Misplaced Pages

#3996

147-519: The Great Wall of Gorgan is a Sasanian-era defense system located near modern Gorgan in the Golestān Province of northeastern Iran , at the southeastern corner of the Caspian Sea . The western, Caspian Sea, end of the wall is near the remains of the fort at: 37°08′23″N 54°10′44″E  /  37.13981°N 54.1788733°E  / 37.13981; 54.1788733 ; the eastern end of

294-402: A Roman counter-offensive two years later ended inconclusively. Ardashīr began leading campaigns into Greater Khurasan as early as 233, extending his power to Khwarazm in the north and Sistan in the south while capturing lands from Gorgan to Abarshahr, Marw, and as far east as Balkh . Ardashir I's son Shapur I continued the expansion of the empire, conquering Bactria and the western portion of

441-540: A ball drive, gear drive, or impact mechanism. Rotors can be designed to rotate in a full or partial circle. Guns are similar to rotors, except that they generally operate at very high pressures of 275 to 900 kPa (40 to 130 psi) and flows of 3 to 76 L/s (50 to 1200 US gal/min), usually with nozzle diameters in the range of 10 to 50 mm (0.5 to 1.9 in). Guns are used not only for irrigation, but also for industrial applications such as dust suppression and logging . Sprinklers can also be mounted on moving platforms connected to

588-419: A circular or semi-circular pattern. Traveling Sprinklers: These move along the hose path on their own, watering as they go, ideal for covering long, narrow spaces. Each type offers different advantages based on garden size and shape, water pressure, and specific watering needs. Subirrigation has been used for many years in field crops in areas with high water tables . It is a method of artificially raising

735-589: A clock or timer. Most automatic systems employ electric solenoid valves . Each zone has one or more of these valves that are wired to the controller. When the controller sends power to the valve, the valve opens, allowing water to flow to the sprinklers in that zone. There are two main types of sprinklers used in lawn irrigation, pop-up spray heads and rotors. Spray heads have a fixed spray pattern, while rotors have one or more streams that rotate. Spray heads are used to cover smaller areas, while rotors are used for larger areas. Golf course rotors are sometimes so large that

882-426: A computerized set of valves . In sprinkler or overhead irrigation, water is piped to one or more central locations within the field and distributed by overhead high-pressure sprinklers or guns. A system using sprinklers, sprays, or guns mounted overhead on permanently installed risers is often referred to as a solid-set irrigation system. Higher pressure sprinklers that rotate are called rotors and are driven by

1029-494: A direct financial cost to the farmer. Irrigation often requires pumping energy (either electricity or fossil fuel) to deliver water to the field or supply the correct operating pressure. Hence increased efficiency will reduce both the water cost and energy cost per unit of agricultural production. A reduction of water use on one field may mean that the farmer is able to irrigate a larger area of land, increasing total agricultural production. Low efficiency usually means that excess water

1176-416: A flood (spate), water is diverted to normally dry river beds (wadis) using a network of dams, gates and channels and spread over large areas. The moisture stored in the soil will be used thereafter to grow crops. Spate irrigation areas are in particular located in semi-arid or arid, mountainous regions. Micro-irrigation , sometimes called localized irrigation , low volume irrigation , or trickle irrigation

1323-418: A fortlet or watchtower at the inland end: 36°43.360′N 54°3.675′E  /  36.722667°N 54.061250°E  / 36.722667; 54.061250  ( Wall of Tammishe: inland fortlet or watchtower ) ); OSL and radiocarbon dating indicated a date for both walls in the late 5th or 6th century AD. These dates suggest that the current wall, at least, is Sassanid rather than Parthian, and that

1470-559: A general amnesty, which brought Armenia back into the Sassanid Empire. Around 570, "Ma 'd-Karib", half-brother of the King of Yemen, requested Khosrow I's intervention. Khosrow I sent a fleet and a small army under a commander called Vahriz to the area near present Aden , and they marched against the capital San'a'l, which was occupied. Saif, son of Mard-Karib, who had accompanied the expedition, became King sometime between 575 and 577. Thus,

1617-409: A higher profit than potatoes. The land is flood irrigated twice a day to simulate tidal flooding; the water is pumped from the sea using wind power. Additional benefits are soil remediation and carbon sequestration . Until the 1960s, there were fewer than half the number of people on the planet as of 2024. People were not as wealthy as today, consumed fewer calories and ate less meat , so less water

SECTION 10

#1732858970004

1764-577: A highly advantageous peace treaty with the new emperor Philip the Arab , by which he secured the immediate payment of 500,000 denarii and further annual payments. Shapur soon resumed the war, defeated the Romans at Barbalissos (253), and then probably took and plundered Antioch . Roman counter-attacks under the emperor Valerian ended in disaster when the Roman army was defeated and besieged at Edessa and Valerian

1911-495: A hunting trip in 309. Following Hormizd II's death, northern Arabs started to ravage and plunder the western cities of the empire, even attacking the province of Fars, the birthplace of the Sassanid kings. Meanwhile, Persian nobles killed Hormizd II's eldest son, blinded the second, and imprisoned the third (who later escaped into Roman territory). The throne was reserved for Shapur II , the unborn child of one of Hormizd II's wives who

2058-581: A major Byzantine offensive in Armenia was defeated at Anglon . Also in 541, Khosrow I entered Lazica at the invitation of its king, captured the main Byzantine stronghold at Petra , and established another protectorate over the country, commencing the Lazic War . A five-year truce agreed to in 545 was interrupted in 547 when Lazica again switched sides and eventually expelled its Persian garrison with Byzantine help;

2205-681: A member of the Parthian House of Karen , one of the Seven Great Houses of Iran , quickly raised a new force and stopped the Hephthalites from achieving further success. Peroz's brother, Balash , was elected as shah by the Iranian magnates, most notably Sukhra and the Mihranid general Shapur Mihran . Balash (484–488) was a mild and generous monarch, and showed care towards his subjects, including

2352-616: A number of battles he crushed them and drove them out beyond the Oxus river in 450. During his eastern campaign, Yazdegerd II grew suspicious of the Christians in the army and expelled them all from the governing body and army. He then persecuted the Christians in his land, and, to a much lesser extent, the Jews . In order to reestablish Zoroastrianism in Armenia, he crushed an uprising of Armenian Christians at

2499-410: A rational system of taxation based upon a survey of landed possessions , which his father had begun, and he tried in every way to increase the welfare and the revenues of his empire. Previous great feudal lords fielded their own military equipment, followers, and retainers. Khosrow I developed a new force of dehqans , or "knights", paid and equipped by the central government and the bureaucracy, tying

2646-424: A rectangular or square pattern. They are good for covering large, flat areas evenly. Impact (or Pulsating) Sprinklers: These create a rotating, pulsating spray, which can cover a circular or semi-circular area. They are useful for watering large lawns. Stationary Sprinklers: These have a fixed spray pattern and are best for smaller areas or gardens. Rotary Sprinklers: These use spinning arms to distribute water in

2793-457: A relatively peaceful era with the Romans, and he even took the young Theodosius II (408–450) under his guardianship. Yazdegerd also married a Jewish princess, who bore him a son called Narsi. Yazdegerd I's successor was his son Bahram V (421–438), one of the most well-known Sasanian kings and the hero of many myths. These myths persisted even after the destruction of the Sasanian Empire by

