Euphrates-Tigris River Research Articles

Hydroeconomic insights for transboundary water challenges and potential collaboration in the Tigris-Euphrates river basin

Abstract For countries sharing transboundary water resources, measuring changes in water availability and ensuing economic outcomes is challenging due to downstream impacts and interconnected agricultural markets. Using a coupled modeling approach that combines a detailed multi-sector model of international trade with a gridded hydrological model, this paper quantifies the impacts of climate change and anthropogenic activities on water scarcity and its economy-wide consequences for the riparian countries in the Tigris-Euprates (TE) river basin and evaluates scenarios of collaboration in basin water management as an adaptation strategy. By mid-century climate change will significantly increase water scarcity in the basin: up to 30% in Iran, 27% in Türkiye, 17% in Iraq, and 14% in Syria. Depending on the climate change scenario, average annual GDP losses from water scarcity and changes in crop yields range from 12 to 84 billion USD for these economies. However, collaboration among the TE river basin riparian countries in water allocation and use could mitigate the adverse economic effects and, relative to the status quo, generate direct GDP gain in the 42–58 billion USD range for these countries and indirect gains for other countries in the Middle East region. The results suggest that collaboration in water management in the TE river basin is an effective option to tackle emerging challenges such as the impact of climate change on water availability.

Exploring the future hydropower production of a run-of-river type plant in the source region of the Tigris Basin (Türkiye) under CMIP6 scenarios

This assessment presents a framework for exploring the changing climate impacts on the energy production capacity of a run-of-river type plant, using the Basoren Weir and Hydropower Plant (HPP) as a case study. The Basoren Project is planned considering historical streamflow records in the source region of the Euphrates-Tigris River Basin (ETRB), which is a prominent hotspot warming at nearly double the global average rate. The quantification is built on precipitation and maximum/minimum temperature datasets from 24 Global Climate Models (GCMs) belonging to the sixth phase of the Coupled Model Intercomparison Project (CMIP6) under the moderate- and high-end Shared Socioeconomic Pathway (SSP) scenarios of SSP2-4.5 and SSP5-8.5, as well as the CMIP6 historical experiment (HEXP) scenario. The distribution mapping method is employed to adjust the raw GCM datasets for systematic biases. The Soil and Water Assessment Tool (SWAT) is preferred in producing daily runoff time series for the bias-adjusted simulations of each GCM over the historical (1988-2009) and three future (2025-2049, 2050-2074, and 2075-2099) periods. The ramifications of the changing climate on the Basoren HPP's energy production capacity are assessed based on the medians of the operational results reached for each GCM under the future societal development scenarios of SSP2-4.5 and SSP5-8.5, considering the medians achieved under the HEXP scenario as the reference case. The results indicate potential reductions in the mean yearly energy production of the Basoren HPP by 7.9%, 5.5%, and 5.3% under the SSP2-4.5 scenario, and by 5.8%, 8.0%, and 17.3% under the SSP5-8.5 scenario for the periods 2025-2049, 2050-2074, and 2075-2099, respectively. While declining spillway releases are expected to partly offset the impact of decreasing streamflow rates on energy production, the shift from a snow-dominated to a rain-dominated hydrologic regime necessitates re-optimizing the power capacities of the ETRB plants to maintain effective use of hydropower potential.

Water for Food in the Tigris–Euphrates River System

Water scarcity is an important threat to food security in the Tigris–Euphrates river system. Water scarcity is a huge worldwide problem that results from the rapid increase in water demand, which exceeds the amount of available water. The most significant problems currently affecting countries are food insecurity water scarcity. The Tigris–Euphrates river system countries suffer from different political issues, such as the Syrian war and internal civil conflicts in Iraq. In addition, this area consists of only three countries: Iraq, Syria, and Turkey, but it affects the entire Middle East. Turkey has established many irrigation projects compared to Iraq, which still suffers from the previous American invasion. Therefore, this study examines the Tigris–Euphrates river system (using two countries) to examine the relationship between water scarcity and food security from 1992 to 2020. This study will be conducted using a fixed and random regression approach over 18 years. The results show a negative relationship between water scarcity and food security in the short run, at a 10% significance level, and a long-term positive relationship of 1%. Thus, the use of research and development and the encouragement of investments will help policymakers to develop a nexus between water scarcity and food security.

