Hydrology Chapters 4-6 Handouts PDF

CHAPTER 4. INFILTRATION 4.1. Definition of Infiltration Infiltration is the process by which water on the ground surface enters the soil. It is a crucial component of the hydrological cycle, playing a significant role in replenishing groundwater, maintaining soil moisture, and reducing surface runof...

CHAPTER 4. INFILTRATION 4.1. Definition of Infiltration Infiltration is the process by which water on the ground surface enters the soil. It is a crucial component of the hydrological cycle, playing a significant role in replenishing groundwater, maintaining soil moisture, and reducing surface runoff. Infiltration is influenced by various factors, including soil characteristics, land cover, and the intensity and duration of precipitation. Key Concepts in Infiltration IN LU Y 1. Infiltration Rate:.I P M ◦ C O The infiltration rate is the speed at which water enters the soil. It is typically measured in millimeters per hour (mm/hr) or inches per hour (in/hr). C ◦ The infiltration rate starts high when the soil is dry but gradually decreases as the YN T soil becomes saturated. The maximum rate of infiltration when the soil is dry is AL EN called the "initial infiltration rate," and the rate when the soil is fully saturated is the "steady-state infiltration rate." IZ D 2. Infiltration Capacity: R U Infiltration capacity is the maximum rate at which the soil can absorb water under ST ◦ specific conditions. When the rainfall intensity exceeds the infiltration capacity, excess water will result in surface runoff. ◦ Factors affecting infiltration capacity include soil texture, structure, and organic content. 3. Percolation: ◦ After water infiltrates the soil, it continues to move downward through the soil profile. This downward movement is known as percolation. CE 118-HYDROLOGY PANGASINAN STATE UNIVERSITY RIZALYN C. ILUMIN, MSME, MSCE URDANETA CAMPUS (1st Sem, AY 2024-2025) Instructor Page 1 of 24  ◦ Percolation is driven by gravity and capillary forces and contributes to the recharge of groundwater aquifers. Factors Affecting Infiltration 1. Soil Texture: ◦ Soil texture, determined by the proportion of sand, silt, and clay particles, significantly affects infiltration. Sandy soils, with larger pore spaces, allow for faster infiltration, while clayey soils, with smaller pores, have slower infiltration rates. IN LU Y 2. Soil Structure:.I P M ◦ C O Soil structure refers to the arrangement of soil particles into aggregates or clumps. Well-structured soils with stable aggregates have more macropores C (larger pores) that facilitate faster infiltration. Compacted or poorly structured soils have fewer macropores, leading to reduced infiltration. YN T Soil Moisture Content: AL EN 3. ◦ The moisture content of the soil before a precipitation event influences infiltration. IZ D Dry soils can absorb water more quickly, but as the soil becomes saturated, the infiltration rate decreases. R U ST 4. Vegetation and Land Cover: ◦ Vegetation enhances infiltration by reducing the impact of raindrops on the soil surface, which prevents soil compaction and promotes the formation of macropores. Plant roots also create channels in the soil, enhancing water movement. ◦ Conversely, impervious surfaces like roads, pavements, and buildings prevent infiltration, leading to increased runoff. 5. Surface Conditions: CE 118-HYDROLOGY PANGASINAN STATE UNIVERSITY RIZALYN C. ILUMIN, MSME, MSCE URDANETA CAMPUS (1st Sem, AY 2024-2025) Instructor Page 2 of 24  ◦ The condition of the soil surface, including crusting, compaction, and the presence of organic matter, affects infiltration. A crusted or compacted surface reduces infiltration, while organic matter improves soil structure and increases infiltration. 6. Slope of the Land: ◦ The slope of the land influences how quickly water moves over the surface. Steeper slopes tend to have less infiltration because water moves more quickly across the surface, reducing the time available for infiltration. 7. Precipitation Intensity and Duration: IN LU Y ◦ The intensity and duration of precipitation events impact infiltration. Light, steady.I P M rainfall is more likely to infiltrate the soil, while intense, heavy rainfall can exceed C O the soil's infiltration capacity, leading to runoff. C Infiltration Process YN T Initial Infiltration: AL EN 1. ◦ When rain begins, water starts to infiltrate the soil at the initial infiltration rate. At IZ D this stage, the soil is often dry, and the infiltration rate is high. R U 2. Soil Saturation: ST ◦ As more water infiltrates, the soil moisture content increases. The infiltration rate gradually decreases as the soil pores fill with water. 