satellite images

Urban growth pattern classification comprises three types of expansion, namely horizontal or scattered expansion, intensive growth, and smart growth. This study is a practical investigation focusing on the development and assessment of the physical transformations occurring in Yazd City. The research has utilized multi-temporal Landsat satellite images from 1996, 2016, and Ester satellite 2006. The supervised classification method with the most similarity has been employed to analyse the levels of green space, urban built space, road, and barren land and track their changes. The study revealed that the size of the city did not change between 1996 and 2016, but the population density increased. However, during the same period, there was a significant 43.6% reduction in the amount of green space. According to the graph, there has been a consistent rise in urban development from 1996 to 2016. Throughout the duration of the construction period, there has been a 1.65-fold expansion in the urban area, leading to a reduction of 32% in the barren land within Yazd city. The collective evidence of modifications in Yazd city, both in terms of physical alterations and spatial expansion, indicates that the utilization of barren land within the urban setting and the elimination of gardens and reduction in green areas have led to an increase in urban spaces by a factor of 1.65.

Knowledge of the quantitative and qualitative characteristics of changes in environmental planning, land- use planning and sustainable development is of great importance and today, the use of vegetation maps is one of the key pillars in information production for macro and micro- planning, and vegetation considered as one of the most important components of any ecosystem. Determining the percentage of vegetation in order to understand the interactions between the Earth and the atmosphere, its effect on climate, soil erosion, drought surveying, and natural resource management is essential. Since most of the methods proposed to assess drought conditions so far estimate drought indices based on stationary data at one point, researchers were looking for a way to better achieve regional estimates in order to better manage the damage caused by this gradual phenomenon. Therefore, in this research, remote sensing and Landsat 8 satellite imagery techniques and Infrared Percentage Vegetation (IPVI), Normalized Difference Vegetation Index (NDVI), Weighted Difference Vegetation Index (WDVI), Soil Adjusted Vegetation Index (SAVI), Optimized Soil Adjusted Vegetation Index (OSAVI) and Modified Soil Adjusted Index (MSAVI) were used to calculate the percentage of vegetation and the Modified Perpendicular Drought Index (MPDI) was used to estimate regional drought. After preparing the drought map, the areas which were in mild, moderate and severe drought in terms of severity, were well classified.

Nowadays, various systems and, tools have been used to study the components of the atmosphere. In atmospheric correction of satellite images, it is necessary to identify and use the specifications of the atmosphere during satellite crossing. For this purpose, in this research, designed and constructed an optimal sun-photometer system to determine the local atmospheric parameter. LabVIEW environment has been used to record Aerosol Optical Depth (AOD) data and guide motors in two axes for accurate sun tracking. In this research, by calculating the aerosols optical depth and studying its behavior on different days, two CCD (Charge-Coupled Device) and CMOS (Complementary Metal–Oxide–Semiconductor) sensors have been compared to record data. A comparison of the two sensors under the same conditions showed that the responsibility of the CCD sensor is more linear than the CMOS sensor. To evaluate the performance of the designed sun-photometer system, the MODIS sensor data of Aqua and Terra satellites were used. The results showed the high capability of the developed system in measuring AOD in comparison to MODIS AOD data. By comparing the CCD and CMOS sensor data with the Terra satellite data, 80% and 71% data matching, respectively, are observed.

Land use planning is the most important issue of sustainable urban development and a major priority in urban planning. This study was conducted with the aim of investigating the extent of physical expansion of Yazd city, identifying the land use changes to urban use and determining the city growth directions during the years 2013 to 2018, using Landsat 8 satellite imagery over a time period of 5 years for Yazd city. Using the technique of detection of changes by comparative method after classification of images, changes in green space and moor lands were identified for urban use. Then, regional statistics techniques were used to determine the extent of city expansion and the nature of changes were obtained in different geographical directions. From 2013 to 2018, based on the results, 24.73% of the moor lands and 32.22% of the green area has had urban use. The growth of the city during this period were towards the East and South directions in the central and southern sectors in the marginal sector. The greatest amounts of green space changed to urban use were in the central and peripheral sectors, and the largest conversions of the moor land to urban use were in the central eastern region and in the southern marginal sector. The results showed that inappropriate distribution of applications in some parts of the city disrupted the spatial distribution of the land use.