Redescription of Cyprinion muscatense (Teleostei: Cyprinidae) with the first phylogenetic analysis of the genus.

Members of the genus Cyprinion (Cypriniformes: Cyprinidae) are found in the Indus River basin west to the Arabian Peninsula and the Tigris-Euphrates River drainages (Persian Gulf basin). The taxonomic status of Cyprinion including Cyprinion muscatense is poorly understood when compared to other cyprinid genera. C. muscatense has been considered as a member of the Cyprinion watsoni-microphthalmum group and a valid species endemic to the Arabian Peninsula. Here, we redescribe C. muscatense based on an integrative morphological and molecular approach and freshly sampled material from several localities in the Oman Mountains ecoregion. The results showed that C. muscatense is distinguished from the other Cyprinion species in the Arabian Peninsula by having a short, thin, and slightly serrated last unbranched dorsal fin ray; the lower number of circumpeduncular scales; lateral line scales; and also scales between the lateral line and the dorsal-fin origin. Subterminal mouth, presence of one pair of small barbels at the mouth corner, 3-4 unbranched and 9½-10½ dorsal-fin branched rays, 12-14 pectoral-fin rays, 7-8 pelvic-fin rays, 2-3 unbranched and 6½-7½ branched anal-fin rays, and 37-40 lateral line scales are other morphological characteristics of C. muscatense. C. muscatense is also well distinguished by molecular characters among its congeners. The first molecular phylogenetic analysis of the genus, covering all currently recognized Cyprinion species except for C. watsoni, is also presented. C. muscatense is resolved as the sister species to another endemic fish of the Arabian Peninsula Cyprinion mhalense, with a Kimura-2-Parameter model distance of 5.3%.

The impact of some metals, molecular docking and molecular dynamic calculations on glucose 6-phosphate dehydrogenase activity in Capoeta trutta (Heckel, 1843) tissue

The first enzyme of the pentose phosphate metabolic pathway is glucose 6-phosphate dehydrogenase (d-glucose-6-phosphate: NADP + oxidoreductase EC1.1.1.49; G6PD). G6PD has essential functions such as membrane lipid synthesis, ribose 5-phosphate, and NADPH production. In this study, the G6PD enzyme was purified from kidney, liver, and gill tissues of Capoeta trutta, one of the dominant fish species in the Euphrates-Tigris River System, and the in vitro effects of some metals (Ag+, Cd2+, Cu2+, Fe2+, Ni2+, Pb2+ and Zn2+) on the enzyme activity were investigated. For this purpose, firstly, the G6PD enzyme was purified from tissues using a 2′, 5′-ADP Sepharose 4B affinity column. The purity of the enzyme was checked by the SDS-PAGE method and a single band was seen in the gel. After the purity of the enzyme was determined, the effects of metals on the enzyme activity were determined using the spectrophotometric method. As a result of the study, it was determined that the Ag+ ion was the most potent inhibitor for C. trutta gill, kidney, and liver G6PD enzymes. Lastly, calculations were made to examine the activity of the glucose 6-phosphate dehydrogenase molecule against the G6PD enzymes. Afterwards, the interaction of the glucose 6-phosphate dehydrogenase molecule with the protein (PDB ID: 5JYU and 2BH9) with the highest activity was calculated in the range of 0–100 ns. Finally, ADME/T calculation was made to predict the effects and reactions of glucose 6-phosphate dehydrogenase molecule in human metabolism. This study explores the physiological functions and environmental sensitivities of G6PD in a dominant fish species, while also investigating its potential interactions and metabolic roles in humans. Understanding these aspects can contribute to environmental monitoring, fish health management, and even pharmaceutical development.

Spatiotemporal variability of dust storm source susceptibility during wet and dry periods: The Tigris-Euphrates River Basin

