GEOG1016 Exam Notes PDF

GEOG1016 High Resolution Mapping = “Large Scale Map” Net Primary Productivity (NPP) = Information about health and status of vegetative communities. Renewable Energy -​ Continuous use -​ Natural source Types of Renewable Energy Solar, Wind, Hydropower, Tides, Waves, Biomass, Biofuel, Geothe...

GEOG1016 High Resolution Mapping = “Large Scale Map” Net Primary Productivity (NPP) = Information about health and status of vegetative communities. Renewable Energy -​ Continuous use -​ Natural source Types of Renewable Energy Solar, Wind, Hydropower, Tides, Waves, Biomass, Biofuel, Geothermal **Nuclear and Coal is NOT renewable/sustainable (Part of Alternative Energy) Fossil Fuels (Natural Fuel/Hydrocarbon) -​ Hydrocarbon-containing (Petroleum/Crude Oil) materials formed naturally -​ Non-renewable -​ Oil (i.e. crude oil) -​ Coal -​ Gas (i.e. natural gas) -​ Made from decomposing animals/plants/organic matter Alternative Energy -​ Alternative energy sources are options to fossil fuels that are non-traditional and have lower environmental impacts. -​ Benefits: ​ Help decrease CO2 emissions and mitigate global warming. ​ Generally have a smaller environmental footprint. -​ Controversial: The perception and acceptance of alternative energy sources have changed over time, often sparking debate. (Due to reliability and environmental impact) -​ Types of Alternative Energy (Renewable + Nuclear Energy) ​ Solar: Harnessing energy from the sun. ​ Wind: Using wind turbines to generate electricity. ​ Geothermal: Utilizing heat from the Earth’s interior. ​ Biofuel: Energy from organic materials. ​ Nuclear: Using nuclear fission to generate energy. ​ Hydropower: Generating electricity from flowing water Petroleum (Refined Crude Oil/Fossil fuel) -​ All naturally occurring hydrocarbons (hydrogen + carbon) -​ Mixture of different hydrocarbons ​ Solid Hydrocarbons - Asphalt ​ Liquid Hydrocarbons - Crude oil ​ Gas Hydrocarbons - Natural gas: methane, butane, propane, etc. -​ Simplest hydrocarbon is Methane (CH4) Crude Oil (Type of fossil fuel) -​ Crude oil is the liquid term for petroleum -​ All crude oil is petroleum, not all petroleum is crude oil -​ Subset of petroleum -​ Unrefined, needs to be processed for usage Formation of Petroleum -​ The transformation of plankton into petroleum takes millions of years. -​ Most oil and gas start as microscopic plants and animals that live in the ocean. -​ Plankton die > Sink to seabed (Form organic mush) > (Time) > Fossil Fuel (Petroleum) -​ Plankton thrive where deep ocean currents bring nutrient-rich water to the surface, allowing them to bloom. -​ If there’s little to no oxygen, the organic mush accumulates because animals cannot survive. Black Shale Formation 🪨 Sediment with more than 5% organic matter forms a type of rock called black shale. As black shale is buried, it heats up = generates hydrocarbons At higher temperatures, the organic matter changes into kerogen (a solid form of hydrocarbon). At about 90°C, it turns into liquid oil. At around 150°C, it becomes gas. -​ Source Rock 🪨: Rock producing oil and gas -​ Oil and gas migrate upwards  -​ Eventually, the rising oil and gas get trapped in pockets within the rock, known as reservoirs. -​ Rising oil and gas trapped in pockets within the rock (reservoirs) -​ Reservoirs = Underground rock formations NOT the ones with flowing water Crude Oil and Natural Gas Windows -​ Kerogen (Exists in Sedimentary Rocks) ​ Mixture of organic chemical compounds with very long carbon chain ​ -​ Vitrinite Reflection (VR, %): The reflectance of light from a sample's surface, indicating the maturity of organic material. For crude oil, it ranges from 0.5% to 1.2%. ​ -​ Diagenesis: The process of sedimentation at low temperature and pressure, where organic kerogens are converted into hydrocarbons. Exploration - Drilling the Well -​ Once oil or gas is identified, a hole is drilled to access it -​ Cost of drilling is expensive -​ Offshore rig: May cost around $10K for each metre drilled -​ A company faces vast losses for every “dry hole” drilled Directional Drilling (Vertical Vs Horizontal) -​ Most wells are vertical (Inexpensive, easy) -​ Angled drilling 5-8% in the US -​ Horizontal drilling more common as it exposes a lot of formation to the borehole, less surface disturbance Unconventional Oil 🛢️ Oil shale: Organic-rich, fine-grained sedimentary rock containing kerogen -​ Substitute for crude oil -​ Expensive -​ Easy to find in the US (Have major deposits) -​ Surface or open pit mining causes extensive environmental concerns Tar sands/Oil Sands (Mixture of sand, clay, and water) -​ Sandstone/sedimentary rock with viscous forms (Bitumin = solid/half-solid petroleum)) of petroleum -​ Unconventional source of oil -​ Large quantities in Canada -​ Higher oil prices  -​ Unconventional oil deposits (Conventional techniques CANNOT be used) -​ Environmental concerns Oil Transport -​ Pipelines (i.e. Trans-Alaskan Pipeline) ​ Transports most of world’s oil from well to refinery -​ Oil Tankers (By boat) Composition of Natural Gas Methane (82% of natural gas composition) CH4 Ethane C2H6 (H3C-CH3) Propane C3H8 (H3C-CH2-CH3) Butane C4H10 (H3C-CH2-CH2-CH3) Hydrogen H2 Acid Gases CO2, H2S, and other S contained components Conventional VS Unconventional Natural Gas -​ Conventional: Easy to produce -​ Unconventional: Difficult to produce Shale Gas -​ Natural gas produced from Shale (Sedimentary Rock) -​ Low permeability allowing gas to flow in economical quantities -​ Requires fractures artificially created by hydraulic fracturing -​ Major source of natural gas in US, Canada Hydraulic Fracturing (Extract natural gas and oil) -​ Drilling technique using water and additives pumping under high pressure into a completed well -​ Used to blast open fractures in fossil fuel-bearing rocks -​ One of the key technologies making gas extraction from impermeable shales