GISdevelopment.net --> Application --> Archaeology
Ancient ports of Gujarat
Scientist, SAC, Ahemdabad
M. H. Raval
Ex. Director, Directorate of Archaeology, Ahemdabad
A. R. Dasgupta
Deputy Director, SIIPA, SAC, Ahemdabad
Gujarat state is situated on the West Coast of India between Latitude 20o02’N and 24o41’N and Longitude 68008’E and 74o23’E. On the basis of geographical features, Gujarat comprises three regions, namely,
Fig. 1: Some of the ancient/historical ports of Gujarat
Fig. 2: Mosaic of IRS imagery of Gujarat region
A book which was written after the Solanki period named ‘Nabhi Nandan Jinoddhar Prabandh’ mentions about Gujarat: “Residents of this region are small traders doing trade at ports and hence prosperous.”
At present, along the coastline of Gujarat, there are about 38 ports. Out of these one is an important major port Kandla in Kachchha district, 11 ports are medium or second grade ports and 26 are small ports. It is believed that Gujarat had a longer coast line in ancient times. Historical information shows that there were 84 ports in Gujarat during the medieval period. There were 62 ports in Saurashtra as late as 1842. It is also mentioned in the literature that ships from 84 different ports from various countries having different flags on them used to visit Mandavi port in Kachchha before hundred years. Figure 1 shows some of the ancient and historical ports of Gujarat. Figure 2 shows a mosaic of IRS imagery over Gujarat. Table shows ancient and historical ports of Gujarat mentioned in literature.
Fig. 3: A boat coming from Tharad and a prominent citizen receiving a guest.
Fig. 4: Rann of Kachchha as a part of the Arabian Sea (8th to 6th century BC)
Fig. 5: Soil marks in the IRS data of Gujarat
Remote Sensing and Archaeology
Archaeology is a science of the human past and its spread over space and through time. Remote sensing provides a snapshot perspective that iindispensable in today’s study of mankind. The utility of remote sensing is mainly for reconstructing historical geography as it provides confirmatory scientific evidences for the same, such as location and spread of palaeo-channels, palaeo-mudflats, settlements and agricultural area, etc. Aerial photographs were first used in 1921 for archaeological applications in North America. This marks the birth of archaeological applications of remote sensing. Remotely sensed data can be used for addressing problems associated with various types of site discovery, site prediction, preliminary reconnaissance and mapping of sites. The data can also be used for confirmatory evidences. The obvious significance of the information of remote sensing to the archaeologists is the problem of site discovery. Unfortunately, although the use of various forms of remote sensing data, primarily aerial data, has proven valuable as a means of site detection in other countries, archaeologists in India have not used remote sensing data for this purpose due to various constraints. Aerial data are generally not available of the required area and even if they are, their use is prohibited for general purposes for defence reasons. To get aerial photography done in India is a difficult task. To get the permission to fly over coastal areas itself is difficult. Further, even after getting the necessary permission from the Directorate General of Civil Aviation (DGCA), the aerial survey itself is time consuming. On the other hand, multi-date satellite data is easily available. Satellite data can successfully be used for archaeological applications. However, applications of orbital remote sensing data for archaeological uses have been limited in India.
Application of Remote Sensing for Archaeological Site Location
The archaeologist must know the location of sites. This information in itself can be valuable for studies in location analysis and settlement pattern. Given the current emphasis on viewing archaeological sites in a broad regional context, the synoptic coverage/overview provided by satellite data is of great value. Techniques that may be used to discover archaeological site locations from satellite data are:
On arid land with little plant cover and bare soil without any vegetation cover, the colour of the surface provides the most important, though not the only, means by which ancient structures may be detected. Marks on bare soil on cultivated land are also useful in detecting certain areas of archaeological interest. Colour variations of this type are caused by differences in the mineral and organic content of the soil. Partially obscured features may be revealed in arid regions. The positions of buried ditch fillings may be shown in some places by variations in the water content of the soil, which also affect its colour (Figure 5).
Fig. 6: Palaeo-Mudflats and strand lines on Gujarat coast
Information on underground structures or positions of earth works may be shown by differences in vegetation growing on them, which may take various forms according to local circumstances. The vegetation may be greener on the ditches and paler on the banks, which shows different moisture content of the palaeo-channels, palaeo-mudflats or coastal areas. In arid areas, the scanty vegetation may similarly show the positions of ancient remains. Shrubs may grow in favourable places at the base of ruined walls, and vegetation may be denser in ditches but almost absent on the banks.
