. índice . Prefacio . Preface . . aguas . 1 . 2 . 3 . 4 . 5 . 6 . . contamina 1 . 2 . 3 . 4 . 5 . 6 . . holocausto 1 . 2 . 3 . 4 . 5 . 6 . 7 . 8 . 9 . 10 . 11 . 12 . 13 . . lineas 1 . 2 . 3 . 4 . . hidrotermias 1 . 2 . 3 . 4 . 5 . 6 . . nuevas 1 . 2 . 3 . . Reconquista 1 . 2 . . hidrogeo 1 . 2 . 3 . 4 . 5 . 6 . . esbozos 1 . 2 . 3 . 4 . 5 . 6 . 7 . 8 . . corredorcentral 1 . 2 . 3 . 4 . 5 . . cordones 1 . 2 . 3 . 4 . 5 . . epiola 1 . 2 . 3 . 4 . 5 . 6 . . deriva 1 . 2 . 3 . 4 . 5 . 6 . 7 . 8 . 9 . 10 . 11 . 12 . 13 . 14 . . archivo 1 . 2 . 3 . 4 . . Halcrow 1 . 2 . 3 . 4 . 5 . 6 . . frentehalino 1 . 2 . 3 . 4 . 5 . 6 . 7 . . emicampanaoculto 1 . 2 . 3 . 4 . 5 . 6 . 7 . . Costa del Plata 0 . 1 . 2 . 3 . 4 . 5 . 6 . . Costa del oro 1 . 2 . . IRSA 1 . 2 . 3 . 4 . . flujos . . segmentos . . pendientes 1 . 2 . 3 . 4 . 5 . 6 . . delta 1 . 2 . 3 . 4 . 5 . . propuesta . 1 . 2 . . correconvectivo 1 . 2 . 3 . 4 . 5 . 6 . . plataforma 1 . 2 . . termodinamica 1 . 2 . 3 . . ABL 1 . 2 . . congreso . . girh . . Acumar 1 . 2 . 3 . 4 . . evaluacion 1 . 2 . . BocaRiachuelo 1 . 2 . 3 . 4 . 5 . 6 . 7 . 8 . 9 . 10 . 11 . 12 . 13 . 14 . 15 . 16 . 17 . 18 . 19 . 20 . . StoDomingo . . urgenciasatadas 1 . 2 . . inundabaires 1 . 2 . 3 . 4 . . sinsustento 1 . 2 . . emisarios 1 . 2 . 3 . 4 . 5 . 6 . 7 . 8 . 9 . 10 . . UAG 1 . 2 . 3 . . áreas nuevas 1 . 2 . 3 . . acreencias 1 . 2 . 3 . 4 . 5 . . audiencia 1 . 2 . 3 . 4 . 5 . 6 . 7 . 8 . 9 . . Valls 1 . 2 . . contrastes 1 . 2 . 3 . 4 . 5 . 6 . 7 . 8 . 9 . 10 . . convexterna . . playas 1 . 2 . 3 . 4 . 5 . 6 . 7 . 8 . 9 . . Plan Maestro 1 . 2 . 3 . . Parque Norte . 1 . 2 . . ribera . 1 . 2 . 3 . 4 . 5 . . jurisdiccion 1 . 2 . 3 . 4 . 5 . 6 . 7 . 8 . 9 . 10 . 11 . 12 . . CSJNpisamr 1 . 2 . 3 . 4 . . zonas muertas . . Bermejo 1 . 2 . . Pilcomayo . . Samborombon . . Salado . . Uruguay 1 . 2 . . Parana . . Mar del Plata 1 . 2 . 3 . 4 . 5 . . PuntaRasa 1 . 2 . . PuntaMedanos . . Mar Chiquita . . Necochea . . Areco 1 . 2 . . Colonia . . MartinGarcia 1 . 2 . 3 . . Puertos 1 . 2 . . formula1 . . disocio . . senderos . . bajante . . . . oceano 1 . 2 . . hidrolinea 1 . 2 . 3 . . sustentable. 1 . 2 . . agua 1 . 2 . 3 . . antarticflows . . derrame . . luna 1 . 2 . 3 . 4 . 5 . 6 . . index .