3. Steady-State Infiltration: ◦ Eventually, the soil reaches a point where it can no longer absorb water as quickly. At this stage, the infiltration rate stabilizes at the steady-state infiltration rate, and any additional water will result in surface runoff. CE 118-HYDROLOGY PANGASINAN STATE UNIVERSITY RIZALYN C. ILUMIN, MSME, MSCE URDANETA CAMPUS (1st Sem, AY 2024-2025) Instructor Page 3 of 24  4. Deep Percolation: ◦ Water that has infiltrated into the soil may continue to move downward through the soil profile, eventually reaching the water table and contributing to groundwater recharge. Importance of Infiltration 1. Groundwater Recharge: IN LU Y ◦ Infiltration is the primary mechanism for recharging groundwater aquifers. It.I P M ensures a sustainable supply of groundwater for drinking water, irrigation, and C O other uses. C 2. Reducing Runoff and Erosion: YN T ◦ By allowing water to enter the soil, infiltration reduces surface runoff, which in turn AL EN minimizes soil erosion and the risk of flooding. 3. Maintaining Soil Moisture: IZ D R U ◦ Infiltration is crucial for maintaining soil moisture levels, which support plant growth and maintain ecosystem health. ST 4. Water Quality Improvement: ◦ As water infiltrates through the soil, it is filtered by soil particles, which can remove contaminants. This process helps improve the quality of groundwater. Challenges and Impacts 1. Urbanization: CE 118-HYDROLOGY PANGASINAN STATE UNIVERSITY RIZALYN C. ILUMIN, MSME, MSCE URDANETA CAMPUS (1st Sem, AY 2024-2025) Instructor Page 4 of 24  ◦ Urban development often leads to the creation of impervious surfaces, such as roads and buildings, which significantly reduce infiltration and increase surface runoff. This can exacerbate flooding and reduce groundwater recharge. 2. Soil Degradation: ◦ Agricultural practices, deforestation, and overgrazing can degrade soil structure, reduce organic matter content, and compact the soil, all of which decrease infiltration capacity. 3. Climate Change: IN LU Y ◦ Changes in precipitation patterns, including more intense and less frequent rainfall events, can alter infiltration dynamics. Increased rainfall intensity may.I P M exceed infiltration capacity, leading to more frequent runoff and flooding. C O C Example: Infiltration in Agriculture YN T In agriculture, managing infiltration is crucial for optimizing water use and maintaining soil health. For example, farmers may use conservation tillage practices to enhance infiltration by AL EN preserving soil structure and organic matter. Crop rotation, cover cropping, and maintaining vegetative cover also promote infiltration by reducing soil compaction and increasing organic matter content. Proper management of irrigation, ensuring that water is applied at a rate the soil IZ D can absorb, is also vital for preventing runoff and maximizing the efficiency of water use. R U In conclusion, infiltration is a fundamental process in the hydrological cycle, influencing ST groundwater recharge, surface runoff, soil moisture, and overall ecosystem health. Understanding and managing infiltration is essential for sustainable water resource management, agriculture, and urban planning. 4.2. Factors affecting infiltration, and infiltration measurements Factors Affecting Infiltration CE 118-HYDROLOGY PANGASINAN STATE UNIVERSITY RIZALYN C. ILUMIN, MSME, MSCE URDANETA CAMPUS (1st Sem, AY 2024-2025) Instructor Page 5 of 24 Infiltration is influenced by a wide range of factors, each playing a crucial role in determining how water moves from the surface into the soil. Understanding these factors is essential for effective water management in agriculture, urban planning, and environmental conservation. 1. Soil Texture Definition: Soil texture refers to the relative proportion of sand, silt, and clay particles in the soil. Impact on Infiltration: ◦ Sandy Soils: These soils have large particles and larger pore spaces, allowing IN LU Y water to infiltrate quickly. However, they may not retain water well, leading to rapid drainage..I P M ◦ C O Clayey Soils: These soils have very fine particles and small pore spaces, C resulting in slow infiltration rates. Once saturated, clay soils can hold water tightly, but they can also become compacted and resist further infiltration. YN T ◦ Loamy Soils: A balanced mix of sand, silt, and clay, loamy soils typically have AL EN good infiltration rates and water-holding capacity, making them ideal for agriculture. IZ D Example: In a sandy desert region, the soil's high infiltration rate might mean that rainfall R U quickly disappears into the ground, while in a clayey area, water might pool on the surface due to slower infiltration. ST 2. Soil Structure Definition: Soil structure refers to the arrangement