This study develops a framework for spatiotemporal modeling of dust storm source susceptibility in a critical case study, the Tigris-Euphrates River Basin, as a significant source of dust storms in the Middle East. The study period was divided into four periods, 2000–2004 (hydrological dry year), 2005–2007 (hydrological wet year), 2008–2012 (hydrological dry year), and 2013–2021 (hydrological wet year) representing hydrological conditions in the study area. Initially, visual interpretations of true color composites of the MODIS satellite images were conducted to spot dust storm sources in the studied periods. Topographical, hydrological, soil texture, and vegetation health datasets were prepared to model dust storm source susceptibility in each period. The random forest algorithm was implemented on the four study periods’ datasets. For each period, 70% of dust and non-dust storm sources and conditioning factors were used for training the models. The models were then validated using the validation datasets (remaining 30%), and the importance of the variables was determined for each study period. In the 2008–2012 period, experiencing an extensive drought in the region, a higher number of dust storm sources were detected, and 383 locations (pixels) in the area were considered highly susceptible to dust storm sources. In all study periods, as well as in the ensemble model (integrating the results of four study periods into one overall model), high susceptibility to dust storms was detected in areas where lakes and marshlands had dried up due to climate factors, inappropriate water management strategies, and land use policies. The results also depicted that elevation, wind speed, precipitation, vegetation coverage, slope degree, distance from rivers, and soil texture had high impacts on the susceptibility of land to be a dust storm source.

Water-based regional security complexes in the Middle East and North Africa: the Jordan River, the Tigris–Euphrates river system, the Nile – what role, if any?

Abstract. Water and rivers have played an essential role in the existence and development of mankind ever since the most ancient times. The first great civilizations emerged along the great rivers: along the Jordan, the Tigris–Euphrates and the Nile in the Middle and East North Africa (and elsewhere, such as along the Ganges-Brahmaputra system). While nowadays this very same region is exposed to probably the most severe water shortage and even scarcity, declining water resources are expected to cause major issues in the region due to the population increase and the effects of climate change. This may soon result in water related local or regional conflicts if not wars. The paper examines what role water plays in the rationale of regional security (sub-)complexes of the Middle East and North Africa, respectively. Összefoglalás. A víz és a folyók a legrégebbi idők óta alapvető szerepet játszottak az emberiség létében és fejlődésében. Az első civilizációk a nagy folyók mentén alakultak ki, a Közel-Keleten és Észak-Afrikában a Jordán, a Tigris-Eufrátesz, illetve a Nílus mentén (a világ más térségeiben pl. a Gangesz vagy az Indus mentén). Míg ma ugyanez a térség a legnagyobb vízszűkösségnek, sőt, vízhiánynak van kitéve, a népességnövekedés és a klímaváltozás következtében fogyatkozó vizek hamarosan konfliktusokhoz, szélső esetben vízháborúkhoz vezethetnek. A jelen tanulmány azt vizsgálja, hogy milyen szerepet játszik a víz a Közel-Kelet és Észak-Afrika regionális biztonsági komplexumainak létrejöttében. Bár a Közel-Kelet és Észak-Afrika régióját számos különböző keretben lehet kijelölni – a történelmi, vallási, kulturális és/vagy politikai jellemzőktől a természeti kincsekig, vagy azok hiányáig –, a három nagy folyamrendszer, a víz és a klímaváltozás következtében egyre növekvő vízszűkösség és vízhiány magukban hordozzák mind az együttműködés, mind a konfliktusok, illetve háborúk (vízháborúk) lehetőségét. A saját – akár belsőnek is tekinthető – földrajzi jellemzők mellett azonban a térségre gyakorolt külső hatások, elsősorban az európai gyarmatosítás alatt meghúzott államhatárok, azaz a területi állam fogalmának bevezetése, a sok helyen ma is érvényes vízmegosztási egyezmények tovább bonyolították a helyzetet. Az immár száz éve megállapított határok között az államok saját érdekei versengést eredményeztek, ami – az időközben zajló népességrobbanás következtében – egyre súlyosabb érdekellentétekhez vezettek/vezethetnek. Ezek egyik legfontosabb kérdésévé a víz és a vízhez való hozzáférés válik. Így bár a víz nem feltétlenül az elsődleges oka a regionális biztonsági komplexumok kialakulásának, a jövőben egyre fontosabb meghatározóvá válik. Ugyanakkor a Közel-Kelet és Észak-Afrika három folyamrendszerének mint biztonsági komplexumoknak a hátterében a víz különböző aspektusai állnak. A Jordán-folyó esetében a vízmegosztás problémái és együttműködései alapvetően Izrael Állam megalakulásához, az arab-izraeli háborúkhoz és békefolyamathoz kapcsolódnak. A Tigris-Eufrátesz esetében az 1990-es években a víz elsősorban mint stratégiai szállítási útvonal jelentett biztonságpolitikai kihívást, amennyiben Irak háborúiban az olaj kijuttatása a világtengerekre volt a cél. A Nílus esetében azonban – tulajdonképpen az ókor óta változatlanul – az egyiptomi lakosság vízzel és élelemmel való ellátása, életének biztosítása a cél, miközben Etiópiában – emellett – az ország áramellátása az elsődleges. Azt mondhatjuk tehát, hogy bár a jövő konfliktusainak egyik fő oka valószínűleg a víz lesz/lehet, a víz különböző fenyegetéseket és lehetséges konfliktusokat idézhet elő: az élet és megélhetés veszélyeztetésétől a közlekedésen és szállítmányozáson keresztül az áramellátásáig.

