LOCATION
The region in which the Indus civilization developed lies at the intersection of two major zones: the dry Iranian plateau and the largely tropical South Asian peninsula, watered by the monsoons. These belonged originally to two differ-ent landmasses separated by a vast stretch of ocean. In the geologically recdiffer-ent past, the peninsula broke away from the southern continent of Gondwanaland and around thirty-five million years ago crashed into Asia (Laurasia), being driven against it, slipping beneath it, and causing the edges of both plates to buckle and rise, forming the Himalayas. A trough was created at the junction of the plates and gradually filled with eroded material, forming the Indo-Gangetic plain. The collision zone is still active, with the result that periodi-cally earth tremors are experienced in and beyond the mountains, altering the landscape and often causing massive destruction. Areas rise or sink, and rivers change their courses. The annual flooding and alluviation also promote changes in the course of the major rivers and have impacted the coastline.
The Indus River rises in the Himalayas, as do the other rivers that form the Punjab. These come together at the Panjnad to form the massive lower course of the Indus, flowing through Sindh, a region that is largely desert beyond the alluvial stretches along the river. Other tributaries join the Indus from the mountains of Baluchistan, which separate the Indus plains from the Iranian plateau, and the mighty river fans out into a delta in the Arabian Sea. To the east of the Punjab other rivers rise from the Himalayas and the Siwalik Hills:
These include the Ganges, flowing east to a huge delta in the Bay of Bengal, and the Yamuna, now the companion of the Ganges but in antiquity probably contributing to a major river that flowed southwest. Identified as the Saraswati River eulogized in early Indian literature, this is now reduced to a series of small seasonal rivers periodically flowing into the largely dry Ghaggar-Hakra riverbed. The ancient Saraswati may have spent its waters in an inland delta in the Great Indian (Thar) Desert that borders the Indus region to the south, or it may have continued to the sea, joining the Indus delta or flowing into the Gulf of Kutch in Gujarat. Gujarat was the southern province of the Indus civilization: Today Kutch is separated from the Indian mainland by the marshy Ranns, but in Indus times the latter were probably open water. Rabi (winter)
II
cultivation is the main practice in most of the greater Indus region, as it is in the lands farther west, with wheat and barley as the principal crops. In many areas where cultivation is not possible, grasslands offer pastures for feeding substantial numbers of domestic animals; forests in upland areas and various minerals, such as metal ores and gemstones, are also exploited.
A satellite photograph of the Indus Basin showing the cultivated areas along the Indus River, the mountains that frame it to the north and west, the desert to its east, the fringe created by the Aravalli Hills, and the salt wastes and shallow seas that surround Kutch; to its south, only the northern part of Saurashtra is visible. East of the Punjab in the north, traces may be seen of the dry beds of the once-mighty Saraswati River. (NASA)
Beyond the desert to the south and into the lands of the Ganges to the east, the environment of the subcontinent changes. The most dramatic difference is a substantial increase in rainfall, particularly during the southwest monsoon from June to September; there is also far less seasonal variation in temperature, and in the Ganges Valley there was originally dense forest that presented a major barrier to agricultural settlement. Here kharif (summer) cultivation is the norm and the staple crops are rice and a variety of millets: Most of these grains, however, did not come under cultivation until the late third millen-nium or later. At the time of the Indus civilization, the peninsula and eastern South Asia were sparsely occupied by groups living by hunting, gathering, and fishing or by farming often dominated by animal husbandry. Econom-ically the people of the Indus were linked with regions to their west, in Baluchistan and the Iranian plateau, with whom there were longstanding com-munications and trade; but in the Indus period links were also established and developed with the cultures of the Gulf, initially with those of Oman but also with the emerging empires of southern Mesopotamia and with the lands between the two civilizations. Seaborne trade continued to be of great impor-tance to the subcontinent from the first millennium BCE onward.
THE ENVIRONMENTAL SETTING The Indo-Iranian Borderlands
The eastern edge of the arid Iranian plateau rises to form the mountains of Baluchistan, whose northeast members are continuous with the much higher ranges of the Himalayas. Several ranges of high mountains border the Indus Valley: In the north, the Sulaiman Range runs nearly due south, extending into the Indus plain as the Marri-Bugti Hills. Farther south, the Kirthar Range also runs nearly due north-south, and between the Kirthar Range and the Marri-Bugti Hills lies the Kachi plain, a substantial extension of the alluvial plain.
The valley of the Bolan River, which flows through the Kachi plain, creates one of the major passes giving access from the Indus plains to the Baluchi high-lands and the Iranian plateau beyond. A number of smaller rivers and moun-tain torrents also break through the mounmoun-tains and provide east-west routes:
Of these the most important is the Gomal River in the north of the Sulaiman Range. To the west the mountains are lower and heavily dissected by valleys and streams, those in the north mainly flowing west while those of southern Baluchistan flow north-south. These rivers create narrow valleys and plateaus with limited areas of cultivable soil. A few valleys have more extensive areas of arable land, including the Bannu Basin and Gomal Valley in the north, the Quetta Valley in the center, and the Las Bela plain in the south.