Pendientes mínimas de dos cuencas generadas por la cuña tectónica de la India presionando contra Asia
Los hipertextos que siguen sobre las pendientes de las grandes cuencas apuntan a fortalecer los dos abismos que venimos mentando: el legal sin hidrología y el científico sin la energía convectiva; que le bastó la gravitacional y presumir con ella suficiencia para modelar.
Ninguna hidrología mencionó jamás el sentido que reconocen los esteros en los compromisos del extendido ecosistema y el aporte de sus baterías convectivas a la red de drenajes que nada ostentan de materia gravitacional. De hecho, la palabra convección aparece en el ciclo atmosférico, pero nunca en el superficial.
Quien alcance en escala micro a traducir movimiento con pendientes máximas de 50 milésimas de milímetro por metro que de aviso al cielo por el milagro.
Francisco Javier de Amorrortu, 24 de Agosto del 2011
La colisión de la placa tectónica india con la placa euroasiática y posterior subducción bajo ella dió lugar al lecho marino originado inmediatamente al Sur de los emergentes Himalayas. Ese movimiento de las placas dejó una vasta depresión que fue llenándose con sedimentos del Indo, del Ganges y de sus múltiples tributarios. Allí recocemos hoy las planicies del Indo y del Ganges
The Brahmaputra-Jamuna is the second largest river in Bangladesh and one of the largest in the world, with its basin covering areas in Tibet, China, India and Bangladesh. Actually Jamuna is the downstream course of the Brahmaputra which took place after the earthquake and catastrophic flood in 1787. Presently the Brahmaputra continues southeast from Bahadurabad (Dewanganj upazila of Jamalpur district) as the old Brahmaputra and the river between Bahadurabad and Aricha is the Jamuna, not Brahmaputra. The Hydrology Directorate of the Bangladesh water development board (BWDB) refers to the whole stretch as the Brahmaputra-Jamuna.
It originates in the Chemayung-Dung glacier, approximately at 31°30'N and 82°0'E, some 145 km from Parkha, an important trade centre between lake Manassarowar and Mount Kailas.
The Brahmaputra is known as the Dihang in Assam Himalayas before it comes into the Great Plains of Bengal. It enters Bangladesh through Kurigram district (at the border of Kurigram Sadar and Ulipur upazilas). The total length of the Tsangpo-Brahmaputra-Jamuna river up to its confluence with the Ganges is about 2,700 km. Within Bangladesh territory, Brahmaputra-Jamuna is 276 km long, of which Jamuna is 205 km.
The width of the river varies from 3 km to 18 km but the average width is about 10 km. In the rainy season the river is nowhere less than five kilometres broad. The river is in fact a multi-channel flow. Channels of many different sizes, from hundreds of meters to kilometres wide, and of different patterns including braiding, meandering and anastomosing pattern in the country. It is, through most of its course within Bangladesh, studded with islands (chars) many of which are submerged during the rainy season and makes a single water channel.
Thus, by breadth alone, this river qualifies as one of the largest in the world. The width/depth ratios for individual channels of the Brahmaputra vary from 50:1 to 500:1. The gradient of the river in Bangladesh is 0.000077, decreasing to 0.00005 near the confluence with the Ganges.
The catchment of the mighty Brahmaputra-Jamuna river is about 5,83,000 sq km of which 293,000 sq km are in Tibet, 241,000 sq km in India and only 47,000 sq km within Bangladesh.
