Sistan Region Of Iran Research Articles

Effect of Kharkhona on thermal comfort in the indoor space: A case study of Sistan region in Iran

Achieving thermal comfort in buildings is one of the major concerns of studies in energy in buildings. One of the ways to achieve thermal comfort is to study and optimize vernacular solutions, especially in extreme climates. The Sistan region in the east of Iran is one of the special climatic regions in the world. The present study was conducted to achieve the thermal comfort conditions quantitatively updating one of the vernacular architectural techniques of the Sistan region called Kharkhona. Accordingly, the authors performed field measurements in two rooms with and without a Kharkhona on certain days and hours in the summers of 2019, 2020, and 2021. The results revealed that, on average, the thermal comfort index of PMV was 1.39 units lower, the PET index was 7.69 °C lower, and the SET* index was 3.98 °C lower than the room without a Kharkhona and throughout the day and night in the space with a Kharkhona. Moreover, based on the semantic range of PMV, PET, and SET*, it was determined that by creating a Kharkhona, the thermal perception of the room without Kharkhona was moderated primarily from the very unfavorable status of hot and very hot to much more favorable status of warm and comfortable with a Kharkhona. This change in this status is due to the presence of the Kharkhona and its positive climatic impacts, so it could bring the extreme climatic condition of the Sistan region closer to a comfortable thermal condition in a closed space..

Developing a Bankruptcy Theory to Resolve Stakeholders’ Conflict over Optimal Water Allocation: The Case of Hirmand Catchment

The growing increase in demand for water and the lack of balance between water supply and demand have led to conflicts among the downstream stakeholders of the international Hirmand River. This river is shared between Iran and Afghanistan and is located in the southeast of Iran, in the Sistan region. The Vardkhaneh is divided into two branches, Parian and Sistan, and it is the only main source of water in the Sistan region of Iran. The inner part of Hirmand catchment is considered bankrupt concerning its water resources, so there is a need to take the current status and resulting issues into account in order to resolve conflicts. In Hirmand catchment, four different games of bankruptcy theory, namely proportional (Pr), adjusted proportional (AP), constrained equal award (CEA), and constrained equal losses (CEL), were developed as optimization models based on genetic algorithms. For this purpose, the catchment was simulated with 26 scenarios using the WEAP 2022 version software for an average time period. The results of the bankruptcy game modeling showed that water could be effectively allocated to resolve conflicts among stakeholders. It is therefore recommended to use such a model to resolve fights and optimally allocate resources, even in bankrupt catchments.

Effect of awning on thermal comfort adjustment in open urban space using PET and UTCI indexes: A case study of Sistan region in Iran

Adjustment of thermal comfort conditions in open urban spaces is now a substantial issue for using these spaces. The creation of an awning is one of the cost-effective strategies for adjusting the thermal comfort conditions of open space. This study examined the difference between thermal comfort indexes in two types of awnings made of straw with and without trees on the Campus of Zabol University located in Sistan in the east of Iran. This study has been conducted based on two widely used PET and UTCI indices of thermal comfort in open space. Therefore, the authors selected and assessed three stations; base station, straw awning without trees and straw awning with trees. The results showed that awning can averagely reduce the PET and UTCI indices up to 3.34 °C and 2.14 °C, respectively. Also, a comparison between stations located beneath the awning indicates that at 12:00 and 15:00, the station beneath the straw curtains with trees has better thermal comfort conditions equal to 1.3 °C and 1.1 °C based on the PET and UTCI indices, respectively compared to the station without trees. This improved situation is explained by the higher humidity in the station with trees, which has somewhat adjusted the thermal comfort conditions rather to the station without trees. The results of this study may be helpful for designers to take a suitable strategy for designing awnings in open urban spaces in similar climates.

Towards more efficient fish farming systems in the Sistan region of Iran: An emergy-based analysis

The environmental and economic inputs of three different fish farming methods, (semi-natural, concrete, and galvanised ponds) were investigated in a region with a hot and dry climate and a severe water shortage. The data were collected in 2020 through direct interviews with fish farmers, as well as regional weather information. The inputs and outputs of each system, both environmental and purchased, as well as the water quality parameters and fish growth rates, were also recorded. Emergy analysis was applied to assess the economic, and environmental aspects of these systems and to compare their performance and sustainability. According to the emergy efficiency indicators (Tr and SpE), concrete ponds had a higher efficiency for fish farming than the other two systems. Semi-natural fish farming was sustainable, as shown by the emergy yield ratio, which measures the system's reliance on environmental inputs. Semi-natural ponds had an economic advantage (O/I, BN, O/IEmV and BNEmV) over concrete and galvanised fish farming, because they used environmental inputs more effectively for fish rearing. Environmental efficiency can be improved by taking suitable management actions, such as increasing the size of fingerlings, while economic efficiency can be enhanced by enlarging the scale of fish farms. At the same time, using economic inputs more efficiently in concrete and galvanised ponds can boost both their sustainability and economic efficiency.