of soil particles into aggregates or clumps. Impact on Infiltration: ◦ Well-Structured Soils: Soils with stable aggregates create more macropores, which facilitate quicker water movement and higher infiltration rates. CE 118-HYDROLOGY PANGASINAN STATE UNIVERSITY RIZALYN C. ILUMIN, MSME, MSCE URDANETA CAMPUS (1st Sem, AY 2024-2025) Instructor Page 6 of 24  ◦ Poorly Structured Soils: Compaction or a lack of aggregation can lead to fewer macropores, reducing infiltration and increasing surface runoff. Example: In agricultural fields, tillage practices can break down soil structure, leading to reduced infiltration. Conservation tillage methods help preserve soil structure, promoting better infiltration. 3. Soil Moisture Content Definition: The amount of water already present in the soil before a precipitation event. Impact on Infiltration: IN LU Y.I P M ◦ Dry Soils: Initially have a higher infiltration rate as they can absorb water quickly. C O However, as they become saturated, the rate decreases. C ◦ Wet Soils: Already saturated soils have a low infiltration rate, leading to increased surface runoff during rainfall. YN T AL EN Example: After a prolonged dry spell, the infiltration rate will be high at the beginning of a rainstorm, but it will decrease as the soil becomes saturated. IZ D 4. Vegetation and Land Cover R U Definition: The type and density of plant cover on the soil surface. ST Impact on Infiltration: ◦ Vegetated Areas: Vegetation reduces the impact of raindrops, which helps prevent soil compaction and crusting. Plant roots also create channels in the soil, enhancing infiltration. ◦ Bare or Impervious Surfaces: Areas with little or no vegetation, such as urban landscapes with roads and buildings, reduce infiltration and increase surface runoff. CE 118-HYDROLOGY PANGASINAN STATE UNIVERSITY RIZALYN C. ILUMIN, MSME, MSCE URDANETA CAMPUS (1st Sem, AY 2024-2025) Instructor Page 7 of 24  Example: A forested area will have higher infiltration rates compared to a paved urban area, where water cannot penetrate the ground and instead runs off quickly. 5. Surface Conditions Definition: The physical state of the soil surface, including factors like crusting, compaction, and organic matter content. Impact on Infiltration: ◦ Crusted or Compacted Surfaces: These surfaces reduce the number of macropores, leading to lower infiltration rates. IN LU Y.I P M ◦ Organic Matter: Enhances soil structure, increases porosity, and improves C O infiltration by promoting aggregate stability. C Example: Agricultural fields with compacted soil from heavy machinery might have reduced infiltration, leading to ponding after rainfall. YN T AL EN 6. Slope of the Land Definition: The gradient or steepness of the land surface. IZ D R U Impact on Infiltration: ST ◦ Steep Slopes: Water moves quickly down steep slopes, giving less time for infiltration. This can lead to higher runoff and increased soil erosion. ◦ Gentle Slopes: Slower water movement allows more time for infiltration, reducing runoff and promoting groundwater recharge. Example: In mountainous regions, water tends to flow rapidly downhill, resulting in less infiltration compared to flat plains where water can infiltrate more easily. CE 118-HYDROLOGY PANGASINAN STATE UNIVERSITY RIZALYN C. ILUMIN, MSME, MSCE URDANETA CAMPUS (1st Sem, AY 2024-2025) Instructor Page 8 of 24 7. Precipitation Intensity and Duration Definition: The rate and length of time over which precipitation occurs. Impact on Infiltration: ◦ Light, Steady Rain: More likely to infiltrate the soil because it does not exceed the soil’s infiltration capacity. ◦ Heavy, Intense Rain: Can quickly exceed the infiltration capacity, leading to surface runoff. IN LU Y Example: During a short but intense thunderstorm, most of the water may run off rather.I P M than infiltrating, especially in areas with compacted soil. C O 8. Human Activities C Definition: Activities such as agriculture, urbanization, and deforestation that alter the YN T natural landscape. AL EN Impact on Infiltration: IZ D ◦ Urbanization: Leads to the creation of impervious surfaces, significantly reducing R U infiltration. ST ◦ Agricultural Practices: Certain practices like tillage, crop rotation, and cover cropping can either enhance or reduce infiltration depending on how they are implemented. ◦ Deforestation: Removal of trees reduces the soil's organic content and structure, leading to reduced infiltration. Example: A newly developed suburban area with roads, driveways, and roofs will have significantly lower infiltration rates compared to the natural forested area that previously existed there. CE 118-HYDROLOGY PANGASINAN STATE UNIVERSITY RIZALYN C. ILUMIN, MSME, MSCE URDANETA CAMPUS (1st Sem, AY 2024-2025) Instructor Page 9 of 24 Infiltration Measurements Measuring infiltration is essential for understanding how much water is entering the soil, which is critical for managing water resources, predicting flood risks, and planning agricultural activities. Several methods are used to measure infiltration, each with specific applications. 