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The indirect rainfall estimates by satellites and numerical models are the alternative options for the regions lacking enough and accurate ground observations. However, these indirect estimates often lack homogeneity and need to be evaluated before application. This study used gauge observations to test the accuracy of recently produced high-resolution satellite-based and numerical model output rainfall products over Ethiopia. Tropical Applications of Meteorology Using Satellite data and Ground-Based Observations (TAMSAT v3.1), Climate Hazard group Infrared Precipitation with Stations (CHIRPS v2.0), and the ERA5 reanalysis products were evaluated at monthly, seasonal, and annual temporal scales for the years 1992–2009. The satellite products showed nearly similar characteristics with much better accuracy than the model reanalysis output, which underestimated the rainfall amounts. Both satellite and reanalysis products captured the shapes of the rainfall at a monthly scale but less accurately at a seasonal scale. In general, the satellite-based products outperformed the reanalysis data set with a high correlation coefficient and index of agreement values, as well as low Root Mean Square Error and BIAS values. On the other hand, the reanalysis (ERA5) product showed a considerable underestimation in all sites. Therefore, satellite-based products are more reliable for researches in the region. However, the algorithms in both satellites need further calibration for a better estimation of seasonal rainfall amounts.

최근에는 항측기에 GPS/INS 장비를 탑재하여 사진의 활영과 동시에 외부표정요소를 직접 결정할 수 있는 Direct Georeferencing기술의 개발로 인하여 지상기준점을 최소로 측량하거나 생략이 가능하게 되었다. Direct Georeferencing 기법을 이용하게 되면 외부표정요소를 구하기 위한 전처리 과정을 생략할 수 있다. 따라서 지상기준점을 이용한 사진기준점측량(AT)을 수행하지 않더라도 수치표고모델만 미리 확보되어 있으면 촬영과 동시에 수치정사사진을 생성할 수 있다. 본 연구에서는 촬영과 동시에 GPS/INS에 의해 획득한 외부표정요소와 항공사진을 이용하여 영상매칭에 의하여 수치표고모델(DEM)을 자동 생성하고, 이 결과를 바탕으로 정사사진을 제작하였다. 실제 도화데이터와 Direct Georeferencing 정사영상과의 오차를 평가한 결과, 표준편차가 X는 약 62㎝, Y는 약 76㎝ 정도가 발생하였다. 이 결과는 축적 1:5,000 수치지도의 정확도 요구를 충분히 만족시킬 수 있는 양호한 결과임을 알 수 있다. Direct Georeferencing에 의한 정사영상의 제작방법은 큰 크기의 과대오차가 발생하는 부분을 수작업 또는 반자동으로 해결할 수 있으면 효율적으로 수치지도를 수정/갱신 할 수 있을 것으로 판단된다.

Flooding is one of the most problematic natural events affecting urban areas. In this regard, developing flooding models plays a crucial role in reducing flood-induced losses and assists city managers to determine flooding-prone areas (FPAs). The aim of this study is to investigate on the prediction capability of fuzzy analytical hierarchy process (FAHP) and Mamdani fuzzy inference system (MFIS) methods as two completely and semi-knowledge-based models to identify FPAs in Tehran, Iran. Six flooding conditioning factors including density of channel, distance from channel, land use, elevation, slope, and water discharge were extracted from various geo-spatial datasets. A total of 62 flooding locations were identified in the study area based on the existing reports and field surveys. Of these, 44 (70%) floods were randomly selected as training data and the remaining 18 (30%) cases were used for the validation purposes. After the data preparation step, data were processed by means of two statistical (FAHP) and soft computing (MFIS) methods. Unlike most statistical and soft computing approaches which use flooding inventory data for both training and evaluation of models, only conditioning factor was involved in data processing and inventory data were used in the current study to assess models prediction accuracy. Also, the efficiency of two approaches was evaluated by pixel matching (PM) and area under curve to validate the prediction capability of models. The prediction rate for MFIS and FAHP was 89% and 84%, respectively. Moreover, according to the results obtained from PM, it was found out that about 90% of known flooding locations fell in high-risk areas, whereas it was 83% for FAHP, indicating that flooding susceptibility map of MFIS has higher performance.

