The importance of the Indus River

The great river outside the Himalayas is one of the longest rivers in the world, with a total length of 2,900 kilometers (1800 miles). The total area of the basin is about 1,165,500 square kilometers (450,000 square miles), of which 453,250 square kilometers (175,000 square miles) are located in the Himalayas and its foothills, and the rest are located in the semi-arid plain of Pakistan. The annual flow is about 207 billion cubic meters (272 billion cubic yards)-twice that of the Nile and three times that of the Tigris and Euphrates rivers combined. It is the earliest record and ode of Aryans in ancient India, Rigveda (Rigveda, 1500? BC), which is also the source of the name of India.

Indus River is the main river in Pakistan and an important water source for agricultural irrigation in Pakistan. The name of this river comes from the Latin spelling of Sanskrit Sindhu, which means "river". Before the division of India in 1947, the Indus River was the cultural and commercial center of this region, second only to the Ganges River. The total length of the river is 2900 ~ 3200 kilometers. Indus civilization is one of the first major civilizations in the world to enter agricultural civilization and settle in society.

The Indus River originates from the Shiquan River in China in the western Himalayas, flows through Kashmir from southeast to northwest, then flows through Pakistan in the southwest, and flows into the Arabian Sea near Karachi. Most of the upper reaches of the left tributaries are in Indian territory, a few are in China, and some tributaries on the right originate in Afghanistan. The Indus River basin has a total area of 65.438+0.34 million km2, the length of the main stream is about 2900km, the average annual runoff is 207 billion m3, the annual sediment transport is about 540-630 million t, and the average sediment concentration is 3 kg/m3.

The mainstream of the Indus River originates from the Himalayan mountain system in China and Tibet-the northeast of Mount Kailas. The average elevation of the peak is about 5500 meters, and it is covered with snow all year round. In India, rivers basically flow to the northwest. This river crosses between the Himalayas and the Karakorum Mountains, accepts many glaciers, enters Pakistan, joins the Gilgit River near Bungi, and then turns southwest. Indus valley

The main stream of the Indus River is about 1368km from its source upstream to Karabakh. The river runs through the canyon, with narrow channel, large slope, steep beach and high velocity. The Grand Canyon has two sections, one from Skadu to Bangji and the other from Atok to Karabakh. Karabakh to Hy-Derabad is the downstream reach, with small river bed gradient, wide channel, branched rivers and slow flow rate, which has the characteristics of plain rivers. However, between Sukur and Rory, the river channel is narrow, and the steep wall of Lahi Mountain with a height of about 1.82m appears near the town of Sehewan. Below Hyderabad is the estuary section, which is the Indus Delta. Because the upper reaches are mostly glacier snow-capped mountains, snowmelt brings a lot of sediment to accumulate on the river bed, which leads to the expansion of the delta area year by year, and the estuary extends outward about 1 1.8m every year. There are delta lagoons and oxbow lakes between river branches in the delta.

[Edit this paragraph] Water system composition

There are many tributaries of the Indus River, and there are 8 tributaries on the left bank. There are three tributaries on Potwar Plateau, namely Soan River, Haro River and Siran River, with relatively small flow. There are five tributaries in Punjab Plain, namely Jie Hellem River, chenab river River, Ravi River, Sutleji River and Bis River. Among them, the Jie Hellem River and the Ravi River are tributaries of chenab river, and the Biyus River is a tributary of the upper reaches of the Sutleji River.

The Jie Hellem River runs from Muazffarabad to Jie Hellem town, with a total length of 692 kilometers and a drainage area of 63,500 square kilometers, mainly flowing through the border between Pakistan and Kashmir. Jie Hellem River is relatively narrow above Khushab, with a width of about 3km, and turns sharply south below Khushab, with a riverbed width of about 19km and a width of 24km below Sahiwal. There are many winding ancient rivers between the two banks.

