فصلنامه فضای جغرافیایی
پیاپی 80 (زمستان 1401)

At the same time as entering the third millennium and with increasing population, in many countries demand for water in order to supply dem world population needs has increased considerably. But because of scarcity of water resources and water crisis in intire world the concept of water security and water poverty persresented into the economic literature of countries wich facing water crisis. Water poverty is one of the greatest challenges of this century and the multidimensional crisis of the next incoming decades in the world, especially in countries with low lelvel of water resources. This crisis can lead to many changes in the world. In this paper, unlike the usual methods op other lasr aricles to calculate water poverty, we calculate the water poverty index is on the base of Catastrophe theory multi-criteria evaluation system and mathematical fuzzy logic method. The sub-indices  wich used to calculate the water poverty are including: water resources (water deficit ratio, surface water supply ratio, the proportion of other factors in water supply), access to water (per capita water resources, price elasticity of water demand, Gini coefficient for domestic use), capacity of Underground aquifers (groundwater utilization rates, surface water utilization rates, dilution rates), using of water resources (per capita consumption of water for irrigation in the agricultural sector, per capita consumption of drinking water, per capita consumption of water in Industrial sector) and environmental integrity (surface water drying, desertification rate, create desert rate). The results of calculating the water poverty index during the period from 1989 to 2015 indicate the upward trend of this indicator and its subset components, which indicates the worsening of the state of water security in Iran in recent years and possibly the deterioration and continuation of this complicated situation for next decades. In the other hand, as the current trend continues, both in terms of resources and in terms of managing the production and consumption of the country's water resources, Iran is gradually losing its ground and becoming poorer in terms of water resources.

Late spring frosts and early autumn are a detrimental climate phenomenon that affects the economy, agriculture especially crop production and it is certain this phenomenon will change with climate change and global warming, therefore, it is important to study the timing of their occurrence and predict their future changes. The purpose of this study evaluates changes in frost start and end data using the general circulation of the atmosphere model data (HadGEM2-ES) based on the latest Climate Change Report (Fifth Report) as RCP Scenario using LARSWG model under two scenarios RCP85 and RCP45. For this purpose, 20-year daily data (1981-2010) including minimum and maximum temperature, precipitation and solarization were entered into the model and minimum daily temperature data were predicted for the next 20 years (2021-2040). First and last frost data were extracted at three slight, moderate, and severe temperature thresholds. The results showed that in all three temperature thresholds and under both scenarios the mean minimum temperature would increase in all months and the duration of the frost would decrease and the date of occurrence of the first autumn frost and the last spring frost would be earlier than the ground state.

One of the factors that sometimes leads to the complete destruction of vineyards is the danger of temperatures below zero degrees Celsius. The purpose of this study was to investigate the effect of temperature hazards on the destruction of the western and northwestern vineyards of Iran.The results show that the most frequent days with a devastating cold wave in the region's vineyards occur on average on January 14 (January 25th). The lowest critical temperature among meteorological stations is related to Saghez weather station in Kurdistan province with negative 33 ° C and afterwards, Hamadan, Bostanabad and Sarab cities with record temperatures below 30 ° C. The cities of the study area are. The results showed that 60% of the studied cities with all available Iranian and foreign cultivars could survive the cold season without the threat of severe winter cold conditions.

Vegetation plays an essential role in regional and global ecosystem stability. The change in terrestrial net carbon uptake is principally affected by varying vegetation productivity and the Earth’s climate is regulated by vegetation through evapotranspiration, surface albedo, and roughness. The purpose research is monitoring the trend of vegetation changes (NDVI) in Najaf abad County using Time Series Images and Mann-Kendall test (2003-2019). In this study, 16-day data of normalized vegetation difference index (NDVI) of MODIS Aqua in time interval 2003- 2019 temporal resolution of 500 meters have been used. Mann-Kendall test used for assessing trend of the index in Najafabad County. The results showed that in the first period (2003- 2013) the amount trend of vegetation is moderate and increasing. The peak of amount increase in vegetation 2005-2007. From 2013- 2016 year the increasing- decline trend shows itself in the same way, until from 2016- 2019 year, decline intense trend witness and once in amount of vegetation in this area, once land use changes and climate fluctuations and drought can be considered one of the main reasons the declining trend vegetation in Najafabad County. The greatest trend of declining vegetation in the southern and southeastern as occurred in urban areas, this trend can indicate high urban growth and land use change from vegetation to construction in this county. Aa well as, irrigated cultivation in the county has during the study period intense decline faced, this issue leads to change land use from irrigated cultivation to other uses in the area.