2940-708: A result of irrigation and the subsequent effects on natural and social conditions in river basins and downstream of an irrigation scheme . The effects stem from the altered hydrological conditions caused by the installation and operation of the irrigation scheme. Amongst some of these problems is depletion of underground aquifers through overdrafting . Soil can be over-irrigated due to poor distribution uniformity or management wastes water, chemicals, and may lead to water pollution . Over-irrigation can cause deep drainage from rising water tables that can lead to problems of irrigation salinity requiring watertable control by some form of subsurface land drainage . In 2000,

3087-424: A single sprinkler is combined with a valve and called a 'valve in head'. When used in a turf area, the sprinklers are installed with the top of the head flush with the ground surface. When the system is pressurized, the head will pop up out of the ground and water the desired area until the valve closes and shuts off that zone. Once there is no more pressure in the lateral line, the sprinkler head will retract back into

SECTION 20

#1732858970004

3234-711: A small discharge to each plant. Micro-irrigation uses less pressure and water flow than sprinkler irrigation. Drip irrigation delivers water directly to the root zone of plants. Subirrigation has been used in field crops in areas with high water tables for many years. It involves artificially raising the water table to moisten the soil below the root zone of plants. Irrigation water can come from groundwater (extracted from springs or by using wells ), from surface water (withdrawn from rivers , lakes or reservoirs ) or from non-conventional sources like treated wastewater , desalinated water , drainage water , or fog collection . Irrigation can be supplementary to rainfall , which

3381-778: A strategically critical area for control of the Silk Road . Shapur therefore marched east toward Transoxiana to meet the eastern nomads, leaving his local commanders to mount nuisance raids on the Romans. He crushed the Central Asian tribes, and annexed the area as a new province. In the east around 325, Shapur II regained the upper hand against the Kushano-Sasanian Kingdom and took control of large territories in areas now known as Afghanistan and Pakistan . Cultural expansion followed this victory, and Sasanian art penetrated Transoxiana , reaching as far as China. Shapur, along with

3528-438: A wall, 195 km (121 mi) long and 6–10 m (20–33 ft) wide, with over 30 fortresses at intervals of between 10 and 50 km (6.2 and 31.1 mi). The building materials consist of mud-brick , fired brick, gypsum , and mortar . Clay was also used during the early Parthian period . Mud-bricks were more popular in the early period in the construction of forts and cities, while fired bricks became popular in

3675-399: Is supplementary to rainfall as happens in many parts of the world, or whether it is ' full irrigation' whereby crops rarely depend on any contribution from rainfall. Full irrigation is less common and only happens in arid landscapes experiencing very low rainfall or when crops are grown in semi-arid areas outside of any rainy seasons. Surface irrigation, also known as gravity irrigation, is

3822-480: Is a form of sprinkler irrigation utilising several segments of pipe (usually galvanized steel or aluminium) joined and supported by trusses , mounted on wheeled towers with sprinklers positioned along its length. The system moves in a circular pattern and is fed with water from the pivot point at the center of the arc. These systems are found and used in all parts of the world and allow irrigation of all types of terrain. Newer systems have drop sprinkler heads as shown in

3969-503: Is a system where water is distributed under low pressure through a piped network, in a pre-determined pattern, and applied as a small discharge to each plant or adjacent to it. Traditional drip irrigation use individual emitters, subsurface drip irrigation (SDI), micro-spray or micro-sprinklers, and mini-bubbler irrigation all belong to this category of irrigation methods. Drip irrigation, also known as microirrigation or trickle irrigation, functions as its name suggests. In this system, water

4116-441: Is also employed to protect crops from frost , suppress weed growth in grain fields, and prevent soil consolidation . It is also used to cool livestock , reduce dust , dispose of sewage , and support mining operations. Drainage , which involves the removal of surface and sub-surface water from a given location, is often studied in conjunction with irrigation. There are several methods of irrigation that differ in how water

4263-415: Is also the means of delivery of fertilizer. The process is known as fertigation . Deep percolation, where water moves below the root zone, can occur if a drip system is operated for too long or if the delivery rate is too high. Drip irrigation methods range from very high-tech and computerized to low-tech and labor-intensive. Lower water pressures are usually needed than for most other types of systems, with

4410-422: Is common in many parts of the world as rainfed agriculture , or it can be full irrigation, where crops rarely rely on any contribution from rainfall. Full irrigation is less common and only occurs in arid landscapes with very low rainfall or when crops are grown in semi-arid areas outside of rainy seasons. The environmental effects of irrigation relate to the changes in quantity and quality of soil and water as

4557-422: Is delivered at or near the root zone of plants, one drop at a time. This method can be the most water-efficient method of irrigation, if managed properly; evaporation and runoff are minimized. The field water efficiency of drip irrigation is typically in the range of 80 to 90% when managed correctly. In modern agriculture, drip irrigation is often combined with plastic mulch , further reducing evaporation, and

Great Wall of Gorgan - Misplaced Pages Continue

4704-457: Is dependent upon farmers having sufficient access to water. However, water scarcity is already a critical constraint to farming in many parts of the world. There are several methods of irrigation. They vary in how the water is supplied to the plants. The goal is to apply the water to the plants as uniformly as possible, so that each plant has the amount of water it needs, neither too much nor too little. Irrigation can also be understood whether it

4851-424: Is less expensive to install than a center pivot, but much more labor-intensive to operate – it does not travel automatically across the field: it applies water in a stationary strip, must be drained, and then rolled to a new strip. Most systems use 100 or 130 mm (4 or 5 inch) diameter aluminum pipe. The pipe doubles both as water transport and as an axle for rotating all the wheels. A drive system (often found near

4998-421: Is often no alternative for farmers but to use water polluted with urban waste directly to water their crops. There can be significant health hazards related to using untreated wastewater in agriculture. Municipal wastewater can contain a mixture of chemical and biological pollutants. In low-income countries, there are often high levels of pathogens from excreta. In emerging nations , where industrial development

5145-443: Is often the irrigation choice for developing nations, for low value crops and for large fields. Where water levels from the irrigation source permit, the levels are controlled by dikes ( levees ), usually plugged by soil. This is often seen in terraced rice fields (rice paddies), where the method is used to flood or control the level of water in each distinct field. In some cases, the water is pumped, or lifted by human or animal power to

5292-580: Is one of several Caspian Gates at the eastern part of a region known in antiquity as Hyrcania , on the nomadic route from the northern steppes to the Iranian heartland. The wall is believed to have protected the Sassanian Empire to the south from the peoples to the north, probably the White Huns . In his book Empires and Walls , Chaichian (2014) questions the validity of this interpretation using historical evidence of potential political-military threats in

5439-422: Is outpacing environmental regulation, there are increasing risks from inorganic and organic chemicals. The World Health Organization developed guidelines for safe use of wastewater in 2006, advocating a ‘multiple-barrier' approach wastewater use, for example by encouraging farmers to adopt various risk-reducing behaviors. These include ceasing irrigation a few days before harvesting to allow pathogens to die off in

5586-581: Is practiced in the vineyards at Lanzarote using stones to condense water. Fog collectors are also made of canvas or foil sheets. Using condensate from air conditioning units as a water source is also becoming more popular in large urban areas. As of November 2019 a Glasgow-based startup has helped a farmer in Scotland to establish edible saltmarsh crops irrigated with sea water. An acre of previously marginal land has been put under cultivation to grow samphire , sea blite , and sea aster ; these plants yield