cost-effective “Fire Ice” (Methane Hydrates) -​ Methane molecules trapped by ice crystals -​ Widespread within shallow sediments of the world’s continental shelves to slopes  -​ X2 the size of all Biofuels -​ Easy to find -​ No technology existent for commercial production -​ Exists in moderately low temperatures and moderately high pressures -​ Potential future energy source Methane Hydrate: Crystalline solid consisting of gas molecules, usually methane, surrounded by a cage of water molecules (CH4.5.57H2O) Sedimentary methane hydrate reservoir probably contains 2-10 times the currently known reserves of conventional natural gas as of 2013. Formation of Methane Hydrates -​ Form by migration of gas from deep along geological survey -​ Followed by precipitation or crystallization -​ On contact of the rising gas stream with cold sea water 🪨 Coal (Carbon, hydrogen, oxygen, nitrogen, sulfur) -​ Coal is a black to brownish-black rock that can catch fire. -​ It’s a complex mixture of many compounds, mainly carbon (over 85%), with hydrogen, oxygen, nitrogen, and sulfur. -​ Coal has been used as fuel for hundreds of years. -​ It is the largest source of energy for electricity production globally, providing 41% of the world's electricity. -​ In the U.S.: About 90% of coal is used to generate electricity. Formation of Coal (Time + Pressure) -​ Coal forms from decaying plants that are buried under layers of rock. -​ The weight of the rocks applies pressure, which helps remove impurities. -​ Carbonization: This process converts dead vegetation into coal, increasing its carbon content. -​ Organic matter mainly comes from land plants. -​ It builds up in low-energy environments, like swamps. -​ Examples of coal ​ Peat and lignite - High moisture content, Soft texture ​ Bituminous/soft coal - Most common, widely used ​ Anthracite - Hard, high carbon content Coke (Fuel made from coal)  -​ How It’s Made: Coal is heated to 2,000°C in an oven without oxygen. -​ High carbon content -​ Loses water and impurities (ammonia and gas) during the process -​ Used as fuel for heating Coal Tar (Purifying coal gas + Making coke / Used for agriculture) -​ Comes from making coke and purifying coal gas -​ Can be used for: ​ Shipbuilding ​ Construction (Roofs and roads) ​ Modern uses: Pavements, road construction, medical application Coal Gas (Used for energy production) -​ Coal + O2 + Steam CO + H2 ​ Heating coal in the presence of oxygen and steam -​ Chemical Reaction: The reaction creates carbon monoxide (CO) and hydrogen (H₂), among other gases. -​ Used for energy production -​ Before 1950s in the US, all fuel and lighting gas came from coal gas Coal Reserves -​ Coal expected to be mined -​ A total of 800-900 gigatons (2006) -​ Last for approximately 132 years Coal Mining -​ Depends primarily on depth, density, thickness -​ Surface mining (Occurs at depths above 180ft) -​ Underground mining (Occurs at depths below 300ft, 60% of world coal production) Release of Nuclear Energy -​ Released by three exoenergetic (energy release) processes (Nuclear Fission, Fusion, Radioactive Decay) -​ Radioactive decay (Emits geothermal energy) ​ Some tiny parts (Neutron/Protons) inside atoms are unstable ​ Breaks down and send out tiny particles (EM radiation, Gamma rays) and energy (Gives off heat) ​ Helps warm the inside of the earth (Emit geothermal energy) -​ Fusion (Think 2 things fusing together) ​ Two atomic nuclei fuse together to form a heavier nucleus (NOT a chain reaction)  -​ Nuclear Fission ​ Process of splitting a heavy atom's nucleus to release energy. (Continuous, a chain reaction) ​ Heavy Atom: Fission usually happens in heavy atoms like uranium or plutonium. ​ The 2 split nucleus is called “daughter nuclei” ​ All fission products have kinetic energy ​ Energy is released during the fission process Moderator -​ Slows down neutrons through colliding with light atoms -​ In many US reactors, water is used as the moderator. -​ Neutrons lose most energy when hitting atoms of same mass (i.e. hydrogen) -​ Slowing down neutrons makes it easier to cause fission in the reactor Control Rods (Controls neutrons and rate of fissions) -​ Made of material absorbing excess neutrons (usually Boron or Cadmium) -​ Controlling # of neutrons, ability to control rate of fissions Basic Ideas of Nuclear Power Plant -​ Fuel: Uranium -​ Fission Process: Neutrons cause fission, which releases energy. -​ Moderator: Water acts as a moderator, slowing down neutrons, and also transfers heat. -​ Control Rods: Control rods are used to regulate the energy output by absorbing excess neutrons. -​ Energy Conversion: The nuclear energy is converted into heat, which generates steam. This steam drives a turbine connected to a generator, producing electricity Processing of Uranium -​ Uranium Ore: Rock containing Uranium ​ Steps of Processing Uranium: 1.​ Process uranium ore near mine (Produce “yellow cake” (concentrated form of uranium called U3O8) 2.​ In this yellow cake, 0.7% is uranium-235 (235U), the isotope here is useful for nuclear fission and power 3.