Makran-Flood
Annually, 569 million cubic meters of surface water from regional rainfall enters the Oman Sea as runoff. Recent unofficial reports estimate the volume of runoff entering the Oman Sea to be as high as 2 billion cubic meters.
Images captured by NASA's Aqua satellite of the movement of the January 1398 (January 2020) floods in Sistan and Baluchestan province
Natural structures related to floods in province:
The important rivers of the province include the Hirmand River in Sistan, which is the vital artery of this region. In Baluchistan, the important rivers include the Bampur River in Iranshahr, the Sarbaz River in Sarbaz, the Cashew and Kehir rivers in Nikshahr, the Bahuklat River in Chabahar, and the Mashkid River in Saravan.Hamon International Wetlands in Sistan region with an area of 4000 square kilometers and an average depth of 5 meters is the largest freshwater lake in the country and is divided into three parts: Puzak, Sabouri and Hirmand.The importance of this lake is due to its fresh water and the possibility of catching fish in the years of high water and providing fodder for livestock through its margins and reeds. Also, when the wetlands are full of water, the water flow returns to the border of Afghanistan through the Shila waterway.Jazmurian lagoon is a seasonal lake in Balochistan region and it is located in the west of Balochistan between Makran and Shahsavaran mountains. A large part of this lake is located in Kerman province. This lake has fresh water. Jazmurian wetlands are considered one of the most important wetlands in the province.
Investigating the flood situation of Sistan and Baluchistan :
As seen in the map, the northern cities of this province (Sistan) are located in the catchment area of Hirmand and Hamon rivers, which have experienced cold weather and even snow during the recent winter. The southern cities of Makran province and the coast of the Oman Sea (Baluchistan) have also faced floods in recent rains by receiving high amounts of torrential rains and dams overflowing. It should be noted that the natural conditions of the province are such that the rainfall of the northern cities flows downstream, and due to the location of these cities next to the Makran coast, the condition of the underground water level, the conditions of the coastal soil and its permeability, the land surface faces flooding for some time.
The following table shows the damage that occurred in Sistan and Baluchistan province after heavy rains in the southern regions of this province. Seasonal rivers overflowed and closed 15 main and secondary roads in this province. About 3,000 houses were damaged in the areas of Iranshahr, Sarbaz, Nikshahr, Kanarak, etc. Also, 3 villages were completely evacuated due to their proximity to the river.
In the two years ending 1395, the average rainfall in this province was reported to be 105 mm, but only in the rains of the end of January and the beginning of February, the amount of rainfall reached at least 100 mm. It is important to note that this phenomenon does not stop even during the periods of water shortage and drought, and sometimes it occurs with greater intensity and higher amount of damages.
On average, a major flood occurs in Sistan and Baluchestan province every one and a half years. These floods have caused significant financial and human losses.
According to the report of the Crisis Management Organization of the country and the Ministry of Interior, the amount of flood damage in the past fifteen years (2006-2021) in Sistan and Baluchestan province is as follows
The amount of flood damage in the past fifteen years (2006-2021) in Sistan and Baluchestan province is as follows
The average annual damage of floods in the past fifteen years (1385-1400) in Sistan and Baluchestan province has been estimated at 2000 billion tomans.
The damage includes residential areas, agriculture, livestock, industry, services, health and environment
Examining the records of previous floods in South Baluchistan region
Sistan and Baluchistan province has been affected by severe floods many times in recent years due to weather conditions. One of the most important floods in recent years in this province is Hirmand flood in 2016.
The severity of the flood in Esfand 1402 in the catchment area of Bent Hemgan is higher due to its geographical location, special climatic conditions, geology and basin factors, and every year a huge amount of flood flow causes the destruction of residential places, agricultural lands and many human and financial losses.
Bent city is the center of Bent district of Nikshahr city, 85 km northwest of Nikshahr and 45 km south of Fanuj city, at an altitude of 400 meters above sea level. The urban area of Bent has an area of about 15 square kilometers. Bent is a semi-mountainous region where the yellow hills are located in the west and north. In the eastern part of the city, the path of the river called Bent, which originates from the north of Fanuj and passes through the eastern part of Bent, is located. and is located about 8 km in the urban area. South of the city of Bent is the path of the mentioned river, on both sides of which there are villages. After passing through the Fanuj Strait and crossing the Sefidkouh mountain range, when the Bent river reaches the area of Bent city, there are villages on both sides of it.