The total length of Chenab River is 1030km, and the drainage area is13.610,000km2 (including the Jie Hellem River), which originates at 40km east of Garang in northern Himachal Pradesh. The river flows south first, then turns northwest, flows through Kashmir and enters Pakistan near Aknur. Geneb's rivers are undulating. Except for the reach above Chiniot, the riverbed is generally about 6.5km wide.

Ravi River, with a total length of 660km and a drainage area of 1. 1.6 million km2, originates in the central Indian state of Himachal Pradesh and flows into Pakistan from Mad Hapl south of Besoli. The riverbed width is less than 3km, but the river channel is curved.

The total length of Satlej River is 65,438+448 km, and the drainage area is 86,000 krn2 (excluding Bias River). It originates from Zangbo River in Qin Lang, Tibet, China, flows through India, and enters Pakistan in the north of Ferozt Bohr, Ferozt Province. The river bed is very wide. From Rupar to 32km above Ba-Hawalpur, the riverbed width is about 6- 12km. From here to the confluence, the width of the river bed is reduced to about 1, 5km.

There are six tributaries on the right bank of the Indus River, namely Kabul River (with a drainage area of 88,500 km2 and a length of about 5 10km), Ko Hattoy River in kohat, Tritori River, Gurram River, Goumard River and Balao River in Tritto. The first five tributaries flow through the mountainous and hilly areas on the northwest border of Pakistan, all of which flow from west to east. The Kabul River, the Guram River, the Toye River in kohat and the Tritto River all originate in Afghanistan. The first two tributaries have a large amount of water, and the last two tributaries are small rivers. Located in Sindh province, the Baren River is the only tributary accepted by the mouth of the Indus River. It is a river with water all the year round, which is of great significance for irrigation in Karachi Plain of Pakistan.

The countries in the basin cover an area of 52,920 square kilometers in China, 66,000 square kilometers in Afghanistan, 354,000 square kilometers in India and 56 square kilometers in Pakistan. 65,438+0,000 square kilometers.

[Edit this paragraph] Natural features

1. Topography: Indus Valley is located between 24 degrees north latitude .. ~37. , about 66 east longitude. —82。 It is bordered by Karakorum Mountains and Himalayas in the northeast, thar desert in the southeast, Hindu Kush in the northwest, Baluchistan Plateau in the southwest and Arabian Gulf in the south. Both the upper reaches of the main stream and the upper reaches of the left bank tributaries are in mountainous areas. The lower reaches of the main stream and the estuary are located in the Indus Plain. Between the mountain and the plain is a complex terrain composed of Zhongshan, low mountains, hills and intermountain basins. The total area of the plain area is about 580,000 square kilometers. Rivers flowing through mountainous areas are high in mountains and deep in valleys, with a large gap between people and rich in hydraulic resources. Indus Plain is one of the largest alluvial plains in the world, covering an area of about 266,000 km2, accounting for about 1/3 of Pakistan's land area. It extends from the foothills of the Himalayas to the Arabian Sea, with an average east-west width of about 320 kilometers. The maximum width is about 560km in Pangxiexi Plain, and the narrowest part is 16 1km. This fertile land is the richest place in Pakistan.

The eastern part of the Indus Plain is an extension of thar desert, which is divided into north and south. The northern desert is called Choliston Desert, and the southern desert is still called thar Desert, covering an area of about 34,000 km2. The northwest of the Indus Plain reaches the Suleiman Mountains in Baluchistan Plateau. Indus plain is divided into upper Indus plain and lower Indus plain, with latitude of 29'. The upper reaches of the Indus River plain is the confluence of five rivers (Sutleji River, Ravi River, chenab river River, JieHellem River and Indus River), and the land between the rivers is wide, generally 5 ~ 20m higher than the riverbed. The riverbed is constantly moving, and a large amount of sediment brought by floods often accumulates into new alluvial deposits and shoals. The lower Indus River plain is an obvious meandering belt and flood plain. Embankments are built along the banks of the Indus River, and the dike spacing is generally 19-24km. The western and southern parts of the lower Indus plain are low-lying areas, and floods often occur.