The region is semiarid, with limited and often unreliable winter rainfall over most of the region, brought by westerly winds. Agriculture therefore relies heavily on other sources of water: springs and wells in some areas, and, more widely, hill runoff when rain and snowmelt feed seasonal streams and rivers.
This water is often captured and stored for later use or diverted onto fields, us-ing a variety of small dams (bunds and gabarbands): although hard to date,
some of these dams seem likely to have been constructed as early as in the pre-Indus period. Given the scarcity of water, cultivation in the region is therefore of less importance than pastoralism: keeping sheep, goats, and cattle. Many pastoralists spend their summers at home in Baluchistan and migrate with their animals to the Indus region during the cold winter months, a pattern that stretches back into antiquity. A wide range of wild game lives in the hills, in-cluding gazelle, markhor and other wild goats, wild sheep (urial), boar, and onager, as well as predators such as wolf, bear, leopard, and in the past proba-bly Asiatic lion. The native vegetation is largely of the steppe or scrub type, with scattered trees such as acacia, tamarisk, and euphorbia, as well as juniper, jujube (zizyphus), almond, pistachio, and other edible species in some parts.
Native grasses include a variety of wild barley. Both trees and other vegetation were more abundant in antiquity.
The mountains of the Indo-Iranian borderlands, particularly the Chagai Hills and those of the Sarawan region, are the source of many useful minerals, some exploited since remote antiquity: salt, steatite, agate and other semi-precious stones, alabaster, copper, and others.
The narrow Makran coast bordering the Arabian Sea is a bleak and inhos-pitable region, waterless except for occasional oases and rivers. The Kech-Dasht Valley in the west is the main focus of settlement and also provides a major route into the interior. East of the Makran is Las Bela, also a fertile plain, watered by the Porali and Hingol Rivers. Other rivers also provide paths from the coast into the mountains for most of the year when they are dry, and they are navigable after the rains. Fish furnish the main source of food for those dwelling on the coast; dates are the main crop in areas where cultivation is possible. The indented coast provides numerous small natural harbors and an-chorages and is sheltered from the full impact of the monsoon winds.
Maritime trade is important, as it was to the Indus people who established a number of coastal settlements in strategic locations. Seaborne relations with the people of the Oman peninsula, on the western side of the Gulf of Oman, may have been established by the early third millennium.
Punjab
The Indus River rises in the heights of the Himalayas in a spring near the Manasarover Lake in Tibet, the source also of the Sutlej River, which becomes a tributary of the Indus far downstream. Flowing west and then south, fed by spring snowmelt and summer monsoon rain, its waters swelled by mountain streams and tributaries, including the Kabul River, the Indus descends steeply and passes through the dissected terrain of the Potwar plateau and the low hills of the Salt Range. To their south it enters the plains and becomes naviga-ble. It skirts the western edge of the alluvial plain; between it and the moun-tains of the Sulaiman Range runs the Derajat, a low treeless plain, through which run routes that link the Indus plain with passes into the mountains. The alluvial plain extends eastward from the Indus, eventually running into that of the Ganges. A number of rivers cross the northern part of the plain: today five, the Jhelum, Chenab, Ravi, Beas, and Sutlej, gradually converge with each other
and eventually join with the Indus at the Panjnad east of the Marri-Bugti Hills.
Whereas the rivers are well entrenched in the north, farther into the plains they have broader, shallower beds and are apt to change their course. Within the areas flooded by the rivers, which vary in width from a few hundred meters to 10 kilometers or more, deposits of alluvium provide rich fertile soils that are extensively cultivated and that supply the agricultural needs of the region. The natural vegetation of the alluvial valleys includes grasses and some trees, such as acacia and sissoo, now much reduced by clearance but probably forming a dense forest in antiquity. Apart from the Thal Desert (the central part of the Sindh Sagar doab between the Indus and the Jhelum Rivers), the slightly higher ground of the interfluve areas is mainly grassland, providing abundant pasture for large numbers of cattle and other animals. The foothills and lower slopes of the Himalayas to the north are densely forested, including many species useful for timber, and in antiquity the forest cover was far greater. The mountains were also the source of minerals, including bitumen from the Mianwali district, steatite from various areas, salt from the Salt Range, and various gems and other stones from Kashmir. Small amounts of gold can be panned from the Indus sediments, and gold and a little silver and lead are also available in Kashmir and in some other parts of the Himalayas.
The Punjab receives some winter rainfall and some rain in the summer from the southwest monsoon, with winter rainfall highest in the west, decreasing eastward as the monsoon rainfall increases. The principal crop is wheat, grown in the winter through the spring, while large numbers of cattle and smaller numbers of sheep and goats are raised on the rich pastures of the interfluve savannah. The region abounds in wildlife today, and a wider range of species lived here in the past, including perennial and migratory birds (such as grouse, partridge, jungle fowl, peafowl, and cranes), deer, gazelle, onager, boar, rhino, elephant, and predators such as tigers and bears, while the rivers are home not only to fish but also to crocodiles and the bulhan, or blind Indian dolphin. In the adjacent hills live wild sheep and goats (urial and markhor).