​ Most uranium (99.3%) is 238U = CANNOT be used for fission power. -​ Uranium = Nuclear energy source ​ Can be used for energy ​ Nuclear weapons Controlling Chain Reaction Depends on… (Arrangement, Quality, Neutron energy)  -​ Arrangement of fuel/control rods -​ Quality of moderator -​ Quality of Uranium fuel -​ Neutron energy required for high probability of fission Daya Nuclear Power Plant (80% of its output supplies HK) -​ First in Mainland China Hydropower and Dams (Renewable Resource) -​ Power taken from the energy of falling water/ running water -​ Hydroelectric power comes from the potential energy of a dammed water driving a water turbine and generator -​ Emission-free -​ Low operating and maintenance cost -​ Cons: ​ Potential loss of habitat ​ Dependent of rainfall/snowfall ​ Impacts on river flows and aquatic ecology Tidal Power (A form of hydropower) -​ Converts energy of tides into electricity -​ More predictable than wind and solar -​ High cost, limited availability of sites -​ First large-scale tidal power plant in France (1966) Wave Power (Form of hydropower) -​ Transport of energy through ocean surface waves -​ First experimental wave farm in Portugal (2008) Wind Power -​ No emissions -​ No fuel needed -​ Distributed power -​ Remote locations Solar Energy (Pros / Cons)  Pros Cons -​ Clean/Renewable -​ Sun does not shine consistently -​ Converts into usable energy -​ Solar energy is a DIFFUSE SOURCE -​ No chemical/radioactive polluting ​ Hard to harness byproducts ​ Max 33% of convert efficiency -​ Energy reaching Earth is strong -​ Requires little maintenance Solar Energy Facts: -​ The surface receives about 51% of the total solar energy that reaches the Earth (Only this amount is usable) -​ Solar thermal energy has mirrored surface that reflects sunlight to heat up liquid to make steam to generate electricity Photovoltaics (PV) (Light > Electric currents) -​ Photo + Voltaic = convert light to electricity -​ PV systems employs solar panels composed of a number of solar cells to convert solar power -​ Solar cells are devices that take light energy as input and convert it into electrical energy Cell-Module-Array -​ Module: A number of cells connected to each other -​ Array: Multiple modules wired together Silicon-Based Solar Cell Attributes (Photovoltaic cell, expensive) -​ Expensive ​ Made in high vacuum at high heat ​ High manufacturing costs -​ Hard to handle ​ Fragile, rigid, thick -​ Long return on investment ​ Takes 4 years to produce energy savings equipment to cost of production Biofuel -​ Fuel containing energy from recent carbon fixation (i.e. plants or microalgae) -​ Made by biomass conversion (thermal, chemical, biochemical) -​ Fuels can be solid, liquid, or gas form -​ 2 most widely used biofuels (Ethanol, Biodiesel) -​ First-generation or conventional biofuels made from sugar, starch, or vegetable oil -​ Can easily be extracted using conventional technology Biomass (Burning organisms) -​ Biological material taken from living or recently living organisms -​ Mostly plant or plant-based materials -​ Can be burned directly, or converted to various biofuels -​ Largest biomass source ​ Wood ​ Forest residues ​ Yard clippings ​ Wood chips ​ Etc. Ethanol -​ Produced by action of microorganisms and enzymes through fermentation of sugar, starches, or cellulose -​ Most common biofuel worldwide -​ Used in petrol engines as a replacement for gasoline -​ Can be mixed with gasoline to any percentage -​ ⅓ lower energy content per unit of volume compared to gasoline Biodiesel -​ Vegetable oil or animal fat based diesel fuel consisting of long-chain alkyl esters -​ Can be used alone or blended -​ Can significantly dissolve crude oil, used to treat oil spills -​ Blends: 100% biodiesel is referred to as B100 -​ Produced through the chemical reaction of transesterification -​ Reacting with methanol or ethanol -​ Generally base-catalyzed reaction Second-generation Biofuels -​ Made from lignocellulosic biomass or woody crops, agricultural residues or waste -​ Harder to extract required fuel Water -​ Inorganic compound H2O -​ Transparent, tasteless, odorless, colorless chemical substance -​ Main constituent (成分) of Earth’s hydrosphere and the fluids of all known living organisms -​ Covers 71% of Earth’s surface -​ Becomes less dense when frozen Lake Baikal -​ Largest freshwater lake by volume (636km x 79km x 11642m) -​ Containing ~20% of the world’s unfrozen surface fresh water -​ More than the Great lakes combined -​ World’s deepest, clearest, oldest (25 million years) lake -​ More than 1000 species of plants and 2500 species of animals Hydrologic Cycle (Or the global water cycle/ water cycle) -​ Water transported from oceans to atmosphere to land and back to ocean -​ Effects on climate (Evaporative cooling, 67c otherwise on Earth surface) -​ Effects on biogeochemical cycling Global Water Consumption -​ US, Australia, Italy, Japan, and Mexico are top 5 average water use per person per day -​ Water use by sector ​ Agriculture 67% ​ Households 9% ​ Water supply 8% ​ Power 7% ​ Manufacturing 4% ​ Mining 2% ​ Other 3% -​ US 41% Agriculture, whereas China uses water for 87% of agriculture Water Use -​ 1,857 gallons = 1 pound of beef -​ 469 gallons = 1 pound of chicken -​ 84 gallons = 1 pound of apples -​ During a cow’s lifetime, 816,000 gallons of water for food, drinking, and hygiene Water Availability -​ Water scarcity:Less than 1,000 m³ of freshwater per person per year. This indicates serious and widespread freshwater issues. -​ Water stress: Less than 1,700 m³ of freshwater per person per year. This results in temporary and localized shortages. -​ Relative sufficiency: More than 2,500 m³ of freshwater per person per year. This indicates adequate water availability. -​ Regions in Africa and Southeast Asia face economic water scarcity Water Crisis -​ 785 million people worldwide lack access to water -​ Inadequate sanitation is a problem for 2.4 billion people -​ Exposure to diseases (i.e. Cholera and typhoid fever, other water-borne illnesses) -​ By 2025, ⅔ of world’s population may face water shortages Water Footprint - Measuring of direct and indirect water use -​ Total volume of freshwater used to produce the goods and services consumed by an individual or community -​ All human activities use water -​ Water consumption Solutions to water crisis/stress (Sustainable development) -​ UNWDR 3, 2009 (Conserving, developing resources and allocation) Rainwater Harvesting -​ Collection and storage of rain -​ Collected from a roof like surface redirected to a tank -​ Reservoirs can also collect rainwater -​ Ponds for rainwater harvesting Water recycling and re-use -​ Urban use -​ Agricultural irrigation -​ Recreational use -​ Environmental use -​ Groundwater recharge -​ Industrial reuse -​ Portable reuse Water Reclamation -​ Reuse of water -​ Reclaims water from a range of different sources -​ Water is purified for reuse -​ Treat wastewater to appropriate standard -​ Impose crop restrictions on use of reclaimed water Price of Water -​ Consumer attitudes and behaviours are a problem when determining the price of water  -​ Economic incentives in the form of water-use metering and implementation of tariff systems can help discourage wasteful use of water -​ But can potentially disadvantage those who can’t afford it -​ Too many people, not enough water -​ Asian and African countries will have to adopt new practices for more efficient use of water -​ US Census Bureau (2011) shows that global water use and global population per cent growth since 1900 has increased by 90% in 2025 -​ Water withdrawals have increased from about 500 cubic kilometres in 1900 to about 3,830 cubic kilometres in 2000 Water related hazards -​ Floods -​ Drought -​ Salinization of soils ​ Evaporation leaves salts behind, if the content of salt in soil is too high, plants cannot grow -​ Subsidence (Unsustainable groundwater extraction, sinking of land) Ions in Natural Waters and Drinking Waters Remember: Calcium, Magnesium, Sodium, Potassium Groundwater (aka. Fresh water underground) -​ Water located beneath the Earth’s surface in soil pore spaces and in the fractures of rock formation -​ 97% of all liquid freshwater on the Earth -​ 50% of drinking water in the US -​ 30% of all streamflow charged by groundwater -​ Groundwater fills up spaces between soil, sand, rocks (the area is called “zone of saturation”) Aquifer 💧 -​ An aquifer is a water-bearing layer of porous soil or rock that can yield significant amounts of water to wells. -​ Exists in the “Zone of Saturation” Types of Aquifers Unconfined Aquifers: (Top/ near surface) -​ Characteristics: Water is in direct contact with the atmosphere through porous material. -​ Water Source: Receives water from the surface. -​ Water Table: The surface of the water table can fluctuate up and down based on recharge (water entering) and discharge (water leaving) rates. Confined Aquifers: ​ (Bottom, Impermeable layer) -​ Characteristics: Separated from the atmosphere by an impermeable layer. -​ Pressure: Groundwater is under high pressure. -​ Well Behavior: Water in a well can rise to a level higher than the water level at the top of the aquifer due to this pressure. -​ Low hydraulic conductivity (Measure of rock’s ability to transmit water) Groundwater Pollution -​ Very cold -​ Low dissolved oxygen -​ No bacterial breakdown -​ Slow water movement -​ Pollutants can stick to rocks in aquifer, pollute new water -​ Comes from… ​ Landfills ​ Leaky underground storage tanks ​ Mines ​ Septic tanks ​ Hazardous waste ​ Any pollutant in runoff that percolates -​ Types of contaminants ​ Inorganic: 1.​ Salts 2.​ Nitrate 3.​ Ammonia 4.​ Heavy metals ​ Organic: 1.​ Volatiles  2.​ Semi-volatiles 3.​ Dissolved 4.​ Non-Aqueous Water Pollution in China (Only 50% safe, 300mil dependent on it) -​ Many lakes and major rivers are severely polluted. -​ Only 50% of China’s 200 major rivers are safe for drinking water after treatment. -​ Over 300 million people depend on unsafe drinking water sources. -​ Water-related diseases from pollution cost China 2% of its rural GDP. Alkalinity (Capability of water to neutralize acid) -​ Buffering capacity is resistant to pH changes -​ Common natural buffer (Carbonates i.e. Limestone) -​ Protects aquatic life -​ Commonly linked to water hardness Hard Water and Hardness Index -​ Hard water contains high concentration of dissolved calcium and magnesium ions -​ Soft water contains few of these dissolved ions -​ Hardness = [Ca2+] + [Mg2+] -​ Hardness is expressed in parts per million of calcium carbonate (CaCO3) by mass Types of Water Hardness Temporary Hardness (Carbonate Hardness) = Caused by Calcium Carbonate -​ Definition: Caused by solid deposits like calcium carbonate (CaCO₃). -​ Reaction: Calcium carbonate reacts with water and carbon dioxide to release calcium ions (Ca²⁺) and bicarbonate ions (HCO₃⁻). Boiling water removes this hardness since the dissolved carbon dioxide decreases with heat. -​ Effects: Causes deposits in pipes and scale buildup in boilers. -​ Treatment: Temporary hard water must be softened before entering boilers, hot-water tanks, or cooling systems.​ Permanent Hardness (Non-Carbonate Hardness) = Metal ions cannot be removed by boiling -​ Definition: Caused by metal ions that cannot be removed by boiling. -​ No solid deposits: This type does not form solid deposits like temporary hardness. Total Hardness = Temporary + Permanent Hardness -​ Definition: The sum of temporary hardness and permanent hardness. Dissolved Oxygen (DO) -​ Measurement of oxygen dissolved in water -​ Amount of oxygen in water (Low oxygen = aquatic life will die) -​ Available for fish and other aquatic life -​ Indicates health of an aquatic system -​ Can range from 0-18 ppm (parts per million) -​ Most natural water systems require 5-6 ppm to support a diverse population -​ DO is affected by ​ Temperature ​ Pressure ​ Salts ​ Organic matter Hypoxia -​ Definition: Hypoxia refers to an aquatic system that lacks dissolved oxygen​ (Often termed anaerobic, reducing, or anoxic.)