Flood on July, December 2016
On July 2016, due to the overflow of seasonal rivers following long rains in different regions of the province and again the flood occurred in December, around 3000 houses were damaged in Iranshahr, Sarbaz, Nik Shahr and Konarak areas. Also, 3 villages were completely evacuated due to their proximity to the river.
Investigating the flood event of January 2020
This rain system has moved from the eastern end of the Mediterranean Sea since the middle of Wednesday, 18 Day 1398 SH and moving eastward, it entered the country from the west side of the country and affected the areas located in the northwest, west, southwest, and a threshold located on the slopes of the southern Alborz. Then, with the strengthening of the southerly currents, since late Thursday (19 Day 1398 SH), the intensity and amount of rainfall in the southern provinces has gradually increased. The wind velocity potential anomaly map at the limit of the atmosphere on Saturday, 21 Day 1398 SH also shows a divergence. It has been severe in the upper level, which has led to the convergence of the lower level and strengthening and intensifying the instabilities in these areas.
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At the same time, the rotational level of 500 hPa on Saturday, 21 Day 1398 SH also showed two low pressure centers (L) which are consistent with the areas of maximum rainfall.
Heavy rain, momentary gusts, fog, 10-degree drop in air temperature and night frost were among the most important phenomena that affected Sistan and Baluchistan province during the three days of the flood event. The intensity of these rains was in the cities of Nik Shahr, Fanuj, Konarak, Chabahar, Dalgan and in general the central and southern areas of the province. Despite the existence of two big dams in the region, the Pishin and the Zirdan, due to their overflowing, the villages were surrounded by floods in the Dashtiari and Bahu Kalat areas.
The statistics recorded in the meteorological stations of Sistan and Baluchistan province, according to the general affairs office statements of the Meteorological Department of this province, show that Sistan and Baluchistan province has received unprecedented rainfall compared to the last 20 years.
According to the latest information received from 15 rain gauge stations, the amount of rainfall received in the province is reported to be more than 100 mm, which is equivalent to the rainfall of one agricultural year in the province in the long term. According to the statistics provided regarding the amount of rainfall received, 17 stations of this province have recorded rainfall between 100 and 186 mm, and out of 145 rain gauge stations, 94 stations have received more than 50 mm of rainfall.
Among the dimensions of this event, we can mention the flow of flood at some points, so that the volume of water overflowed to 3500 cubic meters per second after some dams were filled in the area affected by the event, including: Zirdan, Pishin, Kalk and Khairabad.
Topographic effects lead to flood events
The effect of topography in some areas on the occurrence and intensification of floods can be seen. Among the areas that received the most impact from the floods in the province, we can mention the area of Jaz Murian Lake and the southern and coastal areas of Sistan and Baluchistan province and in the vicinity of the Oman Sea.
According to the topographic conditions around the lake, the paths of the runoff movement in different directions towards the lake are shown. According to these images, the influence of topographic conditions in creating and intensifying this flood was identified.
Sources of images: the website of the Natural Disasters Research Institute
The effect of topographic slope on the formation of floods 2020 in Sistan and Baluchistan province
14 cities in Sistan and Baluchistan province were affected by flood on 18 Day 1398 SH. These cities included: Iranshahr, Chabahar, Khash, Dalgan, Zahedan, Sarbaz, Saravan, Sib and Suran, Fanuj, Konark, Mehrestan, Mirjaveh, Nik Shahr and Hirmand. In this flood, the cities of Konark, Fanuj, Dalgan, Chabahar and Sarbaz, which were among the southern half of the province, experienced critical conditions.
The surface runoff resulting from the recent flood in different parts of the south of Sistan and Baluchistan province, which is shown in turquoise blue color.
The cities affected by the flood are: Nik Shahr, Qasr-e Qand, Dashtiari, Chabahar, Konarak, Khash, Sib and Suran, Fanuj, Iranshahr, Bampur, Mirjaveh, Dalgan, Saravan, Zarabad, Sarbaz, Rask, Mehrestan, Lashar, Taftan.
Flood 1400
This year, in the months of June and July, several floods caused damage to gardens and some rural houses in different cities.
Flood 1401
In July, due to the rains caused by the monsoon rains, the cities of Dashtiari, Qasr-e Qand,Nik Shahr and Chabahar and their villages were affected by floods and a lot of damage was caused to infrastructures and facilities, houses and gardens.