Utilizing the strategic concession behavior in a bargaining game for optimal allocation of water in a transboundary river basin during water bankruptcy

In basins that lie across multiple administrative boundaries, for instance in international river basins like the Nile, water tends to be contested especially during times of scarcity. Riparian countries sharing a transboundary river basin may emphasize the multi-dimensionality of their water demands to obtain access to a greater portion of the available shared water. As a result, the frequency and intensity of water conflicts may increase, hindering the sustainable development of riparian countries and threatening the security and stability of the whole region. Therefore, designing a fair, reasonable, and adaptive allocation scheme is of paramount importance to ensure the integrity of livelihoods and ecosystem health. This paper analyzed the general features of transboundary river basins and built an allocation mechanism combining Bankruptcy Theory with Bargaining and Concession games. A Bankruptcy-Concession-Bargaining Game Model (BCBGM) was constructed to ensure multi-agent participation, multi-stage negotiation, and optimal allocation. Considering the different water demand preferences and linked satisfaction functions, the framework yielded an optimal solution by making concessions on the water claims of riparian countries. As a case study, the proposed model was applied to allocate the limited water resources of the Euphrates-Tigris River. To further measure the stability of model allocation results, a model was built to evaluate the stability of water allocation. The results show that the stability of the allocation output from the proposed allocation framework was relatively high compared to those obtained from classical allocation rules, such as Proportion, Adjusted Proportion, Constrained Equal Loss, and Constrained Equal Award. The model's results satisfied the Pareto efficiency, individual rationality, and maximized group utility. Therefore, for the most part, the allocation outputs of the proposed scheme were generally self-enforceable and sustainable.

TRANSBOUNDARY RIVER BASIN EUPHRATES-TIGRIS: INTERNATIONAL LEGAL REGULATION

Countries all around the globe have shown a strong desire to restrict the utilization of international water channels for non-navigational uses since they are important to human civilisation. This is to avoid issues that may occur because of the usage purposes of international water bodies such as rivers and streams. This research covers a narrow scope, which is limited to legislation addressing the use of international water channels to effectively settle international water disputes, to cover the lawful use of international watercourses. It also provides an overview of transboundary water interactions in the Euphrates-Tigris River basin, followed by a discussion of key topics. From the standpoint of international law, this study discusses the connections among Turkey, Syria, and Iraq regarding their shared water, the Euphrates and the Tigris. Finally, the paper concluded that Iraq must review its entire water policy and identify its flaws, including irrigation methods, dam maintenance, and the management of water resources by international standards. Iraq's deviation from these matters constitutes a violation of the international obligations to which it is bound by international treaties, particularly the framework agreement. This study concludes that Iraq's evaluation of its internal legislation and all of its projects built on the Tigris and Euphrates rivers adds significantly to the resolution of these issues.

The Impacts of Interannual Climate Variability on the Declining Trend in Terrestrial Water Storage over the Tigris–Euphrates River Basin

