To achieve this goal، model ran with 24 hour meteorological data from Yazd synoptic station as input data and EAF stack monitoring data of I. A. S. Co. as the on-site data. Also، Global maper software version 13 was used for creating model''s requirements for DEM format with different resolutions of 30، 50 and 90 meters. After that، model ran on both situations، flat and non-flat area (with applying topography)، and then results compared together. The results indicated that the average concentration of pollutant in condition using topography is 0. 036 µg/m3 higher than condition without usage topography. Also، the results showed the maximum concentration of pollutant in the case without using AERMAP، is 1 µg/m3 in opposite direction to the prevailing wind، in stack western direction and with using AERMAP، the maximum concentration is equal to 17. 5 in prevailing wind direction in stack eastern and south eastern direction. Furthermore، by usage DEM with different resolutions، little difference was found in the mean concentrations predicted by the model. The result is that without implementation of AERMAP، the prediction was not sufficiently accurate. Furthermore، AERMAP could also be run with DEM 90 m and finally model could run.

Unsuitable positioning in national and regional development plans and projects in Iran results in irreversible spending of budget and time mainly. The aim of this study is to decline the costs and loss of opportunities، using a model that can effectively reduce the error of expert. This study was performed in the Ghourchay Ramian basin. Firstly، distinct scenarios and conceptual and tree model were created for biological and mechanical measures (masonry corrective dams). Then the constraints and vector maps entered into the SMCE in ILWIS®3. 7. Constraints (slope، land use، soil and streams) with Boolean method and factors (slope، height، soil، soil erosion، land use and proximity to road، village، fault، rock sources and landslide) with Fuzzy method (benefit، cost and compound methods) have been standardized. Then weighting of factors performed using the results of questionnaires and expert opinions with procedures as ranking، pairwise comparisons and direct method. Validity and reliability of the questionnaire، was controlled. Results showed that four ranking، which was specified in priority map، in biological plans، places with first priority allocated 0. 73 to 0. 97 scores and over 3 km of waterways and in dam and concrete plans، 0. 65 to 0. 86 and an area of 2470 hectares، respectively. The model type is logical and uses logical and optimization principles not experimental principles. So there was no try to test it with the previous schemes were implemented. Projects that many errors because lack of the possibility of combining several criteria and GIS advanced techniques. Finally، it was suggested that due to the high performance of this model for evaluating watershed management projects and prediction of projects for implementation، this model will be used in the same watersheds in the country.

Landslides are one of the most destructive phenomena of nature that cause damage to both property and life every year، therefore، landslide susceptibility zonation (LSZ) is necessary for planning future developmental activities. In this study، the operator of fuzzy logic in landslide hazard zonation has been used in the Chamsangar watershed. For study the stability of slopes in the Chamsang field، in first step the sliding point and subsequent distribution maps of landslide were prepared using satellite images and field excursions (recording the sliding points by GPS). The correlation level between sliding points and each effective factor in landslide occurrence including slope، aspect، landuse، elevation، lithology، rainfall، drainage and distance to road determined using frequency ratio model. The fuzzy values prepared by expert view and the membership functions appointed for all effective factors in ArcGIS®10. 1environment. The Sum of Quality (QS) index used for evaluation and deviation of operators outputs which applied in estimation of sliding risk. Results show that Gama operator 0. 9 with QS=0. 554 is the more suitable than Fuzzy Algebraic Sum with QS=0. 042 and Fuzzy Algebraic Product with QS=0. 008 for prepare the landslide risk maps in Chamsangr field. According the zoning based on the gamma operator 0. 9، the 13. 39، 47. 58، 32. 7، 5. 44، and 0. 884 percent of the area is located in very low، low، medium، high and very high risk classes، respectively.

Assessment of Watershed management practices is one of the main subjects for future planning of natural resources management and restoration projects. In terms of، there are no tools for assessment of watershed management practices in many basins of the country، and then distributed hydrological models can be used this purpose. The purpose of this study was evaluation of cover changes and it effect on runoff in Sarab Sefid basin in Borujerd county-Lorestan Province by HEC-HMS (Hydrologic Modeling System). For this purpose، based on the rainfall-runoff observed events، HEC-HMS model was optimized and calibrated. Then، to determination of rangeland condition changes، concentration time was measured after each scenario. Inputs of model were determined by SCS method and simulated runoff for available data from climatology stations. Criteria''s such as runoff pick and amount of flow determined for evaluation and measured in two situations of before and after land use. Results show that this model (HEC-HMS) is suitable for predicting and simulating of sun off in basin according to acceptable accuracy. Because of decreasing of Curve Number (CN) cause of plant cover increasing، the best scenarios to decreasing runoff are exclusion، available management of rangelands، conflagration and heavy grazing respectively. Therefore to decreasing of runoff must increase plant cover by any management tools even exclusion which it is the last way. Because of forestalling of natural hazardous and land degradation، orchards، built places beside of river and beside of Borujerd city.

nformation about the stability of the atmosphere is a very important factor in now casting and short term forecasting. Atmospheric Stability is usually estimated based on Radiosonde instability indices data. But due to a very low number of meteorological stations having Radiosonde and the cost of lunching them using satellite images could be a proper alternative. In this study، the accuracy of survey data obtained from Moderate Resolution Imaging Spectroradiometer (MODIS) atmospheric profile products in order to predict atmospheric instability versus Radiosonde observed values has been investigated. Three extracted MODIS instability indices TT، L and K are compared with Tabriz station Radiosonde data at 00 (UTC). The Tabriz weather، airport station has been selected due to its high frequency of thunderstorms (over 35 thunderstorm days per year) and the existence of an upper air station in the spring and summer of 2007as a case study. It has been observed that the TT، L and K instability indices obtained from Radiosonde and MODIS show good correlation with respectively the correlation coefficient of 0. 46، 0. 55 and 0. 60 in spring and 0. 64، 0. 65 and 0. 67 in summer، and therefore the spatial interpolation of these indices in areas where there is no Radiosonde information is possible. Also by the investigation of the average absolute error، the K and TT indices showed less error in summer than spring while the L index showed less error in spring than in the summer. It was also observed that the instability indices values obtained from MODIS were underestimated compared with Radiosonde and it''s much more significant in the spring.