Exploring and predicting the biocapacity of various fish farming systems based on modified emergy footprint accounting in the Sistan region of Iran

Aquaculture is a form of agriculture that is practised in the Sistan region. This practice not only enhances water usage efficiency but also generates additional income for the local farmers. The extensive dependence of the aquaculture sector on energy and chemicals poses a jeopardises environmental stability and endangers the sustainability of production in the long run. The study employs emergy footprint accounting to assess the relationship between input flows and the ecological security of sustainable aquatic production in the region, across different fish farming systems, including semi-natural, concrete, and galvanised ponds. To achieve the desired outcomes, the emergy footprint accounting method requires comprehensive data on both environmental and economic inputs. The present investigation spanned four years, from 2018 to 2021. We obtained the data for this study from multiple sources, including surveys of fish farmers, expert opinions from media reports, and meteorological data obtained from weather stations located in the Sistan region. The study findings suggest that fish farming in semi-natural ponds has an ecological surplus when compared to the other two systems, owing to its higher emergy biocapacity in relation to its emergy footprint. However, it is noteworthy that semi-natural fish farming exhibited a more pronounced adverse effect on non-renewable environmental resources and resulted in the elimination of their supporting function, in comparison to the other two farming systems. This phenomenon occurred less frequently in ponds made of concrete and galvanised material. However, the ecological impact generated by these ponds surpassed their biocapacity, leading to an ecological deficit, insecurity, and exertion on the surrounding ecosystem. The findings suggest that enhancing the efficient utilisation of inputs in both concrete and galvanised ponds can lead to improved sustainability and ecological safety of their production. The adoption of strategies such as augmenting the size of juvenile fish to curtail the duration of aquaculture production in semi-natural fish farming is expected to have a limited effect on non-renewable ecological resources.

Impacts of dust storms on indoor and outdoor bioaerosol concentration in the Sistan region of Iran

Monitoring indoor and outdoor bioaerosol concentrations is essential for environmental management and evaluation of the health impact of air pollution. This study assessed indoor and outdoor microbial air quality for two cities of the Sistan region in Iran, Zabol and Zahak, in summer (July and August) and autumn (October and November) of 2022. Indoor air quality was compared between two rooms with varying conditions associated with windows (living room: windows opened to the north and to the prevailing wind; bedroom: opened to the south and opposite to the prevailing wind). Bacterial concentrations were monitored using the settle plate method inside and outside household environments at 6:30 a.m., 10:30 a.m., 4:30 p.m., 7:30 p.m., and 12:30 a.m. Zahak exhibited higher PM10 and bacterial concentrations compared to Zabol. Bacterial concentrations in the outdoor environment were significantly higher than those in indoor air and also higher in summer than autumn in both cities. There was no significant difference in indoor air samples between the two rooms (p> 0.05) in Zabol, indicating that the bacteria pollution was similar in the two rooms. Diurnal and day-to-day patterns of airborne bacteria were similar in indoor and outdoor air, consistent with PM10 variations, pointing to the association between outdoor and indoor air quality. PM10 and bacterial concentrations peaked at 10:30 a.m. and were lowest at 4:30 p.m. Results of this study have implications for other dust-prone cities of the world and offer a valuable dataset for bacterial concentrations to compare with other regions of the world.

Relationship between Indigenous Knowledge Development in Agriculture and the Sustainability of Water Resources

The relationship between agricultural knowledge and water management is very important. Indigenous knowledge in agriculture can improve the water crisis situation and alleviate water stress from dry and semi-arid areas. Therefore, the combination of these two impacts can improve the agricultural sector and reduce the effects of drought. The purpose of this study was to investigate the factors affecting indigenous knowledge and the sustainable management of water resources for optimal water use in agriculture in the Sistan region of Iran. Alongside field research and interviews with 40 indigenous experts and experts from the Jihad-e-Agriculture sector of the Sistan region, the required information was collected by means of a questionnaire. Using the fuzzy hierarchy process (FAHP), the factors affecting indigenous knowledge and the sustainable management of water resources for optimal water use in the Sistan region were ranked. The final rankings of the factors influencing indigenous knowledge for optimal agricultural use of water resources indicate that the educational-extensional factor, with a final weight of 0.37, is the first priority, while social factors, government support, economics, farmers’ knowledge, and information, with weights of 0.24, 0.21, 0.13, and 0.03, respectively, are the next priorities. It is recommended that the indigenous knowledge of local authorities be augmented, and that farmers be encouraged to use modern irrigation techniques to optimize the agricultural irrigation of water.