Iran is one of the countries with the highest number of the cases of capital relocation throughout its history. During the past four centuries, at least, six different cities have played the role of the capital for the country. This paper examines the most recent push for the capital relocation in Iran. By examining the public debate over the topic in the major periodicals of the country, the paper analyzes the underlying discourse that gives political impetus for the capital relocation. It shows that while the majority of the academics opposes such a move, politicians eagerly pursue such a massive project. More importantly the analysis suggests that in the twenty-first century, an old-established discourse on the role of the capital still plays a significant role in forming the public debate and political decisions on the capital relocation in Iran. Based on this discourse, the political system observes the capital relocation as a vital way for encouraging decentralization and decreasing the population of Tehran. The paper suggests that the underlying discourse for the capital relocation in Iran is in bold contrast to the common themes of capital relocation in other countries, particularly newly formed nations.

We investigated the simultaneous and sympatric movements of a coalition of two Asiatic Cheetahs (Acinonyx jubatus venaticus) and a Persian Leopard (Panthera pardus saxicolor), two rare and highly m...

Water is a valuable resource for which demand often exceeds supply in dry climates. Managing limited water resources becomes increasingly difficult in circumstances of recurring drought, rising populations, rapid urbanisation, industrial development, and financial constraints, such as occur in Iran. Newspapers both report on and influence people’s understanding of water-related issues. An analysis was undertaken of two major Iranian daily newspapers over a 7-year period. Structure Query Language (SQL) was employed to identify relationships among a total of 1275 records/fields which were extracted from 84 water-related news items. They were analysed for message, contributor, spatiality and allocated space. Of the water-related items, wetlands comprised 33% (class), public awareness 54% (message), local level 56% (spatiality), and authorities 53% (contributor). Space allocation on each page was mostly &lt, 40% (94% of items). Four examples were highlighted of ambitious engineering projects adopted in response to water distribution issues. It is concluded that the general lack of educating messages about water use efficiency in rural areas and water consumption in cities does not assist in developing positive water-saving local behaviours. Newspapers could be a useful tool in a broader strategy for addressing and managing the demand side of the water crisis in Iran.

A major challenge for any dryland country affected by climate change, like Iran, is exploring the ways to cope with low and scattered precipitation while conserving fragile ecosystems. Extensive extraction of underground water and frequent severe droughts have compounded water scarcity both temporally and spatially. Therefore, the relevant important questions remain at the national level: what sort of strategies would be effective to tackle land degradation and water shortage simultaneously; to what extent, the implemented approaches have been efficient to address the concerns; and how new national policies reduce the pressure on water and soil resources. This article will portray the real contemporary situation of water resources in Iran and answer these pivotal questions and concerns. The methodology will be based on a thorough literature review while employing reliable data and statistics to fortify the discussions.

International audience; Climate change adaptation, mitigation and food security may be addressed at the same time by enhancing soil organic carbon (SOC) sequestration through environmentally sound land management practices. This is promoted by the “4 per 1000” Initiative, a multi-stakeholder platform aiming at increasing SOC storage through sustainable practices. The scientific and technical committee of the Initiative is working to identify indicators, research priorities and region-specific practices needed for their implementation. The Initiative received its name due to the global importance of soils for climate change, which can be illustrated by a thought experiment showing that an annual growth rate of only 0.4% of the standing global SOC stocks would have the potential to counterbalance the current increase in atmospheric CO2. However, there are numerous barriers to the rise in SOC stocks and while SOC sequestration can contribute to partly offsetting greenhouse gas emissions, its main benefits are related to increased soil quality and climate change adaptation. The Initiative provides a collaborative platform for policy makers, practitioners, scientists and stakeholders to engage in finding solutions. Criticism of the Initiative has been related to the poor definition of its numerical target, which was not understood as an aspirational goal. The objective of this paper is to present the aims of the initiative, to discuss critical issues and to present challenges for its implementation. We identify barriers, risks and trade-offs and advocate for collaboration between multiple parties in order to stimulate innovation and to initiate the transition of agricultural systems toward sustainability.