The evidence shows that Tehran as the capital and the most populous city of Iran is exposed to consequences of climate changes but proper measures are not taken to deal with such consequences. Considering the increasing threats and consequences of the climate changes, adaptation is among the most important issues in urban management. This study firstly identified the barriers to climate change adaptation in Tehran metropolis urban management and then assessed the impact of the barriers. A mixed method was applied in this study for data gathering and analysis. Focus group discussion (FGD) was used to identify the barriers. Then the identified barriers were assessed quantitatively by rapid impact assessment matrix and qualitatively by assessing the impacts of the themes to specify their impact and the way each barrier affects the climate change adaptation. The FGDs were held by participation of 59 experts and resulted in nine main themes and 31 sub-themes. The main themes were: structure and culture of research, awareness, education and knowledge, social factors, resources and its management, laws and regulations, communications and interactions, economic factors, institutional and administrative factors, and planning. The rapid impact assessment matrix showed that the impact of planning, laws and regulations, structure and culture of research barriers are bigger than other barriers. The qualitative assessment showed that the impacts of most of the barriers are regional, long-term, irreversible, permanent and certain. Among the sub-themes, the biggest impact belonged to lack of a higher institute or center for research and policy development on climate change adaptation which had the score -72. The average score of the impacts of the barriers was calculated to be -32.32. This score is placed in the -C region and means that the average impact of the barriers is negative. Findings of this study may help the decision makers and policy makers of urban management to have better understanding of the barriers to climate change adaptation, to better cope with, and to overcome them.

In recent years, dust has been Iran's most important environmental crisis. On 25 February 1396, there was heavy dust in Iran which was important for research in two aspects: spatial extent and time of occurrence (winter). The purpose of this research is to analyze the synoptic conditions and to trace the phenomenon. For this purpose, satellite and re-analyzed data were used. Modis data showed that more than 60 percent of Iran's area to this day was affected by dusty airwaves, indicating that this phenomenon is widespread. The maximum optical depth of aerospace was observed in the northeast of Yazd province with a mean of 2.03. The results of the synoptic analysis of this phenomenon showed that at sea level a low-lying core comprises northeast and central parts of Iran. At a level of 850 hPa, a low altitude north of Lake Baikal and a high altitude over southern Pakistan and their resulting cyclonic and anticyclonic movements have led to the convergence of airflow in central Iran. The thermal contrast caused by the cold air of the upper latitudes and the warm air of the lower latitudes have resulted in the formation of a core of the hornbeam at a level of 500 hPa in central Iran. Minimum moisture content in all levels as well as rising air (based on equilibrium values) have provided the conditions for the rise of sweeping dust in Iran. Analysis of air mass routing 48 hours before the dust peak in three parts of southwest, central and northeast of Iran showed that air mass transfer route was in all parts of western Iran. However, even in the center of Iran, even at a height of 500 meters, the air mass has shifted from the Arabian deserts to Iran, resulting in heavy winter dust transfer to central Iran.