5733-478: Is similar in principle and action to subsurface basin irrigation. Another type of subirrigation is the self-watering container, also known as a sub-irrigated planter . This consists of a planter suspended over a reservoir with some type of wicking material such as a polyester rope. The water is drawn up the wick through capillary action. A similar technique is the wicking bed ; this too uses capillary action. Modern irrigation methods are efficient enough to supply

5880-437: Is supplied at one end using a large hose. After sufficient irrigation has been applied to one strip of the field, the hose is removed, the water drained from the system, and the assembly rolled either by hand or with a purpose-built mechanism, so that the sprinklers are moved to a different position across the field. The hose is reconnected. The process is repeated in a pattern until the whole field has been irrigated. This system

6027-419: Is supplied to plants. Surface irrigation , also known as gravity irrigation, is the oldest form of irrigation and has been in use for thousands of years. In sprinkler irrigation , water is piped to one or more central locations within the field and distributed by overhead high-pressure water devices. Micro-irrigation is a system that distributes water under low pressure through a piped network and applies it as

Great Wall of Gorgan - Misplaced Pages Continue

6174-524: Is surpassed only by the walls systems of the Great Wall of China and Cheolli Jangseong (in modern-day North Korea ) as the longest single-segment building and the longest defensive wall in existence. Among archaeologists the wall is also known as " The Red Snake " ( Turkmen : Qizil Alan) because of the colour of its bricks. In Persian , it was popularized by the name " Alexander Barrier " ( سد اسکندر Sadd-i-Iskandar ) or " Alexander's Wall ", as Alexander

6321-432: Is the practice of applying controlled amounts of water to land to help grow crops , landscape plants , and lawns . Irrigation has been a key aspect of agriculture for over 5,000 years and has been developed by many cultures around the world. Irrigation helps to grow crops, maintain landscapes, and revegetate disturbed soils in dry areas and during times of below-average rainfall. In addition to these uses, irrigation

6468-583: Is used for irrigation in agriculture, the nutrient (nitrogen and phosphorus) content of the treated wastewater has the benefit of acting as a fertilizer . This can make the reuse of excreta contained in sewage attractive. In developing countries , agriculture is increasingly using untreated municipal wastewater for irrigation – often in an unsafe manner. Cities provide lucrative markets for fresh produce, so they are attractive to farmers. However, because agriculture has to compete for increasingly scarce water resources with industry and municipal users, there

6615-556: Is usually not considered as a form of irrigation. Rainwater harvesting is the collection of runoff water from roofs or unused land and the concentration of this. Irrigation with recycled municipal wastewater can also serve to fertilize plants if it contains nutrients, such as nitrogen, phosphorus and potassium. There are benefits of using recycled water for irrigation, including the lower cost compared to some other sources and consistency of supply regardless of season, climatic conditions and associated water restrictions. When reclaimed water

6762-628: The Battle of Hormozdgan in 224, Ardashir's dynasty replaced that of the Arsacids and promptly set out to restore the legacy of the Achaemenid Empire by expanding the newly acquired Sasanian dominions. At its greatest territorial extent, the Sasanian Empire encompassed all of modern-day Iran and Iraq and parts of the Arabian Peninsula (particularly Eastern Arabia and South Arabia ), as well as

6909-533: The Battle of Vartanantz in 451. The Armenians, however, remained primarily Christian. In his later years, he was engaged yet again with the Kidarites right up until his death in 457. Hormizd III (457–459), the younger son of Yazdegerd II, then ascended to the throne. During his short rule, he continually fought with his elder brother Peroz I , who had the support of the nobility, and with the Hephthalites in Bactria . He

7056-638: The Caucasus , the Levant , and parts of Central Asia and South Asia . One of the high points in Iranian civilization, the Sasanian dynasty's rule was characterized by a complex and centralized government bureaucracy, and also revitalized Zoroastrianism as a legitimizing and unifying ideal. This period saw the construction of many grand monuments, public works, and patronized cultural and educational institutions. The Sasanian Empire's cultural influence extended far beyond

7203-578: The Iranians ' ), was the last pre-Islamic Iranian empire . Named after the House of Sasan , it endured for over four centuries, from 224 to 651, making it the second longest-lived Persian imperial dynasty after the directly preceding Arsacid dynasty of Parthia . It fell to the Rashidun Caliphate during the early Muslim conquests , which marked the beginning of a monumental societal shift by initiating

7350-632: The Islamization of Iran . Upon succeeding the Parthians, the Sasanian dynasty re-established the Persian nation as a major power in late antiquity , and also continued to compete extensively with the neighbouring Roman Empire . It was founded by Ardashir I , a ruler who rose to power as Parthia weakened amidst internal strife and the Roman–Persian Wars . After defeating Artabanus IV of Parthia during

7497-683: The Mamikonian family, touching off a revolt which led to the massacre of the Persian governor and his guard in 571, while rebellion also broke out in Iberia . Justin II took advantage of the Armenian revolt to stop his yearly payments to Khosrow I for the defense of the Caucasus passes. The Armenians were welcomed as allies, and an army was sent into Sassanid territory which besieged Nisibis in 573. However, dissension among

SECTION 50

#1732858970004

7644-652: The Shabuhragan , to him) and sent many Manichaean missionaries abroad. He also befriended a Babylonian rabbi called Samuel . This friendship was advantageous for the Jewish community and gave them a respite from the oppressive laws enacted against them. Later kings reversed Shapur's policy of religious tolerance. When Shapur's son Bahram I acceded to the throne, he was pressured by the Zoroastrian high-priest Kartir Bahram I to kill Mani and persecute his followers. Bahram II

7791-499: The Tigris , taking Ctesiphon. Narseh had previously sent an ambassador to Galerius to plead for the return of his wives and children. Peace negotiations began in the spring of 299, with both Diocletian and Galerius presiding. The conditions of the peace were heavy: Persia would give up territory to Rome, making the Tigris the boundary between the two empires. Further terms specified that Armenia

7938-559: The United States , China , and European countries like the United Kingdom , also fund and organize some schemes within other nations. By 2021 the global land area equipped for irrigation reached 352 million ha, an increase of 22% from the 289 million ha of 2000 and more than twice the 1960s land area equipped for irrigation. The vast majority is located in Asia (70%), where irrigation

8085-573: The commercial greenhouse production, usually for potted plants . Water is delivered from below, absorbed by upwards, and the excess collected for recycling. Typically, a solution of water and nutrients floods a container or flows through a trough for a short period of time, 10–20 minutes, and is then pumped back into a holding tank for reuse. Sub-irrigation in greenhouses requires fairly sophisticated, expensive equipment and management. Advantages are water and nutrient conservation, and labor savings through reduced system maintenance and automation . It

8232-745: The king says "I am the lord of the Empire of the Iranians". More commonly, as the ruling dynasty was named after Sasan , the empire is known as the Sasanian Empire in historical and academic sources. This term is also recorded in English as the Sassanian Empire , the Sasanid Empire , and the Sassanid Empire . Conflicting accounts shroud the details of the fall of the Parthian Empire and subsequent rise of