Abstract The Tigris–Euphrates dryland river basin has experienced a declining trend in terrestrial water storage (TWS) from April 2002 to June 2017. Using satellite observations and a process-based land surface model, we find that climate variations and direct human interventions explain ∼61% (−0.57 mm month−1) and ∼39% (−0.36 mm month−1) of the negative trend, respectively. We further disaggregate the effects of climate variations and find that interannual climate variability contributes substantially (−0.27 mm month−1) to the negative TWS trend, slightly greater than the decadal climate change (−0.25 mm month−1). Interannual climate variability affects TWS mainly through the nonlinear relationship between monthly TWS dynamics and aridity. Slow recovery of TWS during short wetting periods does not compensate for rapid depletion of TWS through transpiration during prolonged drying periods. Despite enhanced water stress, the dryland ecosystems show slightly enhanced resilience to water stress through greater partitioning of evapotranspiration into transpiration and weak surface “greening” effects. However, the dryland ecosystems are vulnerable to drought impacts. The basin shows straining ecosystem functioning after experiencing a severe drought event. In addition, after the onset of the drought, the dryland ecosystem becomes more sensitive to variations in climate conditions. Significance Statement The purpose of the research is to better understand climate impacts on terrestrial water storage over dryland regions with declining water storage. In our study, we disaggregate three components of climate impacts, namely, decadal climate change, interannual variability, and intra-annual variability. We then use observational datasets and a process-based model to quantify their individual effects on water storage. We find that interannual variability is the most significant climatic contributor to the declining water storage, mainly caused by prolonged drought periods and corresponding quick drying rates due to plant transpiration. We also find that the dryland ecosystem is sensitive and vulnerable to severe drought events. This study is important because 1) it provides a framework to investigate climate impacts on water fluxes and storages, 2) it highlights the importance of vegetation dynamics on dryland hydrology, and 3) it emphasizes the negative impacts of extreme hydroclimatological events on ecosystem functioning.

Evaluation of annual total precipitation in the transboundary Euphrates–Tigris River Basin of Türkiye using innovative graphical and statistical trend approaches

The Euphrates–Tigris River Basin (ETRB), one of the largest river basins in the Middle East, is also among the most risky transboundary basins in the world. ETRB has a critical importance for the region both politically and economically due to its location. Evaluating the increasing regional impacts of climate change is even more important for the sustainable management of water and soil resources, especially in transboundary basins such as ETRB. Türkiye is one of the most important riparian countries of the ETRB and the Türkiye part of ETRB constitutes the headwater of the basin. In this study, the temporal variability of the annual total precipitation data for the period 1965–2020 of eighteen stations located in the Türkiye part of the ETRB was investigated. Classical Mann–Kendall (MK) test was used to statistically determine the monotonic trend of precipitation. In addition to the MK method, analyses were carried out with three innovative trend methods, which have the ability to interpret trends both statistically and graphically. These innovative trend methods are Şen innovative trend analysis (Şen-ITA), Onyutha trend test (OTT) and trend analysis with combination of Wilcoxon test and scatter diagram (CWTSD). The results obtained show that there is a decreasing trend in annual total precipitation in ETRB according to all trend methods generally used for the examined period. In addition, the results obtained from the relatively new OTT and CWTSD methods show strong consistency with the results of the other two methods. The advantages such as performing numerical and visual trend analysis with innovative OTT and CWTSD methods, identifying trends in low–medium–high value data and detecting sub-trends have shown that these methods can be used as an alternative to the widely used MK and Şen-ITA.

Effects of upstream activities of Tigris-Euphrates River Basin on water and soil resources of Shatt al-Arab Border River

The Tigris-Euphrates River Basin (TERB) is one of the key transboundary basins among the developing countries in the Middle East which has been significantly damaged by mismanagement, exploitation for energy production and unsustainable water use. This study aimed to evaluate the water and soil resources in the lower parts of this basin. More specifically, how the area of the Shatt al-Arab River (SAR) formed at the confluence of the Tigris and Euphrates rivers is affected in terms of quality by upstream activities. Four mathematical models of hydrodynamics, advection-dispersion in the river, and convection-dispersion in soil were used in conjunction with assessment of soil salinization by irrigation water. The soil salinization based on direct saltwater infiltration from riverbanks and soil salinization by irrigation with river water were predicted after simulating the intrusion of saline seawater by considering the tidal conditions of the SAR. The results showed that by applying six optimistic and probable scenarios of freshwater inflows for the future, changes in the water and soil quality in downstream riparian countries (Iran and Iraq) reflect this basin's developments and water allocation upstream. Regarding the possible scenario of maximum inflow reduction in the future, the findings of this study can be used to create a comprehensive view of the current condition and development challenges. This emphasizes the need for participatory crisis mitigation strategies between the upstream and downstream countries.

