Locating Archaeological Sites in the Ajay River Basin, West BengalAn Approach Employing the Remote Sensing and Geographical Information System

Sutapa Roy

Research Assistant

CENTRE FOR ARCHAEOLOGICAL STUDIES & TRAINING, EASTERN INDIAAn Autonomous Institution under the Information &Cultural Affairs Department Government

Kolkata

DEVELOPMENT OF RS & GIS IN THE FIELD OF ARCHAEOLOGY

In Europe, GIS has been used in the field of archaeology, since early 1980s and the Aerial Photography has had a long history of use. English Heritage's Finland Survey Project is supposed to be the beginning of the application of the GIS and RS in the field of archaeology. Since 1988 there has been rapid growth in the application of GIS, a tool both for Archaeological Research and Cultural Resource Management.

IN THE FIELD OF ARCHAEOLOGY, THE APPLICATION OF GIS AND RS HAS BEEN RATHER A NEW PHENOMENON IN INDIAN CONTEXT.

In the late 1990s when an attempt was made to establish that the Arayans had their roots by the side of the old course of the river Sarasvati, RS nd GIS were employed. Signatures of the old course of the river (i.e. the palaeo-channel) was detected by using satellite data.

The next pioneering attempt was made in this direction in 1993 by the Department of Space, Government of India in collaboration with the Deccan College, Pune. In 1995 a training course on the application of RS for Archaeology was also conducted by the National Remote Sensing Agency (NRSA), Hyderabad for university teachers.

DEVELOPMENT OF RS & GIS IN THE FIELD OF ARCHAEOLOGY

A few years ago, Dr. Ashis Bhattacharya, former director, NRSA made an endeavour to trace the potential sites of Satavahana period on the alluvial terrains of Andhra Pradesh, near Kondapur.

In present decade, the Centre for Archaeological Studies & Training, Eastern India for the first time in West Bengal has been making use of RS and GIS in its attempt to locate the archaeological sites on present landscape.

IMPORTANCE AND SCOPE OF GIS & RS IN THE FIELD OF ARCHAEOLOGY

Remote Sensing is increasingly important to archaeology and GIS is rapidly becoming indispensable.

Archaeological data are inherently spatial and archaeologist are naturally concerned with the distribution of archaeological sites across the landscape. From these distribution one can understand the past use of landscape in many ways- as settlement patterns, the size of the domains, aspects of resource procurement, site catchments analysis. Here GIS can also be used as database management tool and can generate new information.

RS data are currently used for exploration and discovery of new sites and there have been successful attempts to use satellite data to identify landscape or cultural features, such as stone quarries, structural remains and ancient river courses i.e. palaeo-channels (as of the rivers Kunur, Kansai etc)

Particularly in the context of Bengal where the riverine activity has been of greater consequence, site density mapping, resource zone mapping by using GIS could be more fruitful for research.

IMPORTANCE AND SCOPE OF GIS & RS IN THE FIELD OF ARCHAEOLOGY

GIS based modeling approaches to analyse regional-scale data include the estimation of cost surfaces, network models of trade and cultural interaction, predictive models of site location, view-shade analysis (for determining of visibility between monuments of the landscape), intra-site relationship is assessed as well as number of other models derived from geography and spatial analysis.

This case study tries to utilize GIS and RS to represent a past archaeological settlement ( i.e. Chalcolithic – Early-historic period ) in the present landscape with a scientific pictorial view.

DRAINAGE PATTERN OF THE AJAY VALLEY

Based on unpub.GSI Report, 1986.

The Ajay, originating from the southeastern part of the Chakai Plateau, Jharkhand, enters West Bengal near Chittaranjan and meets the Bhagirathi river at Katoya in Bardhaman.

The Kunur nala originating from the north of Kaksa PS. and falling into the river Ajay at Mangalkot.

The river Kopai, a tributary of Bakreswar, drains the northern bank of the Ajay valley.