The drainage area above Bahadurabad is 536,000 sq km. This is the widest river system in the country flowing north-south. There are gauges and discharges records for this river at Bahadurabad, where amount represents the flow entering Bangladesh plus those of the Dudhkumar, the Dharla and the Tista, and minus those of the Old Brahmaputra and Bangali. The discharge during the rainy season is enormous, averaging 40,000 cumec, by which measure it ranks with the Amazon, Congo, La Plata, Yangtse, Mississippi and Meghna as one of the seven largest rivers. The highest recorded flood was 98,600 cumec in August 1988.
Average annual flow at Bahadurabad is estimated to be 501 million acre-feet. August has always been the month when widespread flooding has been most likely. Floods from May to July are usually due to the Brahmaputra-Jamuna and Meghna. From August to October due to the combined flows of those river and the Ganges.
As a rule, the flow of the Brahmaputra-Jamuna is more erratic than that of the Ganges. The gradient of the Jamuna averages 1:11,850 which is slightly more than that of the Ganges.
The Jamuna discharges a large volume of water and at the same time brings in huge amounts of sediments. During the rainy season it brings down something like 1.2 million tons of sediment daily, and the annual silt runoff at Bahadurabad is estimated at 735 million tons.
It has four major tributaries: the Dudhkumar, the Dharla, the Tista and the Karatoya-Atrai system. The first three rivers are flashy in nature, rising from the steep catchment on the southern side of the Himalayas between Darjeeling in India, and Bhutan. Of all the distributaries, the Old Brahmaputra is the longest and was actually the course of the present Brahmaputra some 200 years ago.
The Jamuna is braided in nature. Within the braided belt of the Jamuna, there are lots of chars of different sizes. An assessment of the 1992 dry season Landsat image shows that the Jamuna contained a total of 56 large island chars, each longer than 3.5 km. There were an additional number of 226 small island chars, varying in length between 0.35 and 3.5 km. This includes sandy areas as well as vegetated chars.
In the Jamuna the period between 1973 and 2000, chars have consistently appeared in the reaches opposite to the Old Brahmaputra offtakes, north and east of Sirajganj and in the southernmost reach above the confluence with the Ganges. In entire Bangladesh during 1981 to 1993, a total of about 729,000 people were displaced by riverbank erosion. More than half of the displacement was along the Jamuna.
Brahmaputra-Jamuna River System one of the three major river systems of Bangladesh. Brahmaputra-Jamuna and old brahmaputra, with their main tributary tista, and a good number of small tributaries and distributaries constitute the largest floodplain of Bangladesh. Excepting for a small portion in the north, the entire floodplain lies within the pleistocene terrace regions. The floodplain and the Pleistocene terraces almost completely cover two of the six administrative divisions of the country, rajshahi and dhaka.
The brahmaputra enters Bangladesh east of Bhabanipur (India) and northeast of kurigram district. It first flows south and then turns southeast and travels through the madhupur tract to meet the meghna near bhairab bazar. The river seems to be much younger than the ganges. Along with the Meghna, it is making a major contribution to the building up of the delta. Among the major rivers, Brahmaputra-Jamuna is the most energetic and has the highest stream power. This river, despite having a smaller drainage basin than the Ganges, has a steeper slope, a larger discharge, and higher sediment transport and higher sediment content.
The Ganges or Ganga, or Gônga, is a trans-boundary river of India and Bangladesh. The 2,525 km (1,569 mi) river rises in the western Himalayas in the Indian state of Uttarakhand, and flows south and east through the Gangetic Plain of North India into Bangladesh, where it empties into the Bay of Bengal. By discharge it ranks among the world's top 20 rivers. The Ganges basin is the most heavily populated river basin in the world, with over 400 million people and a population density of about 1,000 inhabitants per square mile (390 /km2).
The Ganges is the most sacred river to Hindus and is also a lifeline to millions of Indians who live along its course and depend on it for their daily needs. It is worshiped as the goddess Ganga in Hinduism. It has also been important historically: many former provincial or imperial capitals (such as Patliputra, Kannauj, Kara, Kashi, Allahabad, Murshidabad, Munger, Baharampur and Kolkata) have been located on its banks.