Dust sources in Westernmost Asia have a different geochemical fingerprint to those in the Sahara

Dust is an important component of Earth's climate system, directly affecting the global radiation budget and hydrological cycle. The interaction of aerosols with clouds and its impact on regional and global energy budgets remains one of the largest sources of uncertainty in climate model predictions. Records of terrigenous dust accumulation in geological archives also provide a potentially powerful way to assess past changes in hydroclimate. Western Asia, including the Arabian Peninsula, is second only to the Saharan Desert in contributing dust to the global atmosphere. Yet, while satellite-derived maps of dust source activation frequency (DSAF) provide an increasingly granular understanding of the different dust sources within these regions today, our ability to fingerprint their windblown contributions to geological archives is rudimentary, severely limiting the use of dust-based records to reconstruct past changes in continental hydroclimate. A main limitation is a poor understanding of the mineralogical and geochemical composition of the bedrock geology and, more importantly, of the readily deflated unconsolidated sediments in these regions. Here we use published data to produce a DSAF map, centred on the Arabian Peninsula and extending from North Africa to Western Asia (∼40-10 °N; ∼25–65 °E), and we present new radiogenic isotope (Sr and Nd) data from unconsolidated surface sediment samples at active dust-producing sites. We combine our new Sr and Nd data with sparse data on sediments from the literature and the DSAF data to define three new preferential dust source areas (PSAs) in Westernmost Asia: (i) the central belt of the Arabian Peninsula, (ii) the Southern Levant and (iii) Mesopotamia. All three of these PSAs are geochemically distinct from Saharan dust sources. Long-range sediment transport by the Blue Nile and its tributaries, and the Tigris-Euphrates river systems exerts a strong influence on the geochemical fingerprints of dust sources in the Eastern Sahara and Mesopotamia, respectively. The isotopic signature of active dust sources in the central belt of the Arabian Peninsula shows only modest correspondence to underlying bedrock geology suggesting wide scale mixing by aeolian transport internally and/or a weak imprint of palaeo humidity (e.g. localized river reactivation) on dust source composition in comparison to the Eastern Sahara. Our results provide surer foundations for fingerprinting the sources of continental dust accumulating in marine, lacustrine, speleothem and ice archives, an important step in improving our understanding of Quaternary rainfall climate in arguably the most water-stressed region on Earth.

Two-stage water resources allocation negotiation model for transboundary rivers under scarcity

In this article, the bankruptcy theory and bargaining games are used to construct a two-stage water resources allocation negotiation model (TSANM). A Nash-bargaining game model is used for the initial allocation, followed by an adjustment stage which considers factors such as water circumstances, water satisfaction, water risk, and water efficiency. The TSANM systematically considers the multi-dimensional attributes of water resources in the allocation process and may likely increase the participation of riparian countries. The proposed method is applied to allocate the contested water capital of the Tigris-Euphrates River. This gives initial allocation to Turkey, Syria, and Iraq of 30.00%, 22.00%, and 48.00%, respectively, and adjusted allocation of 24.98%, 21.30%, and 53.72%. Through collective bargaining and group negotiation, the stability and acceptability of allocation are effectively improved, absolute egalitarianism and utilitarianism are both avoided, and instead objectivity and fairness are emphasized in the water resources allocation process.

Buffering the impacts of extreme climate variability in the highly engineered Tigris Euphrates river system

More extreme and prolonged floods and droughts, commonly attributed to global warming, are affecting the livelihood of major sectors of the world’s population in many basins worldwide. While these events could introduce devastating socioeconomic impacts, highly engineered systems are better prepared for modulating these extreme climatic variabilities. Herein, we provide methodologies to assess the effectiveness of reservoirs in managing extreme floods and droughts and modulating their impacts in data-scarce river basins. Our analysis of multiple satellite missions and global land surface models over the Tigris-Euphrates Watershed (TEW; 30 dams; storage capacity: 250 km3), showed a prolonged (2007–2018) and intense drought (Average Annual Precipitation [AAP]: < 400 km3) with no parallels in the past 100 years (AAP during 1920–2020: 538 km3) followed by 1-in-100-year extensive precipitation event (726 km3) and an impressive recovery (113 ± 11 km3) in 2019 amounting to 50% of losses endured during drought years. Dam reservoirs captured water equivalent to 40% of those losses in that year. Additional studies are required to investigate whether similar highly engineered watersheds with multi-year, high storage capacity can potentially modulate the impact of projected global warming-related increases in the frequency and intensity of extreme rainfall and drought events in the twenty-first century.

