The torrential rains that occurred in April 2017 in Lorestan Province exemplified severe precipitation that inflicted substantial damage on agricultural, urban, transportation, and communication infrastructures. This study aims to investigate and elucidate the relationship between the physical structure of clouds responsible for two waves of heavy rainfall in April 2017 within the Doroud catchment area of Boroujerd. In this context, the statistical characteristics of two precipitation events on March 25 and April 1, 2019, were analyzed. The microphysical properties of the clouds generating these two heavy rainfall events were examined utilizing the Madis superconductor product and MOD06. Four microphysical factors contributing to the formation of clouds during these two rainfall waves in the Doroud-Borujerd basin—including cloud top temperature (CTT), cloud top pressure (CTP), optical cloud thickness (OCT), and cloud cover ratio (CFR)—were analyzed. Statistical assessments indicated that the first wave of heavy rainfall, occurring on March 25, 2019 (5 April 1398), accounted for 15% of the total annual rainfall, while the second wave on April 1, 2019 (12 April 1398) contributed 20% of the region's average annual rainfall within these two days. The findings from the analysis of the microphysical structure of the clouds producing these two precipitation waves, based on data from the MODIS cloud sensor product, revealed a significant spatial correlation between the four microphysical factors and the recorded precipitation values of these two heavy rainfall events. Specifically, the cloud top temperature and pressure, indicative of vertical cloud expansion in the area, exhibited a significant inverse relationship with the precipitation amounts in the basin. Conversely, the cloud cover ratio and optical thickness demonstrated a direct and significant spatial correlation with the recorded rainfall values. The results of this study thus establish a significant and robust relationship between the microphysical structure of clouds and the precipitation amounts recorded in the region during these two heavy rainfall events. 

Considering that urban land-use change in metropolises such as Tehran has been increasing in recent decades; Therefore, the formation of the thermal island phenomenon in the city can be studied as one of the environmental problems. Increasing construction, density, and building heights will change the complexes' geometry and shape, followed by changes in climatic conditions and micro-urban climates. Therefore, in this study, we tried to investigate urban geometry's effect on forming a thermal island in Tehran. The study region in this research includes regions one, two, and three of Tehran.
The methods used in this research included (1) Oak's numerical equation and algorithm design to simulate the intensity of the heat island. In the first stage, digital GIS data including building blocks (parcels) in polygon format and street widths, which were prepared and prepared by Tehran Municipality based on the 2016 detailed audit plan, were used. (2) Modeling was performed in Envi-met software to study the effect of city geometry on wind. The results of the studies showed that the two factors of building height and street width (ratio (H/W)) play an important role as two key factors in studying urban geometry; therefore, in studying the intensity of the heat island, the factor of building height and high-rise construction can play an important role in the formation of the heat island. However, the higher the height of the building compared to the width of the streets, the more it acts as a barrier against the heat island. The intensity of the heat island adjusted with the Oak equation showed that the factor of building roughness coefficient can be an important factor in adjusting the intensity of the heat island. Spatial analysis of images and outputs of the Envi.met model showed that the two main factors of construction density And the height of the building has a greater impact on wind speed transmission than the slope and topography of the area. Therefore, in the study of urban design for future studies, appropriate planning and proper management of resources are needed for the climatic comfort of residents, which can be designed to be beautiful and safe cities by considering the principles of architectural safety.

Climate change and global warming are very important issues of the present century. Climate change process, especially temperature and precipitation changes, the most important issue is environmental science. Climate change means a change in the long-term average. Iran is located in the subtropical high pressure zone in arid and semi-arid regions and the Hyrcanian forest is a green area between the Caspian Sea and the Alborz mountain range. At the 43rd UNESCO Summit, the Hyrcanian forests were registered as the second natural heritage of Iran. Beech is one of the most important tree species and the most industrial species of Hyrcanian forests It accounts for about 18 percent of the northern forest volume (from Astara to Gorgan with a life span of about 250 years). The study area is located in the Shanderman basin in western Guilan province. In this research using tree dendroclimatology, Use of vegetative width of beech tree rings, Weather station statistics located in the study area, And Mann-Kendall nonparametric statistical method, To Investigate Climate Change Trend on Growth Time Series and Pearson Statistical Method, in order to evaluate the correlation of diameter growth of beech tree rings with climate variables in the region, an attempt was made. Results of time series of beech tree growth rings over 202 years. Using the nonparametric method Mann- Kendall showed, Changes in growth rings of beech trees have a downward and negative trend, at level 5 %, it was significant. Temperature Minimum, Average, Maximum, and Evaporation during the growing season, there was an upward trend and Annual precipitation there was a downward trend. Using the Pearson method Fit correlation of growth ring diameter with temperature, For the average monthly in February and the average minimum temperature in July, August and September and Negative correlation, for average maximum temperature in February, July, August and September at 95% level, it was significant and precipitation in June, the correlation was 95% positive and significant.

