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The new rise of Babylon is reported and its domination of the old world is described; when two dynasties ruled Neo- Babylonia from 612 BC to 330 BC. First, the Chaldeans had taken over from the Assyrians whom they had defeated and established their empire, which lasted for 77 years followed by the Achaemenid dynasty, which was to rule Babylonia for the remaining period as part of their empire. Out of the 77 years of the Chaldean period king, Nebuchadnezzar II ruled for 43 years, which were full of military achievements and construction works and organization. Apart from extending the borders of the empire, he had managed to construct large-scale hydraulic works which were intended for irrigation, navigation and even for defensive purposes. He excavated, re-excavated, and maintained four large feeder canals taking off from the Euphrates, which served the agriculture in the whole area between the Euphrates and the Tigris in the middle and lower Euphrates regions. Moreover, he was concerned with flood protection and so he constructed one large reservoir near Sippar at 60 km north of Babylon to be filled by the Euphrates excess water during floods and to be returned back to the river during low flow season in summer. His works involved river training projects, so he trained the Euphrates by digging artificial meanders to reduce the velocity of the flow and improving navigation and allow the construction of the canal intakes in a less turbulent flows. It seems also that he had diverted the river during the building of Babylon Bridge and trained the Euphrates River penetrating Babylon by constructing riverside revetments. Nebuchadnezzar II had the foresight for building extensive defensive fortifications to secure the country against possible enemy attacks from the north and adding to the walls and fortifications deep moats filled with water for higher security. This was the case with the wall he built north of Sippar. It extended over the whole distance between the two rivers, and the wall around Sippar itself. Similarly, he had dug a great moat alongside the wall of Babylon, which he supplied with water from the Euphrates. Moreover, he had introduced improvements on the four large feeder canals and the extensive canal networks that belonged to them to be used as water barriers against the advance of any enemy troops. Building temples and grand royal palaces and the Babylon Bridge took part of Nebuchadnezzar's attention and his name was linked with the "Babylon Hanging Gardens", one of the seven wonders of the ancient world, which he had built to please his wife. Description of the gardens according to historians is given in this book in addition to reporting the results of archeological digging of the supposed site, which can shed light on the irrigation method used to irrigate these elevated gardens. The flourishing agriculture and wealth and prosperity it had brought to Babylon during Nebuchadnezzar's reign is described in details, and the active trading and commercial dealing it had generated is also treated. The first banking services in history related to this period, which was linked to one Jewish family known as "House of Êigibi" is described. This family continued to serve for very long time by collecting the land rents and water taxes for canals use for the government, in addition to concluding contracts and ratifying transactions for the public. As bankers, they gave farmers loans to invest in all types of agrarian operations and practiced money transfers between various cities which helped trading especially with large scale export and imports of the various crops. The Chaldeans rule of Babylon came to an end in 539 BC when Babylon fell to the Achaemenids attacks that were already established in Persia led by Cyrus II. Babylon, however, kept a special position between the various capitols of this empire due to its splendor and wealth. It served therefore as the economical capitol and the winter residence of the kings Achaemenid Empire for most of this period while its agriculture continued to generate a great portion of the empire's revenue. The archive gave us information on the agrarian relations and the agricultural outputs in Babylonia at that period. During the Achaemenid times, as it was the case during the Chaldean times, irrigation systems in Babylonia were kept under close observation and good maintenance which kept agriculture at its best. The inevitable decline of this empire came in the end due to the rule of weak kings, conspiracies and palace intrigues, and finally the bitter defeat came on the hands of Alexander the Great who entered Babylon in 331 BC and kept it as the Jewel of his new empire. ; Validerad;2020;Nivå 1;2020-04-24 (alebob)