The Indus River rises in southwest Tibet, with an altitude of about 5,500 meters (18,000 feet). It flows about 322 kilometers (200 miles) to the northwest and crosses the southeast border of Jammu and Kashmir at an altitude of about 4,572 meters (15,000 feet). Not far from the lower reaches of Ladakh Mountain Liecheng, its first tributary, the Zaska River, flows into the left bank. After driving in the same direction for 24 1 km (150 miles), it accepted its famous tributary Shyok River on the right bank. After merging with Shyork River, it is supplemented by huge glaciers on the slopes of Karakorum Mountain, Nanga Mountain Plateau and Kohistan Plateau, until Kohistan region. Rivers such as Shyork, Higl and Gilgit inject glacial meltwater into the Indus River. Because the current precipitation in this area is not enough to supply these large glaciers, it is quite certain that the huge glaciers in the Karakorum Mountains are the remains of the last ice age in the Himalayas.

The Higl River flows into the Indus River from the right bank near Bertistanskadu. The Gilgit River is another tributary of the downstream right bank, which flows into Bunji. A few miles downstream, the Astor River, a tributary of the left bank, joins. Then it flows west, crosses the Kashmir border, turns south and southwest, and enters Pakistan. At a depth of 4572? 5182m (15000? 17000 feet) and 19? 26 km (12? 16 mile) around the edge of Nanga Mountain Plateau (8 126 meters [26,660 feet]). The path winds on a steep hillside from 1, 2 19? 1.524m(4000m？ Overlooking the river is daunting.

After the Indus River flows out of this high altitude area, it becomes a fast-flowing mountain river between Swat and Hazara until it reaches the Talbela Dam Reservoir. The Kabul River flows into the Indus River in the upper reaches of the Atok River. In this section, the Indus River flows at an altitude of 665,438+00 meters (2,000 feet), and the first railway highway bridge flies overhead. Finally, cross the salt ridge of Karabakh and enter the Punjab Plain. The upper reaches of the Indus River between Skardo and the entrance to the Gilgit River.

The five most famous tributaries from the East Punjab Plain-Jie Hellem River, chenab river River, Ravi River, Biyus River and Satleji River-give the land owned by Pakistani and Indian * * * the name Punjab ("State of Five Rivers").

The Indus River widens after accepting the water from Punjab. During the flood season (7? September) can be miles wide. Run at an altitude of about 79 meters (260 feet). The slow flow rate in this section of the river leads to sediment accumulation on the river bed, which is higher than the plane of this sandy plain; In fact, most of the plains in Sindh province are formed by alluvial sediments abandoned by the Indus River. The dam was built for flood control, but occasionally it collapsed, so a large area was destroyed by the flood. The floods occurred in 1947 and 1958. During flooding, rivers sometimes change course.

The Indus River begins to flow into the delta near Tata, divides into several tributaries and empties into the sea at different locations south-southeast of Karachi. The delta covers an area of over 7,770 square kilometers (3,000 square miles) and extends about 209 kilometers (130 miles) along the coast. Existing and abandoned waterways make the delta surface uneven. The seaside is about 8? 32 kilometers (5? 20 miles) was submerged by the tide at high tide.

2. Climate and hydrology: The Indus Valley belongs to subtropical climate with obvious monsoon climate characteristics. However, due to the influence of the northeast mountains, the climate is usually between dry and arid, tropical and subtropical. A year is divided into four seasons: 12- March of the following year is the northeast monsoon season, with low temperature, little precipitation and low humidity; July-September is the southwest monsoon season, with a lot of precipitation, thunderstorms and high humidity, and it is a rainy season all year round. April-June is the transition period from northeast monsoon to southwest monsoon, also known as hot season, with dry air and high temperature; 10-165438+10 is the retreat season of southwest monsoon, that is, the transition season from southwest monsoon to northeast monsoon, with less rainfall and large temperature difference between day and night, but the season is relatively cool. The highest temperature in the basin is about 46C, and the lowest temperature is about minus 15C. The average annual precipitation is about 300 mm.