for the spatial analysis of precipitation in the Middle East, have been used gridded precipitation data from the World Precipitation Climatology Center (GPCC) with a monthly temporal resolution and a spatial resolution of 0.5×0.5 arc degrees. Therefore, a matrix of 80 x 160 dimensions was obtained for the Middle East region (160 longitudinal cells and 80 transverse cells). The reason for choosing network data is their proper spatial and temporal separation and their up-to-date compared to station data. The period under investigation is from 1970 to 2020 AD. Finally, the long-term maps of the Middle East precipitation were drawn on an annual and monthly basis. The results indicate that precipitation in the Middle East tends to concentrate and cluster in the spatial and temporal dimension. In other words, due to the special geographical location of the Middle East region, such as uneven topography, distance and proximity to moisture-feeding sources (Caspian Sea, Black Sea, Mediterranean Sea, Atlantic Ocean, and Indian Ocean) and the direction of unevenness, Precipitation in high altitude areas, It is concentrated in the neighborhood of seas and oceans and also in the windy slopes of the mountain range of the region. The uneven distribution of geographical conditions has caused uneven distribution of Precipitation in the Middle East. So that; The center and gravity of the Middle Eastern Precipitation is concentrated in the eastern end of the Black Sea, southern Turkey in the neighborhood of Syria and Iraq, the Ararat-Zagors belt in the west of Iran, the southern shore of the Caspian Sea, the Pamir highlands and the Bay of Bengal in India, and the Hindu Kush highlands in Pakistan. Is. However, the many parts of the Middle East, due to their proximity to large deserts (African Sahara, Lut Desert, Dasht-Kavir, Arabia's Rab-al-Khali and Afghan deserts), have less than 100 mm of Precipitation. The results showed that the maximum Precipitation of this region has been transferred to the winter season, and the summer season is still the driest period in the Middle East, and only the coasts of the Indian Ocean and the Bay of Bengal have monsoon rains

This study investigates the impact of natural and anthropogenic factors on the physicochemical composition of groundwater in the Qazvin aquifer. Based on the optimized Gibbs diagram, the concentration of samples at the end of the freshwater interaction path with silicate units results from geochemical evolution due to the dissolution of these geological units and an increase in the Na/(Na+Ca) ratio. The ion exchange mechanism was assessed using bivariate diagrams of Ca+Mg vs. SO4+HCO3 and Schoeller's chloro-alkaline indices CAI-1 and CAI-2. The results indicate that in 68% of the samples, direct ion exchange, and in 32%, reverse ion exchange control the groundwater chemistry. The changes in Ca vs. SO4 indicate that gypsum dissolution alone is not the source of these ions. These changes could be due to ion mobility and transport during pedogenic processes (sulfur biogeochemical cycle) and anthropogenic factors. The study also examined the role of factors such as agricultural input, atmospheric input, soil nitrogen, sewage input, manure input, chemical fertilizers, and the denitrification process in groundwater pollution using NO3/Na vs. Cl/Na and the NO3/Cl vs. Cl diagrams. The results reveal that agricultural and sewage inputs significantly impact the NO3 and Cl content. Furthermore, in some locations, especially in the southeast of the aquifer, the denitrification process causes a decrease in NO3 concentration. These findings can contribute to effective water resource management in this strategic aquifer by understanding the controlling mechanisms of physicochemical composition and identifying potential groundwater pollution sources.