Indus River Delta
The Indus River Delta forms where the Indus River flows into the Arabian Sea, mostly in the southern Sindh province of Pakistan with a small portion in the Kutch Region of India. The delta covers an area of about, and is approximately across where it meets the sea. The active part of the delta is. The climate is arid, the region only receives between of rainfall in a normal year. The delta is home to the largest arid mangrove forests in the world, as well as many birds, fish and the Indus dolphin. The fifth largest in the world, the Indus Delta is a designated wetland and Ramsar site, containing seventeen major creeks or estuaries and numerous minor creeks. Major estuaries of the Indus are home to the Indian Ocean humpback dolphin.
The population of the active part of the delta was estimated at 900,000 in 2003. Most of the population depends on agriculture and fishing. Mangrove forests provide fuel wood. Many former settlements have been abandoned as result of lack of water in the Indus and the encroaching Arabian Sea.
The delta faces several issues. Since 1883, due to land erosion and sea intrusion it has shrunk by 92 percent from around to nearly in 2018. Since the 1940s, the delta has received less water as a result of large-scale irrigation works capturing large proportions of the Indus' flow before it reaches the delta. The result has been catastrophic for both the environment and the local population. As a result, the 2010 Pakistan floods were considered "good news" for the ecosystem and population of the river delta as they brought much needed fresh water.
History
According to some accounts, the Macedonian fleet anchored itself for some time in the Indus river delta. It was damaged by a tsunami generated by an earthquake off the Makran Coast in 325 BC.According to Tarikh-i-Hind by 6th century AD there existed a port called Debal in what is now the western part of the Indus delta. Debal also seemed to be the base of pirates from the tribe of Nagamara. These pirates' raids against the Umayyads, and the refusal to redress the issue by the ruling prince, precipitated the Muslim conquest around 710 AD. Debal remained a port, and the last recorded mention of it was in 1223 AD. By the time Ibn Batuta reached the Indus delta, Debal had been abandoned due to increased shoaling preventing the then-port from accessing the sea.
When the Abbasid caliphate began to disintegrate, the delta came under the control of the increasingly autonomous province centered at Mansura. The eastern part of the delta was even more independent and controlled by the Sumra tribe until 1053 AD, when the region was brought under the control of the Khalji Delhi Sultanate by Alauddin Khalji. The tribe had several capitals, but none are populated today. In 1333 AD, the Samma Dynasty ruled all of the delta, and established their capital first at Samu-i and later at Thatta. It was during this dynasty that the "golden age of native rule" happened in the delta and Sindh, under the rule of Jam Nizamuddin II.
From 1591 to 1592, the Mughal empire waged a campaign to bring lower Sindh under imperial rule, resulting in the delta coming under the province of Multan and ruled by Mirza Ghazi Beg. In 1739, the region, along with many others, was ceded to Nadir Shah. The Kalhora ruled the region until 1783. The power then transferred to the Talpurs until the British East India Company conquered them in 1839. In 1947, the Indus delta, along with rest of Sindh became a part of Pakistan.
Since 1957, the Sindh Forest and Wildlife Department has been tasked with protecting and managing of mangrove-forested area of the Indus delta. In 1973, were transferred to Port Qasim. The Sindh Board of Revenue continues to manage of the area. In December 2010, realizing the importance of mangrove conservation, the Government of Sindh declared all the mangrove forests in the Indus Delta as "Protected Forests", under the Forest Act of 1927. Apart from this action, a Mangrove Conservation Committee, with membership of all the relevant stakeholders has been formed to ensure the sustainable conservation of the Indus Delta Mangroves
Geography
The Indus river started to form some 50 million years ago. 25 million years ago, the Indus Plain was lifted.Coastline
The estimated coastline of the Indus delta with the Arabian Sea is approximated at, 220 km, and. Because the Indus river has switched its location at various points in history, it has an "active" delta region, and total delta region. The total area is estimated at, and. The active area is estimated at, and. The length of the total delta along the axis of Indus is estimated at, whereas the current delta stretches from the Arabian Sea to just south of Thatta.Estuaries
Indus Delta has 17 major creeks or estuaries and numerous minor creeks. The estuaries in the Indus delta are spread across Sindh in Pakistan in the west and Gujarat in India in the east.Pakistan
Creeks in Indus Delta in Pakistan are listed from west to east as follows, many of which fall within the Keti Bunder South Wildlife Sanctuary which is a Ramsar site.Listed west to east"
- Korangi Creek: southeast coastline of Karachi.
