فصلنامه سنجش از دور و سامانه اطلاعات جغرافیایی در منابع طبیعی
سال نهم شماره 1 (بهار 1397)

Lithological studies and geological unit's mapping are generally applicable to the many fields of natural resources management. Satellite remote sensing images have been widely used for separating of geological units which can generate accurate results, as well as time and cost saving. This research aims at comparing the performance of different enhancement techniques in order to separate four geological units in the study area of Taft watershed, Yazd. In this study, Landsat 8 satellite images (OLI sensor) were used, analyzed and classified. Geological maps were also up to dated using google earth images. A comparison of the results of the satellites classified images and base geological maps, indicates the Kappa coefficient and overall accuracy of the classified supervised maps of the ration of b7/b5 have the highest values of 0.78 and 86.7%, respectively. To verify the accuracy of the comparison results, QQ plots were used to compare the percentage of areas. Comparing the percentage of areas, the oblique angle of the b7/b5 bands ratio was lower (i.e. better) than the other different ratio combinations. Finally, the values of accuracy assessment for the reflection of lithological units in the observation and estimation range of supervised classification map of the ratio bands of the b7/b5 in the geological units Ks, gd, Kt-1, and Qal were 0.993, 0.980, 0.948, and 0.985, respectively, indicates that the b7/b5 band ratio separate four different geological units of the study area more precisely, and easily than the other classification methods.

Land use and land cover (LULC) change because of its impact on natural ecosystems has become a concern for natural resources protectors and managers. The present study aimed to predict LULC changes and also to study the relation of drought with these changes in the sub-basin Parsel B2 with an area of 21100 hectares using CA-Markov model and Standard Precipitation Index (SPI). For this purpose, using the preprocessed images of the sensors TM, ETM, and OLI for the years 1986, 2001 and 2016, respectively, the LULC map was provided with supervised classification and maximum likelihood method. To validate the CA-Markov model, the LULC maps have been predicting for 2016 and they were compared to the reference land use map of 2016. After ensuring the accuracy of the predicted results for the year 2016, the related land use and land cover maps were predicted for the year 2030. The result showed a relation between LULC changes and drought condition. Based on result predicted for the year 2030, rain-fed agriculture 6.95% increase and range land 6.66% decrease in area. Thus In the event of drought and abandonment rain-fed agriculture land, soil erosion, increasing and also grazing pressure on the remaining range land causing range land degradation. Therefore, if the current land use strategy with current management remain, land degradation in the region will be inevitable.

Change detection algorithms of remote sensing image can be divided into two categories: pixel-based and object-oriented, according to the minimum processing unit. This paper deals with the comparison between application of pixel-based and object-oriented approaches in land use classification in Isfahan-Borkhar, Najafabad and Chadegan plains and evaluation of land use changes with Landsat TM (1985) and OLI (2015) data during the study period. The object-oriented approach involved the segmentation of image data into objects with multi-resolution segmentation algorithm by eCognition software. Then objects were assigned and classified with the nearest neighbour algorithm in object-oriented classification The supervised pixel-based classification involved the selection of training areas and a classification using a maximum likelihood algorithm. Accuracy assessments of both classifications were undertaken. The results show better overall accuracy (higher 90%) of the object-oriented classification over the pixel-based classification. The land use maps indicate that residential area is increased 2.09, 9.66 and 3.74% and rangeland area is decreased 7.48, 10.94 and 17.73% in Isfahan-Borkhar, Najafabad and Chadegan plains in the study period, respectively. In Chadegan plain the increase in agriculture and fallow land use has been equal to 8.31 and 5.64%, respectively.

In recent years, dust storms have been one of the most important air pollution crises in Khuzestan province. According to various studies, the countries of Iraq and Syria is reported as the main sources of dust over Khuzestan, it is necessary to monitor the spatial patterns of dust sources in the western region of Iran in different years. In this study, using Aerosol Optical Depth (AOD) from the MODIS, annual trend of dust in Khuzestan province was determined from March 2000 through the end of 2016. Three years 2005, 2009, and 2015 as representative of the main changes in the Khuzestan dust index, the spatial variation of dust in the neighbouring western region of Iran were investigated. According to the results, the dust indexes of the western region of Iran in 2005 were similar to 2015. Nevertheless, in 2015, the activities of dust source points in the eastern and northern part of Iraq (north of the Tharthar Lake) were reduced, and the activity of dust source points in the south of Kuwait and northeastern Arabia increased. The activity of dust source points in areas in the northwest of Iraq and eastern Syria in 2009 has temporarily increased significantly, which has led to an increase in dust index of Khuzestan province that year. Along with these changes, the increase of dust activity in southeast Ahwaz in 2015 compared with the years 2005 and 2009, due to the proximity to the city of Ahwaz, could play a significant role in the dust waves of the recent years.