The Ganges ranks among the top five most polluted rivers of the world with fecal coliform levels in the river near Varanasi more than hundred times the official Indian government limits. Pollution threatens not only humans, but also more than 140 fish species, 90 amphibian species and the endangered Ganges river dolphin.
The Ganga Action Plan, an environmental initiative to clean up the river, has been a major failure thus far, due to corruption and lack of technical expertise, lack of good environmental planning, Indian traditions and beliefs, and lack of support from religious authorities.
El primer problema a considerar no es el déficit del recurso cultural; sino el del recurso natural que entendido desde mecámica de fluidos proyecta energía gravitacional donde no la hay. Hasta no entender cómo funcionan los enlaces termodinámicos en sistemas naturales abiertos olárquicos, no imagino alcancen estas dificultades horizonte de salida alguno.
Descargas de las cuencas superiores: del Ganges al Brahmaputra (foto inclinada)
The Indian subcontinent lies atop the Indian tectonic plate, a minor plate within the Indo-Australian Plate. Its defining geological processes commenced seventy-five million years ago, when, as a part of the southern supercontinent Gondwana, it began a northeastwards drift—lasting fifty million years—across the then unformed Indian Ocean. The subcontinent's subsequent collision with the Eurasian Plate and subduction under it, gave rise to the Himalayas, the planet's highest mountains. In the former seabed immediately south of the emerging Himalayas, plate movement created a vast trough, which, having gradually been filled with sediment borne by the Indus and its tributaries and the Ganges and its tributaries, now forms the Indo-Gangetic Plain.
The Indo-Gengetic Plain is geologically known as a foredeep or foreland basin.
The hydrology of the Ganges River is very complicated, especially in the Ganges Delta region. One result is different ways to determine the river's length, its discharge, and the size of its drainage basin.
The name Ganges is used for the river between the confluence of the Bhagirathi and Alaknanda rivers, in the Himalayas, and the India-Bangladesh border, near the Farakka Barrage and the first bifurcation of the river. The length of the Ganges is frequently said to be slightly over 2,500 km (1,600 mi) long, about 2,505 km (1,557 mi), to 2,525 km (1,569 mi), or perhaps 2,550 km (1,580 mi). In these cases the river's source is usually assumed to be the source of the Bhagirathi River, Gangotri Glacier at Gomukh, and its mouth being the mouth of the Meghna River on the Bay of Bengal. Sometimes the source of the Ganges is considered to be at Haridwar, where its Himalayan headwater streams debouch onto the Gangetic Plain.
In some cases, the length of the Ganges is given for its Hooghly River distributary, which is longer than its main outlet via the Meghna River, resulting in a total length of about 2,620 km (1,630 mi), from the source of the Bhagirathi, or 2,135 km (1,327 mi), from Haridwar to the Hooghly's mouth. In other cases the length is said to be about 2,240 km (1,390 mi), from the source of the Bhagirathi to the Bangladesh border, where its name changes to Padma.
For similar reasons, sources differ over the size of the river's drainage basin. The basin covers parts of four countries, India, Nepal, China, and Bangladesh; eleven Indian states, Himachal Pradesh, Uttarakhand, Uttar Pradesh, Madhya Pradesh, Chattisgarh, Bihar, Jharkhand, Punjab, Haryana, Rajasthan, West Bengal, and the Union Territory of Delhi.
The Ganges basin, including the delta but not the Brahmaputra or Meghna basins, is about 1,080,000 km2 (420,000 sq mi), of which 861,000 km2 (332,000 sq mi) are in India (about 80%), 140,000 km2 (54,000 sq mi) in Nepal (13%), 46,000 km2 (18,000 sq mi) in Bangladesh (4%), and 33,000 km2 (13,000 sq mi) in China (3%).