​ -​ Oxygen Levels: It is characterized by low oxygen concentrations, typically between 1-30% saturation. -​ Categories: ​ Hypoxic: Low oxygen levels. ​ Dysoxic: Very low oxygen levels but not completely absent Hypoxia in the Gulf of Mexico -​ Causes: Pollution and eutrophication lead to phytoplankton blooms. -​ Impact of Phytoplankton: During the day, phytoplankton increase dissolved oxygen (DO) through photosynthesis. -​ At night, they consume oxygen through respiration, reducing DO saturation. -​ Decomposition: When phytoplankton cells die, they sink to the bottom and decompose, which further reduces dissolved oxygen in the water column. Organic/Biological Species in Water -​ Biochemical Oxygen Demand (BOD) (# needed) ​ Tells us how much oxygen is needed by microorganisms to break down organic material in water -​ Chemical Oxygen Demand (COD) (Measurement) ​ Measures the amount of organic compounds in water ​ Measures everything that can be chemically oxidized -​ Total Organic Carbon (TOC)  ​ The total amount of carbon from the organic material dissolved or suspended in water -​ Dissolved Organic Carbon (DOC) ​ Portion of total organic carbon dissolved in water -​ (TOC) - (DOC) = Suspended carbon in water ​ When subtracted the remainder is the organic carbon attached to particles suspended in water. ​ Helps understand different forms of organic material in water ​ Can be used for… -​ Water treatment -​ Environmental monitoring -​ Understanding pollution sources + behavior Measure Turbidity (NTU = Nephelometric Turbidity Units) -​ Measuring amount of light passing through the sample water column -​ Nephelometer with the detector set up to the side of the light beam -​ Low turbidity = (generally) clean water -​ High turbidity = contaminated water ​ Caused by: Dirt, construction, pollutants etc. Makes water cloudy = high turbidity ​ Impacts: -​ Aquatic animals health (Sight + Breathing) -​ Decreases aquatic plants ability to photosynthesize -​ Hinders growth rates of aquatic animals Conductivity -​ Ability of a substance to conduct an electrical current -​ Siemens per meter -​ In water, conductivity determined by types and quantities of dissolved solids (Total Dissolved Solids = TDS) ​ Combined content of all inorganic and organic substances in water ​ Two principle methods of measuring total dissolved solids are gravimetry and conductivity -​ Current carried by ions (Negatively or positively charged particles) Salinity -​ Saltiness or dissolved salt content of a body of water -​ Influences the types of organisms living in a body of water -​ Salt is expensive to remove from water -​ The degree of salinity is a driver of the world’s ocean circulation contributing to global changes in CO2 as more saline waters are less soluble to carbon dioxide  -​ Brine water -​ Saline water -​ Brackish water -​ Freshwater Oil pollution/spill -​ Ocean and land -​ Crude and refined petroleum -​ Tanker accidents (Exxon Valdez) -​ Urban and industrial runoff Effects of Oil Pollution on Ocean Ecosystems -​ Volatile organic hydrocarbons ​ Kill larvae ​ Destroy natural insulation and buoyancy -​ Heavy oil ​ Sinks and kills bottom organisms ​ Coral reefs die Oil Cleanup Methods 🛢️ -​ Current methods recover no more than 15% -​ Surface Dispersants ​ Organic chemicals break down the oil into smaller droplets ​ More readily to mix with water ​ Has environmental concerns themselves -​ Underwater dispersants -​ Controlled burns -​ Booms and skimmers (Collect and remove oil from water surface) -​ Absorbent materials (i.e. Sawdust) Air, Air Quality and Air Pollution 💨 🌎 -​ Air: O2 + N2 (Human breathable) -​ Atmosphere = Layer of gases surrounding a planet or other material body Air Quality (The term changes constantly over time, can be qualitative and quantitative) -​ Measure of the condition of air relative to the requirements of one or more biotic species and or to any human need or purpose -​ Measure of pollutants in the air -​ A description of the healthiness of the air Air Quality Index (AQI) -​ Number used to show how polluted the air it currently is or how polluted it is forecast to be -​ Different countries, different AQI -​ Developed by EPA Clean Air Act (1990) Air Pollutants: Natural Sources -​ Dust storms -​ Volcanoes -​ Fires Sources of human-caused air pollution include (Anthropogenic Sources) -​ Stationary sources -​ Mobile sources -​ Controlled burn/fires -​ Landfills/landfill gases Primary VS Secondary Pollutants -​ Primary: Air pollutant emitted DIRECTLY from a source -​ Secondary: NOT DIRECTLY emitted Composition of the Atmosphere (Nitrogen, Oxygen, Argon = NOA)  -​ Nitrogen (N2) = 0.78 = 78.08% -​ Oxygen (O2) = 0.21 = 20.95% -​ Argon (Ar) = 0.0093 = 0.93% Atmospheric Layers (Temperature and other characteristics vary with altitude) -​ Thermosphere (up to 500km) -​ Mesosphere -​ Stratosphere (Ozone concentration, Ozone layer) -​ Troposphere ​ Tropopause: Marks the boundary between troposphere and stratosphere Soil -​ “The skin of Earth” -​ Natural covering formed throughout ages by forces of nature -​ Formed through acting upon native rocks and vegetation -​ All life is dependent on soil’s productivity Soil thickness reflects the balance between rates of soil production and rates of downslope soil movement How is Soil Formed? (Breakdown of organisms) -​ Organisms (Types of native vegetation, production of humic acids, increase of erosion) -​ Time (Development and destruction of soil horizons) -​ Parent Material (Starting point of soil development) -​ Topography (Ground slope, elevation, aspect i.e. north/south facing slopes) -​ Climate (Temperature and precipitation, weathering rates) Soil texture -​ Percentage of sand, slit, and clay -​ Related to water flow potential, water holding capacity, fertility potential, etc. -​ Loam: Soil of approximately equal amounts of sand, slit, and clay Land -​ Solid, dry surface of earth -​ 29.2% of Earth’s surface -​ Earth’s land surface is almost entirely covered by regolith -​ Regolith - A layer of rock, soil, and minerals that form the outer part of the crust -​ ⅓ of land is covered in trees -​ Another third is used for agriculture -​ 10% is covered in permanent snow and glaciers Land Cover - Material physically present on land surface Land Use - Human allocation of land​ Terrain - Shape and features of land (Height, steepness, direction) ​ *Elevation, slope, orientation Landform - Natural/Artificial feature on the surface of the Earth ​ Landscape - Part of Earth’s surface, related to nature or human Natural Land Resources 1.