From Heyuan to Hekou, the annual rainfall in the Indus region 125? 500 mm (5? 20 inches). Apart from the mountainous areas of Pakistan, the Indus Valley is the driest area in the subcontinent. In winter, westerly winds swept the upper valley of the Indus River, bringing 102? 204 mm (4？ 8 inches) of rainfall-this is extremely important for the growth of wheat and barley. Snowfall is the main form of precipitation in the mountainous area of the basin. A large part of the Indus River is provided by melting snow and glaciers in Karakorum, Hindu Kush and Himalayan Mountains. Monsoon rainfall (7? September) provide the remaining water. The climate of the Indus Valley includes the semi-desert climate of Sindh and Lower Punjab, and the harsh alpine climate of Kohistan, Hansa, Gilgit, Ladakh and Tibet. In the north, the temperature in June 5438+ 10 is below freezing point, while in Sindh and Punjab provinces, the highest temperature in July is about 38℃( 100 ℉). Jacob Abad is one of the hottest places on earth, located to the west of the Indus River in Upper Sindh Province, and the highest temperature in summer is often recorded at 49℃( 120 ℉).

The main rivers in the Indus River system take snowmelt as their source. Its discharge varies greatly in different periods of the year: in winter (12? February) the lowest flow, spring and early summer (3? June) The water level rises, and the rainy season (7? September) floods occur, with occasional devastating flash floods. All the water sources of the Indus River and its tributaries come from the mountains in the upper reaches of the basin. Therefore, when they flow out of the foothills, the flow is the largest, and there is almost no surface water flowing in the plains, but a lot of water is lost due to evaporation and leakage. On the other hand, in a period of time after the rainy season, leakage will also increase some water. In the main stream of the Indus River, the water level is the lowest from mid-February to mid-February. From then on, the river began to rise, at first slowly, but at the end of March, the rising speed accelerated. High water level usually occurs from mid-July to mid-August. After that, the river dropped sharply until 10, and the water level began to drop gently. The annual water volume of the Indus River is about 65.438+0.44 billion cubic yards-slightly more than half of the total water volume of the Indus River system. The total water volume of Jie Hellem River and chenab river is about1/4; The total water volume of the Ravi River, the Bis River and the Satlej River constitutes the rest of the total water volume of the water system.

A great deal of geographical and historical evidence shows that since the beginning of civilization-at least from the Mohenjo-Darrow era 4,000 years ago-the Indus River has diverted from South Punjab to the seaside.

Part of the surface runoff of the Indus River comes from mountain snowmelt and part from monsoon rainfall. The former changes little, while the latter changes with the climate, but the annual runoff changes little. According to the statistics of 1940- 1975, the annual runoff of the Indus River (excluding the Sutleji River) is 1959-650. Runoff changes greatly during the year, and the average water volume in rainy season from April to September accounts for 84% of the whole year.

According to the measured data of 1924- 1978, there have been many floods in the main stream and tributaries of the Indus River, with the maximum peak discharge of 1955, 1689 1m3/s and/for the tributaries of the Bis River. Ravi River 1955, flood peak flow19244m3/s; 1957 The peak flow of Chenab Hema Salad Station is 31120m3/s; 1929 Hellem river Mangra station flood peak discharge 31120m3/s; 1942 The peak flow on the Indo-China River is 23122m3/s; 1973, the flood peak discharge of chenab River was 28,300m3/s, and the flood peak discharge of the lower reaches of Indus River was 30,500m3/s. Pakistan flooded 3.6 million hectares of land and affected 8 million people. 1976 in the lower reaches of the Indus River, the flood peak flow at Sukur Station is 33,988m3/s, which is equivalent to a 50-year flood. 1976 the flood flooded 8.09 million hectares of land, washed away more than 10,000 houses 10, and killed 425 people.