Sometimes the Ganges and Brahmaputra–Meghna drainage basins are combined for a total of about 1,600,000 km2 (620,000 sq mi), or 1,621,000 km2 (626,000 sq mi). The combined Ganges-Brahmaputra-Meghna basin (abbreviated GBM or GMB) drainage basin is spread across Bangladesh, Bhutan, India, Nepal, and China.
The discharge of the Ganges also differs by source. Frequently, discharge is described for the mouth of the MeghnaRiver, thus combining the Ganges with the Brahmaputra and Meghna. This results in a total average annual discharge of about 38,000 m3/s (1,300,000 cu ft/s), or 42,470 m3/s (1,500,000 cu ft/s).
In other cases the average annual discharges of the Ganges, Brahmaputra, and Meghna are given separately, at about 16,650 m3/s (588,000 cu ft/s) for the Ganges, about 19,820 m3/s (700,000 cu ft/s) for the Brahmaputra, and about 5,100 m3/s (180,000 cu ft/s) for the Meghna.
Hardinge Bridge, Bangladesh, crosses the Ganges-Padma River. It is one of the key sites for measuring streamflow and discharge on the lower Ganges.
The maximum peak discharge of the Ganges, as recorded at Hardinge Bridge in Bangladesh, exceeded 70,000 m3/s (2,500,000 cu ft/s). The minimum recorded at the same place was about 180 m3/s (6,400 cu ft/s), in 1997.
The hydrologic cycle in the Ganges basin is governed by the Southwest Monsoon. About 84% of the total rainfall occurs in the monsoon from June to September. Consequently, streamflow in the Ganges is highly seasonal. The average dry season to monsoon discharge ratio is about 1:6, as measured at Hardinge Bridge. This strong seasonal variation underlies many problems of land and water resource development in the region. The seasonality of flow is so acute it can cause both drought and floods. Bangladesh, in particular, frequently experiences drought during the dry season and regularly suffers extreme floods during the monsoon.
In the Ganges Delta many large rivers come together, both merging and bifurcating in a complicated network of channels. The two largest rivers, the Ganges and Brahmaputra, both split into distributary channels, the largest of which merge with other large rivers before themselves joining. This current channel pattern was not always the case. Over time the rivers in Ganges Delta have changed course, sometimes altering the network of channels in significant ways.
Before the late 12th century the Bhagirathi-Hooghly distributary was the main channel of the Ganges and the Padma was only a minor spill-channel. The main flow of the river reached the sea not via the modern Hooghly River but rather by the Adi Ganga. Between the 12th and 16th centuries the Bhagirathi-Hooghly and Padma channels were more or less equally significant. After the 16th century the Padma grew to become the main channel of the Ganges. It is thought that the Bhagirathi-Hooghly became increasingly choked with silt, causing the main flow of the Ganges to shift to the southeast and the PadmaRiver. By the end of the 18th century the Padma had become the main distributary of the Ganges. One result of this shift to the Padma was that the Ganges joined the Meghna and Brahmaputra rivers before emptying into the Bay of Bengal, together instead of separately. The present confluence of the Ganges and Meghna formed about 150 years ago.
Also near the end of the 18th century, the course of the lower Brahmaputra changed dramatically, altering its relationship with the Ganges. In 1787 there was a great flood on the Teesta River, which at the time was a tributary of the Ganges-Padma River. The flood of 1787 caused the Teesta to undergo a sudden change course (an avulsion), shifting east to join the Brahmaputra and causing the Brahmaputra to shift its course south, cutting a new channel. This new main channel of the Brahmaputra is called the Jamuna River. It flows south to join the Ganges-Padma. Since ancient times the main flow of the Brahmaputra was more easterly, passing by the city of Mymensingh and joining the MeghnaRiver. Today this channel is a small distributary but retains the name Brahmaputra, sometimes Old Brahmaputra. The site of the old Brahmaputra-Meghna confluence, in the locality of Langalbandh, is still considered sacred by Hindus. Near the confluence is a major early historic site called Wari-Bateshwar.