Response to “The “4p1000” initiative: A new name should be adopted” by Baveye and White (2019)

We analyzed the movement behavior of a male Asiatic cheetah (Acinonyx jubatus venaticus), a critically endangered species, to understand its habitat preferences and relationship to its ambient environment. Using a hidden Markov chain approach, we identified distinct behavioral phases within the cheetah's movement track. We explored the conditions under which the cheetah switched between these behavioral phases. We computed summary statistics of the displacement and duration for the portion of time that the animal had constant behavior and found a linear pattern between its displacement and duration per behavioral phases. We then employed resource-selection and step-selection approaches to understand the cheetah's habitat preferences in general. The cheetah preferred intermediate elevations, low to intermediate slopes, intermediate distances from villages and shorter distances to the water resources. The cheetah moved over a range of 1137 km2, mainly staying in the more montane northern part of the range. With further validation, the environmental variables and their relationship with the cheetah's behavior could be employed to aid in the conservation of this rare cat.

International audience; The objective of this study was to exploit the synergy between SMOS and SMAP based on vegetation optical depth (VOD) to improve brightness temperature (TB) simulations and land surface soil moisture (SM) retrievals in arid regions of the world. In the current operational algorithm of SMAP (level 2), vegetation water content (VWC) is considered as a proxy to compute VOD which is calculated by an empirical conversion function of NDVI. Avoiding the empirical estimation of VOD, the SMOS algorithm is used to retrieve simultaneously SM and VOD from TB observations. The present study attempted to improve SMAP TB simulations and SM retrievals by benefiting from the advantages of the SMOS (L-MEB) algorithm. This was achieved by using a synergy method based on replacing the default value of SMAP VOD with the retrieved value of VOD from the SMOS multi angular and bi-polarization observations of TB. The insitu SM measurements, used as reference SM in this study, were obtained from the International Soil Moisture Network (ISMN) over 180 stations located in arid regions of the world. Furthermore, four stations were randomly selected to analyze the temporal variations in VOD and SM. Results of the synergy method showed that the accuracy of the TB simulations and SM retrievals was respectively improved at 144 and 124 stations (out of a total of 180 stations) in terms of coefficient of determination (R2) and unbiased root mean squared error (UbRMSE). Analyzing the temporal variations in VOD showed that the SMOS VOD, conversely to the SMAP VOD, can better illustrate the presence of herbaceous plants and may be a better indicator of the seasonal changes in the vegetation density and biomass over the year.

Take these eight steps to make soils more resilient to drought, produce more food and store emissions, urge Cornelia Rumpel and colleagues. Take these eight steps to make soils more resilient to drought, produce more food and store emissions, urge Cornelia Rumpel and colleagues.

Based on remotely sensed imagery and socioeconomic data, this research analyzes the reasons why farmers choose one crop over another in the Bekaa Valley in Lebanon. This study mapped the area of the cultivated crop in 2017 with Sentinel-2 images. An accurate and new method was developed to extract the field boundaries from the evolution of the normalized difference vegetation index (NDVI) profile throughout the season. We collected 386 GPS locations for fields that are used for crop cultivation, from which the NDVI profile was extracted. The 386 reference fields were separated into two groups: reference locations and test locations. The Euclidean distance (ED) was calculated between these two groups, and the classification was strongly correlated to the known crop type in the field (overall accuracy: 90%). Our study area cultivated wheat (32%), spring potatoes (25%), spring vegetables (27%), orchards (11%), vineyards (7%), and alfalfa (&lt, 1%). Socioeconomic surveys showed that farmers favored these crops over others on account of their profitability. Nonetheless, the surveys highlighted a paradox: despite the lack of a political frame for agriculture in Lebanon, farmers&rsquo, crop choices strongly depend on a few existing policies.