1. Double-Ring Infiltrometer Description: ◦ A common tool for measuring infiltration rates in the field. IN LU Y ◦ Consists of two concentric rings driven into the soil. Water is added to both rings,.I P M but the inner ring is used to measure infiltration while the outer ring minimizes C O lateral water movement. C Procedure: YN T ◦ Water is poured into the rings, and the rate at which the water level drops in the AL EN inner ring is measured over time. ◦ The infiltration rate is calculated based on the change in water level. IZ D R U Applications: Commonly used in agricultural and environmental studies to assess the infiltration capacity of soils. ST Example: A soil scientist uses a double-ring infiltrometer to measure the infiltration rate in a field before deciding on irrigation practices. 2. Single-Ring Infiltrometer Description: ◦ Similar to the double-ring infiltrometer but uses only one ring. CE 118-HYDROLOGY PANGASINAN STATE UNIVERSITY RIZALYN C. ILUMIN, MSME, MSCE URDANETA CAMPUS (1st Sem, AY 2024-2025) Instructor Page 10 of 24  Procedure: ◦ The single ring is driven into the soil, and water is added. The drop in water level is measured over time to determine the infiltration rate. Applications: Used in situations where double-ring infiltrometers are impractical or when a quicker, less detailed measurement is sufficient. Example: A quick field assessment of infiltration rates on a construction site to determine potential runoff issues. 3. Tension Infiltrometer IN LU Y.I P M Description: ◦ C O A device that measures infiltration under controlled soil moisture conditions by C applying a known tension (negative pressure) to the water. YN T Procedure: AL EN ◦ The tension infiltrometer is placed on the soil surface, and the water is allowed to infiltrate under a specific tension, simulating natural conditions. IZ D R U Applications: Useful for understanding infiltration in unsaturated soils and for studying soil hydraulic properties. ST Example: Researchers use a tension infiltrometer to measure infiltration in a semi-arid region where the soil is typically dry. 4. Rainfall Simulation Description: CE 118-HYDROLOGY PANGASINAN STATE UNIVERSITY RIZALYN C. ILUMIN, MSME, MSCE URDANETA CAMPUS (1st Sem, AY 2024-2025) Instructor Page 11 of 24  ◦ A method that involves using a rainfall simulator to apply water to a specific area and measure the resulting infiltration and runoff. Procedure: ◦ Water is sprayed onto the soil surface at a controlled rate to mimic natural rainfall. Infiltration is measured by collecting and analyzing the water that does not run off. Applications: Often used in erosion studies, land management research, and agricultural experiments to understand how different soils respond to rainfall. Example: A study uses a rainfall simulator to compare infiltration rates between a no-till IN LU Y field and a conventionally tilled field..I P M 5. Soil Moisture Sensors C O C Description: YN T ◦ Sensors that measure changes in soil moisture content over time to infer AL EN infiltration rates. Procedure: IZ D R U ◦ Sensors are placed at different depths in the soil profile. As water infiltrates, the sensors record changes in moisture content, allowing for the calculation of ST infiltration rates. Applications: Used in long-term studies of infiltration, irrigation management, and drought monitoring. Example: A farmer uses soil moisture sensors to monitor infiltration after irrigating a crop field, adjusting water application based on sensor data. 6. Permeameters CE 118-HYDROLOGY PANGASINAN STATE UNIVERSITY RIZALYN C. ILUMIN, MSME, MSCE URDANETA CAMPUS (1st Sem, AY 2024-2025) Instructor Page 12 of 24  Description: ◦ Devices used to measure the permeability of the soil, which is closely related to infiltration. Procedure: ◦ A permeameter applies water to a soil sample, and the rate at which the water moves through the soil is measured. Applications: Often used in laboratory settings or in situ to understand soil properties related to infiltration and drainage. IN LU Y.I P M Example: Engineers use a permeameter to assess soil permeability before designing a stormwater management system. C O C Conclusion YN T Infiltration is a complex process influenced by various factors, including soil properties, AL EN vegetation, land use, and climatic conditions. Understanding these factors is crucial for