ENVIRONMENTAL GEOLOGY

3 VIEWS OF WHAT “ENVIRONMENTAL GEOLOGY” IS1. (Textbook definition 1) A branch of ecology in that it deals with relationships between

man and his geological habitat; it is concerned with the problems that people have in using the earth, and the reaction of the earth to that use.

2. (Textbook definition 2) Application of geologic information to solving conflicts, minimizing environmental degradation, or maximizing possible advantageous conditions resulting from man’s use of the natural and modified environment.

3. The Osborn view…..

ENVIRONMENTAL GEOLOGICAL STUDIES INCLUDE:1. Evaluation of natural hazards.

2. Evaluation of landscape for site selection, land-use planning, impact analysis.

3. Evaluation of earth materials re potential (a) use as resources, b) use for waste disposal, c) effects on human health.

A FEW EXAMPLES1. Geochemistry and health

2. Volcanic hazards evaluationLong-range

Predict future on basis of past activity; includes mapping of ash, mudflows, etc.

Short-rangeHeat flow, earthquakes, gas temperatures

3. Coastal erosionStabilization measures create different problems or transfer problems elsewhere

4. Land subsidencee.g. extraction of fluids (groundwater, oil/gas):

pore pressure declines→ compaction→ subsidenceExamples: Houston/Galveston 3 m

S-central Arizona 2.2 mLas Vegas 1 mLondon, England 0.7 mMexico City 7 mTokyo 4 m (2 million people below high-tide sea

level)

5. Behavior of sedimentse.g. problems with Bankers Hall excavation in downtown Calgary

6. River/land relationsDuisburg, Germany: Ruhr River near confluence with Rhine

Ruhr Industrial District: largest inland port in world45 km of wharves, cargo-handling equipment

Progressive straightening of Rhine in 20th century for navigation→ increased gradient degradation→ lowering of river (2.2 m since 1900)

Wharves too high, future of port in jeopardy

But 3 coal seams below harbor area; if they could be mined the wharves would subside.....