- Phiti Creek:
- Kadiro Creek:
- Chann Waddo Creek:
- Khuddi Creek :
- Khai Creek:
- Pitiani Creek :
- Dabbo Creek :
- Sisa Creek:
- Chan Creek :
- * Sheeshah Creek:
- * Jua Wali Creek:
- * Rumwah 1 Creek:
- Gorabio Creek:
- Hajamro Creek : location of the historical port town Keti Bandar in Thatta District.
- Turshian Creek:
- Khobar Creek : Mouth of Indus, designated as the main flow of Indus.
- * Chann Chati Creek
- Qalandri Creek:
- Gaghiar Creek:
- Bajari Creek :
- Gehbar Creek:
- Kahr Creek:
- Jongo Jalbani Creek:
- Wari Creek:
- Mangra Creek:
- Bhitiaro Creek:
- Kajhar Creek:
- Sir Creek: disputed border between India and Pakistan.
India
- Sir Creek: disputed between India and Pakistan.
- Vian Wari Creek :
- * Harami Dhoro : name of Vian Vari after it leaves India and enters Pakistan.
- * Harami Nala : name of Vian Vari after it leaves Pakistan and re-enters India.
- * Bondho Dhoro channel: enters India further north of Harami Nala in the Sujawal District of Sindh province of Pakistan.
- Pir Sanai Creek:
- Pabevari Creek:
- Padala Creek: southeast of Sir Creek.
- Kori Creek: southeast of Sir Creek. Kori, the easternmost creek of Indus Delta, is also the location of Narayan Sarovar and Narayan Sarovar Sanctuary and 18th century Lakhpat Fort - both reachable by the NH-41.
Water volume
Climate
The climate of the delta is described as arid. It receives only of rain in a normal year. Average temperatures for the delta region range from in July, and in January.During the summer, the delta experiences intense monsoonal winds from the southwest, causing parts of the delta to be covered by sea-water. When this water retreats, it leaves behind salts in the delta's soil. During the winter the winds in the delta come from the northeast.
The summer monsoonal winds also contribute to high wave energy levels. In fact, the delta is subjected to the highest wave action of any river delta in the world. Throughout history the delta has survived this wave action because of the large discharge of fresh water to counter the erosional impact of waves. This large amount of wave energy, coupled with lack of silt flowing in from the Indus river, has resulted in the formation of sand beaches.
Biodiversity
Flora
forests are one of the most abundant ecological communities of the delta, but they have declined over the years. According to Haq et al., they covered an area of until the 1980s and could be found along the entire 240 km coastline, in 40% of the tidal zone, and in 10% of the delta fan. Memon reports that the area of mangrove forests was 263,000 hectares in 1977 and in 1990. Both agree that they were sixth-largest mangrove forests in the world. Previously there had been eight species of mangroves, although only four now remain: Aegiceras corniculatum, Avicennia marina, Ceriops tagal, and Rhizophora mucronata. Among these Avicennia marina constitutes 99% of the mangrove population. As of 2007, the mangroves of the Indus delta are the largest desert climate mangrove forests in the world. However the Indus Delta saw an increase in number of mangroves after preservation and plantation initiatives. Mangrove forests of Indus delta now cover an area of around 600, 000 hectares. The mangroves are under control of three different organizations, namely:- Sindh Forest Department
- Port Qasim Authority
- Sindh Board of Revenue
Arthrocnemum macrostachyum is also found growing in the delta.
Threats
The natural flow of water and fertile sediments from Indus river into the delta has been impeded due to the construction of dams along the river. The reduction of freshwater due to the dams also increases salinity, making the waters of the delta unsuitable for the freshwater species. In case of the Indus dolphin, the damming of the river has isolated the delta dolphin population from those dolphins upstream.The 2010 Pakistan floods were considered "good news" for the ecosystem of the river delta as they brought an excess of much needed fresh water. The Sindh government announced that 8,000 hectares of mangrove forests had been planted, and more plantation was considered.
The delta faces pollution both from sea and the Indus river. Chemical run-off into the river threatens many species. Most of this chemical run-off consists of agriculture pesticide and fertilizer. The delta faces pollution from the Arabian Sea. Karachi, Pakistan's largest city, releases sewage and discharge from industrial units into the Arabian sea, most of which is untreated. Both Port of Karachi and Port Qasim handle significant shipping traffic, resulting in oil discharge, some of which reaches the delta. All of this pollution lowers the river water quality, causes eutrophication, reducing the amount of habitat.
Indus delta has shrunk by 92% since 1833. In light of the threats, Indus Delta was designated a Ramsar site on November 5, 2002. The WWF is working on conservation methods to alleviate the Indus delta's shortage of freshwater.