8379-409: The 400-year-old Parthian Empire to an end, and beginning four centuries of Sassanid rule. In the next few years, local rebellions occurred throughout the empire. Nonetheless, Ardashir I further expanded his new empire to the east and northwest, conquering the provinces of Sakastan , Gorgan , Khorasan , Marw (in modern Turkmenistan ), Balkh and Chorasmia . He also added Bahrain and Mosul to

8526-623: The Alchon Tamgha and the name "Alchono" in Bactrian script on the obverse, and with attendants to a fire altar on the reverse. Shapur II pursued a harsh religious policy. Under his reign, the collection of the Avesta , the sacred texts of Zoroastrianism, was completed, heresy and apostasy were punished, and Christians were persecuted. The latter was a reaction against the Christianization of

8673-591: The Arabs. Bahram gained the crown after Yazdegerd's sudden death (or assassination), which occurred when the grandees opposed the king with the help of al-Mundhir , the Arabic dynast of al-Hirah . Bahram's mother was Shushandukht , the daughter of the Jewish Exilarch . In 427, he crushed an invasion in the east by the nomadic Hephthalites , extending his influence into Central Asia, where his portrait survived for centuries on

8820-478: The Byzantine Empire and met little effective resistance. Khosrow's generals systematically subdued the heavily fortified frontier cities of Byzantine Mesopotamia and Armenia, laying the foundations for unprecedented expansion. The Persians overran Syria and captured Antioch in 611. In 613, outside Antioch, the Persian generals Shahrbaraz and Shahin decisively defeated a major counter-attack led in person by

8967-422: The Byzantine Empire held a small portion of western Armenia. Bahram IV's son Yazdegerd I (399–421) is often compared to Constantine I . Both were physically and diplomatically powerful, opportunistic, practiced religious tolerance and provided freedom for the rise of religious minorities. Yazdegerd stopped the persecution against the Christians and punished nobles and priests who persecuted them. His reign marked

SECTION 60

#1732858970004

9114-584: The Byzantine emperor Heraclius . Thereafter, the Persian advance continued unchecked. Jerusalem fell in 614, Alexandria in 619, and the rest of Egypt by 621. The Sassanid dream of restoring the Achaemenid boundaries was almost complete, while the Byzantine Empire was on the verge of collapse. This remarkable peak of expansion was paralleled by a blossoming of Persian art , music , and architecture . While successful at its first stage (from 602 to 622),

9261-631: The Byzantine generals not only led to an abandonment of the siege, but they in turn were besieged in the city of Dara , which was taken by the Persians. Capitalizing on this success, the Persians then ravaged Syria, causing Justin II to agree to make annual payments in exchange for a five-year truce on the Mesopotamian front, although the war continued elsewhere. In 576 Khosrow I led his last campaign, an offensive into Anatolia which sacked Sebasteia and Melitene , but ended in disaster: defeated outside Melitene,

9408-506: The Christians. However, he proved unpopular among the nobility and clergy who had him deposed after just four years in 488. Sukhra, who had played a key role in Balash's deposition, appointed Peroz's son Kavad I as the new shah of Iran. According to Miskawayh (d. 1030), Sukhra was Kavad's maternal uncle. Kavad I (488–531) was an energetic and reformist ruler. He gave his support to the sect founded by Mazdak , son of Bamdad, who demanded that

9555-486: The Eastern Romans, founded several cities, some of which were named after him, and began to regulate taxation and internal administration. After the reign of Kavad I, his son Khosrow I , also known as Anushirvan ("with the immortal soul"; ruled 531–579), ascended to the throne. He is the most celebrated of the Sassanid rulers. Khosrow I is most famous for his reforms in the aging governing body of Sassanids. He introduced

9702-462: The Euphrates in 296, he was eventually decisively defeated by them. Galerius had been reinforced, probably in the spring of 298, by a new contingent collected from the empire's Danubian holdings. Narseh did not advance from Armenia and Mesopotamia , leaving Galerius to lead the offensive in 298 with an attack on northern Mesopotamia via Armenia. Narseh retreated to Armenia to fight Galerius's force, to

9849-548: The Great is thought by early Muslims to have passed through the Caspian Gates on his hasty march to Hyrcania and the east. It is also known as the " Anushirvân Barrier " ( سد انوشیروان Sadd-i Anushiravan ) and " Firuz/Piruz Barrier " ( سد پیروز ), and is officially referred to as " Gorgan Defence Wall " ( دیوار دفاعی گرگان ). It is known as Qïzïl Yïlan or Qazal Al'an to local Iranian Turkmens . The barrier consists of

9996-437: The Hephthalites. Smbat, with the aid of a Persian prince named Datoyean, repelled the Hephthalites from Persia, and plundered their domains in eastern Khorasan , where Smbat is said to have killed their king in single combat. After Maurice was overthrown and killed by Phocas (602–610) in 602, however, Khosrow II used the murder of his benefactor as a pretext to begin a new invasion, which benefited from continuing civil war in

10143-548: The Kushan Empire, while leading several campaigns against Rome. Invading Roman Mesopotamia , Shapur I captured Carrhae and Nisibis , but in 243 the Roman general Timesitheus defeated the Persians at Rhesaina and regained the lost territories. The emperor Gordian III 's (238–244) subsequent advance down the Euphrates was defeated at Meshike (244), leading to Gordian's murder by his own troops and enabling Shapur to conclude

10290-727: The Nile river in Egypt and Sudan; and in the Mississippi-Missouri river basin, the Southern Great Plains, and in parts of California in the United States. Smaller irrigation areas are spread across almost all populated parts of the world. By 2012, the area of irrigated land had increased to an estimated total of 3,242,917 km (801 million acres), which is nearly the size of India. The irrigation of 20% of farming land accounts for

10437-564: The Persians in Anatolia and the Caucasus, winning a string of victories against Persian forces under Shahrbaraz , Shahin , and Shahraplakan (whose competition to claim the glory of personally defeating the Byzantine emperor contributed to their failure), sacking the great Zoroastrian temple at Ganzak , and securing assistance from the Khazars and Western Turkic Khaganate . Irrigate Irrigation (also referred to as watering of plants )

10584-548: The Persians suffered heavy losses as they fled across the Euphrates under Byzantine attack. Taking advantage of Persian disarray, the Byzantines raided deep into Khosrow's territory, even mounting amphibious attacks across the Caspian Sea . Khosrow sued for peace, but he decided to continue the war after a victory by his general Tamkhosrow in Armenia in 577, and fighting resumed in Mesopotamia. The Armenian revolt came to an end with

10731-534: The Roman Empire by Constantine the Great . Shapur II, like Shapur I, was amicable towards Jews , who lived in relative freedom and gained many advantages during his reign. At the time of his death, the Persian Empire was stronger than ever, with its enemies to the east pacified and Armenia under Persian control. From Shapur II's death until Kavad I 's first coronation, there was a largely peaceful period with

10878-517: The Romans (by this time the Eastern Roman or Byzantine Empire ) engaged in just two brief wars with the Sasanian Empire, the first in 421–422 and the second in 440 . Throughout this era, Sasanian religious policy differed dramatically from king to king. Despite a series of weak leaders, the administrative system established during Shapur II's reign remained strong, and the empire continued to function effectively. After Shapur II died in 379,