3. Animals and plants: The climate in the Indus Valley is closely related to vegetation. In Upper Sindh and Punjab provinces, overgrazing and logging for fuel have led to the destruction of many natural vegetation. In addition, the long-term human intervention in the natural water system and the deforestation of Shiwaliks have led to the obvious deterioration of groundwater conditions and vegetation. It seems that there were more trees in the middle of the Indus River in prehistoric times and early history than now: About Alexander the Great (325? From the 6th century BC to the 6th century BC, the records of Indian expedition and Muir hunting party showed that there were a considerable number of forests growing here. Even today, there are acacia tropical xerophytes, shrubs and undergrowth plants, such as poppy, nest vegetables, thistle and chickweed, on the Indus plain not far from the river. There are patches of tall grass like reeds by the river. There are often tamarisk trees and some dense shrubs on both sides of rivers and canals, but there are no natural forests. The northern part of the Indus Valley is rich in conifers.

The Indus River has moderate fish resources. Teda, Gautri and Sukur in Sindh are all important fishing centers. Fish farming has become very important in Yanba Reservoir. A modern fishing port has been established near Karakorum Port, providing refrigeration and sales services.

[Edit this paragraph] Residents

Ethnic groups living in the upper reaches of the Indus River (such as Tibetans, Ladaks and Barthes) show close relations with Central Asia rather than South Asia. They are Asian, speak Tibetan and believe in Buddhism (although Barthes has converted to Islam). Animal husbandry is an important local economic activity.

There are some agricultural groups living in the North Indian Plain. They speak Punjabi and related dialects and become the largest ethnic group in the Indus Valley. Language, race and tribal organizations play a secondary role in distinguishing groups. The obvious main feature of Punjab nationality is caste, but it has no religious and ritual significance of Hindu system. Jat and Rajput who believe in Islam are important social components of Punjab.

Some agricultural nationalities living in the lower reaches of the Indus River believe in German and related dialects. Many cultural features in this area seem to have quite ancient customs, and Sindh people are proud of the uniqueness of their own area. Although Karachi is in Sindh province, it is mainly an Urdu-speaking city, Punjabi and Indian immigrants who arrived in Pakistan after the division of the subcontinent in 1947.

[Edit this paragraph] Economy

(1) irrigation. Since ancient times, Indian River irrigation has been the foundation of successful agriculture. The modern irrigation project started around 1850, and the huge irrigation canal system was built by the British administrative agency. Many old channels and spillway in Sindh and Punjab provinces have been repaired and modernized; As a result, the world's largest irrigation canal network was established. During the division of 1947, the international boundary between India and West Pakistan divided the originally designed irrigation network and the Satlej Valley project into two parts. Its source project is in India and the irrigation canal flows through Pakistan. This led to the interruption of water supply in parts of Pakistan. The dispute that lasted for several years was resolved through the mediation of the World Bank, and Pakistan and India signed the Indus Treaty (1960). According to this treaty, the water quantity of three rivers in the west of the Indus Valley-Indus River, JieHellem River and chenab river (except a small amount for Kashmir) is used by Pakistan, while the total water quantity of three rivers in the east-Ravi River, Buys River and Satleji River is all supplied to India.

The experience of Indian subcontinent and other places shows that canal irrigation will cause a lot of damage to cultivated land unless it is carefully controlled. The water in the unpaved irrigation canal seeped into the soil, raising the water level and making the soil waterlogged and unable to cultivate. Due to the expansion of canal irrigation area of Indus River and its tributaries, groundwater in some areas has risen to the surface, forming shallow lakes. Elsewhere, water evaporates at the high temperature in summer, leaving layers of salt, making crops impossible to produce. Measures have been taken to provide adequate drainage system to avoid water and salt accumulation.

(2) shipping. Until about 1880, some rivers in the Indus River and Punjab were navigable, but after the rise of railways and the expansion of irrigation projects, only ships could travel back and forth in the lower reaches of the Indus River in Sindh Province. There are fishing boats in the lower reaches of the Indus River. Above the first railway gate, the upper reaches of rivers and canals are now used to exile timber from the foothills of Kashmir.