Sedimentaciones a la plataforma continental y al talud del borde.
La limpieza de los surcos tallados en la plataforma continental y en especial aquellos tallados en el talud oceánico, hablan de una buena mezcla de energías gravitacionales y convectivas.
Valle del Indo
Geologically, Pakistan overlaps with the Indian tectonic plate in its Sindh and Punjab provinces, while Balochistan and most of Khyber Pakhtunkhwa lie within the Eurasian plate which mainly comprises the Iranian plateau. Gilgit-Baltistan and Azad Kashmir lie mainly in Central Asia along the edge of the Indian plate and are hence prone to violent earthquakes.
The geography of Pakistan is a blend of landscapes varying from plains to deserts, forests, hills, and plateaus ranging from the coastal areas of the Arabian Sea in the south to the mountains of the Karakoram range in the north.
Pakistan is divided into three major geographic areas: the northern highlands; the Indus River plain; and the Balochistan Plateau. The northern highlands of Pakistan contain the Karakoram, Hindu Kush and Pamir mountain ranges, which incorporate some of the world's highest peaks, including K2 (8,611 m or 28,251 ft) and Nanga Parbat (8,126 m or 26,660 ft).
The Balochistan Plateau lies to the West, and the Thar Desert in the East. An expanse of alluvial plains lies in Punjab and Sindh along the Indus river. The 1,609 km (1,000 mi) Indus River and its tributaries flow through the country from the Kashmir region to the Arabian Sea.
Among Pakistan Rivers, Indus is the most important river. Without Indus and its tributaries, Pakistan would have been a dry barren land long ago. Apart from Indus, the other important rivers in Pakistan are Sutlej, Chenab, Beas, Ravi and Jhelum. These rivers merge into the Indian rivers at the India-Pakistan border.
The Indus Delta is the fifth largest delta in the world, characterized by high river discharge, moderate tides, and evidently the highest wave energy of any river in the world. The fan-shaped delta consists of creeks, estuaries, mud, sand, salt flats, mangrove habitat, marshes, sea bays, and straits and rocky shores. Its 129,000 ha. of mangrove, mostly Avicenna marina, comprises 97% of the total mangrove area in the country and is said to be the 7th largest mangrove forest in the world. The area is rich in archaeological and religious heritage.
If there was no Indus river, there would not have no people living in this part of the world. Originating from the glacial Tibetan mountains, the Indus gushes in to Pakistan with all its might and fright from the northern areas. Near Attock, the River Kabul also joins this ferocious river and one can vividly see the blue KabulRiver merging with the muddy Indus while standing on the bridge over Indus at Attock. Both join hands together and irrigate the entire length of Pakistan, approximately 2,900 km (1,800 mi), till it steadily calms down and fades away in the Arabia Sea.
Besides Indus, four other rivers also enter Pakistan from the neighbouring India, namely the Jhelub, Chenab, Ravi and Sutlej and all empty into the Indus to add to its might and power. The place where all these four rivers meet the Indus is known as "Panj Nadh (meaning in local language Five Rivers) south of the famous ancient city of Multan.
Having almost lost its impetus near the ArabiaSea, it fans out and forms the Indus Delta. Here the forests of mangroves and many a species of birds and fish flourish on the sweet waters of the Indus. The total area of the deltas that includes swamps and mangroves is approximately 225,000 hectares (556,000 acres). The port city of Karachi and marches of Ran of Kutch shoulder this delta during its final stages of journey
Cuenca superior del Indo
Cuenca media e inferior del Indo
Sedimentaciones en la plataforma continental
Las planicies del Indo antes del Monsón
Dust and Pollution Rise Before the Monsoon
August 24, 2011
In the days and weeks before the monsoon, heat builds over India. Hot air rises over the baked earth and westerly winds rush in to fill the void, bringing dust-laden air from the deserts of southwest Asia and the Arabian Peninsula. Through April, May, and June, as monsoon conditions build, the air over the Ganges River plain grows thick with dust, smoke, and haze. Air quality over India is at its worst at this time of year. Finally, in mid- to late-June, the winds shift and cleansing monsoon rains fall.