Declining stage of the Abbasid Khilafa is followed meticulously until its collapse in the fall of Baghdad to the Mongols in 1258. The full sequence of events, which had resulted in this most important event to Mesopotamia is followed and the decline in agriculture in the whole of al- Sawad during this is period, is carefully described. Agriculture had formed the main contributor to the economy and strength of the Khilafa State, but it had continuously suffered neglect and destruction during this period due to negligence of the central governments of the irrigation systems and the destruction of these systems during conflicts and revolts that became dominant during the last phase of al- Khilafa State. The large spending of the late Khalifahs and the depletion of the treasury, and their dependence on foreign military troops, who were mainly Turks, to support their rule, mark the beginning. By loss of sizable revenues, this had interacted again with the Khalifahs weakness causing more revolts and anarchy by various unsatisfied groups and by the troops themselves over their unpaid salaries. The war between al-Muntasir and his brother al- Mu'tazz over the thrown following the assassination of their father al-Mutawakkil is detailed by giving full attention to the large damages it caused to irrigation canals and flooding of large areas between Baghdad and Samarra. Following this the revolt of Zanj in Southern al- Sawad and the long conflict with the Qarmatians are then outlined by reporting the reasons and describing the consequences of those important wars in details, accounting at the same time the high costs of these wars and the extent of severe damages to population centres, cultivation lands and their irrigation works. During the Buwayhids period, the Abbasid Khlilafa experienced its worst moments as the Buwayhids did not contribute much to the welfare of the people, nor could they do much to reverse the trend of decline that was progressing. As a matter of fact they had committed their biggest mistake in tearing apart the land ownership system prevailing till that time by introducing a new form of Iqta' known as the Military Iqta's. New methods of land and crops tax collection system were introduced and thus disrupting long established procedures that were followed since the Sassanid era and had proved their success. Conflicts and wars during the Buwayhid rule and the large-scale corruption, which are fully reported here, had undermined the central power needed for the proper management of agriculture and for the well keep of the irrigation canal systems. Finally, when the Buwayhid strength was drained they were expelled under a new rising power in the Seljuks. The Seljuks proved during this period to be not much different from the Buwayhids and their Sultans kept the real power in their hands making the Khalifah a titular head of state only. The conditions of the economy was as bad as it was before, and the people complained much over the recurrent crises of extremely high food prices during these times. Worst of all the Seljuk Sultans surpassed the Buwayhids in practicing the Iqta' of the cultivated land by distributing qati'as not only to the military leaders as the Buwayhids did but they extend this to an unprecedented levels for the Seljuk Sultans had granted all the land to their Seljuk soldiers, their relatives and friends who were only Seljuks. To comprehend the magnitude of this; the number of the soldiers only in the time of Malik Shah who benefited from this system was forty six thousand horsemen; many more high ranking Seljuk persons were also entitled to qati'as under the same rules. With the passage of time the basic principle of this system were violated, and most of the beneficiaries succeeded in keeping the land as their own , used all sorts of abuses towards their farmers and even passed it in inheritance to their children. Some others encroached on neighboring qati'as, which belonged to others, and injustice and corruption became widespread. Negligence to repair these canals in so many cases leading to the permanent abandonment of land is also cited illustrated with many examples. In addition, many striking cases of failures of canals and their head works after large floods are fully described based on the reports given by contemporary writers. The details presented give an insight to the scale of the large fertile areas and the cities and towns that were badly affected and give evidence to the very low level that the State had reached during its last days after losing so much fertile lands and their agriculture. ; Validerad;2020;Nivå 1;2020-04-24 (alebob)

The Achaemenid Empire collapsed after the failure of King Darius III to stop the sweeping advance of Alexander in Anatolia towards Persia. Therefore, Alexander entered Babylon in 331 BC before advancing into the heartland of Persia itself and occupying its other major cities and advancing from there into India. At this point, begins to describe the period of the Greek domination at the return of Alexander to Babylon, which was followed, later on by yet another period of Persian domination of Mesopotamia. During his stay in Babylon Alexander looked into the conditions of the irrigation and water works. Although the canal networks were in good conditions when they were left from the Archimedean's time, he nevertheless ordered the cleaning of all the canal intakes on the Euphrates River. His major undertaking, however, was to solve the problem of the canal called the Popallacopas. This canal was used to pass the floodwater of the Euphrates down to the marshes and from there to the Persian Gulf while the Euphrates continued its course through Babylon in the reach, which was known, as the Babil River. Every flood season the Popallacopas closing dike was breached to pass the flood but the task of constructing it back afterwards was very difficult. The closure was necessary to ensure suitably high water levels to serve Babylon itself during the low water season, the closing operation of the intake, which was located in a ground of sandy soils, needed large working force of not less than 10000 men. Following the advice of his engineers, Alexander solved this problem by excavating a new head reach channel from another location above the first one but located in good and firm