Chapter 14: Soils & Environment

soil composition

organicsair waterweathered earth materials (parent material)

mechanical weatheringsmaller, rounder pieces (if moved)

chemical weatheringfeldspars and water = clayscalcite - dissolvesorganics - dissolve - acidify waterquartz - usually left behind

transported vs residual

formation

dominated by downward movement of water

weathers parent material

moves dissolved substances downward

Soil profile - fig p 440created by downward movement of waterhorizons

O - organic humus little or no parent materialA

weathered parent material w/ organics zone of leaching

E - few organics or ironB - zone of accumulation

Bt - clay enrichedBk - calcium enriched - calcium coats

Kcalcium dominatedcaliche - calcium layers

C - partially altered parent materialR - parent material

soil properties

colorrelated to composition

organics - dark yellowiron - red or grey - dominatescalcium - light or white

describe wet - use charts

texturegrain size distribution (among fraction <2mmestimate in field - measure in lab

structurepedsgranular, blocky, prismatic, platy >clay

Soil fertilitynutrients available for plantsnatural

parent material - flood deposits, till, bedrock]organicsclimate

tempprecip– rain supports vegitation– leaches nutrients

• Northern IL forests vs rainforests

humansalter vegadd and remove nutrients

single crops– crop rotation

erosionpesticides

Water in soil

saturated vs moist vs dry

What effect does soil moisture have on soil cohesion?

sand (moist vs wet vs dry

clay (wet vs dry

flowsaturated - hi pressure to lo pressure

unsaturated - film of water attached to grains

Soil classification

taxonomy - based on physical and chemical props of soil

morphologynutrientsorganics

classification methodsorder, suborder, great group, subgroup, family, series

focus on ag use

universal soil classificationfocus on size and compositionused by engineers

What are the engineering properties of soils?

How will soil affect buildingbased on particle size, compostion, water content

behavior based on water contentsolid/plastic/liquid

plastic limit, liquid limit - diff is plasticity indextake soil, add water until ribbons form, flowswet weight - dry weight over dry weight

strength - how well does soil hold together and supportcohesion of particles - esp for fine grain

molecular and electrostatic forcesmoisture

friction - density, size, and shape of particles - esp for coarse grainvegetation

sensitivitychange in strength as a result of disturbance

coarse - lowfine - high esp clay

compressibilitycoarse - lowfine - high

erodabilitysusceptibility to wind and water erosionaffected by

particle sizeexposurewater contentcohesivenesscementationdead zone at surface

hydraulic conductivitycoarse - highfine - low - clays less permeable, attract water

corrosion potential - ion exchange with waterof buried objects [ie pipe & UST’s]affected by ability of soil to carry current

water contentresisitivity

cathodic protection

ease of excavationcommon excavationrippable excavationblasting or rock cutting - hard pan may be here

shrink - swell potentialincrease and decrease in volume w/ water contentexpansive soils

usually absorbant clayscan destroy houses and hiwaysmontmorillonite can x-pand 15x> 3% is badmost swell less than 25-50%change is problemresponse of soil is based on – soil type % of expansive clays– moisture content– climate wet & dry seaons vs steady– veg - trees suck water– topo - pounding water– drainage - can keep soil dry

overall - clay soils low strength bad featuresclay hi sensitivityhigh shrink - swell

Land use and soilsWhat are the causes and effects of soil erosion?

landscape modificationresulting in increased erosion, esp during modificationurbanization– sharp sed load increase followed by long term decrease

timber harvests– removes cover and roots

• clear cut vs select cut• equipment = disturbance

agriculture - tilling and grazing– exposes soil to wind and water– management - wind breaks, contour farming, no-till, terracing, strip cropping, CRP, buffer zones– other effects

• chemical pollution - fertilizer, pesticides, herbicides• nutrient loss

off-road vehicles– mechanical - motorcycles, 4wd, mountain bikes– animal - horses, hikers

Sediment pollutionstreams move sed– increase sediment load

• aggradation - full channel enhanced flooding– decrease sediment load - degradation - incision or bank erosion

sediment deposited - flood plains, alluvial fans, lake bottoms, wetlands, deltas, local problem areas components– normal sediment load– flood load– disturbed sediments (farming, construction, logging, channelization– wastes (municipal, industrial, mining

solutions– farm management– sediment traps - fig p 452– clean water act– re-vegetation

Soil pollution

addition of toxic or carcinogenic substances to soilfactors

mobilitysolubilityattraction to claysdecompostion– chemical (agrichems– biological

presence of– oxygen– water– microorganisms

What is desertification?

conversion of productive land to desertfactors

deforestationsoil erosionpoor drainage of irrigated landoverdraft of wateraccelerated by drought stressaffects long term hydrologic cycle - climate

North American examplewater tables salinization of soil and near-surface soil water from irrigationreduction of surface water in streams and lakeshigh rates of soil erosionloss of native vegetationinterrelated factors - salinization - veg loss - erosionpatchy occurrences

Soil surveys and land use planning

soil mapssoil cross-sectionssoil descriptions

inc grain size distributionmoisture contentstrength

may rate soilsagriculture, prime, important etchousingindustryforestryhydric

derivitive mapsbased on specific characteristics

building limits, slope, thickness, moisture content– none-slight– moderate– severe

Chapter 16: Global Climate Change

Global changeEarth has been changing since beginning early preCambrian (over 4.5 billion years)Scale of variability - days to >10,000's yrsCauses of variability

Sun - output, angleEarth

rotation speed (slowing)continental movementsVolcanic output

Life - O2 + CO2 cycles, humans

Research priorities

is there change?

on what scale?

what are the causes?

what are the affects?