Soil chemical properties variability and value of their variability have specific importance in sustainable production. Measuring methods of these which usually possible with soil testing, in a large scale are so timing and cost consuming. One of methods which use for monitoring these properties and decrease the costs of sampling in large scale is interpolation. Interpolation has many methods and each one has a different accurate in various conditions. In current research three ordinary interpolation methods were used for interpolation some chemical properties of Khuzestan’s agricultural soils. These variables in this research were Total Nitrogen (TN), Absorbable Phosphorous (P), Absorbable Potassium (AK), Calcium Carbonate percent (CaCo3%), Organic Carbon percent (OC%),  Electrical Conductivity (EC), and Soil Acidity (pH), which measured in 270 soil samples. Due to the skewness and Kurtosis of these data, it was found they have not a normal distribution. In order to normalize the data, after deleting the outdated data, logarithm and Cox-box method were used.   The interpolation methods which used were kriging (OK), Radial Basic Functions (RBF), and Inverse Distance Weighted (IDW). Mean absolute error (MAE), mean bias error (MBE), and root mean square error (RMSE) were used for detecting the optimum method. Examination of variographic results showed that the spatial structure (correlation ratio) of absorbable phosphorus (0.243) and absorbable potassium (0.159), strong, total nitrogen weak (measurement error 0.816) and the other parameters had a moderate spatial structure. Based on the results of this table, the ordinary kriging method with exponential model can be considered as the best and most accurate method (MAE = 0.01515, RMSE = 0.0890, MBE = 0.0006 and R2 = 0.912) for interpolation the total nitrogen.However, the best method for interpolation of organic carbon, absorbable phosphorus, absorbable potassium, calcium carbonate, acidity and electrical conductivity of soil are RBF, ordinary kriging (spherical model), ordinary kriging (spherical model), RBF, ordinary kriging (with exponential model) and RBF respectively.The results showed that the IDW method was not a suitable method for interpolating any of the parameters. From the prepared maps, it can be clearly seen the non-uniformity of fertilization, amount of absorbable phosphorus in the southern parts of the study area is higher but amount of absorbable potassium in the northern and central parts of the study area has been more.While in the eastern and western part of the study area and in places where the pH is above 7.7, the amount of calcium carbonate in soils is at its highest level of 46 to 49 percent. Preparing maps with appropriate accuracy by geostatistical methods for parameters that have good spatial dependence is a suitable method for monitoring and land management at the macro level.

Wind chill is the feeling of a colder temperature due to the loss of heat through the wind. This phenomenon has important effects on human life, especially in the cold period of the year, and is highly dependent on atmospheric pressure patterns that cause changes in air temperature and wind speed. The present study investigates wind chill and the effect of Siberian high pressure on it in the neighboring provinces of Alborz mountain range. For this purpose, first daily temperature and wind data of 13 synoptic stations adjacent to Alborz mountain range in a period of 31 years (1986-2016) were obtained from the Iranian Meteorological Organization. Then the Wind Chill Index (WCI) in the stations was calculated daily. To investigate the effect of Siberian high pressure on wind chill, 30 sample events were selected and analyzed. For this purpose, NCEP/NCAR data including sea level pressure, geopotential heights of 500, 700, 925 hPa, vector wind of 700 hPa and temperature of 700 hPa were used and the relevant maps were prepared using GrADS software. The results showed that in the southern stations of Alborz mountain range, wind chill occurs with more frequency and intensity. Qazvin and Abali stations in the south with the annual average of 16 and 15 days, respectively, have the highest and Babolsar and Anzali stations in the north with the annual average of 0.58 and 1.1 days, respectively, have the lowest frequency of wind chills. The highest number of days with more severe wind chills (WCI less than -10) also occurred in Abali and Qazvin stations (5.39 and 3.65 days per year, respectively), while the northern stations have basically not experienced more severe wind chills. On a monthly basis, the highest frequency of occurrence of the phenomenon is related to January and February. Combining station data with pressure data showed that out of the 30 selected events, Siberian high pressure was the cause of wind chill occurrence in only 4 events. In the rest of the studied events, factors such as trough formation, high pressure penetration from the Mediterranean and Black Seas, or a combination of factors (Siberian high pressure, trough formation and migratory high pressure) caused wind chills. But the role of trough has been more important.

The prosperity of tourism in any geographical place, along with the positive and negative economic and social consequences, has environmental effects that, if the negative effects of tourism continue, can cause irreparable damage. The present study aims to assess the environmental effects of tourism on the sustainable development of rural areas of Namin city. The research method in this study is applied in terms of purpose and based on the descriptive-analytical nature, the data of which have been collected based on field studies. The statistical population of the study consists of 11 tourist villages of Namin city with a population of 5471 people. The sample size was estimated based on Cochran's formula of 98 people, which was distributed according to the number of heads of households in each village. In order to study the environmental effects of tourism in the studied villages, 10 indicators and 33 indicators based on the studies of other researchers were used. The face validity of the questionnaire was examined by experts and its total reliability was estimated 0.88 based on Cronbach's alpha. The general results of the study showed that in terms of sustainability, the studied villages are in a moderate stability situation with 0.44 points. Also, among the studied villages, none of the villages are in a stable condition. It is relatively unstable and Khankandi village is in an unstable situation.