This image provides a profile of the pre-monsoon air over India on May 12, 2007. The lower image was made with data from the CALIPSO satellite, which sends pulses of laser light through the atmosphere at night and measures the light signal that returns to the sensor. This measurement reveals the concentration of particles—ice, dust, soot, and so forth—in the atmosphere. The dark orange areas in the profile show where the particle concentration was most dense. Pale orange and white reveal fewer particles.
The top image is a daytime scene captured that same day by the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra satellite. The yellow line across the top image shows the path of the satellite on May 12 when it collected the profile in the lower image.
The dense particle concentration included a combination of dust, smoke from fires, and urban smog. Measurements from other satellites and ground-based instruments revealed that the bulk of the pollution was dust.
Dust carried on westerly winds moves over the Gangetic Plain and hits a barrier: the massive Himalayas. Trapped against the mountain front, the dust builds until concentrations are higher than at any other time of year. The rising of hot air from the land, combined with the incoming winds, push the dust and haze high into the atmosphere along the front of the Himalaya. In this image, the bulk of the dust reaches about four kilometers in altitude; along the mountains, it reaches six to seven kilometers. (The particles over the mountains and the Tibetan Plateau are probably ice clouds, but may also contain some dust.)
This dust and haze over the Ganges Plain may increase the intensity of monsoon rains. The dust particles and soot both absorb energy, heating the atmosphere. The added heat pushes the air higher than it would otherwise rise. The rising air sucks up more air, and when that air is moist, the monsoon circulation may strengthen, leading to more rainfall during the early summer.
The high dust and haze also might hasten the melting of snow in the Himalayas. Particles settle on the surface, darkening the snow. White snow reflects energy, but the particle-darkened surface absorbs it, causing the snow to melt faster. This has been demonstrated in other regions.
NASA Earth Observatory image created by Jesse Allen, using data provided by the CALIPSO team. Caption by Holli Riebeek, with information from Ritesh Gautam.
Instrument: CALIPSO - CALIOP
De los ciclos y provechos del Indo
Fed by glaciers and monsoon rains, the Indus River swells and shrinks each year. Because the river irrigates millions of acres of farmland, the strong seasonal cycle changes not just the river, but also the surrounding landscape.
The images show a small portion of the Indus River around the Guddu (or Gudu) Barrage, just south of the border between Punjab and Sindh Provinces in Pakistan. The Thematic Mapper on the Landsat 5 satellite acquired these natural-color images of the area on September 10, 2009 ,
Later on April 22, 2010 .
A type of dam, the Guddu Barrage diverts water from the Indus for irrigation during Pakistan’s two main growing seasons—Kharif (May to November) and Rabi (November to May). Some water is stored in the holding structure east of the river.
The Indus River typically crests in July and August. Although water levels recede somewhat by September, the river remains high, and Kharif, or summer, crops peak around that time. On September 10, 2009, muddy water fills the river channel, abundant water rests in the holding structure, and lush vegetation carpets the land on either side of the river.
By April 22, 2010, the water level in the Indus has dropped considerably. But the more noticeable changes occur in the surrounding landscape. Rabi, or winter, crops have mostly been harvested, and the landscape appears in shades of brown, rust, and beige. Hardly any water remains in the holding structure east of the barrage, having been consumed by the irrigation of summer and winter crops.
Just three months after Landsat acquired the image from April 2010, unusually heavy monsoon rains caused historic floods. In the long run, however, water is scarce in Pakistan, and farmers depend on irrigation from the Indus to tease crops out of an arid landscape. Residents of this region have relied on the river to support agriculture for 4,000 years.