Photogeology

                      INTRODUCTION

Photogeology is the interpretation of the geological and geomorphological features as well as various lithofacies on the aerial photographs. Some other terms such as "aerogeology" and "airgeology" are also used. Aerial photographs are a source of geological information that may be unobtainable elsewhere. An aerial photograph is the picture of the ground surface taken from the air with a camera pointing downward. The study of the aerial photographs can't substitute the field investigations but rather it helps and contributes to them. The advantages of the study of the aerial photographs can be listed as follows: a. it saves time b. it provides to observe a larger area c. it has more detailed ground surface than maps d. photographs can be studied anytime and at anywhere e. studies carried out on the photographs are cheaper than studies in the field f. studies carried out on the aerial photographs are easier than studies in the field The only disadvantage of the aerial photographs is the absence of the topographic contours and the geographic names.