Emergy ecological footprint analysis of Yaghooti grape production in the Sistan region of Iran

The Yaghooti grape is the most important garden product in Sistan County, Sistan and Baluchestan Province, Iran, and plays a significant role in the region's economy and way of life. This novel study employs the emergy ecological footprint method to investigate the sustainability of the Yaghooti grape production system. Towards this end, this study employs data collected in 2019 from grape production systems in five cities located in Iran's Sistan region, including Zabol, Zahak, Hamoun, Hirmand, and Nimroz Counties. Using the emergy environmental burden index, this study attempts for the first time to quantify the nonrenewable environmental resources that are lost during the production process. Emergy carrying capacity was calculated to be 3.93E+08 Gha for all grape fields in this study. The emergy ecological footprint in this study was 1.125E+08 Gha. The grape production system in this region has an emergy ecological burden of 0.401 and an emergy ecological footprint intensity of 0.286. As a result of its prominent role in environmental protection, the production system maintains an ecological surplus, does not face significant ecological pressure, and is thus ecologically secure. Despite these positive effects of the production system, 1.35E+09 ha of fertile land is unavailable annually in the Sistan region due to grape production.

A field study of the surface disturbance effects of animals and motor vehicles on aeolian sediment emission from a silty playa surface

Dry playa surfaces can be extremely vulnerable to disturbance which breaks their surface crusts resulting in increased aeolian sand and dust emissions. Trampling by livestock and motor vehicles is an important source of this disturbance. The Hamoun Lakes in the Sistan region of Iran are a major source area of dust storms which are causing damage to infrastructure and communities. This study performed portable wind tunnel tests of controlled surface disturbance by animals (cow, sheep) and motor vehicles (automobile, motorcycle) on a silty playa surface of Hamoun Saberi lake. The aim of this study was to assess the effect of different levels of trampling and disturbed surfaces by both vehicles and livestock on dust emission at wind speeds of 6 and 12 m s−1. A significant increase of sediment emission was found with increased number of passes of vehicles and livestock and the degree of surface disturbance, more so at the high wind speed (12 m s−1). No significant differences were observed between a 10–20% disturbance level and an undisturbed surface, but statistically significant differences became apparent when disturbances reached 50–60% to 90–100% compared to undisturbed surfaces. Greater emission rates were reached by disturbances provided by automobile and cow compared to motorcycle and sheep, indicating greater trampling effects of automobile and cow likely related to greater weight and larger footprint. The automobile was the most surface-destructive of the four anthropogenic disturbances, providing emission in a lower number of passes compared to the motorcycle, cow and sheep. Better management of vehicle and livestock allocation on playas subject to disturbance, such as the Hamoun Lakes, will be a useful strategy to reduce disturbance and the frequency and intensity of dust storms.

The semi-intensive production model: A strategy based on emergy and economic analyses to realize sustainability in the ecosystem of Sistani beef cattle raising in Iran