This paper is a first attempt to compute the total water needs of an agricultural plain with remote sensing and ground data in Iran. The cropping areas were mapped with Sentinels-2 images, based on NDVI profiles classification. This model was validated and 85% of the areas were correctly classified. Second, the crop water needs were computed using PYSEBAL and Landsat-8 images. Crop evapotranspiration (ETseason) and Irrigation Requirements (IRseason) were calculated for each crop and then validated by comparing IR collected in the field from farmers with computed IRPYSEBAL on 5 plots. IRPYSEBAL underestimated the reality with an average of 10% while the overestimation average was 17%. The second validation was the comparison of Daily ET from FAO-56 method and Daily ET PYSEBAL showed a RMSE of 0.67 mm/day and MAE of 0.52 mm/day, which assesses the accuracy of PYSEBAL. ETseason varies according to weather parameters in the plain and IRseason, according to different irrigation practices. The most water demanding crops were identified: rice (IR: 1427 mm) and corn (669). The total water balance of Marvdasht was negative in 2018 with 0.2859 km3 of extracted groundwater for irrigation for only 0.098 km3 of available water for aquifers recharge.

The United Nations Convention to Combat Desertification (UNCCD) has lacked an efficient mechanism to access scientific knowledge since entering into force in 1996. In 2011 it decided to convene an Ad Hoc Working Group on Scientific Advice (AGSA) and gave it a unique challenge: to design a new mechanism for science-policy communication based on the best available scientific evidence. This paper outlines the innovative ‘modular mechanism’ which the AGSA proposed to the UNCCD in September 2013, and how it was designed. Framed by the boundary organization model, and an understanding of the emergence of a new multi-scalar and polycentric style of governing, the modular mechanism consists of three modules: a Science-Policy Interface (SPI); an international self-governing and self-organizing Independent Non-Governmental Group of Scientists; and Regional Science and Technology Hubs in each UNCCD region. Now that the UNCCD has established the SPI, it is up to the worldwide scientific community to take the lead in establishing the other two modules. Science-policy communication in other UN environmental conventions could benefit from three generic principles corresponding to the innovations in the three modules—joint management of science-policy interfaces by policy makers and scientists; the production of synthetic assessments of scientific knowledge by autonomous and accountable groups of scientists; and multi-scalar and multi-directional synthesis and reporting of knowledge.

Aquifer storage and recovery (ASR) with treated wastewater, is considered as an effective solution for a critical aquifer decline due to groundwater overexploitation. In ASR operational step and after the aquifer storage phase, the problem is the new groundwater right for stakeholders and specifically farmers. In a 2-year study, the potential of a participatory approach for solving this problem was investigated and applied in Fashafoeyeh aquifer in southern Tehran Province. This aquifer faces a critical situation of groundwater from point of view of quantitative and qualitative aspects. Firstly, five indicators were considered including agricultural efficiency, water resource efficiency, water governance, local participation, and economic factors. Then 23 farmers and agricultural landowners were selected based on age, education, and gender. A questionnaire was designed, surveyed, and filled out after interviewing them in several field trips to the site. The results of data analysis showed that 96% of farmers and landowners were highly motivated in the implementation of the participatory approach in ASR management. Moreover, 91% showed a high desire to decrease the groundwater withdrawal from wells. A high percentage of stakeholders had a tendency to participate in some aspects of ASR system. In the meantime, many farmers had a negative viewpoint about government supports. The results illustrate a correlation between agriculture efficiency with participation in the government's projects and implementation. Moreover, a correlation exists between water management in the field and participation in government's projects as well as local participatory. This research emphasises on proper planning through face-to-face dialogue with farmers and landowners. In this regard, they collaborate in a participatory approach, as well as a technical and social team to implement the aquifer storage and recovery management.

