| چکیده انگلیسی مقاله |
Introduction: Land surface temperature is a parameter that affects many natural and human processes. For example, the temperature of the land surface has an effect on energy consumption in cities; Or the growth of plants is affected by the temperature of the land surface and soil. On the other hand, the physics of the land surface, land use, topography,amount and aspect of slope have a significant effect on this parameter. Therefore, the temperature of the land surface can be diverse in short distances.
The review of the conducted studies shows that the temperature of the land surface has been evaluated and investigated less in spatial scales larger than the city. Knowing the spatial and temporal distribution of the surface temperature on regional scales can be one of the bases for explaining climate variability and the relationships between environmental factors and climate on regional and smaller scales. However, especially in our country, few studies can be found that have investigated the temporal or spatial distribution of the land surface temperature on scales larger than the city.
In this study, the spatial distribution of the mean temperature of the land surface in Zanjan province in the period 2001-2023 has been investigated using MODIS products for day and night. In this regard, the mean annual temperature, its variability, the relationship of the land surface temperature with longitude, latitude, and elevation, and the spatial pattern of temperature and temperature zones in Zanjan province were investigated.
Methodology: Zanjan province is located in the northwest of Iran with an area of nearly 22164 square kilometers between the provinces of Guilan, Ardabil, Eastern Azerbaijan, Western Azerbaijan, Kurdistan, Hamadan, and Qazvin. The elevation of the province is between 264 and 3300 m, and the direction of its mountains is mostly north-west to south-east. Therefore, the slopes mostly have an eastern, northeastern, western, and southwestern aspect. The height lands of the province are separated by valleys and lower lands, and the slope is between 0° and 57°.
The land surface temperature survey in Zanjan province was performed using the MOD11A2 V6.1 MODIS product, Terra satellite. The spatial resolution of these data is 1000 m by 1000 m and is available to users in the form of 8-day means. The data were received from the Google Earth Engine website from 2001 to 2023. In addition, an SRTM digital elevation model with a spatial resolution of 90 m by 90 m was used to identify elevation features.
To analyze the surface temperature of Zanjan province, the received temperature data, which are mean of 8 days, were converted to annual mean for day and night. Then, the mean and standard deviation of the annual land surface temperature from 2001 to 2023 were calculated and displayed. Partial correlation was used to investigate the relation between latitude, longitude, elevation, and temperature. In addition, G* method was used to identify the spatial pattern of temperature distribution, and clustering analysis was used for zoning the land surface temperature.
Results and Discussion: The highest mean temperature of the land surface of the province during the days was between 26°C and 31°C, and the lowest value was between 11 Co and 16 Co. At night, the highest mean temperature was 9°C–13°C and the lowest was between 0 Co and 3 Co.
The analysis of the relationship between the temperature of the land surface with longitude, latitude, and elevation showed that the relation between the temperature of all three mentioned factors in the province is negative and significant with more than 99% confidence.
The zoning of the land surface temperature of Zanjan province using the cluster analysis method showed that Zanjan province is divided into four zones. The first group covered the largest area of the province (49.36 percent) with a mean temperature of 23.9 Co on days and 4.4 Co at night. The second temperature zone experienced a mean temperature of 27.3 Co on days and 6.9 Co at night. The third zone contains the warmest lands of the province with mean temperatures of 28.8 Co and 12.1 Co during the day and night. At the end of the fourth group, it is the coldest temperature zone of the province with a mean day temperature of 18.8 Co and 1.9 Co at night.
Conclusion: The result of this study showed that the mean temperature of the land surface was 24.6 ± 3.6 degrees at day and 5.3 ± 2.6 degrees Celsius at night. The zones with maximum and minimum temperatures are more affected by the elevation, so they coincide with the highest and lowest lands of the province. The partial correlation test also shows that the effect of elevation on the spatial distribution of land surface temperature is greater than that of latitude and longitude. Also, the maximum and minimum temperature clusters that follow the lows and highs of the land indicate the presence of significant spatial correlation in the mountains and lowlands of the province.
The clustering of land surface temperature of the province also shows that there are four distinct temperature zones in Zanjan. The spatial distribution of these four zones also follows the elevations of the earth more than anything else. Such a way that the warmest temperature zone corresponds to the Ghezel OzanValley in the northeast and the coldest temperature zone corresponds to the highest lands and mountains of the province. Therefore, among the three factors of altitude, longitude, and elevation, elevation has the most effect on the spatial distribution of land surface temperature in the area of Zanjan province.
|
| نویسندگان مقاله |
قباد رستمی زاد | Ghobad Rostamizad
Soil Conservation and Watershed Management Department, Zanjan Agricultural and Natural Resources Research Center, AREEO, Zanjan, Iran
بخش تحقیقات حفاظت خاک و آبخیزداری، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی استان زنجان، سازمان تحقیقات، آموزش و ترویج کشاورزی، زنجان، ایران
حسن شادمان | Hassan Shadman
Soil Conservation and Watershed Management Department, Zanjan Agricultural and Natural Resources Research Center, AREEO, Zanjan, Iran
بخش تحقیقات حفاظت خاک و آبخیزداری، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی استان زنجان، سازمان تحقیقات، آموزش و ترویج کشاورزی، زنجان، ایران
|