TERRAIN EVALUATION OF DOON VALLEY AND ADJOINING REGION USING REMOTE SENSING DATA

Abstract

'Nature abhores fixed boundary lines and sudden transitions... Everywhere she keeps her borders meltinglwavering,advancing and retreating.' I---Semple,1911 The knowledge of existing landforms,landuse and other characteristics of the terrain is essential for planning and management of 'devlopemental projects in any given region.The conventional methods of collecting such data are time consum-ing and uneconomical, Aerial photographs have been used for these purposes since the 40's,and a new era ocened in 70's with the availability of Landsat data products,because. of their synoptic coverage, low cost and easy availability in multi-temporal and multi-spectral modes. The present study of terrain evaluation,using remote sensing data ,covers the Doon valley,the Shiwalik range and the flat plains between the river Yamuna and Ganga. Lou cost visual interpretation techniques using • various remote sensing. data products viz. Landsat Black and White imagery,False Colour Composite(F.C.C.)and Computer, Compatible Tapes(C.C.T.) have been used in evaluating the terrain of the above region,primarily considering its engineering aspects only.To use tnis data for a railway alignment from Saharanpur to Paonta Sahib,on the western fringe of the region,it was suppli'aented with detailed infor-mation gathered by analysis of aerial photographs of the area through whiCh the proposed route passed.Digital classi-fication of the same area was done on MIDAS using Landsat C.C.T. The introductory cnapter deals with the objectives of the present study, the basic requirements of terrain evaluation along with their usefulness and applications. It also describes the application of remotely sensed data in Civil engineering and in particular for route location. The earlier research work carried out in the. field of terrain evaluation has been discussed in the second chapter. The third chapter deals with route surveying in general,giving the different factors which effect the alignment process, with a brief review of some work already done in this field. The study area is described in the fourth chapter to be followed oy the cnapter on the metho dology adopted for terrain evaluation and route surveying. Details of tne proposed railway alignment along with the ex-pected cost of the project are in chapter six. The seventh chapter gives the results and discussions on the various aspects of the study.It also gives a comparision of the cost of study between conventional methods and that adopted in the present study. The last chapter deals with the conclu-sions and recommendations besides mentioning the future scope of research work which can be carried out in this field.• Digital Terrain ifodel(DTM) for route alignment along with the description any: working of MIDAS, have been included in the Appendices. On the basis of this study it can be said that (i) Landsat imageries are very useful for terrain evaluation as they provide a synoptic view and repeated coverage of the area under investigation, although in some select-ed portions aerial photographs are more useful for detailed analysis for a particular engineering project such as a railway alignment project. (ii) The method adopted is both time saving and economical. This is seen by the time and cost analysis,by which it was calculated that the cost of terrain evaluation comes out to be only 5.04 paisa per hectare and the time taken as only four months.On the other hand the cost of railway survey came to only Ps 300/= per Kn. It is only 1.42% of the expected expenditure by conven-tional survey methods,at the rate of 1% of the total estimated cost of the whole project. It is also recomfnended that detailed tectonic studies are to be made especially in the faulted mountain-eous zones,where the track may