Occasionally, flood water outlines ancient earth works. They may protrude from a sheet of water on low ground or the water may fill the hollows. Wetter or drier patches may form above the buried features producing darker or lighter marks which are usually described as damp marks and when the soil dries, they fade out.
An Example of the Use of Satellite Remote Sensing Data
By delineating the strand lines based on remote sensing data along the SE Saurashtra coast, it is found that the shore line has been shifted more than once. One can also sea the wide streams with many tributaries end abruptly against these strand lines. The mud flats are related to the phenomenon of regression of the sea. They represent the sites of older mud flats when the sea level was several metres higher than the present, Figure 6.
Fig. 7: Flow of river Saraswati upto Rann of Kachchha
Varahi, Benap and Tharad are located on the bank of a palaeo-channel that might have been a mighty river (Saraswati?) as the width of the palaeo-channel is very large. Thus these ports might have been riverine ports in those days. Some of the ports might have closed out due to unfavourable conditions. Mavsari, Padan, Amarapur, Kodadha, Zinzuwada and Guntaligadh located on the bank of the Great Rann or the Little Rann of Kachchha, which were once a part of the sea, are examples of such ports. Thus, remote sensing data shows that most of the places mentioned in literature which are believed to be the ports were indeed ports in the past. Thus it is possible to find out or confirm the location of old riverine ports or seaports using satellite data.
An Attempt to Locate New Sites
New sites of archaeological interest can be located using soil marks, vegetation marks and anomalous landforms from the satellite data. New sites can be found out on the old seacoast, palaeo mudflats or present coast or in the old seabeds. An attempt has been made to find out whether any such sign is there in the Rann of Kachchha or not. It is reported that the river Saraswati was flowing along the bank of the Little Rann of Kachchha and pouring its water in the Gulf of Khambhat. It is also reported that the river Saraswati was flowing in Kachchha up to 325 BC. The flow of the river Saraswati has been shown in Gujarat through the Rann of Kachchha up to Saurashtra from north Gujarat. Kota Venkatachelam has also shown the river Saraswati pouring water in the Rann. Figure 6 shows the map from ‘Ancient Bharat Varsha’ showing the flow of river Saraswati up to the Great Rann of Kachchha. In view of this and the recent findings at Dholavira, an attempt has been made to locate the possible sites of ancient ports.
The Great Rann of Kachchha which is dry Rann having encrusted salt in the dry season was examined in the satellite imagery. During monsoon the same area is covered with water. The area was part of the sea for more than 1000 years. IRS Geo-coded data of this area representing the Survey of India Toposheet no. 40L\8 was selected for site location. The image shows signs of a mighty river (Saraswati?) flowing in this area. River flow is between 70o 15' - 70o 30' E, the flow is north to south in direction and shows a bifurcation. The other signs show that there might be probable sites of towns or villages, at about 24o 09' N and 70o 28' E, 24o 13' N and 70o 16' E, 24o 02' N and 70o 29' E. A water body at 24o 09' N and 70o 17' E could be a village tank. Agricultural areas can be seen between 24o 11' - 24o 15' N and 70o 20' - 70o 30' E. SOI Toposheet shows only dry Rann having only one island, Maruda Takkar, having 23m height. The other information given is salt waste and the area remains usually flooded during July to December.
Such signs can also be seen in the south of Jakhel village, in between Jakhel and Chadiyana of Sami taluka. Some anomalous structures can also be seen in the north west of Subapura village of Sami taluka Mehsana district. (SOI toposheet no.41 M/10.) A more detailed survey is required for further confirmatory information. It would be useful if some of these sites could be investigated further to verify the indications seen in the satellite data.
Thus remote sensing technology can play an important role in understanding the past in the context of available historical and ancient literature. Remote sensing data can successfully be used for building up historical records and changes that might have taken place on the surface of the earth in the past. The data may also be used for upgrading historical atlases, which might have been prepared using only limited knowledge, and as per the imagination of certain scholars.
The proper planning, use and application of remote sensing techniques in archaeology will result in economic benefits through reduction of costs of survey. Remote sensing technique can increase efficiency, speed and data extraction at all stages of archaeological research. Aided by the broad, interdisciplinary scope injected by remote sensing data, archaeology may, in the near future, transcend its traditional narrow focus. This may, in fact, be one of the best justifications for a public, and publicly funded, remote sensing based archaeology programme.
|© GISdevelopment.net. All rights reserved.|