ground. Alexander 's next move was aimed at the reclamation of the marshy lands located near the present day of Najaf and to this end he constructed a massive earthen dyke between Babil River and the marsh north of the present day town of al-Shanafiyah as a preliminary step to dry the marsh and then prepare it for canalization and cultivation. Alexander premature death in June of the year 331BC however put an end to this work. In the aftermath of Alexander's death his empire was divided between his generals; Persia, Mesopotamia and Anatolia passed to Alexander's general Seleucus I Nicator who founded the Seleucid Empire (648-312BC) and succeeded in extending it also to cover the whole region of the Fertile Crescent. Various Persian satrapies (vassal kingdoms) such as Aria, Parthia, Fars, Media, Atropatene, paid taxes to the Seleucids but ruled with a great deal of independence. Seleucus inaugurated his reign by building a new capital for the empire, which was the Seleucia-on-Tigris on the western bank of the Tigris 60 kilometers northeast of Babylon, not far from the confluence of Tigris and Diyala.The lands of Mesopotamia at this point in time, had been already irrigated successfully by a system of canals maintained under the supervision of the State and agriculture was as usual the prime and most important basis of all the prosperity the empire had enjoyed. However, being a corridor between east and west Mesopotamia remained at the middle of conflicts with other outside powers and new rising tribal forces seeking to have their own kingdoms and empires. This was the case with the Parthians coming from the Persian heartland that had rebelled against the Seleucids after being vassals to them, and then vanquished their empire and took over its domains including Mesopotamia. In establishing themselves in Mesopotamia the Parthians moved their capital to Ctesiphon on the eastern bank of the Tigris opposite to Seleucia-on-Tigris about 58 BC, and remained the capital of the this empire until it was passed to the hands of the next Persian dynasty of the Sassanid. During the Parthian empire rule the economic prosperity was directly related to the upkeep of the irrigation systems and agricultural practices. Mesopotamia and the Persian lowlands of Khuzestan were the traditional centers of growing wheat, barley, and other cereals, while dates and other fruits were regularly produced and often exported. In the highlands of northeastern part of Mesopotamia and the Persian plateau, pastoralism and other forms of animal husbandry outweighed farming, although sowing various grains, most importantly wheat, as well as growing fruits, was also common. An earlier presence of rice in west Asia especially Mesopotamia might have also occurred through initial farming in eastern Persia and Transoxania. In the middle and south of Mesopotamia the Parthians looked well over the irrigation systems. In northeastern part of Mesopotamia and in Transoxiana the Kariz underground systems were used and maintained for the water supply of agriculture. The maintenance of all these systems was an important task of the Parthian Empire, often hinting on the strength or weakness of the government in certain periods of its history. It was also the case that in times of chaos and destabilization, that the maintenance of both the Kariz and the irrigation canals were neglected, causing further problems by weakening the agrarian, economy and causing further destabilization. Land tenure during the Parthian era did not differ much from the Babylonian or the Achaemenids eras. There were always two groups of people, either landlords or landless population, owners with large land holdings, usually members of the nobility and the court, controlled most of the productive land in the empire and, therefore families having such vast land areas would provide the basis of the later decentralized system under the Parthians. Another class of land-owning gentry, called the Azatan, also existed who were entitled to royal property in exchange for military service. The Azatan cavalry formed the hard core of the Parthian army and was mainly responsible for the Parthian success in external wars and in the quick initial expansion of the empire. ; Validerad;2020;Nivå 1;2020-04-24 (marisr)

Sumerians were the first People in history to invent the cuneiform script, which made the reporting of their achievements possible. Therefore, this had marked the beginning of written history. Moreover, their experience as pioneers in practicing large-scale irrigation is detailed in this paper, which also describes the intricate canal networks systems they had constructed together with the engineering works related to them. The land was flat and the two rivers had built themselves to higher levels than the surrounding lands by the continuous silting process, so gravity irrigation became possible and the people took the opportunity to construct these networks and establish their communities here. Description of the political and social developments, which led to the establishment of the city-states, is also given together with a list of the most prominent ones, and their locations are shown on a map indicating the heartland of Samaria in southern part of Iraq; close to the Persian Gulf. Wars between some city-states over water rights are detailed with their results in excavation of new canals, which are described here. A vivid description of the irrigation canals and the hydraulic structures that were needed and built are also presented which show that the Sumerians