[Edit this paragraph] Governance and development

1. Irrigation: The primary task of Indus River regulation and development is irrigation. Indus River irrigation has a long history. As early as 3000 BC, flood diversion irrigation was developed in narrow areas along the banks of the Indus River. In the fifth and sixth centuries, it developed into a diversion irrigation channel. 1605 The first permanent irrigation canal was built, with a length of 80 kilometers ... The Ravi River was sent to Sheikhupura, about 40 kilometers west of Lahore. At 1850, the Upper Paré Doab Canal was built to divert the Ravi River. 1870, the selhand canal was built to take water from the sutlej river. 1887, Malala Sluice was built on the Ravi River, and it entered the diversion stage of Dingyou Dam. 1905- 19 15 built the first inter-basin water diversion project of the plant, excavated the upper Jie Hellem River aqueduct (canal) and the upper chenab river Aqueduct (canal), transferred the water from Jie Hellem River to chenab river, and transferred the water from chenab river River to Ravi River. By the end of last century and the beginning of this century, the scale of irrigation in the Indus Valley has been very large. Nearly 40 sluices have been built on the main and tributaries, and there are several diversion canals or connecting canals (canals) upstream of each sluice, and a large irrigation area has been developed on the land between rivers. For example, the Sukur Sluice on the main stream of the Indus River was built at 1932, with a sluice length of 1440m and a sluice flow of 42,450m3/s (originally designed at 3 1 130m3/s). Seven main canals are led out on both sides, with the maximum diversion flow of/kloc-.

1947, after the independent partition of India and Pakistan, the upper reaches of the Indus River and its five tributaries were allocated to India, and the lower reaches were allocated to Pakistan, which led to disputes over water use between the two countries, and the contradictions became increasingly fierce. After 13 years of negotiation, with the help of the World Bank, the two governments signed the Indus Treaty in 1960, and established the Indus Standing Committee at the same time. According to the treaty, Pakistan can take water from three western rivers (namely, the main stream of India, the Jie Hellem River and the chenab river), with an annual surface runoff of 654.38+0665 billion m3, accounting for about 80% of the Indus River runoff. India can divide water from three eastern rivers (Ravi River, Satlej River and Beyus River), with an annual surface runoff of 40.7 billion m3, accounting for 19.7% of the Indus River runoff.

Since the signing of the Indus Treaty in 1960, India and Pakistan have comprehensively developed and utilized the Indus resources according to the Treaty. Since then, the management and development of the Indus River has entered a new stage. In other words, the multipurpose water control project, including high dams and large reservoirs, will be built on the main and tributaries. In addition to irrigation, these water conservancy projects also have the benefits of flood control and power generation. Pakistan has completed the huge West-to-East Gas Transmission Project, turning the 6.5438+0.5 million hectares of cultivated land irrigated by the East Three Rivers into the West Two Rivers. The project includes three parts: ① Tabella Reservoir is built on the main stream of the Indus River, with the maximum dam height 143m, total storage capacity13.7 billion m3, and effective storage capacity11500 million m3; When Mangra Reservoir is built on Jie Hellem River, the maximum dam height of stone dam is 138m, the total storage capacity is 1, 65.438+0.8 billion m3, and the effective storage capacity is 6.6 billion m3. (2) Six sluices have been built at the intake, diversion canal line and river junction of 2)Xi 'er River, with a total length of 5km, a total flood discharge of about 65,438+240,000 m3/s and a water intake of 3,000 m3/s; ⑧ Eight interconnected connecting diversion canals (canals) were excavated, and some original gates, connecting canals and irrigation canals were rebuilt. The average annual water regulation of the West-East Gas Transmission Project is about 210.77 billion m3: India has built some high dams and large reservoirs on the water conveyance channels between the three eastern rivers and two rivers, that is, the West-East Gas Transmission Project, to divert water to irrigate India's cultivated land. The project includes: ① 9 high dams and hydropower stations: Bhakla Dam and Naenpajakri Hydropower Station on Satlej River; Pong Dam and Pandoh Dam on Bias River; Dengdam and Chamorra and 1 hydropower stations on the Ravi River; Salal Dam and Durhasti Hydropower Station on Chinab River. ② Two water transfer routes: the water transfer project from Ravi River to Bis River and the water transfer project from Bis River to Satlej River. The latter includes Pam—doh Baggi tunnel with a diameter of 7.62m and a length of13.11km; Sundarnagar waterway, length11.8km; Sundarnagar—Sutlej tunnel, with a diameter of 8.53m, a length of12.35km and a water conveyance capacity of 255m3/s.