Investigating the flood event of Esfand 1402 SH
On 6 Esfand 1402 SH, following heavy rains in 11 cities of Sistan and Baluchistan, floods occurred and more than 110 thousand people from the southern villages of this province were in a critical situation.
The rain on 6 and 7 Esfand SH caused floods in Sistan and Baluchistan province, closing the roads of more than 270 villages in two southern cities of this province, and the flood led to cut off access to 230 villages and caused a lot of damage to residential units, agricultural lands and Public facilities.
16 cities of Sistan and Baluchistan province have been affected by floods and inundation caused by rains since 9 Esfand, which include the cities of Nik Shahr, Qasr-e Qand, Dashtiari, Chabahar, Konarak, Khash, Sib and Suran, Fanuj, Iranshahr, Mirjaveh, Dalgan, Saravan, Zahedan, Nimruz, Sarbaz and Mehrestan.
Meteorology and atmospheric analysis of recent floods
Regarding the flood of Esfand 1402 SH, a Mediterranean low-altitude mass was established in the eastern region of the Mediterranean Sea and a rain line was formed between the high-altitude center of Africa and the cold high pressure of Eurasia, so that developed in the center of the Mediterranean low-pressure mass and has created the start of the activity of a relatively powerful system in the interaction of these conditions. With the relatively abnormal high-altitude retreat of the subtropical zone to the southern regions of the Arabian Sea and the formation of the anticyclone pattern in the middle level, the emission of moist air from the western Indian Ocean in the left arm of this anticyclone has occurred towards the Mediterranean low pressure center and the dense convergent line below it. The Mediterranean system with the support of the waters of the Black Sea and the Mediterranean Sea entered the country from the west and covered the west, center and northeast, and the southern branch, with the support of the moist currents of the East India, covered the southern regions of the country and its activity peak in the south of Sistan and Baluchistan has caused floods and inundation.
The possibility of water ponding, flooding, and powerful thunderstorms in some parts of Sistan and Baluchistan (Nusratabad and Fanuj) is shown in the picture.
Total rainfall on 15 and 16 Esfand 1402 SH in mm based on the American GFS model.
The amount of rainfall recorded in the fall and winter of 1402 SH in Sistan and Baluchistan province
The flood of Esfand 1402 SH caused the overflow of seasonal rivers and heavy rainfall in Qasr-e Qand, Talang, Dashtiari, Polan and Pir Sohrab caused heavy damage to the agricultural sector, adobe houses, rural roads and urban and rural infrastructures, so that the roads of all the villages were closed and there is no connection with other neighboring cities and even one village to another village.
16 cities of Sistan and Baluchistan province have been affected by floods and inundation caused by rains since 9 Esfand SH, which include the cities of Nik Shahr, Qasr-e Qand, Dashtiari, Chabahar, Konarak, Khash, Sib and Suran, Fanuj, Iranshahr, Mirjaveh, Dagan, Saravan, Zahedan, Nimruz, Sarbaz and Mehrestan. According to the 90 meteorological stations of Sistan and Baluchistan province, it can be seen that Zarabad 36 mm, Iranshahr Airport 19.2 mm, Saravan 20.2 mm and Mehrestan 17.2 mm of rain have received.
Heavy rain caused Zirdan dam to overflow and water is flowing downstream of the dam with a very high volume.
Rainfall in the upstream has caused the flow of water in the rivers of the region to exceed 2 million liters per second, for example: the flow of the Kajo River in the upstream reaches 2 million and 200 thousand liters per second. Four years ago, heavy rain since 18 Esfand 2018 SH led to floods in the provinces of Hormozgan, Kerman and Sistan and Baluchistan in the south of Iran.
The report of the National Center for Climate and Drought Crisis Management of the I.R. Of Iran Meteorological Organization also shows that the amount of rainfall in Sistan and Baluchistan from the beginning of the current crop year to the beginning of the rainy systems in Esfand 16.4 mm, which has decreased by 68% compared to the same long-term period and after the activity of the recent systems, the amount of precipitation in the province has reached 54.9 mm, which shows an increase of 1.5% compared to the same long-term period. The highest amount of rainfall in recent systems has been recorded from Qasr-e Qand station with 319 mm, Owraki station with 217 mm, Bahu Kalat station with 207.5 mm, and Negur station with 203 mm and the lowest amount of rainfall in Zhalehi station with 5.5 mm, Mohammad Abad station with 5mm, Rostam Castle station with 6mm, Zehak station with 1.6 mm and Zabul station with 7.6mm.
summary and Conclusion
Planning, lack of dredging and lack of proper management of watershed and aquifer management projects and improper location of some villages and cities can become a threat and cause irreparable damages. In this regard, some of the most important challenges raised in the investigation of the flood of March 2024 in this province are:
•The continuous rainfall and the high volume of received rainfall and the environmental and topographic features of the region such as very low permeability of clay and marl in wide plains with a low slope have led to flooding of a large area of the region.