were versed in hydraulic principles, while in illustrating their methods of land preparation, seeding, irrigation and harvesting indicates they were skillful farmers. Moreover, the tools and implements invented for field operations such as those for water control, land preparation, seeding and harvesting, which are fully described, show that they were also inventors.The type of crops produced are given special attention and the abundance of yield they obtained was outlined indicating that surpluses had encouraged trading with other parts outside Samaria and so new commercial relations were developed. The economic aspects of this civilization such as wages and loans for farmers, work specialization and the appearance of new professions to meet cultivation requirements were described. The social hierarchy on which social relations and organization of work was based are presented especially those related to the agricultural and irrigation works which are given their share of explanation and discussion. Flood protection works needed for better safety from the Tigris and Euphrates rivers recurrent floods were routine practices of the Sumerians to protect themselves and their lands from the grave dangers of these floods. Therefore, they excelled in them, while canals maintenance by constant dredging of the silt brought down by the two rivers every year was a constant concern. The Sumerians over long period had accepted within them some other people namely, the Akkadians who intermingled with them, lived in their cities, and even mixed with them in marriages. This explains how a smooth transition of power had resulted in the rise of the Akkadians King Sargon, after he had started as a high-ranking official at the court of (Ur- Zababa) the last Sumerian king and replaced him to mark the start of the Semitic Akkadian domination, which lasted almost 200 years to 2150 BC. Sargon managed afterwards to unite all the city-states and establish the first empire in the world extending well beyond Sumeria, so it was said that his influence was felt from Egypt in the west to India in the east.Finally, this paper presents briefly the various theories behind the decline of the Sumerian- Akkadians power and the reasons for passing this to the new rising city of Babylon, which took over this civilization to establish its own. ; Validerad;2020;Nivå 1;2020-04-24 (marisr)

As the history of this land continues to unfold, we come to the time when the capitol of the State was moved to a new city to the north of Baghdad, which was called Samarra, and this was the opportunity taken by the Khalifahs to build new palaces and excavate new canals and open more land for cultivation. In this paper details on the building of Sammara by Khalifah al- Mu'tasim, son of Khalifah Harun al- Rashid and moving the capitol to it from Baghdad in the year 836 and remaining as such until 892 are given. One of the main reasons which led al-Muʿtaṣim to build Samarra and moving to it was the problems raised by the presence of his Turkish slave-soldiers in Baghdad and the friction they had created with the population. Al-Muʿtaṣim construction works in Samarra, the various public buildings, and numerous palaces he constructed here are described. As the city was located on the eastern bank of the Tigris, water supply could not be drawn to it by gravity since its location was higher than the river and even higher than the Katul Kisrawi canal adjoining to it from the east. Therefore, the irrigation works of al- Muʿtaṣim were concentrated on the western bank of the Tigris, which he had already connected it to the right bank by building a bridge. The main irrigation work he embarked upon was the construction of Nahr Ishaqi Canal. This old canal dated to the Partho- Sassanid era but it had to be re-excavated and remodeled since it was already filled up by sediments and abandoned. More over the canal had to be extended for a very long distance downstream to irrigate all the qati'as he had given to his top generals and courtiers to develop into cultivations and farms. These farms then produced all sorts of crops and fruits while the large date palm orchards planted here gave the best types of dates. Moreover, the canal in its downward route supplied water to the large tract of land that al- Mu'tasim had reserved for the encampment of his Maghariba troops which was called "Istablat". Details of the barracks, housing quarters, stables and training arena of the encampment are presented in addition to the three branch canals off taking from Nahr Ishaqi, which were to irrigate also the extensive pastureland that was reserved for the 140,000 cavalry horses to graze in. The canal was then followed to its end in the other old canal called al- Dujail canal. The works of al- Mu'tasim, however, were no match to what his grandson al- Mutawakkil had done which are described. This Khalifah was determined to irrigate Samarra by gravity from the Tigris and to have plentiful water supply to the city and to his palaces and to his many artificial ponds. He embarked on a daring project by constructing a dual kariz and open channel conduit system taking water from the Tigris at a location forty kilometers north of Samarra and running for great part of its length along the Katul Kisrawi canal adapting to the hilly topography of the land. The scheme was then described following its course after crossing the Katul by an aqueduct to an earth reservoir. This reservoir was built to retain the incoming water before distributing it to the main city dual Kariz, and