Environmental Engineering and Science Lecture Notes PDF

Environmental Engineering and Science (HS103C) Credit:2 Dr. JYOTI KAINTHOLA Environment Environment can be defined as a sum total of all the living and non-living elements and their effects that influence human life. While all living or biotic elements are animals, plant...

Environmental Engineering and Science (HS103C) Credit:2 Dr. JYOTI KAINTHOLA Environment Environment can be defined as a sum total of all the living and non-living elements and their effects that influence human life. While all living or biotic elements are animals, plants, forests, fisheries, and birds, non-living or abiotic elements include water, land, sunlight, rocks, and air. Environment functions (1) Provides the supply of resources (2) Sustains life (3) Assimilates waste (4) Enhances the quality of life  Earth Science What is Earth Science ? Earth sciences, also known as geoscience, is the study of Earth's structure, properties, processes, and biotic evolution. Earth sciences also covers the interactions between these parts and the environment. Why study Earth Science ? Studying earth science is crucial for understanding our planet's natural systems and processes. It enables us to comprehend the Earth's physical, chemical, and biological components, as well as the complex interactions between them. Earth science plays a vital role in addressing pressing global issues, such as climate change, natural disasters, and resource management. By studying earth science, individuals can develop a deeper appreciation for the Earth's unique conditions and work towards sustainable practices to preserve our planet for future generations.  Systems : Open Vs Closed A system = an isolated portion of the universe under consideration (atmosphere, the earth). The boundaries of the portion define the limits of the system. A system is characterized by whether it exchanges energy or mass with surroundings across its boundaries. Is the earth closed or open System ? a. Open b. Closed c. Neither  Earth only exchanges tiny amount of matter IN OUT Comets Closed System - Implications ? a. Resources are finite b. Can’t throw things away c. Changes in one part of a closed system will eventually affect the other parts  How do we study complex systems 1. Identify the components of the system and they interact 2. Determine the residence time (how fast do the elements interact, and how fast will a change propagate through system) 3. Identify feedback loops - interactions between elements that tend to amplify (positive feedback) or damp (negative feedback) changes to the system.  How do we study complex systems 1. Identify the components of the system and they interact 2. Determine the residence time (how fast do the elements interact, and how fast will a change propagate through system) 3. Identify feedback loops - interactions between elements that tend to amplify (positive feedback) or damp (negative feedback) changes to the system.  How do we study complex systems 1. Identify the components of the system and they interact 2. Determine the residence time (how fast do the elements interact, and how fast will a change propagate through system) 3. Identify feedback loops - interactions between elements that tend to amplify (positive feedback) or damp (negative feedback) changes to the system.  Reservoirs, fluxes and residence times Reservoir: Amount of material of interest in a given form Flux : Amount of material added to (Source), or removed from (Sink) reservoir, in a given period of time. Steady state : Sources = sinks, no net change in amount of material Residence time = the time it would take to empty (or fill) the reservoir. Bathtub holds 30 liters. Water from the taps flows in at 5 liters per minute and water drains out at 5 liters per minute. what is the residence time of a water molecule in the bathtub ? a) 1.5 minutes b) 3 minutes amount inside reservoir c) 6 minutes Residence time = total sources OR sinks d) 18 minutes  Identify the components of the system and how they interact. Reservoir = Lake = 9 km3 Water Fluxes = Inflow (source) = 1.5 km3/year Evaporation (sink) = 1.5 km3/year Evaporation Salton Sea 1.5 km3 per year Inflow 1.5 km3 per year Lake = 9 km3 water  Identify the components of the system and how they interact. Is this system in steady state ? What does this mean about lake level ? a) Yes, level stays the same b) No, level is failing c) No, level is rising Evaporation Salton Sea 1.5 km3 per year Inflow 1.5 km3 per year Lake = 9 km3 water  Determine the residence time a) 6 years b) 60 years c) 600 years Evaporation Salton Sea 1.5 km3 per year Inflow 1.5 km3 per year Lake = 9 km3 water  Earth Spheres Atmosphere Anthrosphere Lithosphere Cryosphere Biosphere Hydrosphere  The Atmosphere " The gaseous envelope that surrounds a planet or other celestial body " Air - mixture of gases and suspended particles that surrounds Earth Why is atmospheric composition important ? Affects Earth's Surface temperature-greenhouse effect because of the presence of gases like water vapour and carbon dioxide. What we breathe - oxygen allows us to exist but atmosphere also contains reactive gases (like ozone) which will react with tissues in your lungs and affect health Ozonehigher in atmosphere protects life on earth by absorbing UV rays which can damage cells  Structure of the atmosphere With increasing altitude.. - Air pressure and air density decreases Structure of the Atmosphere - Pressure What is the main reason that the top of Everest called the Death Zone ? A) because it is too cold for humans to survive for more than a few hours B) because the air pressure at that altitude is very low C) because the proportion of oxygen in the air changes with altitude Weather - the state of the atmosphere a given time and place : temperature air pressure humidity cloudiness wind speed and direction Climate - average weather over a long period of time  Weather vs Climate " Climate is what you expect, weather is what you get"  Hydrosphere The hydrosphere contains all the water found on our planet. Water found on the surface of our planet includes the ocean as well as water from lakes and rivers, streams, and creeks. Water found under the surface of our planet includes water trapped in the soil and groundwater. Water found in our atmosphere includes water vapor. Frozen water on our planet includes ice caps and glaciers. Only about 3% of the water on Earth is “fresh” water, and about 70% of the fresh water is frozen in the form of glacial ice. Calculate how much water you use for various purposes at your home 1. Average for a week 2. Calculate for person 3. List the purposes  Lithosphere The Lithosphere is the solid Earth that includes the continental and ocean crust as well the various layers of Earth’s interior. 94% of the Earth is composed of the elements oxygen, silicon, and magnesium. The lithosphere is not static (unchanging), but its surface (crust) is in a constant state of motion. Mineral resources are mined from the geosphere.  The Biosphere The biosphere is the “life zone” of the Earth, and includes all living organisms (including humans), and all organic matter that has not yet decomposed. The biosphere is structured into a hierarchy known as the food chain (all life is dependent on the first tier – mainly the primary producers that are capable of photosynthesis). Energy and mass is transferred from one level of the food chain to the next. THANK YOU