The Ajay river basin is a potential zone of archaeological settlements in West

Bengal. The study area is restricted to the alluvial plains of Ajay river valley.

The two most important sites in this area are Mangalkot and Pandu Rajar

Dhibi which have been excavated. Most of the sites are buried under the thick

layer of alluvium (4-5m.).

Here two geomorphic units are dealt with i) Illambazar Surface and ii)

Natunhat surface. #9. Slide 9

Chalcolithic or Black and Red Ware (BRW) (3rd century BCE) and Early-

historic (2nd century BCE) sites like Pandu Rajar Dhibi (c.1100B.C.- 700 B.C.),

Basantapur, Deuli, Supur etc. are situated on the Illambazar surface.

#10. Slide 10

On the Natunhat surface the Early-historic sites outnumbers Chalcolithic

sites. Mangalkot (c.1000B.C.- 1800 A.D.), Aral, Kogram etc. are located on this

landform. #10. Slide 10

GEOMORPHOLOGICAL FEATURES OF THE AJAY RIVER VALLEY

• The Study Region belongs to a transitional zone between the Chottanagpur Plateau and the Bengal River Basin.

•Two Geomorphic Units - (i) Laterite upland or Illambazar surface and (ii) Older Alluvial Terrace or Natunhat Suface.

DISTRIBUTION OF ARCHAEOLOGICAL SITES

USING HERMENEUTIC METHOD TO DESIGN AN ARCHAEOLOGICAL DATABASE• GIS incorporates the essential elements of computer cartography and relational database into one system.

• The most important feature of this system is that every mapped feature is linked to a record in a tabular database and may be related in other database.

• Hermeneutics database design (Rivett 1997) has an important role to prepare an Archaeological Database in the GIS application.

Knowledge BasePREJUDICE

Archaeological

Social/Historical

Environmental

DATA

TEMPORAL

Spatial Non-Spatial

DATA DEFINITION

PROBLEM DEFINITION

Archaeological Problem

Real World

Hermeneutic diagram for Archaeological GIS

Methodology

Here archaeological database is not sufficient and hence in the Hermeneutics method the database is only taken as outline and as primary level data. It calls for elaboration.

Data come in two forms- (i) Spatial (like distribution of archaeological sites) and (ii) Non-spatial data (database on ethnographical,

anthropological and archaeological sources.#12. Slide 12

THE ARCHAEOLOGICAL PROBLEM OF THE STUDY REGIONSome Archaeological sites are found scattered from the upland zone to new alluvium terrace. Many settlements in the older alluvial zone are found disturbed as artefacts are often washed away by flood water and redeposited in the younger alluvial zone. This is commonly observed in the Ajay basin where archaeological sites are buried within a few metre of the terrace

surface. So sites are usually found with mixed assemblages.

On the other hand, It is also claimed that catastrophic Sedimentation (flooding) and rapid sedimentation ` and entombs archaeo sediments, creating buried sites

which may be immune to subsequent artefacts displacement (like Sagira).

• Following only the site location, site reference and river categories of the SEER diagram, only the Archaeological Site Database of the Ajay Valley has been made.

Locational Chalcolithic and Early Historic Site Database Showing with a Geomorphic Unit

OBJECTID

Archaeological FindsGeomorphic Unit

LocationCultural chronology

Site Present Village IF/NF/KF*

AFP/KFP/AKC#

Chal/EH

% of total CutureRight Bank ( R)/Left Bank (L)