to the canal supplying the Dakka palace. In addition to the flood escape channel that was known as the Nahr Murayr which took off from the west side of the reservoir and passed down to the Tigris where it poured. The main city Kariz system is followed i and the details of its branching network are fully described. Such details covered the water supply to the racing courses, the Dar Khilafa palace and its unique pools intended for the Khalifah's pleasure and the water supply to Abu Dulaf Mosque congregational mosque with its famous fountain. Having finished in the Tigris at al- Matira this stream could not irrigate the 5000 hectares of land of al- Hayr, or the wild animal reserve created by al- Mutawakkil to practice his hobby of hunting, as this land was above its course. The al- Hayr was so important to al- Mutawakkil that he excavated a new canal directly from the Katul, which commanded the whole area, called it Nahr al Nyzak and gave from its final reach a branch to another palace he built there and supplied one more of his favorite ponds adjoined to it. The construction works of al- Mutawakkil were not confined to Samarra but he extended this to build a new city 18 kilometers to the north of Samarra and called it al- Mutawakkiliyya, and here he again built new government compound, a mosque and gave qati'as to his sons, generals and may more people to build houses and palaces. He built for himself another palace and called it al Ja'fari. To supply the new city with water, he ordered the excavation of a new canal, which he called Nahr al Ja'fari. The intake of this canal was on the Tigris River some forty kilometer north of Tikrit and it followed a course parallel to the river for a considerable distance before it crossed the Katul Kisrawi by an aqueduct and then entered the city. This project proved an engineering failure as the ground, which had to be dug, was extremely hard and the work had to be stopped after spending twenty five million dirham. While some of these works may be considered as grand works, they were very costly and deprived public works such as irrigation networks from their share necessary for their maintenance and proper functioning. This extravagance coupled with political intrigues led to the assassination of al- Mutawakkil in a plot that was planned by his own son. This point marked the beginning of the decline of al- Khilafa which took some more time till it finally collapsed in 1258 fall of Baghdad on the hands of the Mongols. In addition to Samarra and its irrigation work described also the Nahr Dujail canal flowing on the western bank of the Tigris not far downstream from Samarra. Much older than Samarra itself, it was irrigating a large tract of land extending to Baghdad. In description of the course of the canal followed its western branch, which had gone out of use at the Abbasid times and also concentrated attention on the eastern branch that was known as Nahr Batatiya. It irrigated the Tusuj of Maskin before it reached the northern parts of Baghdad and branched into a dense network of watercourses that supplied al- Harbbiyyah quarter. Further details are presented of the various places and parts of this quarter that benefited from these watercourses before the full supply was exhausted. The details as given augment therefore the description of the canal networks serving Baghdad (the round city and the Karkh districts) that had originated from Nahr Isa. The Abbasid Khilafa after it had experienced its golden era began after the assassination of al- Mutawakkil, a long process of slow but steady decline due to multiplicity of reasons. ; Validerad;2020;Nivå 1;2020-04-24 (alebob)

Euphrates and Tigris Rivers are the longest Rivers in southwest Asia. The main utilizers of the water of these rivers and tributaries are Turkey, Syria, Iran and Iraq. The two rivers rise in Turkey, which makes it the riparian hegemon. Some of the tributaries of the Tigris and Shat Al-Arab Rivers rise in Iran, which makes it the riparian hegemon for these rivers. Iraq and Syria are the lower countries in the basin and for this reason, they always to ensure the quantity of water required to satisfy their requirements. All these countries are in the Middle East, which characterized by its shortage of water resources. Since the 1970s conflict between riparian counties were noticed due to population growth rates, food security, energy needs, economic and technological development, political fragmentation, international water laws, water and management availability and public awareness. These caused tensions, which sometimes escalated to the verge of war. To solve this conflict a mediator is required that has the capability to bring all countries concerned to the negotiation table. Syria and Iraq are to give Turkey and Iran some incentives to cooperate. Furthermore, all counties are to adopt prudent strategic plan based on comprehensive resources development to ensure good water management and minimum water loses and waste. This due to the fact that modeling studies of the future suggest that water shortage problem will intensify. ; Validerad;2018;Nivå 1;2018-04-30 (rokbeg)