11025-421: The Romans in the west, where Persian forces won a series of battles but were unable to make territorial gains due to the failure of repeated sieges of the key frontier city of Nisibis, and Roman success in retaking the cities of Singara and Amida after they had previously fallen to the Persians. These campaigns were halted by nomadic raids along the eastern borders of the empire, which threatened Transoxiana ,

11172-469: The Romans; an attempt by the Iberians in 524/525 to do likewise triggered a war between Rome and Persia. In 527, a Roman offensive against Nisibis was repulsed and Roman efforts to fortify positions near the frontier were thwarted. In 530, Kavad sent an army under Perozes to attack the important Roman frontier city of Dara . The army was met by the Roman general Belisarius , and, though superior in numbers,

11319-650: The Sassanian Empire in mystery. The Sassanian Empire was established in Estakhr by Ardashir I . Ardashir's father, Papak , was originally the ruler of a region called Khir. However, by 200, Papak had managed to overthrow Gochihr and appoint himself the new ruler of the Bazrangids . Papak's mother, Rodhagh, was the daughter of the provincial governor of Pars . Papak and his eldest son Shapur managed to expand their power over all of Pars. Subsequent events are unclear due to

11466-410: The Sassanid possessions. Later Sassanid inscriptions also claim the submission of the kings of Kushan , Turan and Makuran to Ardashir, although based on numismatic evidence it is more likely that these actually submitted to Ardashir's son, the future Shapur I . In the west, assaults against Hatra , Armenia and Adiabene met with less success. In 230, Ardashir raided deep into Roman territory, and

11613-527: The Sassanids were able to establish a base in South Arabia to control the sea trade with the east. Later, the south Arabian kingdom renounced Sassanid overlordship, and another Persian expedition was sent in 598 that successfully annexed southern Arabia as a Sassanid province, which lasted until the time of troubles after Khosrow II. Khosrow I's reign witnessed the rise of the dihqans (literally, village lords),

11760-449: The Tigris, and agreed not to interfere in the affairs of Armenia and Georgia. In the aftermath of this defeat, Narseh gave up the throne and died a year later, leaving the Sassanid throne to his son, Hormizd II . Unrest spread throughout the land, and while the new king suppressed revolts in Sakastan and Kushan, he was unable to control the nobles and was subsequently killed by Bedouins on

11907-951: The Tigris, had to hand over all the provinces the Persians had ceded to Rome in 298, as well as Nisibis and Singara, to secure safe passage for his army out of Persia. From around 370, however, towards the end of the reign of Shapur II , the Sasanians lost the control of Bactria to invaders from the north: first the Kidarites , then the Hephthalites and finally the Alchon Huns , who would follow up with an invasion of India . These invaders initially issued coins based on Sasanian designs. Various coins minted in Bactria and based on Sasanian designs are extant, often with busts imitating Sassanian kings Shapur II (r. 309 to 379) and Shapur III (r. 383 to 388), adding

12054-444: The alliance, Khosrow also married Maurice's daughter Miriam. Under the command of Khosrow and the Byzantine generals Narses and John Mystacon , the new combined Byzantine-Persian army raised a rebellion against Bahram, defeating him at the Battle of Blarathon in 591. When Khosrow was subsequently restored to power he kept his promise, handing over control of western Armenia and Caucasian Iberia . The new peace arrangement allowed

12201-688: The archaeological team in 1971, believed that the wall was built during the Parthian Empire (247 BC–224 AD), and that it was reconstructed and restored during the Sassanid era (3rd to 7th century AD). In 2005 a team excavated samples of charcoal from the many brick kilns along the wall, and samples from the Gorgan Wall and the smaller Wall of Tammishe (location of a drowned fort at the northern end: 36°48.595′N 54°1.234′E  /  36.809917°N 54.020567°E  / 36.809917; 54.020567  ( Wall of Tammishe: drowned fort ) ; location of

12348-421: The army and bureaucracy more closely to the central government than to local lords. Emperor Justinian I (527–565) paid Khosrow I 440,000 pieces of gold as a part of the "eternal peace" treaty of 532. In 540, Khosrow broke the treaty and invaded Syria, sacking Antioch and extorting large sums of money from a number of other cities. Further successes followed: in 541 Lazica defected to the Persian side, and in 542

12495-658: The boundary of the historical find by laying cement blocks. Larger than Hadrian's Wall and the Antonine Wall taken together (two separate structures in Britain that marked the northern limits of the Roman Empire ), it has been called the greatest monument of its kind between Europe and China . The wall is third only to the walls that make up the Great Wall of China and the Cheolli Jangseong (in modern-day North Korea ) as

12642-436: The campaign of Khosrau II had actually exhausted the Persian army and treasuries. In an effort to rebuild the national treasuries, Khosrau overtaxed the population. Thus, while his empire was on the verge of total defeat, Heraclius (610–641) drew on all his diminished and devastated empire's remaining resources, reorganised his armies, and mounted a remarkable, risky counter-offensive. Between 622 and 627, he campaigned against

12789-554: The capture of his harem and the loss of all the Roman territories he had occupied. Shapur had intensive development plans. He ordered the construction of the first dam bridge in Iran and founded many cities, some settled in part by emigrants from the Roman territories, including Christians who could exercise their faith freely under Sassanid rule. Two cities, Bishapur and Nishapur , are named after him. He particularly favoured Manichaeism , protecting Mani (who dedicated one of his books,

12936-469: The center pivot. This type of system is known as LEPA (Low Energy Precision Application). Originally, most center pivots were water-powered. These were replaced by hydraulic systems ( T-L Irrigation ) and electric-motor-driven systems (Reinke, Valley, Zimmatic). Many modern pivots feature GPS devices. A series of pipes, each with a wheel of about 1.5 m diameter permanently affixed to its midpoint, and sprinklers along its length, are coupled together. Water

13083-485: The centre of the wheel line) rotates the clamped-together pipe sections as a single axle, rolling the whole wheel line. Manual adjustment of individual wheel positions may be necessary if the system becomes misaligned. Wheel line systems are limited in the amount of water they can carry, and limited in the height of crops that can be irrigated. One useful feature of a lateral move system is that it consists of sections that can be easily disconnected, adapting to field shape as

13230-619: The coinage of Bukhara (in modern Uzbekistan ). Bahram deposed the vassal king of the Iranian-held area of Armenia and made it a province of the empire. Bahram V's son Yazdegerd II (438–457) was in some ways a moderate ruler, but, in contrast to Yazdegerd I, he practised a harsh policy towards minority religions, particularly Christianity . However, at the Battle of Avarayr in 451, the Armenian subjects led by Vardan Mamikonian reaffirmed Armenia's right to profess Christianity freely. This

13377-711: The components of these irrigation systems are hidden under ground, since aesthetics are important in a landscape. A typical lawn sprinkler system will consist of one or more zones, limited in size by the capacity of the water source. Each zone will cover a designated portion of the landscape. Sections of the landscape will usually be divided by microclimate , type of plant material, and type of irrigation equipment. A landscape irrigation system may also include zones containing drip irrigation, bubblers, or other types of equipment besides sprinklers. Although manual systems are still used, most lawn sprinkler systems may be operated automatically using an irrigation controller , sometimes called