​ Forest 2.​ Water 3.​ Land 4.​ Mineral 5.​ Food 6.​ Energy Land Pollution - Deterioration of Earth’s land surface at below ground level -​ Caused by accumulation of solid and liquid waste materials that contaminate groundwater and soil -​ Affects soil on the Earth, and habitats -​ Contributes to pollution of air and water -​ Global warming gases such as methane -​ Main contributors of Land Pollution 1.​ Litter 2.​ Waste 3.​ Urbanization 4.​ Construction 5.​ Mining 6.​ Extraction 7.​ Agriculture Land Pollution in HK (Plastic pollution) -​ ~4.17 million tons of solid waste -​ Plastic Pollution ​ 3.9 Billion disposable food/drink containers per year ​ 170 takeaway meals/180 disposable drinks per HKer ​ 21% of the city’s total municipal solid waste (MSW) Land Degradation (Human causes) -​ Process which the value of biophysical environment is affected by a combination of human-induced processes acting upon the land -​ Natural hazards are excluded as a cause -​ UN estimate that ~30% of land is degraded worldwide -​ ~3.2 billion people reside in degrading areas -​ ~12 million hectares of productive land is degraded every year Causes of Land Degradation 1.​ Agricultural use -​ Poor farming practices -​ Overgrazing/overdrafting of livestock 2.​ Deforestation/Clearcutting 3.​ Climate change Consequences of Land Degradation 1.​ Decline in productive capacity of land 2.​ Loss of capacity to provide resources for human lives 3.​ Loss of biodiversity 4.​ Shifting ecological risk Desertification (Type of Land Degradation) -​ Type of land degradation in drylands -​ Biological productivity is lost due to natural processes/human activities -​ Fertile areas become increasingly invariable -​ Significant global ecological and environmental problem -​ Causes 1.​ Loss of vegetation 2.​ Drought 3.​ Climate shifts 4.​ Overgrazing 5.​ Deforestation Desert is defined as any place where the aridity index (AI) > 4 Arid - dry due to lack of rainfall Aridity VS Humidity (Aridity Index) High aridity = Dry​ Low aridity = Humid “Horse Latitude” - Deserts are created by descending cold/dry air masses Orographic deserts - Existing on the downwind sides of major mountains Polar Deserts - Falls under ice cap climate Global Drylands: Critical Concerns -​ Food security (2 billion of world population) -​ Climate change increasing aridity -​ Land use/land cover change -​ Energy exploration and development -​ Land degradation, woody plant encroachment Woody Plant Encroachment Spread of trees and bushes into areas that used to be mostly only grass/open land -​ Exogenic Drivers (External Factors) 1.​ Regional and global warming (Conditions become better for growth) 2.​ Overgrazing (Grass reduces allowing trees/bushes to grow) 3.​ Increase in atmospheric CO2 4.​ Large-scale fire suppression -​ Endogenic feedbacks (Internal Factor) 1.​ Fire-vegetation 2.​ Soil erosion-vegetation 3.​ Vegetation-microclimate The Green Wall of China -​ Proposed in late 1970s -​ Major ecological engineering project -​ Not predicted to end until 2055 -​ 66 billion trees planted -​ Decreased desert land in China by (1,980 square km annually) -​ Decrease of sandstorm frequency by 20% -​ Highly successful The Green Wall of Africa -​ Started in 2007 -​ Combat desertification in 20 countries -​ 8,000 km wide, stretches across entire width of continent -​ Restored 36 million hectares of land  -​ Goal to restore a total of 100 million hectares by 2030 Soil Restoration -​ Provisioning of water -​ Fixation of soil -​ Use of nitrogen-rich fertilizer -​ Contour trenching -​ Windbreaks Managed Grazing serves as tool to reverse desertification Ecosystem -​ Consists of all organisms and physical environments in which they interact -​ Consisting of all biotic (Living) and abiotic (Non-living) factors in an area -​ Biotic (Dependent) and abiotic components are linked through nutrient cycles and energy flows -​ Ecosystems vary in size -​ Coral reef ecosystem, an example of marine ecosystems -​ Temperate forest ecosystem, an example of terrestrial ecosystems Abiotic (Independent) -​ Determines which organisms can live in an ecosystem -​ Not living but can be made up of biotic things -​ Ecosystems contain different habitats ​ Supplies all of the biotic and abiotic factors an organism needs to survive -​ Habitats supply same basic needs (Air, warmth, water, and food) Niche (Behavior of organism in ecosystem) -​ How an organism acts within its ecosystem -​ Another way to look at this is the organisms role -​ Some plants eat other animals, some eat plants -​ Some plants grow in sunny areas, some needs shade -​ Worms and bacteria break down dead organisms for energy and recycle the nutrients into the ecosystem -​ This creates Biodiversity (The variety of life in the world, or in a particular habitat or ecosystem) Levels of Organization 1.​ Organism is any living thing (Simplest level) 2.​ Species  3.​ Population 4.​ Community 5.​ Ecosystem Biomes -​ Large areas sharing similar climate -​ Similar topographic and soil conditions, thus the same basic types of biological communities -​ Temperature and precipitation are the most important determinants in biome distribution on land -​ Many temperature-controlled biomes occur in latitudinal bands Biosphere -​ Region of the Earth where life can be found (Soil, water, and air) -​ Lithosphere, hydrosphere, and atmosphere are the names for these 3 components 1.​ Lithosphere (Land) 2.​ Hydrosphere (Water) 3.​ Atmosphere (Air) Terrestrial Ecosystems: Forest -​ Forest Definition by Food and Agricultural Organization (FAO) (2000) ​ Land with tree crown cover (or equivalent stocking level) of more than 10% and area of more than 0.5 ha. ​ The trees should be able to reach a minimum height of 5m at maturity in situ. ​ It does NOT include land that is predominantly under agricultural or urban land use. -​ Other wooded land ​ Land with a canopy cover of 5-10% of trees able to reach a height of 5m in situ ​ Or a canopy cover of more than 10% when smaller trees, shrubs, and bushes are included -​ Other land ​ Any land not classified as forest or other wooded land as defined above 1.