Dam safety hazards towards human communities have increased tremendously during the last decades. They have resulted from dam safety problems leading to failure and being exasperated by the large losses at downstream areas due to increasing populations and land use. In this work, an attempt is being made to review the procedures being followed to reduces these hazards by improving dams safety standards. Classification of dams by their potential hazards are explained as used today for prioritize remedial actions in various countries of the world. The guiding principles of these classification are indicated and they are based on height of such dams and their storage and linked to the potential damage and harm they can create. Normally such classification and follow up actions are supported by various legislations and regulations issued by the respective governments. Moreover, conventions signed by riparian countries promote cooperation on mitigating safety problems of dams on transboundary rivers. Examples of such legislations and conventions are mentioned. Looking for having safer dams is an objective continually which is being pursued as more dams are needed in the future while existing dams continue to serve their objectives. Therefore, using lessons learned from previous failures is recommended taking the question of loss of life as a main doctrine. ; Validerad;2020;Nivå 1;2020-06-23 (alebob)

Overtopping is one of the most serious modes of failures for all dams causing great numbers of human fatalities and material damages. Statistics show that overtopping failures are the highest, especially for embankment dams. The main reason for this is the erroneous prediction of the inflow design discharge, which has resulted from lack of realistic flow data and imperfect hydrological procedures. Failure in most cases occurs when the inflow exceeds the spillway design capacity, but to a lesser extent from the buildup of very high wave setup and runs up. This has led to active efforts in upgrading dams for such occurrences, by either upgrading spillways, adding auxiliary spillways, increasing freeboard by either heightening the dams or the parapet walls on the crest. Advancement in predicting the safe inflow discharges are also made by adopting such procedures as the calculation of the Probable maximum flood based on predicting the Maximum Probable Precipitation or using statistical methods by treating long records of available flow data. Recently, another challenge has come up facing dam owners and builders who are represented by the climate change impacts on the hydrological cycle; this has put a new responsibility to the governments to issue new regulations and plans to mitigate these impacts reducing failure possibilities and improve dam safety against overtopping. ; Validerad;2020;Nivå 1;2020-06-23 (alebob)

Climate Change which results from global warming is affecting the Tigris and Euphrates River basins in similar ways to all other parts of the Middle East and the East Mediterranean region. This contains also what is historically known as the "Fertile Crescent", which is threatened in the same way as the other parts and may disappear altogether. The climate change is manifested in increased temperatures, reduced precipitation in addition to erratic weather patterns and decreased annual stream flow of the two rivers. These phenomena have been markedly noticed during the last decades of the last century. Studies show that these changes are linked also to the variations of North Atlantic Pressure Oscillation (NAO) induced by Global Climate Change. Modeling studies on the future trends, in trying to define the magnitude of the changes to be anticipated, reveal clearly that these negative impacts are continuous in the future. But, the widely ranging projections and interpretations of different sources depict an uncertain future for the basin's climatic conditions and indicate theneed for further modeling studies to reach more definitive conclusions. These studies show however, a drastic decline of the Euphrates and Tigris water resources at the end of this century by something like (30 to 70) %; as compared to their resources in the last three decades of the previous century. The wide variations in the projections emphasize the need of further future work on this matter. All in all, these studies should bring alarm to all responsible governments in the region to resort to long range planning by adopting rational policies in soils and water resources management to mitigate the adverse impacts that could hit human societies in these events. ; Validerad;2018;Nivå 1;2018-04-30(andbra)

Gradual shift has been observed lately of dam safety procedures from the conventional technical based towards a widerscope of risk management procedure based on risk analysis. The new approach considers the likelihood level of occurrence of a multitude of hazards and the magnitude of the resulting possible consequences in case of failure using rational cause and effect arguments. Most dam owners are shifting towards the use of the new risk based procedures; and even governments themselves are moving towards formalizing the new trend. Legislations in the United States were promulgated [1] after serious dam failures and the adoption of stringent levels of scrutiny led such federal dam owners to pioneer in this field and in developing the concepts and methods required. The corner stone in risk analysis is the definition of the potential modes that may lead to failure and assessment of the likelihood levels of their occurrence and possible category of the consequences which, after thorough evaluation, will shape thedecision making. This type of analysis was applied to Mosul Dam as a case study and resulted in definite recommendations. ; Validerad;2017;Nivå 1;2017-10-19 (andbra)