Sindh
The rivers that join the Indus at the Panjnad are all substantial, perennial watercourses, carrying large volumes of water, with the result that the Indus is swelled to a mighty river south of the Panjnad. After this meeting, the river turns westward and eventually splits, its main branch running in a southwesterly direction roughly parallel to the Kirthar Hills of southern Baluchistan, with an eastern branch, the Eastern Nara, running parallel.
While the Indus enters the Arabian Sea south of the mountains of Baluchistan in a fan of distributaries, the Nara debouches into the Rann of Kutch. The gentle gradient of lands in Sindh is sufficient to maintain a rapid flow of water in the Indus but inadequate to prevent the river from meander-ing. The river ’s course has changed in detail on many occasions, as the annual floods cause it to cut new channels or as meanders are cut off to form oxbow lakes, and there have also been several major changes in its course since the end of the Pleistocene. The Indus and the Eastern Nara Rivers flow
through land that receives little rainfall and is essentially desert, overlaid by alluvial deposits renewed by the annual inundation; in places these deposits are hundreds of meters thick. During the winter months, when there is little rain, the Indus is confined to its bed, often flowing along a levee. However, swollen in the spring by snowmelt in the Himalayas and in the summer by the rains of the southwest monsoon, the waters carried by the river increase five-, eight-, or even twelve-fold; massive floods on the latter scale now occur on average every five to fifteen years. The floodwaters overflow the levee banks and spread out over a wide area on both sides of the river, depositing first their heavy sediments on the levee banks and adjacent areas, then pro-gressively finer sediments as the waters spread away from the river. Beyond the annually inundated active floodplain are areas that often also receive floodwater. Periodically the river breaks through the levee banks and cuts a new channel through the alluvium of its flood plain. One or both banks may be affected, so the annual provision of water and alluvial silts in any particu-lar area is not entirely reliable, although the fluctuations do not cause pro-longed hardship, due to the fertility of the soil and the abundance of the crops grown there (mainly wheat but also barley, pulses, and other crops).
These are winter sown; some summer crops are also cultivated, including cotton and sesame. The most favored places for cultivation are patches of deep sediment left behind in channels carved out by the floodwaters: These can generally be sown directly, without breaking the soil with a plow. These fertile patches change their location annually and therefore must be searched for; other areas, watered and provided with fresh alluvium by the inunda-tion, are plowed before planting, after the waters have receded. Cattle and water buffaloes are the main livestock kept by Sindhi farmers, whereas the fringes of the plain (the western piedmont and the margins of the Thar Desert) provide grazing for sheep and goats and, in the west, for wild sheep, wild goats, and onagers.
Oxbow lakes, where meanders of the river have been bypassed, are fertile habitats for wildlife. Seasonal lakes are also formed in levees abandoned by the river. Around the lakes grow reeds and palms as well as grasses. Many species of fish, shellfish, turtles, crocodiles, and birds abound in the lakes and rivers, and fishing is a major occupation of a number of groups in the region.
Wild water buffalo, swamp deer, and wild boar were once also found in these wetland locations. Vegetation along the rivers is restricted to plants that can tolerate being immersed annually by the inundation, but substantial gallery forest grows in the meander plain of the river, beyond the active flood plain.
Though reduced over the last century, the natural vegetation of the region includes a range of trees, such as acacia, pipal, sissoo, neem, tamarisk, and jujube. These forests and grassland have been home to tigers and lions, rhinos and elephants, peafowl, and other birds including the francolin.
Settlements are concentrated where water is available but where their inhab-itants are not threatened by the annual inundation, such as on the banks of oxbow lakes and islands. Indus cities were often constructed on an artificial platform, to raise them above the danger of flooding, or were protected with massive brick walls.
To the west of the Indus River a piedmont plain edges the Kirthar Range of the mountains of Baluchistan and Sindh Kohistan to its south; through this run passes leading to the Baluchi uplands. In the summer this zone is watered by seasonal streams and torrents pouring down the mountainsides that deposit alluvium along their foot. The majority of these western watercourses peter out on the plain, but some may in the past have flowed into the Indus. North of the Kirthar Range and west of the Marri-Bugti Hills lies the Kachi plain, a substantial extension of the Indus plain into the mountains of Baluchistan. The Bolan River flows through the center of the plain and is the main access route to the west from the central Indus region. The valley is also watered by rivers flowing from the mountains on both sides, of which the Mula and the Nari are the most important. Unlike Sindh, this plain is also watered by rainfall, mainly in the summer from the southwest monsoon but also in the winter. Cultivation is now mainly in the summer (kharif) though some winter (rabi) cultivation also takes place: In the Indus period, rabi cultivation predominated, making use in some cases of small-scale irrigation using bunds (small dams) and small chan-nels. The Kachi plain is a region transitional between the mountains of Baluchistan and the more challenging Indus plains, and it was occupied by farmers (at Mehrgarh) by the eighth millennium BCE.
In winter, when the Indus keeps to its bed, it is navigable by large boats;
during the summer floods it is often too turbulent for navigation but at other
during the summer floods it is often too turbulent for navigation but at other