​ Agricultural and urban areas 2.​ Barren land 3.​ May have tree cover when the tree cover fulfils the threshold values in the Forest definition, it is reported as Other land with tree cover 4.​ Other land with tree cover may produce timber, fuelwood and wood for other purposes Top countries with the Largest Forest Area 1.​ Russian Federation (20% global forest area) 2.​ Brazil (12% of global forest area) 3.​ Canada (9% of global forest area) Types of Forest -​ Natural Forests (Primary) ​ ONLY native tree species ​ No signs of human activities ​ No disturbances -​ Naturally Regenerated Forests (Secondary) ​ Regenerates on Natural forests ​ Major difference in forest structure and species composition -​ Planted Forests (Secondary) ​ Planting / Seeding processes ​ Trees belong to the same species​ (Whether native or introduced, have the same age and are regularly spaced) Deciduous Forests (Temperate, Broadleaf, Tropical Seasonal) ​ Dominant with trees that lose all their leaves for part of the year ​ Deciduous trees shed their leaves usually as an adaptation to cold or dry/wet season ​ Has regrowth period ​ Hot, humid summer / Mild winters (little snow, frost) ​ Annual precipitation more than 1000m -​ Broadleaf Forests ​ Dominant with trees that have flat leaves ​ Trees that produce seeds inside of fruits -​ Tropical Seasonal Forests ​ 13 million hectares are deforested every year ​ Occupy less than 10% of land surface but contain half of all plant, animal, and bacterial species on Earth Coniferous (Needle-Leaved) Forests (Temperate) ​ Dominant with trees that have needle-like or scale-like leaves ​ Seeds borne in woody cones ​ Leaves throughout the year ​ Mild temperatures year round ​ NO regrowth period -​ Taiga (Northern Canada, Europe, Asia) ​ 17 million km^2 / 11.5% of Earth’s land area  ​ Harsh climate (Cold and dark most times) ​ Russia and Canada dominant -​ Evergreen Forests Mixed Forests ​ Dominated by a mixture of deciduous and coniferous trees -​ Boreal Forests ​ Between 50N and 60N Latitude (North of the equator = cold temperature) ​ North America, Europe, Asia Rainforests -​ Humid, tropical regions support one of the most complex and biologically rich biomes -​ Ample rainfall and uniform temperatures 1.​ Mean annual temperature ~25c with little seasonal variation 2.​ 2000 mm rainfall/yr - dry season no longer than 5 months 3.​ Further from equator, increased seasonality -​ Soil in rainforests tend to be thin and nutrient poor -​ High net primary productivity (NPP) = 40% global terrestrial productivity -​ High biodiversity ​ ½ of ⅔ of all the species of terrestrial plants and animals live in tropical forests Rainforest Vegetation -​ Broad-leaved evergreens dominate in a closed canopy -​ Competition for light causes stratification of canopies and epiphytes (Orchids/Mosses) and lianas (Woody vines) (Adaptive) -​ Distinctive tree types within each stratum (layers/levels) Main use of forests 1.​ Production of timber, fibre, etc 2.​ Protection of soil and water 3.​ Preservation of biodiversity 4.​ Social services (eco-tourism, hunting, etc) Changes in the World’s Forest Area -​ Decline from 4.1 billion ha to just 4 billion ha during 1990-2015 (decrease of 3.1%) -​ Net loss slowed by more than 50% from 1990-2000 and 2000-2015 -​ Reduced forest area loss in some countries, and increased gain in others -​ Net forest area has stabilized in the past decade Causes for Deforestation  1.​ Conversion of forest to agriculture -​ ⅔ of destruction in Africa -​ Soy farming -​ Cattle ranching 2.​ Subsistence agriculture 3.​ Intensive agriculture 4.​ Logging 5.​ Fires 6.​ Fuel wood and biofuel production -​ Responsible for forest destruction in Southeast Asia (Oil palm plantations) 7.​ Urbanization 8.​ Construction of industries and roads, dams, etc 9.​ Acid rain Acid Deposition (Oxidization of sulfur and nitrogen due to combustion) -​ Formed when sulfur and nitrogen oxides produced as by-products of combustion and industrial activity are converted into acids during complex atmospheric reactions -​ Acid deposition consists of rain, snow, dust, or gas with a pH lower than 5.6 = Acid rain Harmful Effects of Harmful Effects -​ Human respiratory disorders -​ Acidification of surface and ground water -​ Damage aquatic ecosystems -​ Release of toxic metals -​ Leaching of soil nutrients -​ Loss of crop sand trees -​ Damage to buildings, statues, and monuments Solutions to Prevent Acid Deposition 1.​ Reduce coal use 2.​ Burn low-sulfur coal 3.​ Increase natural gas use 4.​ Increase use of renewable energy resources 5.​ Tax emissions of SO2 6.​ Reduce air pollution by improving energy efficiency Forest Protection -​ About 12.5% of world’s forests are now protected -​ Asia has the largest protected area (by %)  -​ UN REDD Program (Reducing Emissions from Deforestation and Forest Degradation) ​ Allow less developed countries to protect their forests ​ Receiving money through keeping their forests healthy, stopping deforestation -​ Money comes from more developed countries that want to reduce their own carbon emissions -​ Developed countries buy “offset credits” from the less developed countries showing their carbon emissions have been balanced out by saving forests ​ Fire Management -​ US has had an aggressive fire control policy for the last 70 years -​ Many biological communities are fire-adapted and require periodic burning for regeneration -​ Eliminating fires caused woody debris to accumulate over the years ​ Many fires are now larger and more severe Harvest Methods -​ Clear cutting -​ Strip cutting -​ Shelterwood harvesting -​ Selective cutting Tropical Savannas and Grasslands -​ Climate: Hot, dry