چكيده لاتين
This research was conducted with the aim of revealing environmental changes in the Siah-Koh desert basin using LST data. For this purpose, MODIS sensor data of Aqua satellite with a resolution of 1 km were used for a period of 20 years (2002-2022). First, the frequency of the data was calculated and finally it was converted into a frequency percentage. Linear regression test was used to reveal the trend of process LST changes and the results were presented and interpreted in the form of a map. The appearance of the structure of the natural environment of the Siah Kouh basin is due to the establishment of two very high mountain masses (about 4000 meters): Karkas mountain in the northwest and Shirkoh mountain in the southwest, which are the source of temperature adjustment and water supply for the basin. As a result, two settlement axes were formed along the piedmont of these two mountain masses. Along the piedmont of the Karkas, the settlement axis of Badroud, Mahabad, Ardestan, Zavareh, and along the piedmont of the Shirkuh mountain, the settlement axis of Ardakan, Meibod, Ashk-e-zar, Yazd and Mehriz has been formed. These two axes have been extended in a linear fashion with a northwest-southeast trend, in line with the trend of the central mountains of Iran. It should be mentioned that in the east of the basin in the Zarin region, residential centers have been formed intentionally, whose life is not due to the presence of water and suitable soil, but due to the economic attractiveness of deposits and mining activities. Investigations showed that the decreasing trends of daytime LST are mostly observed along the residential axis of Ardakan-Mehriz, which seems to be caused by the effect of transferring Zayandehrood River water to Yazd, which has led to the expansion of vegetation around residential areas and the formation of urban cool island (UCI) on urban centers. In addition to that, the development in urban areas, tile and iron and steel industries has led to more water consumption and the production of a lot of waste water, which has led to the formation of waste water lagoons towards the east of Ashkazar. On the other hand, the mining activity in the Shahid Rezai-Nejad mining complex has also reduced the areaʹs brightness and led to a decrease in surface temperature. While the increasing trends of daytime temperature are mostly observed along the settlement axis of Badroud-Zavareh in piedmont of Karkas mountain, which is caused by the lack of water and the drying of fields and fields. The decreasing trends of LST at night are observed mostly in the south of Siah-Koh desert and southeast of Dagh-e-Sorkh, which is the reason for the loss of subcutaneous moisture in these areas. While the increasing trends of night LST are mostly in urban centers due to the formation of urban heat island (UHI). The negative trend of the scores of the fourth principal component (PC4) is mostly observed along the mountain ridge of Karkas and Shirkoh, which is caused by the decrease in the snow cover of the region. While the positive trends of the scores of the fourth component can be seen scattered in the middle and lower parts of the basin, which has several reasons, including: the expansion of the water area (wastewater pond), the development of vegetation (increase in the cultivation fields along the Ardakan-Mehriz urban axis), the formation of urban cool islands (UCI), the development of mining activities along with the increase in clarity (Shahid Rezaeinejad Mining Complex), and the accumulation of salts on the soil surface due to evaporation.