13524-408: The crop or field requirements. Increasing the application efficiency means that the amount of crop produced per unit of water increases. Improved efficiency may either be achieved by applying less water to an existing field or by using water more wisely thereby achieving higher yields in the same area of land. In some parts of the world, farmers are charged for irrigation water hence over-application has

13671-403: The current structure did not yet exist, some 800 years earlier, in the time of Alexander the Great (died 323 BC). If Alexander encountered a barrier at this location it was a predecessor of the current wall. If we assumed that the forts were occupied as densely as those on Hadrian's Wall, then the garrison on the Gorgan Wall would have been in the order of 30,000 men. Models, taking into account

13818-404: The elusive nature of the sources. It is certain that following the death of Papak, Ardashir, the governor of Darabgerd , became involved in a power struggle with his elder brother Shapur. Sources reveal that Shapur was killed when the roof of a building collapsed on him. By 208, over the protests of his other brothers, who were put to death, Ardashir declared himself ruler of Pars. Once Ardashir

13965-421: The empire passed on to his half-brother Ardashir II (379–383; son of Hormizd II) and his son Shapur III (383–388), neither of whom demonstrated their predecessor's skill in ruling. Bahram IV (388–399) also failed to achieve anything important for the empire. During this time Armenia was divided by a treaty between the Roman and Sasanian empires. The Sasanians reestablished their rule over Greater Armenia, while

14112-410: The entire field uniformly with water, so that each plant has the amount of water it needs, neither too much nor too little. Water use efficiency in the field can be determined as follows: Increased irrigation efficiency has a number of positive outcomes for the farmer, the community and the wider environment. Low application efficiency infers that the amount of water applied to the field is in excess of

14259-502: The exception of low-energy center pivot systems and surface irrigation systems, and the system can be designed for uniformity throughout a field or for precise water delivery to individual plants in a landscape containing a mix of plant species. Although it is difficult to regulate pressure on steep slopes, pressure compensating emitters are available, so the field does not have to be level. High-tech solutions involve precisely calibrated emitters located along lines of tubing that extend from

14406-786: The first foothills of the Caucasus Mountains . Derbent and its Caspian Gates are at the western part of the historical region of Hyrcania . While the fortification and walls on the east side of the Caspian Sea remained unknown to the Graeco-Roman historians, the western half of the impressive "northern fortifications" in the Caucasus were well known to Classical authors. FURTHER READING Sasanian Empire The Sasanian Empire ( / s ə ˈ s ɑː n i ə n , s ə ˈ s eɪ n i ə n / ), officially Ērānšahr ( Middle Persian : 𐭠𐭩𐭥𐭠𐭭𐭱𐭲𐭥𐭩 , lit.   ' Empire of

14553-567: The former's disadvantage: the rugged Armenian terrain was favourable to Roman infantry, but not to Sassanid cavalry. Local aid gave Galerius the advantage of surprise over the Persian forces, and, in two successive battles, Galerius secured victories over Narseh. During the second encounter, Roman forces seized Narseh's camp, his treasury, his harem, and his wife. Galerius advanced into Media and Adiabene , winning successive victories, most prominently near Erzurum , and securing Nisibis ( Nusaybin , Turkey) before 1 October 298. He then advanced down

14700-493: The frontiers to act as guardians against invaders. He was tolerant of all religions, though he decreed that Zoroastrianism should be the official state religion , and was not unduly disturbed when one of his sons became a Christian. After Khosrow I, Hormizd IV (579–590) took the throne. The war with the Byzantines continued to rage intensely but inconclusively until the general Bahram Chobin , dismissed and humiliated by Hormizd, rose in revolt in 589. The following year, Hormizd

14847-534: The ground. In flower beds or shrub areas, sprinklers may be mounted on above ground risers or even taller pop-up sprinklers may be used and installed flush as in a lawn area. Hose-end sprinklers are devices attached to the end of a garden hose, used for watering lawns, gardens, or plants. They come in a variety of designs and styles, allowing you to adjust the water flow, pattern, and range for efficient irrigation. Some common types of hose-end sprinklers include: Oscillating Sprinklers: These spray water back and forth in

14994-459: The head of a large army granted to him by the Hephthalite king, returned to the empire's capital. Jamasp stepped down from his position and returned the throne to his brother. No further mention of Jamasp is made after the restoration of Kavad I, but it is widely believed that he was treated favourably at the court of his brother. The second golden era began after the second reign of Kavad I. With

15141-409: The image that follows. As of 2017 most center pivot systems have drops hanging from a U-shaped pipe attached at the top of the pipe with sprinkler heads that are positioned a few feet (at most) above the crop, thus limiting evaporative losses. Drops can also be used with drag hoses or bubblers that deposit the water directly on the ground between crops. Crops are often planted in a circle to conform to

15288-490: The irrigation results in flooding or near flooding of the cultivated land. Historically, surface irrigation is the most common method of irrigating agricultural land across most parts of the world. The water application efficiency of surface irrigation is typically lower than other forms of irrigation, due in part to the lack of control of applied depths. Surface irrigation involves a significantly lower capital cost and energy requirement than pressurised irrigation systems. Hence it

15435-498: The kingdom. Peroz tried again to drive out the Hephthalites, but on the way to Balkh his army was trapped by the Huns in the desert. Peroz was defeated and killed by a Hephthalite army near Balkh. His army was completely destroyed, and his body was never found. Four of his sons and brothers had also died. The main Sasanian cities of the eastern region of Khorasan − Nishapur , Herat and Marw were now under Hephthalite rule. Sukhra ,

15582-566: The later period. Sometimes one brick was set in the vertical position, with two horizontal rows of bricks laid above and below. The sizes of mud or fired bricks differ, but in general the standard size was 40 × 40 × 10 cm. The fired bricks were made from the local loess soil, and fired in kilns along the line of the wall. This wall starts from the Caspian coast, circles north of Gonbade Kavous (ancient Gorgan, or Jorjan in Arabic), continues towards

15729-399: The level of the land. Surface irrigation is even used to water urban gardens in certain areas, for example, in and around Phoenix, Arizona . The irrigated area is surrounded by a berm and the water is delivered according to a schedule set by a local irrigation district . A special form of irrigation using surface water is spate irrigation , also called floodwater harvesting. In case of

15876-441: The line is moved. They are most often used for small, rectilinear, or oddly-shaped fields, hilly or mountainous regions, or in regions where labor is inexpensive. A lawn sprinkler system is permanently installed, as opposed to a hose-end sprinkler, which is portable. Sprinkler systems are installed in residential lawns, in commercial landscapes, for churches and schools, in public parks and cemeteries, and on golf courses . Most of

16023-515: The longest defensive wall in existence, and although now in substantial disrepair, it was perhaps even more solidly built than the early forms of the Great Wall. Download coordinates as: The route, from east to west, is represented by the coordinates of the remains of the following forts and other features which lie along the wall. The coordinates and fort numbers, etc. are from Wikimapia: East end of wall West end of wall Dr. Kiani, who led

16170-402: The nomad King Grumbates , started his second campaign against the Romans in 359 and soon succeeded in retaking Singara and Amida. In response the Roman emperor Julian struck deep into Persian territory and defeated Shapur's forces at Ctesiphon . He failed to take the capital, however, and was killed while trying to retreat to Roman territory. His successor Jovian , trapped on the east bank of