•The method of cultivation and development of agricultural lands in the canals and waterways has caused most of the flood left to spread in the agricultural lands and along with the severe erosion of the agricultural lands and the destruction of the flood dams, a large part of the areas, especially in Dashtiari, has gone under water and caused the loss of agricultural products of the region.
•The damage to the infrastructure as well as the blocking of communication routes have led to the creation of emergency situations, especially the lack of access to food, safe drinking water, fuel, etc.
•Demolition of Sarh Dam and flood dams, part of which needs to be investigated in line with the necessity of proper management of watershed and aquifer projects.
•The high volume of mud and sediments carried by the flood has led to traffic problems, unsuitable living conditions in the tents, burial of cattle carcasses damaged by the flood, and accumulation of sediments in gardens in some areas.
•The insufficient carrying capacity of the river, the inadequacy of the bridge on the roads and the interruption of the roads and paths can lead to a situation similar to what has happened in Delgan city located in the Jazmurian catchment area, where due to the presence of a seasonal lake, all the paths are completely interrupted due to the occurrence of rain and floods.
•Ignoring seasonal rivers and not respecting the privacy and bed of rivers, and the location of many villages such as Dashtiari and Chabahar villages on the path of seasonal rivers, leads to injuries when the river floods or the dam overflows; Especially, due to the drought conditions in this region, many people have directed their lives and livestock to the river beds in order to provide water for livestock.
Unresilient soil has led to weakness in the strength of houses, especially in the Makran coast.
Non-establishment of the necessary systems and equipment regarding flood forecasting and warning at the province level and the need to prepare a flood risk zoning map, a map of safe and prohibited areas in terms of construction, agriculture, animal husbandry and the development of urban and rural settlements are among the important challenges in the field. Flood risk management.
The amount of flood damage is estimated at 2000 billion tomans.
History of floods: March 2024, summer 2022, December 2020, December 2017, March 1393 and December 2012 floods started from Pirsohrab in the south of Bahuklat. This river has a capacity of no more than 1000 cubic meters of water per second.
In the recent flood (March 2024), the water flow was 3000 cubic meters per second, and the volume of water was more than 4 billion cubic meters, which is equivalent to 1/5 of the annual flow of Karun River. When the rainfall is too much, the dams are not enough, the solution is in the way of the spring, and the rainwater should be trapped in the river branches. All areas should be controlled as "watersheds and dams". The traditional watershed called Khoshab collects a large volume of water and sediments and reduces the speed of the water. Hotak drilling and semi-wells are also other solutions.
Due to the vastness of the region and the time-consuming solutions such as building a dam, it is necessary to consider other solutions. Among other things, collecting and channeling the flood into the natural reservoirs of the region, such as the Chahan twin floodplain, will play an effective and valuable role in preventing flood damage to residential, agricultural, livestock, industry, services, health and environment areas in the affected areas such as Kanarak and Zarabad. And according to the interpretation of the interpreter, the threat will turn into an opportunity.
Cumulative Precipitation System from 7th to 11th of Esfand (February) 1402
River in the Flooded Province
Kaju Station in Chabahar:
Maximum Water Level (Ashl): 268 centimeters
Maximum Discharge (Debi): 2500 cubic meters per second
Cumulative Precipitation System from 7th to 11th of Esfand (February) 1402
River in the Flooded Province
Kaju Station in Chabahar:
Maximum Water Level (Ashl): 268 centimeters
Maximum Discharge (Debi): 2500 cubic meters per second
5 High-Rainfall Stations:
Pir Saharab Station: 206.5 millimeters
Bahukalat Station: 178 millimeters
Bent Station: 107 millimeters
Chabahar Station: 58 millimeters
Cumulative Precipitation Since the Beginning of the Current Year: 269.2 millimeters
Long-Term Average: 311
Changes Compared to the Previous Year: 214.5