Composition of atmosphere

N - 78%

O2 - 21%

Ar – 0.9%

CO2 – 0.03%

other – 0.07% CH4, 3, CO, NOx, SOx, H2S, etc

water – 0 to 4%

Energy balance

almost all energy ultimately from sun

earth’s energy cyclereflects 30%

absorbs 70% (visible & IR)

emits IR (as much energy as it receives)

Earth’s temperature based on

sunlight receivedamount reflectedatmospheric retention: “greenhouse effect”

H2O vapor, CO2, CH4, CFC’snatural processincreasing in atmos due to humans

CO2 changeshighs - interglacial periods - 125K yrs ago and nowcurrent increase started in 1800's releasing stored CO2 from rxother changes

Tools to study global change

Geologic record

Real time

Mathematical modeling - global circulation models

Earth’s Climate

on average: warmer than present

currentice age - 2MYA to present

last glacial advanceended 10,000 yrs ago

gradually warming since

anthropogenic effects

Potential Effects of Global Warming

climate changemore rain

more violent storms

sea level rise

complex responses (unpredictable)

Chapter 17Geology, Society, and the

Future: Selected Examples

Geology may influence diseases and death rates

acute vs chronic response

Element requirements for lifeMetals - H, Na, Mg, K, Ca

Non-metals - C, N, O, P, S, Cl, Fe - hemoglobin

Trace - Fluorine, Cr, Mn, Cobalt, Cu, Zn, Selenium, Molybdenum, Iodine

Concepts of waste management

dilute and disperse

concentrate and contain

integrated waste management

integrated waste managementresource recovery

goal: zero waste productionrecyclereuse

reduce - pay as you throwmove waste aroundsequential land use (subsequent uses must be limited)front end controls

more efficient processesless packaging

waste stream

Waste typesindustrial

construction

demolition

municipal

commercial

medical

Compositionpaperhard wasteplasticsmetalsfoodglasswood

Disposal methods

on site - any method

sewer (note on-site in book

incinerationproduces ash and air waste

composting – recycles organic waste

landfill - engineered site

Landfills

considerationsleachate

methane

rodents & pests

active face - blowing trash

site selectionlocal approval

IL PCB - legal requirements

IL EPA - engineering requirements

Landfillssite design - fig p 544

geologylinersleachate collection and treatmentwaste types acceptedmonitoring

landfill conditionsmigration routes

cellssubsequent monitoring and design

Hazardous Chemical Wastewaste byproductsuncontrolled sites - CERCLAcontrolled sites - RCRA

responsible managementcradle to gravegeneratorstransportersstoragetreatmentdisposal

Environmental Impact Statement

EIS summarypurpose and needrigorous comparison of alternativesdescription of environmentdiscussion of consequences

identification of issues and alternativesrecord of decision

alternativeswhich are preferredrationaleavoidance and/or mitigation required

Site selection and evaluationphysiographic determinism

design with natureminimize landscape alteration

focus - will site provide needs of useprocess - fig p 555

collect datarecon likely sitescollect addn’t datamagnitude and importance of geologic limitations and possibilities

Methods of site selection and evaluation

cost benefits analysisphysiographic determinism

use map overlays (to show +’s and -’s)choose best siteuse physical, social, aesthetic, etc

Environmental geology mappinginterpretivemay focus on anticipated usescontent based on userGIS

considerations of site selection and evaluation

Landscape aesthetics - scenic resourceshard to evaluate - subjective

uniqueness - overall scenic

sequential land use - fig p 556

multiple land use - fig p 557

Environmental Law: Basis

Trust doctrineeach generation has a moral responsibility to provide the next with healthful, productive and aesthetically pleasing surroundings

Declaration of IndependenceGovernment protects each persons right to life, liberty, and the pursuit of happiness

Environmental Law: Basis

ConstitutionPreamble - “promote the general welfare, and secure the blessings of liberty to ourselves and our posterity”

Article 1, section 8 (Congressional powers)“to regulate commerce among the several states”

“toprovide for the common defense and general welfare of the US”

Environmental Law: BasisConstitution

9th amendment“The enumeration in the Constitution, of certain rights, shall not be construed to deny or disparage others retained by the people”

5th amendmentNo person shall bedeprived of life, liberty, or property without due process of law; nor shall private property be taken for public use without just compensation

10th amendment“The powers not delegated to the US by the constitution, nor prohibited by it to the states are reserved to the states respectively, or to the people”

14th amendment, section 1extends 5th amend to states

Environmental Legislation: Federal

Refuse act of 1899 - unlawful to discharge refuse into tributaries of navigable waters Permit from Sec of ArmyNational Environmental Policy Act

focused attn on potential env degradationprovided a framework for proj eval (EISincreased efforts to protect env in US

Clean Water Act & Clean Air ActCERCLA & RCRA

Environmental Law: local

land use planning and law

zoning

Environmental Law: controversies

highest and best use

most profitable use

takings

conflict with treaties and trade agreements

Environmental Law: International

Law of the seabedup for grabs

no treaties

20 mile limit

treaties

trade agreements