16317-529: The northeast, and vanishes in the Pishkamar Mountains. The wall lies slightly to the north of a local river, and features a 5 m (16 ft) ditch that conducted water along most of the wall. In 1999 a logistical archaeological survey was conducted regarding the wall due to problems in development projects, especially during construction of the Golestan Dam, which irrigates all the areas covered by

16464-435: The oldest form of irrigation and has been in use for thousands of years. In surface ( furrow, flood , or level basin ) irrigation systems, water moves across the surface of agricultural lands, in order to wet it and infiltrate into the soil. Water moves by following gravity or the slope of the land. Surface irrigation can be subdivided into furrow, border strip or basin irrigation . It is often called flood irrigation when

16611-591: The opposite, western, side of the Caspian Sea at the port of Derbent , in the Republic of Dagestan, Russia. There the remains of a line of fortifications run inland for some 3 km (1.9 mi) from the shore of the Caspian Sea ( 42°03′46″N 48°18′26″E  /  42.062643°N 48.307185°E  / 42.062643; 48.307185 ) to what is today an extraordinarily well preserved Sassanian fort ( 42°03′10″N 48°16′27″E  /  42.052840°N 48.274230°E  / 42.052840; 48.274230 ) on

16758-436: The overarching goal of increasing self-sufficiency. Irrigation water can come from groundwater (extracted from springs or by using wells ), from surface water (withdrawn from rivers , lakes or reservoirs ) or from non-conventional sources like treated wastewater , desalinated water , drainage water , or fog collection . While floodwater harvesting belongs to the accepted irrigation methods, rainwater harvesting

16905-417: The petty landholding nobility who were the backbone of later Sassanid provincial administration and the tax collection system. Khosrow I built infrastructure, embellishing his capital and founding new towns with the construction of new buildings. He rebuilt the canals and restocked the farms destroyed in the wars. He built strong fortifications at the passes and placed subject tribes in carefully chosen towns on

17052-449: The physical territory that it controlled, impacting regions as distant as Western Europe , Eastern Africa , and China and India . It also helped shape European and Asian medieval art. With the Muslim conquest of Persia , the influence of Sasanian art , architecture , music , literature , and philosophy was gradually absorbed into nascent Islamic culture , which, in turn, ensured

17199-567: The production of 40% of food production. The scale of irrigation increased dramatically over the 20th century. In 1800, 8 million hectares globally were irrigated, in 1950, 94 million hectares, and in 1990, 235 million hectares. By 1990, 30% of the global food production came from irrigated land. Irrigation techniques across the globe includes canals redirecting surface water, groundwater pumping, and diverting water from dams. National governments lead most irrigation schemes within their borders, but private investors and other nations, especially

17346-479: The region as well as the economic geography of Gorgan Wall's environs. It is described as "amongst the most ambitious and sophisticated frontier walls" ever built in the world, and the most important of the Sasanian defense fortifications . It is 195 km (121 mi) long and 6–10 m (20–33 ft) wide, and features over 30 fortresses spaced at intervals of between 10 and 50 km (6.2 and 31.1 mi). It

17493-470: The regions saw increases in the area equipped for irrigation, with Africa growing the fastest (+29%), followed by Asia (+25%), Oceania (+24%), the Americas (+19%) and Europe (+2%). Irrigation enables the production of more crops, especially commodity crops in areas which otherwise could not support them. Countries frequently invested in irrigation to increase wheat , rice , or cotton production, often with

17640-556: The rich should divide their wives and their wealth with the poor. By adopting the doctrine of the Mazdakites, his intention evidently was to break the influence of the magnates and the growing aristocracy. These reforms led to his being deposed and imprisoned in the Castle of Oblivion in Khuzestan , and his younger brother Jamasp (Zamaspes) became king in 496. Kavad, however, quickly escaped and

17787-476: The size and room number of the barrack blocks in the Gorgan Wall forts and likely occupation density, produce figures between 15,000 and 36,000 soldiers. Even the lowest estimate suggests a strong and powerful army, all the more remarkable as our investigations focused just on 200km of vulnerable frontier, a small fraction of the thousands of kilometres of borders of one of the ancient world's largest empires. A similar Sasanian defence wall and fortification lies on

17934-448: The south with little or no interference from the Parthians. Ardashir was aided by the geography of the province of Fars, which was separated from the rest of Iran. Crowned in 224 at Ctesiphon as the sole ruler of Persia, Ardashir took the title shahanshah , or "King of Kings" (the inscriptions mention Adhur-Anahid as his Banbishnan banbishn , "Queen of Queens", but her relationship with Ardashir has not been fully established), bringing

18081-401: The spread of Iranian culture, knowledge, and ideas throughout the expanding Muslim world . Officially, the empire was known as the Empire of the Iranians ( Middle Persian : 𐭠𐭩𐭥𐭠𐭭𐭱𐭲𐭥𐭩 , ērānšahr , Parthian : 𐭀𐭓𐭉𐭀𐭍𐭇𐭔𐭕𐭓 , aryānšahr , Greek : Ἀριανῶν ἔθνος , Arianōn ethnos ), the term is first attested in the trilingual Great Inscription of Shapur I , where

18228-400: The sprinkler arrives back at the reel the system shuts off. This type of system is known to most people as a "waterreel" traveling irrigation sprinkler and they are used extensively for dust suppression, irrigation, and land application of waste water. Other travelers use a flat rubber hose that is dragged along behind while the sprinkler platform is pulled by a cable. Center pivot irrigation

18375-493: The sunlight; applying water carefully so it does not contaminate leaves likely to be eaten raw; cleaning vegetables with disinfectant; or allowing fecal sludge used in farming to dry before being used as a human manure. Irrigation water can also come from non-conventional sources like treated wastewater , desalinated water , drainage water , or fog collection . In countries where humid air sweeps through at night, water can be obtained by condensation onto cold surfaces. This

18522-431: The support of the Hephthalites , Kavad launched a campaign against the Romans. In 502, he took Theodosiopolis in Armenia, but lost it soon afterwards. In 503 he took Amida on the Tigris. In 504, an invasion of Armenia by the western Huns from the Caucasus led to an armistice, the return of Amida to Roman control and a peace treaty in 506. In 521/522 Kavad lost control of Lazica , whose rulers switched their allegiance to

18669-782: The total fertile land was 2,788,000 km (689 million acres) and it was equipped with irrigation infrastructure worldwide. About 68% of this area is in Asia, 17% in the Americas, 9% in Europe, 5% in Africa and 1% in Oceania. The largest contiguous areas of high irrigation density are found in Northern and Eastern India and Pakistan along the Ganges and Indus rivers; in the Hai He, Huang He and Yangtze basins in China; along

18816-518: The two empires to focus on military matters elsewhere: Khosrow focused on the Sassanid Empire's eastern frontier while Maurice restored Byzantine control of the Balkans . Circa 600, the Hephthalites had been raiding the Sassanid Empire as far as Spahan in central Iran. The Hephthalites issued numerous coins imitating the coinage of Khosrow II. In c.  606/607 , Khosrow recalled Smbat IV Bagratuni from Persian Armenia and sent him to Iran to repel

18963-401: The wall, near the town of Pishkamar , is near the remains of the fort at: 37°31′14″N 55°34′37″E  /  37.5206739°N 55.5770498°E  / 37.5206739; 55.5770498 . The title coordinate is for the location of the remains of a fort midway along the wall. The wall is located at a geographic narrowing between the Caspian Sea and the mountains of northeastern Iran. It