For the sustainable management of water resources, it is necessary to determine the water balance and its components for the correct use of water. In this study, to obtain a general overview of the water balance and its components, the soil moisture balance was calculated using the Thorenthwaite Matter model in the Behesht Abad basin during 2003-2015. Distribution maps, including rainfall, temperature, actual and potential evapotranspiration, soil moisture, infiltration, surface runoff and leaf area index were prepared. The results showed that in spatial distribution, in spring and summer, the highest (8.98 mm) and the lowest runoff occurs at the altitudes and in the basin outlet, and in autumn and winter, the highest (46.72 mm) and the lowest runoff occurs at the outlet and in the altitudes, respectively. The correlation coefficient between observed and simulated surface runoff is 53%. The amount of infiltration decreases during dry months, the highest infiltration (range from 16 to 31 mm) has occurred in the range of sandy loam and clay loam textures and in agricultural areas and rangeland with good and medium coverage. In terms of spatial distribution, agriculture land and good and medium rangeland have more actual evapotranspiration, which often consistent with regions have the highest leaf area index. In general, the results of this research can be useful in identifying the soil moisture condition and various aspects of this complex system and also watershed management.

Access routes are the basic requirements to access recreational areas and tourism planning. The purpose of this study is designing and evaluating of forest road network in order to select the optimal road network for tourism development in Arasbaran protected area. For this purpose, recreational suitable areas were evaluated and identified using Makhdoum systemic methods and Multilayer perceptron (MLP) neural network. In order to prepare the road passing suitability map, effective criteria for road designing have been standardized with the fuzzy logic method and combined according to the relative importance obtained from the analytical hierarchy process. Then, the road network options were designed for access to recreational areas in the GIS environment and evaluated in terms of technical, environmental and socioeconomic. The results of the tourism suitable area assessment showed sections of the region have a capability for intensive recreation class 2 (0.17%), and extensive recreation class 2 (10.09%). According to the weighting results by criteria, slope criterion with a value 0.289 and height criterion with a value 0.033 have the highest and the lowest weight, respectively. Overall, 14 road network variants were designed and based on the final evaluation, variant 7 was selected as the optimal option with density 3.34 m/ha, accessibility (hard) 64.68% and minimum cost and environmental impacts. Therefore, taking into account the cost and environmental impacts and using GIS capabilities, it is possible principle design of the road network, and as a result the development of existing access roads in order to develop tourism in the area.

Geomorphological landscapes are the foundations of natural resources investigations of the watersheds. Because these landscapes are affected by many factors such as climate, soil, hydrology, ecology, geology and so on. In this survey, Sabzevar region with diverse geomorphological processes from mountain to play is selected in order to be identified and classified using RS and GIS. For this purpose, a combination of both overlaying and photomorphic units visual interpretation methods was used. In the overlaying method, slope, elevation and geological maps were prepared and classified. In visual interpretation, the TM 5 sensor satellite images were used. After preprocessing of images, the PCA, OIF index, FCC, HS, NDVI index techniques was used to separate photomorphic units with the aid of the Google Earth. Finally, 4 units, 10 types, and 96 facies (in 261 replications) were separated. Statistical analysis using Chi-square test showed that there was a significant difference at the 99% level among the area of desertification units, types, and facies the confirming suitable spatial separation of the area. Pediment unit (50.97%), lower pediment type (25.97%) and alluvial fan facies with tunnel erosion (375.43ha) had the highest spatial distribution in Sabzevar region. Finally, it can be concluded that the overlaying method is not suitable for deserts and using a combination of visual interpretation method can fix this defect and increase the accuracy of the output map. The mentioned map can be used for development and implementation of land capability, natural resources and combating desertification projects.

Evaluation of the ecological capability of the land is an intermediate stage of the land planning process, which the most appropriate land uses are determined for an area. So these studies which require investigation in locations from different perspectives are necessary for sustainable development. The purpose of this study was to determine the capability and suitability of lands for agricultural and rangeland uses and also to determine the area of unauthorized land uses of the Aqujan watershed of Qazvin province. The maps of the ecological resources of the watershed (including precipitation, elevation, slope, land units (soil depth and texture), vegetation, and erosion) were prepared and crossing in a GIS environment, the homogeneous environmental map units (work units’ map) were obtained. The ecological potential of watershed lands was determined by comparing the characteristics of ecological homogeneous units with the ecological model of agricultural and rangelands. Finally, the area of unauthorized land uses was determined using overlaying the current land use map and the land use map derived from ecological capability. The results showed that 3188 ha (44%) of the area is occupied by unauthorized land uses. The contributions of unauthorized livestock and range management, irrigated orchards and cultivations, and dry farming land uses were 2569 ha (34.9%), 211 ha (2.8%) and 408 ha (5.5%), respectively. The results of this study showed that there is a big difference between the proper and current land uses in the Aqujan watershed, which indicates the degree of deviation from the principles of sustainable development.