Cattle rearing can benefit from the environmental support of native wetlands, through the establishment and proper management of units suitable for raising Sistani cattle ( Bos indicus ) around the Hamoun Wetland in the Sistan region of Iran. In this way, it is possible for cattle rearing to benefits from the environmental support of the wetland, thereby improving food security, fostering economic and social development, and contributing to the environmental protection of this sensitive region. In addition, helping to preserve the Sistani cattle breed, which is in danger of extinction, will be a significant benefit. This study was conducted from 2019 to 2020 on three different beef cattle production systems in the Sistan region. Both emergy and economic analyses were used to examine these production systems; 1) rearing the Sistani breed in an extensive production system, 2) rearing Sistani cattle in a semi-intensive production system, and 3) rearing an exotic breed within an intensive production system. In the extensive indigenous system, the amount of emergy supporting Sistani breed production was 2.30E+17 sej, which was less than the other two systems. Based on the economic output/input ratio (O/I EmV ), the yield of the Sistani breed in the semi-intensive system was 62% higher than that breed in an open system and 84% higher than exotic breeds in the intensive system. The values of the Emergy Exchange Ratio (EER), Transformity (Tr), and Specific Emergy (SpE) indices revealed that the Sistani breed outperformed the open system by 1.5 times and the exotic breed by 2 times in the intensive system. However, the sustainability of the Sistani breed raised under extensive and semi-intensive production systems is not guaranteed in the long run, given their dependence on production from the Hamoun wetland and the long-term meteorological data on declining rainfall, as well as, the decisions of Afghanistan, on the allocation of water rights to the upper watershed and to the downstream wetlands, which poses the risk of reducing the free environmental resources supplied to the Iranian wetland system. Due to these risk factors, designing the system for Sistani cattle raising as a semi-intensive production system is recommended as the way to most reliably attain the aforementioned benefits. • Emergy evaluation can be successful in selecting the right production model to improve the agroecosystems sustainability. • The structure and quantity of purchased inputs differed greatly across the systems studied. • Analyzing the economic and environmental condition of agro-ecosystems may assist evaluate their overall sustainability. • Emergy analysis is a comprehensive and explanatory method for assessing the sustainability of agro-ecosystems.

Eco-Sustainable Methods for Local Conservation of Built Heritage in Sistan’s Castles

Built heritage has an important role in the development of the global tourism industry. Therefore, appropriate conservation methods are required to support cultural identities and the tourism industry. Within the Sistan region of Iran, there are a number of built heritage assets (such as castles) that were constructed in different periods of history. Due to climatic conditions, management issues, and unemployment issues, ineffective conservation measures have been implemented for these types of built heritage assets. Therefore, special conservation methods are required to address different performance issues. This study offers practical solutions for the conservation of Sistan’s castles. An eco-sustainable model is proposed as a method to plan appropriate conservation interventions that consider economical, ecological, and labor-friendly characteristics of sustainability. We demonstrate that this approach to architectural conservation is responsive to local constraints and can be compatible with local requirements.

Evaluation of the antimicrobial activity of plant extracts on Escherichia coli and Candida albicans

This study aimed to investigate the antimicrobial activity of watermelon extracts of Teucrium polium and Citrullus colocynthis on Escherichia coli and Candida albicans isolated from women's Urinary tract infections. T. polium and C. colocynthis were collected from the Sistan region of Iran. Extraction was performed with ethyl acetate, methanol, acetone, and ethanol solvents using a rotary apparatus. E. coli strains were isolated from urinary infections. The minimum inhibitory concentration and the Minimum Bactericidal Concentration were prepared by dilution method in the well. The lowest inhibitory concentration of C. colocynthis ethyl acetate extract was equal to 3.1 ppm, in which 2 strains were inhibited. In comparison, the highest inhibitory concentration was 100 ppm, in which one strain was inhibited in this concentration. The lowest inhibitory concentration of T. polium ethyl acetate extract of E. coli was 3.1 ppm, with 2 strains inhibited. In comparison, the highest inhibitory concentration was 50 ppm, with one strain at this concentration. This study showed that the lower inhibitory concentration of C. colocynthis ethyl acetate extract against C. albicans was 25 ppm. The lowest inhibitory concentration of T.polium methanol extract against C. albicans was 12.5 ppm, which was unilaterally inhibited in this concentration. According to the obtained results and the increasing resistance of bacteria to chemical antibiotics, it is suggested that with further studies on this plant, the antibacterial compounds of this plant can be used in the treatment of bacteria.
 

Signatures of human intervention – or not? Downstream intensification of hydrological drought along a large Central Asian river: the individual roles of climate variability and land use change