There are large-scale irrigation projects in the Indus River (the irrigation area is more than 654.38+0.5 million hm2 or the flow of main irrigation canals is more than Loom 3/s) and large-scale multi-objective projects (reservoirs) built or under construction on ten tributaries of the Indus River. See the Indus Valley Artificial Irrigation Project Table and the Indus Valley Large-scale Multi-objective Project Table.

Irrigation in the Indus Valley has been greatly developed. However, due to flood irrigation and perennial irrigation, the groundwater level is gradually rising, and the land is seriously salinized, which affects the sustainable development of agriculture. Since 1959, the Pakistani government has vigorously implemented SCARP, that is, salinity control and transformation [project]. The basic content of the plan is to build a drainage system with pumping tube wells as the main part and open ditches and underground pipelines as the combination. After the popularization of 10 for many years, remarkable results have been achieved. It can not only reduce groundwater level, reduce waterlogging and control salinization, but also increase irrigation water consumption. The average sediment concentration of the main stream and tributaries of the Indus River is 2.38 ~ 3.30 kg/m3, and that of the Ikabur River is 1.03kg/m3.

2. Flood control: The flood control in the Indus Valley mainly depends on dikes. There are all kinds of dams in Pakistan alone, with a length of about 5,400 kilometers. The main stream of the Indus River is over 3000 kilometers. The dike lengths of the main tributaries are: Jie Hellem River 95km, chenab river 1052km, Ravi River 398km and Satlej River 356km. After dike reinforcement, the highest flood level in history is generally taken as the goal, and the return period is about 50 years. The design water level is 0,665,438+0m higher than the historical flood level, and the embankment superelevation is1.22m.

For some irrigation sluices on the main stream of the Indus River, the original flood control standard is only once in 20-40 years, and the flood discharge capacity will be rebuilt and improved to make the standard once in 200-300 years. For example, Gudu Sluice increased from 3 1 130m3/s to 42,450m3/s; Sukur sluice increased from 25,470 m3/s to 42,450 m3/s; Kotri sluice increased from 24,762 cubic meters per second to 35,575 cubic meters per second.

Large reservoirs built on the main tributaries, although the main task is irrigation, do not leave special flood control storage capacity in mountainous areas, but combined with flood storage, can play a certain role in flood control. For example, in Mangra Reservoir, 1973, the maximum inflow peak flow 14546m3/s, peak clipping 5 179m3/s, accounting for 35.6%. 1976 The maximum inflow of flood peak is 2779 1m3/s, and peak clipping is1122m3/s, accounting for 40%. Therefore, the completion of these large multi-objective reservoirs has greatly improved the flood control situation in the Indus River basin. In addition, Pakistan also attaches great importance to non-engineering flood control measures.

3. Power generation: In addition to some large hydropower stations, it is planned to build the Karabakh hydropower station (with an installed capacity of 2.4-3 million kilowatts) on the main stream of the Indus River, and the Barcelona Dam (with a dam height of 200 meters and an installed capacity of 3.66 million kilowatts) on the upstream; Hitter I (300,000 kilowatts) and II hydropower stations (390,000 kilowatts) will be built on Jinab River; Ciblat Hydropower Station (300,000 kilowatts) will be built on the Ravi River; The Kordo Hydropower Station (600,000 kilowatts) and the Kajiaom Wang Tuo Hydropower Station (600,000 kilowatts) will be built on the Sutleji River upstream of the Bakla Dam. The total installed capacity of hydropower stations built in the basin is about150,000 kW, and the installed capacity under construction or under research is more than150,000 kW, totaling more than 30 million kW. There is a big gap between the tributaries of China and Tibet, which needs research and development.