season/ Short period of heavy rainfall (100-150cm/month) -​ Temperatures 20-30c/ with “cooler” winters -​ Trees are widely spaced enough so that the canopy does not close -​ Sufficient light to support plants -​ Co-exists of trees and grasses -​ Plants with deep, long-lived roots and other adaptations to survive drought, heat, and fire Deserts -​ Precipitation is rare and unpredictable (Usually less than 300mm per year) -​ Sparse vegetation, low in height, very open stands -​ Dependent on water and geomorphology -​ Net primary productivity (NPP) is very low, related to rainfall issues -​ Plants exhibit water conservation characteristics -​ Nocturnal animals -​ Slow growing vegetation is damaged by off road vehicles -​ Overgrazing (Livestock destroying plants of southern Sahara) Mediterranean or Temperate Shrubland -​ Found along Mediterranean coast, southwestern Australian Chile, and South Africa -​ Warm, dry summers -​ Cool, moist winters (Av. temperature of the coldest month is less than 18c but above -3c) -​ Evergreen shrubs, shorter trees, scattered larger trees -​ High biodiversity, medium primary productivity -​ Fires are a major factor in plant succession Temperate Grasslands -​ Annual precipitation more than 500mm -​ Long, dry seasons -​ Coldest month is below -3c -​ Warmest month above 10c -​ Seasonal herbaceous flowering plants -​ Thick organic soil -​ Extensive human impacts, many converted to farmland -​ Overgrazing is a threat -​ Generally devoid of trees -​ Known as Prairie in some regions Tundra -​ Treeless -​ 2-3 month growing seasons -​ Cold, harsh winters -​ Arctic tundra ​ Low productivity ​ Coldest of the biomes ​ Low amounts of precipitation, similar to deserts -​ Alpine tundra - near on mountaintops  -​ Relatively low biodiversity -​ Threatened by global warming and oil drilling in Alaska and Siberia Mountain Biomes -​ Vertical zonation: With an increased altitude are lower temperatures and greater precipitation -​ Mountains have unique biome characteristics and gradients -​ Rain shadow effect (When mountains block rain from reaching land on their far side) Generalized effects of elevation and latitude on Climate and Biomes Mangroves -​ Trees and shrubs that grow in salt water along the coastlines -​ Salt tolerant -​ Adapt to low oxygen -​ Slow-moving waters -​ Allow fine sediments to accumulate -​ Help stabilize shoreline -​ Nurseries for fish, shrimp, crab etc. -​ Can be cut for timber or removed for aquaculture Coral Reef -​ Corals slow growing colonies of animals -​ Underwater structures made from calcium carbonate secreted by corals -​ Occur in shallow tropical areas -​ Sea water should be clean, clear, and warm -​ “Rainforest of the sea” -​ Natural barriers against erosion and storm surge Formation of Coral Reefs 1.​ Coral starts as larvae (Baby coral) floating in the ocean 2.​ Larvae attach to rocks underwater 3.​ Over time Larvae grows and spread (Building of Coral Reefs) Atoll (Type of Coral Reef) -​ Ring shaped reef -​ Sunk completely below sea level -​ Coral continuously grows upward Coastal Salt Marsh -​ Located between land and open salt water -​ Regularly flooded by tides -​ Salt-tolerant plants -​ Aquatic food web -​ Delivery of nutrients to coastal waters -​ Support terrestrial animals, traps sediments, etc Agricultural Ecosystems/Agroecosystems -​ Artificial ecosystems created in the process of developing land and coastal/aquatic areas for farming, animal husbandry, and fishing -​ Cover almost over 40% of Earth’s land area -​ Provide a range of services 1.​ Food production 2.​ Carbon sequestration 3.​ Nutrient recycling 4.​ Climate regulation -​ Agroecosystems include abiotic and biotic factors -​ Natural communities that have been modified by humans for agricultural purposes -​ Planned and unplanned diversity -​ High biodiversity is a key feature of agroecosystems  1.​ Promotes high yields, production and stability 2.​ Suppresses diseases and pets Yield - Measurement of crop growth Vegetation - All plant life Where is food produced (Climate) 1.​ Temperate climate -​ UK, Europe, Northern China, Canada -​ Wheat (Oats etc) 2.​ Lowland tropical climate -​ South and South East Asia -​ Paddy rice 3.​ Sub tropical climate -​ Africa, Asia -​ Sorghum (高粱) Food Security -​ When all people at all times have access to sufficient, safe, nutritious food to maintain a healthy and active life -​ 4 main dimensions 1.​ Physical AVAILABILITY of food 2.​ Economic and physical ACCESS to food 3.​ Food UTILIZATION 4.​ STABILITY of other three dimensions over time -​ Major challenges 1.​ Production 2.​ Consumption 3.​ Distribution 4.​ Politics -​ Farmer management practices = Climate adaptation Climate-smart agriculture (CSA) -​ Sustainability increases productivity -​ Resilience (Adaptation) -​ Reduces and removes greenhouse gases (Mitigation) -​ Enhances achievement of national food security -​ CSA three pillars 1.​ Sustainability increasing agricultural productivity and incomes 2.​ Adapting and building resilience to climate change  3.​ Reducing and/ or eliminating GHG emissions Crop Management -​ Intercropping with legumes -​ Crop rotations -​ New crop varieties -​ Improved storage and processing techniques -​ Greater crop diversity -​ Soil and water -​ Nutrient Diversification of crop systems -​ Provides opportunity to introduce varieties that are more resilient and may also provide economic benefits Soil and Water Management -​ Conservation agriculture -​ Contour planting -​ Terraces and bunds -​ Planting pits -​ Water storage -​ Alternate wetting and drying -​ Dams, pits, ridges -​ Improved irrigation Managing organic matter -​ Important for soil quality, controls critical soil functions -​ Increasing soil organic matter in soils -​ Contribute to improve production -​ Reducing environmental impacts of agriculture Precision Agriculture for Agricultural Sustainability How Vertical Farming Works ​ ​