As the first-ever report in Iran, this paper explores the styles, tones, subjects, and patterns of the coverage of environmental news published in two Iranian newspapers. Involving certain initiati...

International audience; The "4‰" Initiative was launched at the COP21 as part of the Lima-Paris Action Agenda. It aims to improve the organic matter content of soils and promote soil organic carbon (SOC) sequestration to increase soil fertility and thereby contribute to food security, to foster adaptation to climate change and contribute to mitigating climate change. The initiative focuses primarily on agricultural soils, because of their frequent poor soil organic carbon content and degradation and of their crucial role in food provision but also considers forest soils and the preservation of existing SOC stocks. The objectives of the initiative are: (i) to promote research on the knowledge needed for the initiative (mechanisms and potential of organic C sequestration in soils; SOC sequestering management agricultural and forestry practices; adoption and transition to these practices; monitoring SOC stocks) and to (ii) to foster initiatives, by a variety of actors, to better manage SOC in the field via agricultural practices. The gouvernance of the "4‰" Initiative is organised in to three bodies, which will interact closely with each other: the consortium of all members, who elect the president and vice president of the initiative, the forum of partners and the scientific and technical committee (STC). The work of all these bodies is facilitated by the executive secretary. The STC has the mission to support SOC sequestration programs initiated by a wide variety of actors by setting reference criteria for the evaluation of SOC management projects and actions. The committee will give advice on these actions and formulate proposals for the orientations of international scientific research and cooperation programs. The advice given by the STC is founded on the principles and goals of the Initiative and coherent with the Sustainable Development Goals. This presentation will present the on-going work of the STC on the sustainable SOC sequestration indicators. The challenge is to identify easily utilizable indicators relative to SOC storage itself, but also to mitigation of GHG emissions, improved productivity and food security, better adaptation to climate change, but also relative to other impacts of SOC sequestration strategies (on water quality or land tenure for example).

The "4‰" Initiative was launched at the COP21 as part of the Lima-Paris Action Agenda. It aims to improve the organic matter content of soils and promote soil organic carbon (SOC) sequestration to increase soil fertility and thereby contribute to food security, to foster adaptation to climate change and contribute to mitigating climate change. The initiative focuses primarily on agricultural soils, because of their frequent poor soil organic carbon content and degradation and of their crucial role in food provision but also considers forest soils and the preservation of existing SOC stocks. The objectives of the initiative are: (i) to promote research on the knowledge needed for the initiative (mechanisms and potential of organic C sequestration in soils; SOC sequestering management agricultural and forestry practices; adoption and transition to these practices; monitoring SOC stocks) and to (ii) to foster initiatives, by a variety of actors, to better manage SOC in the field via agricultural practices. The gouvernance of the "4‰" Initiative is organised in to three bodies, which will interact closely with each other: the consortium of all members, who elect the president and vice president of the initiative, the forum of partners and the scientific and technical committee (STC). The work of all these bodies is facilitated by the executive secretary. The STC has the mission to support SOC sequestration programs initiated by a wide variety of actors by setting reference criteria for the evaluation of SOC management projects and actions. The committee will give advice on these actions and formulate proposals for the orientations of international scientific research and cooperation programs. The advice given by the STC is founded on the principles and goals of the Initiative and coherent with the Sustainable Development Goals. This presentation will present the on-going work of the STC on the sustainable SOC sequestration indicators. The challenge is to identify easily utilizable indicators relative to SOC storage itself, but also to mitigation of GHG emissions, improved productivity and food security, better adaptation to climate change, but also relative to other impacts of SOC sequestration strategies (on water quality or land tenure for example).

