INTERPRETATION OF PERMAFROST FEATURES FROM AIRPHOTOS

THE USE OF AERIAL PHOTOGRAPHY IS DESCRIBED FOR PREDICTING THE PRESENCE OF PERMAFROST AND CERTAIN PERMAFROST FEATURES IN ARCTIC AND SUBARCTIC REGIONS. FIVE FIELD TRIPS TO ALASKA BY MEMBERS OF THE PURDUE STAFF HAVE PROVIDED AN OPPORTUNITY TO STUDY FROST PHENOMENON OF MANY TYPES UNDER A WIDE RANGE OF ARCTIC AND SUBARCTIC CONDITIONS. IN PERMAFROST REGIONS, ENGINEERING PROBLEMS ASSOCIATED DIRECTLY WITH PERMAFROST RESULT FROM AN UPSET IN THE THERMAL BALANCE IN THOSE SITUATIONS WHERE FINE-TEXTURED SOILS EXIST. INFLUENCING FACTORS ARE TOPOGRAPHIC POSITION, SURFACE INSULATION, SOIL TEMPERATURE, SOIL TEXTURE, EXPOSURE TO HEAT, AND MOISTURE. PROBLEMS ASSOCIATED WITH THE PERMAFROST CAN BE PREDICTED FROM AIRPHOTOS IF SUCH ITEMS AS TOPOGRAPHIC POSITION, SOIL TEXTURE, COVER, AND DRAINAGE CONDITION CAN BE DETERMINED AND EVALUATED IN LIGHT OF THE CLIMATE, TYPE OF PERMAFROST, AND EXPOSURE TO HEAT. IN NONPERMAFROST AREAS OF THE ARCTIC AND SUBARCTIC, FROST SUSCEPTIBLE SOILS CAN BE IDENTIFIED FROM AIRPHOTO STUDY BY APPLYING CERTAIN OF THE AIRPHOTO INTERPRETATION PRINCIPLES. SINCE SILTY SOILS ARE THE MOST SUSCEPTIBLE TO FROST DIFFICULTIES, IT OFTEN BECOMES A MATTER OF IDENTIFYING AND SEPARATING SILT SOILS FROM THOSE IN OTHER TEXTURAL CLASSES. INTERPRETATION IN TEMPERATE REGIONS FOR PREDICTING FROST ACTION IS SOMEWHAT DIFFICULT, PARTICULARLY IN AREAS HAVING A HIGHLY CYCLIC CLIMATE THROUGHOUT A YEAR. FROM THE STANDPOINT OF AIRPHOTO INTERPRETATION AND FROST SUSCEPTIBILITY OF SOILS IT IS BELIEVED THAT PREDICTIONS IN THE ARCTIC AND SUBARCTIC CAN BE DONE WITH A HIGH DEGREE OF ACCURACY. /AUTHOR/

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  • Accession Number: 00237854
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Aug 26 1970 12:00AM