1Aral Aral IF KFP/L EH 1

2Goswamikhanda Mallickpur IF AFP/R Med 1

3Kalyanpur Kalyanpur IF AFP/R CH/EH 2

4Majhigram Majhigram NF AFP/R CH/EH 1

5Mangalkot Mangalkot NF KFP/R CH/EH 3

6Pandu Rjar Dhibi Panduk IF AFP/R CH/EH 2

7Chandra Hazradanga Bahiri NFAFP/L

CH/EH 3

8Beluti Beluti NF AFP/L CH 2

9Bergram Bergram ? Kopai CH/EH 2

10Chandidaser Bhita Nanur ? Kopai EH 2

11Kholamkuchir Math Charkalgram NFAFP/L

CH/EH 2

12Chella Chella IF AFP/L CH/EH 2

13Deuli Deuli KF AFP/L EH 2

14Ghurisha Ghurisha IF AFP/L CH/EH 3

15Kamarpara Kamarpara IF AFP/L EH 1

16Kogram Kogram IF AKC/R EH 1

17Kirnahar Kirnahar ? Kopai CH/EH 2

18Mahishdal Mahishdal ? Kopai CH/EH 3

19Nachansaha Nachansaha IF AFP/L CH/EH 3

20Surath Rajar Dhibi Supur IF AFP/L CH/EH 3

22Sagira Sagira KF AFP/R EH 1

23Hazradanga Basantapur IF KFP/L CH 1

24Bulbuldanga Orgram IF KFP/R CH/EH 2

25Indrani Pargana Bekeihat KF AFP/R CH/EH 2

* IF― Illumbazar Formation, NF― Natunhat Formation and KF― Katoya Formation. # AFP―Ajay Flood Plain, KFP― Kunur Flood Plain and AKC―Ajay Kunur Confluence. ^Chal & CH― Chalcolithic, EH― Ealy Historic

In the major flood plain i.e. River Ajay, some of archaeological sites, like Deuli. Artefacts scattered are most probably in secondary context. In this regard Archaeological sites only can be observedon the present landscape.

GIS and Remote Sensing Techniques can help partially to solve the problem.

Deuli

THE ARCHAEOLOGICAL DATABASE

SEER( Spatially Extended Entity Relationship) Diagram of the Archaeological Database.

Highlight indicates in use

Soil Type (Polygon Feature)

Type of Vegetation

Site (Point feature)

Secondary

Primary

Chronology

Related Field: Altitude, SiteID, Name, Type, Mound

Moat

Main River, Tributary, Canal, Sand-bar, point bar etc. (Polygon and Line Feature)

Soil Locational Reference

Hydrology Site Locational Reference

Vegetation

Location

Artefacts

SITE LOCATION NETWORK ON TRIANGULATED IRREGULAR NETWORK (BASED ON CONTOURS AND BENCHMARK POINTS)

PRELIMINARY OBSERVATIONS

Some sites located on fluvial terraces were stable settlements, where a full range of riverine activities was noticed belonging to the Chalcolithic period to the Early-historic period. Most important thing has to be pointed out here that a few months ago when we were in Mangalkot to survey the Sarkaridanga mound, carbonaceous black soil in exposed section was observed at least 15m below from the upper surface, which indicates the presence of a palaeo-riverine course. When the satellite data(IRS 1D/PAN and Google Earth Data) has been taken into account detection of a palaeo-channel has been confirmed. And the channel must have been that of Kunur. Slide 18

PRELIMINARY OBSERVATIONS

Sites on main flood plain zone (at the juncture of lateritic and older alluvium surfaces, have the rate of preservation qualitatively much higher and this is evident from the extensive existence of modern habitation on top of them. To summarize, by integrating within a unified system, the traditional archaeological methods and new techniques, it is possible to identify new sites (i.e. unexplored sites), explain their location and define the role they played in the regional context.

The application of the technique is limited by the nominal ground resolution of the sensors IRS IC and ID, LISS III (23m x 23m), multi-spectral data from satellite platforms, mainly LANDSAT TM (30m ground resolution), IKONOS (1mx1m) have been successfully used for the archaeological application.

GIS LIMITATIONS IN ARCHAEOLOGY

Single data (Satellite) can hamper the study enormously.

An expensive exercises a large and extensive research might not be always possible logistically.

Above all, through Remote Sensing and GIS technique, one can only study the archaeological sites on the present landscape. But it is not possible to determine the past landscape totally in relation to the chronological period in which the sites have been found.

Thank You