The Pars Special Economic Energy Zone (PSEEZ) is the largest global special economic zone in the field of oil, gas, and petrochemical industry. The Nayband national marine park is located in the PSEEZ and mangrove forests are spread throughout the estuaries (Bidkhun or Asaloyeh, Basatin and Haleh) of the park. Despite important goods and ecosystem services of mangroves and their high economic value, mangroves within the PSEEZ are threatened by activities of the oil industry. Thus, it is necessary to monitor and assess the mangroves and their ecosystem services. In this context, remote sensing technologies provide effective tools for spatio-temporal analysis of mangrove distribution. In this study, Landsat-5, 7, 8 images were used from 1986 to 2018. Support Vector Machine (SVM) and Sen's slope was employed for monitoring mangrove cover changes and estimating Normalized Difference Vegetation Index (NDVI) trends. In assessing the economic value of the ecosystem services of the Mangrove forests, the mangrove distribution changes and global values of mangrove ecosystem services were integrated. The results revealed that the coverage of mangroves had increased to about nearly 204.93 ha in area from 1986 to 2003, followed by a drop to 169.29 ha in 2018. The economic value of mangrove forests of the PSEEZ in 1986, 1998, 2003, 2015 and 2018 was estimated to be about 3.3, 3.8, 6.7, 6.5 and 5.5 million US dollars per year, respectively. Based on Sen's slope, the NDVI trend in Basatin estuary decreased at a rate of −0.001, but showed significant increases of about 0.008 and 0.006 for the Bidkhun and the Haleh estuaries, respectively. Despite the suitable distribution and an economic value of $1.9 million in 1986, conditions of the Basatin estuary seem to have diminished from 1986 to 2018 (economic value of $0.71 million in 2018). The Bidkhun estuary, which showed a positive trend in distribution changes, has also been downgrading since 2015 to about 30.43 ha in size, and an economic value of $1 million. Since 1998, the mangroves of Haleh estuary have been improving distribution-wise, with further elevations in economic value ($ 0.26 million in 2018).

Deforestation is a problem in many developing countries. In Iran, the introduction of forestry management policies in the twentieth century coincided with a period of severe depletion in forest cover. This over-utilization resulted from tree cutting for road construction, the establishment of sawmills and match factories, and in particular, the growing demand for charcoal and fuelwood for a rapidly increasing population. The formal forestry management policies initiated in the early 1900s were inadequately enforced, leading to continuing loss of forests through largely unregulated exploitation. Despite the discovery of oil in 1908 and natural gas in 1937, gas pipeline construction for domestic consumption was slow, kerosene was only gradually substituted for wood, charcoal consumption only fell steeply after 1960, and the established forest cover decreased sharply between 1970 and 1990. In 1991, the first of the post-Revolution national Five Year Development Plans commenced and environmental protection was allocated significant budgetary support. The Five Year Plans implemented substantial reductions in livestock grazing in forests and encouraged reforestation, which partly offset the continuing forest removal. Using estimates based on fuelwood consumption in Brazil and USA, the forested area in Iran in 1850 would have disappeared by 2000 without the Government intervention which provided widespread access to fossil fuels. This energy-source shift decreased local pressure on the dwindling forest resources and was reinforced by Government policies to conserve and extend forests.

Research on vegetation change, rangeland assessment or desertification modelling in drylands using remotely sensed image acquisition normally ignores long-term rainfall as a key criterion in image acquisition. This article will present a novel procedure for image acquisition to investigate vegetation change in a degraded rangeland located in Western New South Wales (Western NSW) Australia. Western NSW experienced an unusually prolonged period of rainfall deficit during the 2000s compared to the 1970, 1980 and 1990s. For this purpose, vegetation changes were assessed using Landsat images supported by field survey. The long-term rainfall variability (42-year) was regarded as a key element in image acquisition. Within the timeframe of the 2000s, 2 years with 25 % lower than the 42-year mean annual rainfall were selected. These images were then compared to an image captured in a year (1988) with rainfall closer to the 42-year mean annual rainfall. Two change detection techniques were used, namely univariate image differencing and GIS approaches. Classification of the produced images was pursued based on the digital numbers (supervised) of ground-checked points within the reference image whilst considering the histogram (unsupervised) of each digital number of the produced image. This research emphasized rainfall as a key variable in image acquisition for vegetation change analysis in rangelands. Image acquisition based on long-term rainfall data allowed for the assessment of changes in perennial plant cover by eliminating the effects of extreme rainfall variation on annual grass dynamics and removing extreme reflections caused by their temporary high photosynthetic activity.