19110-430: The wall. At the point of the connection of the wall and the drainage canal from the dam, architects discovered the remains of the Great Wall of Gorgan. The 40 identified fortresses vary in dimension and shape but the majority are square fortresses, made of the same brickwork as the wall itself and at the same period. Due to many difficulties in development and agricultural projects, archaeologists have been assigned to mark

19257-582: The war resumed but remained confined to Lazica, which was retained by the Byzantines when peace was concluded in 562. In 565, Justinian I died and was succeeded by Justin II (565–578), who resolved to stop subsidies to Arab chieftains to restrain them from raiding Byzantine territory in Syria. A year earlier, the Sassanid governor of Armenia, Chihor-Vishnasp of the Suren family, built a fire temple at Dvin near modern Yerevan , and he put to death an influential member of

19404-405: The water source by a hose. Automatically moving wheeled systems known as traveling sprinklers may irrigate areas such as small farms, sports fields, parks, pastures, and cemeteries unattended. Most of these use a length of polyethylene tubing wound on a steel drum. As the tubing is wound on the drum powered by the irrigation water or a small gas engine, the sprinkler is pulled across the field. When

19551-414: The water table to allow the soil to be moistened from below the plants' root zone. Often those systems are located on permanent grasslands in lowlands or river valleys and combined with drainage infrastructure. A system of pumping stations, canals, weirs and gates allows it to increase or decrease the water level in a network of ditches and thereby control the water table. Subirrigation is also used in

19698-413: Was a key component of the green revolution; the Americas account for 16% and Europe for 8% of the world total. India (76 million ha) and China (75 million ha) have the largest equipped area for irrigation, far ahead of the United States o fAmerica (27 million ha). China and India also have the largest net gains in equipped area between 2000 and 2020 (+21 million ha for China and +15 million ha for India). All

19845-540: Was also amenable to the wishes of the Zoroastrian priesthood. During his reign, the Sassanid capital Ctesiphon was sacked by the Romans under Emperor Carus , and most of Armenia, after half a century of Persian rule, was ceded to Diocletian . Succeeding Bahram III (who ruled briefly in 293), Narseh embarked on another war with the Romans. After an early success against the Emperor Galerius near Callinicum on

19992-426: Was appointed shah (king), he moved his capital further to the south of Pars and founded Ardashir-Khwarrah (formerly Gur , modern day Firuzabad ). The city, well protected by high mountains and easily defensible due to the narrow passes that approached it, became the center of Ardashir's efforts to gain more power. It was surrounded by a high, circular wall, probably copied from that of Darabgerd. Ardashir's palace

20139-503: Was captured by Shapur, remaining his prisoner for the rest of his life. Shapur celebrated his victory by carving the impressive rock reliefs in Naqsh-e Rostam and Bishapur , as well as a monumental inscription in Persian and Greek in the vicinity of Persepolis . He exploited his success by advancing into Anatolia (260), but withdrew in disarray after defeats at the hands of the Romans and their Palmyrene ally Odaenathus , suffering

20286-419: Was crowned in utero : the crown was placed upon his mother's stomach. During his youth the empire was controlled by his mother and the nobles. Upon coming of age, Shapur II assumed power and quickly proved to be an active and effective ruler. He first led his small but disciplined army south against the Arabs, whom he defeated, securing the southern areas of the empire. He then began his first campaign against

20433-443: Was defeated at the Battle of Dara . In the same year, a second Persian army under Mihr-Mihroe was defeated at Satala by Roman forces under Sittas and Dorotheus, but in 531 a Persian army accompanied by a Lakhmid contingent under Al-Mundhir III defeated Belisarius at the Battle of Callinicum , and in 532 an "eternal peace" was concluded. Kavad succeeded in restoring order in the interior and fought with general success against

20580-452: Was given refuge by the Hephthalite king. Jamasp (496–498) was installed on the Sasanian throne upon the deposition of Kavad I by members of the nobility. He was a good and kind king; he reduced taxes in order to improve the condition of the peasants and the poor. He was also an adherent of the mainstream Zoroastrian religion, diversions from which had cost Kavad I his throne and freedom. Jamasp's reign soon ended, however, when Kavad I, at

20727-556: Was killed by his brother Peroz in 459. At the beginning of the 5th century, the Hephthalites (White Huns), along with other nomadic groups, attacked Iran. At first Bahram V and Yazdegerd II inflicted decisive defeats against them and drove them back eastward. The Huns returned at the end of the 5th century and defeated Peroz I (457–484) in 483. Following this victory, the Huns invaded and plundered parts of eastern Iran continually for two years. They exacted heavy tribute for some years thereafter. These attacks brought instability and chaos to

20874-666: Was needed to produce their food. They required a third of the volume of water humans presently take from rivers. Today, the competition for water resources is much more intense, because there are now more than seven billion people on the planet, increasing the likelihood of overconsumption of food produced by water-thirsty animal agriculture and intensive farming practices. This creates increasing competition for water from industry , urbanisation and biofuel crops . Farmers will have to strive to increase productivity to meet growing demands for food , while industry and cities find ways to use water more efficiently. Successful agriculture

21021-519: Was on the north side of the city; remains of it are extant. After establishing his rule over Pars, Ardashir rapidly extended his territory, demanding fealty from the local princes of Fars, and gaining control over the neighbouring provinces of Kerman , Isfahan , Susiana and Mesene . This expansion quickly came to the attention of Artabanus IV, the Parthian king, who initially ordered the governor of Khuzestan to wage war against Ardashir in 224, but Ardashir

21168-480: Was overthrown by a palace coup and his son Khosrow II (590–628) placed on the throne. However, this change of ruler failed to placate Bahram, who defeated Khosrow, forcing him to flee to Byzantine territory, and seized the throne for himself as Bahram VI. Khosrow asked the Byzantine Emperor Maurice (582–602) for assistance against Bahram, offering to cede the western Caucasus to the Byzantines. To cement

21315-494: Was returned to Roman domination, with the fort of Ziatha as its border; Caucasian Iberia would pay allegiance to Rome under a Roman appointee; Nisibis, now under Roman rule, would become the sole conduit for trade between Persia and Rome; and Rome would exercise control over the five satrapies between the Tigris and Armenia: Ingilene , Sophanene ( Sophene ), Arzanene ( Aghdznik ), Corduene , and Zabdicene (near modern Hakkâri , Turkey). The Sassanids ceded five provinces west of

21462-508: Was to be later confirmed by the Nvarsak Treaty (484). At the beginning of his reign in 441, Yazdegerd II assembled an army of soldiers from various nations, including his Indian allies, and attacked the Byzantine Empire , but peace was soon restored after some small-scale fighting. He then gathered his forces in Nishapur in 443 and launched a prolonged campaign against the Kidarites . After

21609-513: Was victorious in the ensuing battles. In a second attempt to destroy Ardashir, Artabanus himself met Ardashir in battle at Hormozgan, where the former met his death. Following the death of the Parthian ruler, Ardashir went on to invade the western provinces of the now defunct Parthian Empire. At that time the Arsacid dynasty was divided between supporters of Artabanus IV and Vologases VI , which probably allowed Ardashir to consolidate his authority in

#3996