Abstract. The transboundary Helmand River basin (HRB) is the main drainage system for large parts of Afghanistan and the Sistan region of Iran. Due to the reliance of this arid region on water from the Helmand River, a better understanding of hydrological-drought pattern and the underlying drivers in the region is critically required for effective management of the available water. The objective of this paper is therefore to analyze and quantify spatiotemporal pattern of drought and the underlying processes in the study region. More specifically we test for the Helmand River basin the following hypotheses for the 1970–2006 period: (1) drought characteristics, including frequency and severity, systematically changed over the study period; (2) the spatial pattern and processes of drought propagation through the Helmand River basin also changed; and (3) the relative roles of climate variability and human influence on changes in hydrological droughts can be quantified. It was found that drought characteristics varied throughout the study period but largely showed no systematic trends. The same was observed for the time series of drought indices SPI (standard precipitation index) and SPEI (standardized precipitation evapotranspiration index), which exhibited considerable spatial coherence and synchronicity throughout the basin, indicating that, overall, droughts similarly affect the entire HRB with few regional or local differences. In contrast, analysis of the SDI (streamflow drought index) exhibited significant negative trends in the lower parts of the basin, indicating an intensification of hydrological droughts. It could be shown that with a mean annual precipitation of ∼ 250 mm yr−1, streamflow deficits and thus hydrological drought throughout the HRB are largely controlled by precipitation deficits, whose annual anomalies on average account for ±50 mm yr−1, or ∼ 20 % of the water balance of the HRB, while anomalies of total evaporative fluxes on average only account for ±20 mm yr−1. Assuming no changes in the reservoir management practices over the study period, the results suggest that the two reservoirs in the HRB only played a minor role for the downstream propagation of streamflow deficits, as indicated by the mean difference between inflow and outflow during drought periods, which did not exceed ∼ 0.5 % of the water balance of the HRB. Irrigation water abstraction had a similarly limited effect on the magnitude of streamflow deficits, accounting for ∼ 10 % of the water balance of the HRB. However, the downstream parts of the HRB moderated the further propagation of streamflow deficits and associated droughts because of the minor effects of reservoir operation and very limited agricultural water in the early decades of the study period. This drought moderation function of the lower basin was gradually and systematically inverted by the end of the study period, when the lower basin eventually amplified the downstream propagation of flow deficits and droughts. Our results provide plausible evidence that this shift from drought moderation to drought amplification in the lower basin is likely a consequence of increased agricultural activity and the associated increases in irrigation water demand, from ∼ 13 mm yr−1 at the beginning of the study period to ∼ 23 mm yr−1 at the end, and thus in spite of being only a minor fraction of the water balance. Overall the results of this study illustrate that flow deficits and the associated droughts in the HRB clearly reflect the dynamic interplay between temporally varying regional differences in hydro-meteorological variables together with subtle and temporally varying effects linked to direct human intervention.

An assessment of the ability of a novel mulch to stabilise sand dunes in the Sistan region of Iran

ABSTRACT The Sistan region in south-east Iran is subject to highly active wind erosion and is considered one of the most important sources of dust in south-west Asia. This research was concerned with the assessment of the efficiency of mulches in stabilising sand dunes. The mulches are mixtures of local silty loam soil and hydrated lime in different concentrations, which were sprinkled on plots on the surface of sand dunes. The amount of wind erosion was measured at two-month intervals from January to September 2015. The results showed a significant increase in the shear strength of the substrate where the soil content of mulches had been increased. The mulch containing 15% local soil and 1% hydrated lime demonstrated the best performance against wind erosion.

Comparison of PCR and Conventional Serological Methods for Detection of Brucella spp. in Ovine and Caprine Blood Serum.

Brucellosis is an anthropozoonotic disease. Infection of livestock with Brucella is endemic in most parts of Iran. Sistan-Baluchestan is bordered on the east by the countries of Afghanistan and Pakistan. The high prevalence of brucellosis in livestock in the eastern neighboring countries results in transmission of the disease to this province. The present research aimed to determine the prevalence of brucellosis in small ruminants in the Sistan region of Iran and to compare serological and molecular tests for the detection of brucellosis. Blood samples were taken from 150 randomly selected sheep and goats, and sera were separated. All sera were analyzed by serological (Wright and 2-ME) and molecular (Polymerase Chain Reaction (PCR)) tests. Serological tests were carried out according to the instructions of the Iranian Veterinary Organization The degree of agreement between serological tests and PCR was determined by kappa value. In this study, 17 cases (11.3%) were identified as positive by the PCR method. Wright and 2-ME tests had the highest agreement with PCR in titers ≥2/80 and ≥2/40, respectively. The results of this study show that the brucellosis in sheep and goats has a greater prevalence in the Sistan region than in most other parts of Iran, and this is important in terms of public health. It is suggested that brucellosis vaccination coverage in livestock be increased in this area and that the people in Sistan region must be notified about methods for preventing brucellosis. Also, further studies to compare conventional serologic tests with the gold standard test are recommended.