Dam Safety and dam incidents are treated here looked at from the "Human Factors" perspective. An attempt is made to explore these factors as an important drive in impairing dams' safety and increases their risks. Distinction is drawn between the "Normal Human Caused Incidents" and the "Extraordinary Human Caused Incidents" together with the description of their root origins and subsequent consequences. The first type includes unintentional mistakes, errors and flaws committed by the operators of dams inadvertently, in addition to negligence, lack of experience or overconfidence. Such failings can happen in manual operation of dams, or through the use of their Supervision, Control and Data Acquisition (SCADA) systems as in industrial control system (ICS). They can occur also due to flaws in software or even in the application of information and communication technology (ICT) in remote control operations. As for the second group; the extraordinary human factors, they are defined here as those committed by man with the full understanding of their possible damage. They are done purposely for destabilizing dams after thoughtful and carefully meditated decision making process and they are manifested in acts of war, sabotage and terrorists actions. In this modern age, these acts are characteristics of hackers' attacks on dam(s) operating systems. This is done through the use of cyberspace by the widespread interconnected digital technology with the accompanying advances in the communication technologies. As such, these technologies have made remote control of such systems possible. Not limited to this, dams remain now, as they were always in the past, the obvious targets in wars and conflicts to inflict losses on the enemy and to use them as weapons, and for terrorism actions for challenging governments. Examples of the aforementioned threats are described with examples given from real cases to elucidate the dangers involved. Lessons to be learned from these incidents are derived and recommendations are presented to be followed to avoid risky situations. ; Validerad;2020;Nivå 1;2020-09-29 (johcin)

When a dam is built, its safety becomes a constant concern for the owner, the public and for governments. Therefore, continuous observation through routine inspections and safety reviews become necessary. Acting as protectors of public safety, governments and professional organizations save no effort in the promulgation of legislations and laying out guidelines for such inspections and reviews. These issues are discussed here starting with the basic first step of visual inspections by the operators and the follow up of detailed safety reviews by specialists. Careful visual inspections assisted by instrumentation measurements may reveal an early negative issue such as, but not limited to, increased seepage, increased uplift pressure, signs of weakness like cracking in the body of the dam, or dams' slope sloughing, and even damaged hydraulic control equipment. Documenting and reporting these observation helps in taking remedial measures in good time and may lead to more intensive safety reviews. Suggested check lists for the inspection engineers are given here, but these may be tailored for each dam according to its needs. These lists cover issues common to both embankment and concrete dams, and include other specific issues related to each type of them. Metal equipment take their share by listing such areas as corrosion, fatigue and cracking, tear, and wear and so on. Instrumentation measurements are also given their due consideration by giving brief mention of types of measurements needed and points to be observed in instrumentation control work. Finally, guidelines, rules, and legislations for Dam Safety Reviews are generally discussed giving examples from four countries in the world. ; Validerad;2020;Nivå 1;2020-09-29 (johcin)

Iraq as a country is now suffering from Climate Change Impacts in similar or even worse ways than many other countries of the world. The manifestations of these climate changes are being felt in global warming, changes to weather driving elements and sea level rise. Increasing temperatures, declining precipitation rates and changed distribution patterns together with increasing evaporation are causing water stress in Iraq. However, they trigger other changes in a sort of chain reaction; such as droughts, desertification and sand storms. Iraq is not even safe from the consequences of sea level rise where the southern part of the Tigris- Euphrates delta is threatened by inundation and Iraq's ports and sea coast line are endangered by such projected rise. So far the agricultural sector in Iraq has been hit very badly by the reduced water availability for arable lands; whether rain fed lands as in the northern part, or irrigated lands using the declining discharges of the Tigris and Euphrates Rivers as in the southern and middle parts. These discharges have already been additionally strained by the unfair sharing practiced by Turkey from which most of the two rivers' water resources originate. The present negative climate change trends seem to be continuing in the future as it is obvious from all projections and studies being performed so far. Loss of cultivable land to desertification, recurrent droughts and sand storms and declining agriculture are the pattern of change in Iraq's already fragile environment; and this will result inevitably in much more distress for the population in the future and will lead to social unrest. These will add to the great pressures facing all future governments unless the government takes protective planning and solutions. ; Validerad;2018;Nivå 1;2018-04-27 (rokbeg)