Desertification in Iran was recognized between the 1930s and 1960s. This paper traces Iran's attempts to reclaim desertified areas, evaluates the anti-desertification approaches adopted, and identifies continuing challenges. Iran has areas vulnerable to desertification due to extensive areas of drylands and increasing population pressure on land and water resources. Over-grazing of rangelands is a particular problem. Initially desertification was combated mainly at the local level and involved dune stabilization measures, especially the use of oil mulch, re-vegetation and windbreaks. Insufficient technical planning in the early years has led to changed approaches to plant densities and species diversity in plantations, and increased on-going management of existing plantations. Since the late 1980s forage and crop production has increased in areas where runoff control techniques are practiced. The social and economic aspects of anti-desertification programs have assisted in poverty reduction by providing off-season employment in rural areas. In 2004 a national plan to combat desertification was ratified and this placed an emphasis on community participation. Continuing challenges include managing existing desertified areas as well as taking into account potential future problems associated with rapidly depleting groundwater supplies and a predicted reduction in the plant growth period accompanying climate change.

Anti-desertification planning in Iran operates at the national level through the Five Year Development Plans, the National Plan to Combat Desertification — a long-running scheme for which the Forest, Rangeland and Watershed Management Organisation (FRWO) is responsible — and the recently developed National Action Programme to Combat Desertification (the NAP). The Iranian NAP was formulated following the country's ratification of the United Nations Convention to Combat Desertification and drew heavily on the experience, expertise and collaboration of personnel in FRWO. Development and implementation of the NAP has had major policy impacts in Iran in the two main areas of generating cross-sectoral cooperation between government instruments at the national planning level and by community participation in local projects to combat desertification. Documenting the evolution of cross-sectoral and participatory approaches to desertification in Iran shows that the NAP provided impetus towards a transformation of previous procedures, a policy impact that is continuing to generate change.

Sand and Dust storms are common phenomena in arid and semi-arid areas. West Asia Region, especially Tigris-Euphrates alluvial plain, has been recognized as one of the most important dust source areas in the world. In this paper, a method is applied to extract SDS (Sand and Dust Storms) sources in West Asia region using thematic maps, climate and geography, HYSPLIT model and satellite images. Out of 50 dust storms happened during 2000–2013 and collected in form of MODIS images, 27 events were incorporated as demonstrations of the simulated trajectories by HYSPLIT model. Besides, a dataset of the newly released Landsat images was used as base-map for the interpretation of SDS source regions. As a result, six main clusters were recognized as dust source areas. Of which, 3 clusters situated in Tigris–Euphrates plain were identified as severe SDS sources (including 70% dust storms in this research). Another cluster in Sistan plain is also a potential source area. This approach also confirmed six main paths causing dust storms. These paths are driven by the climate system including Siberian and Polar anticyclones, monsoon from Indian Subcontinent and depression from north of Africa. The identification of SDS source areas and paths will improve our understandings on the mechanisms and impacts of dust storms on socio-economy and environment of the region.

Snow reserves in mountainous basins are important and reliable water resources in Iran. Identification of their quality is necessary because of an increasing value of freshwater and utilization of water recourses. About 60 percent of surface water and 57 percent of ground water sources in Iran flows in snowy regions (Rayegani, 2005). The water produced from snowmelt process provides soil water, ground water reserves and water in lakes and rivers. Since snow cover is one of the most important sources of provided water, an accurate prediction and timing of snow runoff is necessary for the efficient management and decisionmaking in water supply.