An investigation into climatic and terrestrial drivers of dust storms in the Sistan region of Iran in the early twenty-first century

Dust storms cause a wide range of impacts on environment, economy and human health in the Sistan region of southeastern Iran. This paper investigates long-term variability of dust activity over 23 years (1997–2019) using the Dust Storm Index (DSI) and the frequency of dust-storm days (DSD, visibility <1000 m) and assesses the associated importance of various terrestrial and climatic drivers. A dust storm corridor was identified, based on the prevailing wind direction at Zabol, including parts of the Hamoun lakes and surrounding desert in order to study the effects of vegetation cover and lake water levels on dust activity. The results show maximum intensity of dust storms occurred at 10:30 a.m. and in the summer, consistent with the highest wind speeds – associated with the regionally important Levar wind – and highest air temperatures and lowest precipitation and relative humidity. Strong positive correlations were demonstrated between DSI and wind speed, particularly in summer. The 2000–2004 period saw severe dust-raising activity with a DSI of 530.6. Mean wind speeds were greater and precipitation, humidity, vegetation and water coverage were lower during this severe dust-activity period than in other periods. Comparing 2000–2004 with 1997–1999, DSI was five times higher and DSD eight times higher. The dust storms with the longest duration occurred in July 2001 and June 2008 (114 h and 78 h respectively). The July 2001 event, in which wind speed peaked at 25 m/s and visibility dropped to 100 m on several occasions, may be the longest continuous dust storm on record. The key role of water and vegetation cover in the Hamouns was highlighted, indicating the importance of protecting the Hamoun ecosystems and sustainably managing their water resources in efforts to mitigate dust storm hazards in the Sistan region.

The effect of kharkhona on outdoor thermal comfort in Hot and dry climate: A case study of Sistan Region in Iran

Few, if any, studies have researched the effects of vegetation, water and shading on outdoor thermal comfort in the hot and dry climate. This study identified and examined the effect of kharkhona as an architectural element of Sistan Region, which is often used in closed spaces, on outdoor thermal comfort in the hot and dry climate of Sistan during the summers of 2019 and 2020 with the aim of improving the unfavorable climatic conditions of the region via building on a technique devised by the residents of Sistan. To this end, a kharkhona was designed, built and evaluated in an open urban space. Physiological equivalent temperature index, which has been shown to be highly associated with the sensation of thermal comfort, was used as the indicator for evaluation of outdoor thermal condition. The findings showed that kharkhona can reduce the PET index by 9.34 °C in the space inside kharkhona compared to the environment outside the construct and moderate the “hot” and “very hot” heat sensation of the space outside kharkhona to “warm” and “slightly warm” in the inner space of the construct. Kharkhona can be used as a reference model for designing natural ventilation and is a viable strategy for modification of outdoor thermal comfort since it can provide better comfort conditions than vegetation.

Optimal Utilization of the Chahnimeh Water Reservoirs in Sistan Region of Iran using Goal Programming Method

Optimal Utilization of the Chahnimeh Water Reservoirs in Sistan Region of Iran using Goal Programming Method

Optimal Cropping Pattern for Water Resources Management in Sistan Region of Iran using Goal Programming Method

Optimal Cropping Pattern for Water Resources Management in Sistan Region of Iran using Goal Programming Method

Spatio-temporal variability of dust aerosols over the Sistan region in Iran based on satellite observations

Satellite remote sensing provides important observational constraints for monitoring dust life cycle and improving the understanding of its effects on local to global scales. The present work analyzes the dust aerosol patterns over the arid environment of the Sistan region in southeastern Iran, by means of multiple satellite platforms aiming to reveal the spatio-temporal distribution and trends. The dataset includes records of Aerosol Index (AI) from Total Ozone Mapping Spectrometer (TOMS) (1978–2001) and 6-year AI records from the Ozone Monitoring Instrument (OMI) aboard Aura. Moreover, the aerosol optical depth is analyzed through 11-year records from Multi-angle Imaging Spectroradiometer (MISR) aboard Terra (2000–2010) and from Moderate-resolution Imaging Spectroradiometer (MODIS) onboard Terra (2000–2007) and Aqua (2002–2011). The main focus is to determine the similarities and differences in dust variability over southwest Asia, in general, and the Sistan region, in particular. The results show a marked seasonal cycle with high aerosol loading during summer and lower in winter, while MISR, MODIS, and TOMS/OMI observations agree in both terms of monthly and seasonally mean spatial and temporal patterns. The higher aerosol concentrations during summer are interpreted as a result of the combined effect of the seasonal drying of the Hamoun lakes and the strong northerly Levar winds favoring dust erosion from the alluvial deposits in Sistan. After prolonged drought period, the dust aerosol load over the area has increased in the beginning of the 2000 s and decreased after 2004, thereby leading to an overall declining trend during the last decade. Such a trend is absent during the winter period when dust emission over the region is minimal.