JESIOTR WSCHODNI ACIPENSER GUELDENSTAEDTII BRANDT &amp; RATZEBURG, 1833 (ACTINOPTERYGII, ACIPENSERIDAE) W RZECE EUFRAT, IRAK

Acipenser gueldenstaedtii is recorded for the first time from the Euphrates River, west of Iraq. The species has not previously been mentioned as introduced to the Tigris-Euphrates River basin. There are two possibilities for this occurrence, first, the natural dispersal from adjacent Turkey and second, the aquaculture introduction. Both possibilities were discussed. Confirmation for the origin of the sporadic appearance of individuals of this species will wait for the appearance of more specimens in the inland waters of Iraq.

Effects of Upstream Activities of Tigris-Euphrates River Basin on Water and Soil Resources of Shatt Al-Arab Border River

Effects of Upstream Activities of Tigris-Euphrates River Basin on Water and Soil Resources of Shatt Al-Arab Border River

Testing the “young-species” hypothesis for Alburnus heckeli Battalgil 1944 (Teleostei: Leuciscidae) inhabiting Lake Hazar, Turkey

Alburnus heckeli Battalgil 1944 is endemic to Lake Hazar in the Euphrates-Tigris River system (Persian Gulf basin) and shares morphological and molecular characters with the widespread species A. sellal Heckel 1843, except putatively for the number of gill rakers. This study compared morphometric and meristic data for A. heckeli with lentic and lotic populations of A. sellal. The only significant difference was in the number of gill rakers in lotic populations of A. sellal (10–25) vs. lentic populations of A. sellal (26–35) and A. heckeli (28–35). Although our results are consistent with the interpretation of A. heckeli and A. sellal as “young species”, the amiguity of available morphological and molecular sequence data suggest that A. heckeli is best treated as a junior synonym of A. sellal until reliable differences are found.

Remote sensing applications for the assessment of the geomorphic response of fluvial systems to the Holocene Climate Changes

During the Holocene, the Tigris-Euphrates river system (Lower Mesopotamian Plain) was characterized by a complex morphodynamic due to climatic fluctuations, shoreline shifting, and human activities. Within a wide and barren floodplain with low elevation ranges, a remote sensing multi-sensor approach is suitable to identify the main geomorphological features and associated geomorphic processes. Optical and multispectral imagery (TerraColor and Landsat 8) are adopted for the preliminary visual inspection and the computation of multispectral indices (NDVI and Clay Ratio), as well as for the supervised classification. The topographic analysis of the micro- relief is integrated reclassifying two DEMs (AW30D30 and GDEM2) to highlight the peculiar configuration of the drainage system, which channels are several meters above the surrounding floodplain. This approach allows the investigation of the study area through large and medium scale, identifying active and abandoned channels, discerning between active and abandoned avulsion processes and distinguishing crevasse channels, levees, and deposits. In like manner, human features are recognized, allowing the evaluation of human- environmental interactions.

Dust source susceptibility mapping in Tigris and Euphrates basin using remotely sensed imagery

The present study aims to develop an applicable, robust, and generalizable approach building on the integration of machine learning classifiers into dust source susceptibility mapping. Five machine learning classifiers were used for this purpose, including Support Vector Machine, Random Forest, Naïve Bayes, Logistic Regression, and Artificial Neural Network. The study area includes the Tigris-Euphrates river basin, considered one of the world’s largest active dust sources during the last two decades. A total of 411 active dust sources (i.e. hotspots) were identified as ground truth via visual interpretation of sub-daily MODIS-Terra/Aqua time-series imagery from 2000 to 2020 and then used to train and validate the classifiers. The main environmental drivers of dust formation were incorporated based on remote sensing data/products, including Tasseled Cap components, Soil Crust Index, Modified Fournier Index, and the Sentinel-5 Absorbing Aerosol Index. Dempster-Shafer (D-S) theory was used to merge the results from all classifiers to obtain an accurate susceptible dust sources map of the region. Each of the five classifiers and the final integrated D-S model were assessed using the ROC curve, AUC, and Calibration Plot. The mean prediction accuracy of all five classifiers was 87.7% and 86.3% for dust sources susceptible and non-susceptible classes, respectively. The D-S increased the classification accuracy in susceptible and non-susceptible classes by 7.5% and 12.6%, respectively. Finally, the wind erosion thresholds, as a limiting environmental factor in the emission of dust, were applied over the D-S-based susceptible dust sources map to measure the degree of susceptibility in the identified dust sources.