managing water resources effectively, preventing erosion, and maintaining healthy ecosystems. Measuring infiltration through methods such as infiltrometers, rainfall simulation, and soil IZ D moisture sensors provides valuable data for decision-making in agriculture, urban planning, and environmental conservation. By carefully managing infiltration, we can ensure sustainable water R U use and protect against the negative impacts of surface runoff and soil degradation. ST 4.3. Horton Model and Phillip’s equation Horton Model and Philip’s Equation: Infiltration Models in Detail Infiltration models are essential for predicting how water moves into the soil during rainfall events. Two widely recognized models in hydrology are the Horton Model and Philip’s Equation. These models are used to estimate the infiltration rate over time, which is crucial for water resource management, flood prediction, and agricultural planning. CE 118-HYDROLOGY PANGASINAN STATE UNIVERSITY RIZALYN C. ILUMIN, MSME, MSCE URDANETA CAMPUS (1st Sem, AY 2024-2025) Instructor Page 13 of 24 Horton Model Overview The Horton Model, developed by Robert E. Horton in 1933, describes the infiltration process using an empirical equation that accounts for the decrease in infiltration rate over time. According to Horton, the infiltration rate starts high at the beginning of a rainfall event and gradually decreases to a constant rate, known as the "final infiltration rate." Horton’s Infiltration Equation The Horton equation is given by: IN LU Y.I P M C O C YN T AL EN IZ D R U ST CE 118-HYDROLOGY PANGASINAN STATE UNIVERSITY RIZALYN C. ILUMIN, MSME, MSCE URDANETA CAMPUS (1st Sem, AY 2024-2025) Instructor Page 14 of 24 Characteristics of the Horton Model: The model is empirical, meaning it is based on observed data rather than derived from IN first principles. LU Y.I P M It works well for a wide range of soil types and conditions. C O C The model assumes that the infiltration rate decreases exponentially over time and eventually reaches a constant rate. YN T AL EN IZ D R U ST CE 118-HYDROLOGY PANGASINAN STATE UNIVERSITY RIZALYN C. ILUMIN, MSME, MSCE URDANETA CAMPUS (1st Sem, AY 2024-2025) Instructor Page 15 of 24 Philip’s Equation Overview IN LU Y Philip’s equation, developed by J.R. Philip in 1957, is a physically based model that describes.I P M the infiltration process using principles from soil physics. The equation considers both the C O capillary forces (which drive water into the soil) and gravity. C Philip’s Infiltration Equation YN T The equation is given by: AL EN IZ D R U ST CE 118-HYDROLOGY PANGASINAN STATE UNIVERSITY RIZALYN C. ILUMIN, MSME, MSCE URDANETA CAMPUS (1st Sem, AY 2024-2025) Instructor Page 16 of 24 Explanation of Parameters: Sorptivity (S): This parameter captures the effect of capillary forces, which dominate at the beginning of the infiltration process when the soil is dry. IN LU Y Hydraulic Conductivity (A): Represents the influence of gravity on water movement.I P M through the soil, especially significant when the soil becomes saturated. C O Characteristics of Philip’s Equation: C Philip’s equation is derived from first principles, making it more physically based than the YN T Horton model. AL EN It is especially accurate in the early stages of infiltration when capillary forces dominate. IZ D The equation assumes a homogeneous soil and steady initial conditions. R U ST CE 118-HYDROLOGY PANGASINAN STATE UNIVERSITY RIZALYN C. ILUMIN, MSME, MSCE URDANETA CAMPUS (1st Sem, AY 2024-2025) Instructor Page 17 of 24  IN LU Y.I P M C O C YN T AL EN IZ D R U ST Comparison of Horton Model and Philip’s Equation CE 118-HYDROLOGY PANGASINAN STATE UNIVERSITY RIZALYN C. ILUMIN, MSME, MSCE URDANETA CAMPUS (1st Sem, AY 2024-2025) Instructor Page 18 of 24  Nature of Model: ◦ Horton’s model is empirical, relying on observed data, while Philip’s equation is physically based, derived from the principles of soil physics. Application: ◦ Horton’s model is more general and easier to apply across different soil types and conditions, making it widely used in hydrology. ◦ Philip’s equation provides more detailed insights, especially in the early stages of infiltration, and is often used in research and specific applications requiring IN LU Y precise modeling..I P M Infiltration Rate Over Time: C O C ◦ Horton’s model shows an exponential decrease in infiltration rate, eventually reaching a constant rate. YN T AL EN ◦ Philip’s equation shows a decline in infiltration rate due to decreasing capillary forces, with gravity maintaining the rate as time progresses. IZ D Conclusion R U Both the Horton Model and Philip’s Equation are valuable tools for understanding and predicting ST infiltration. Horton’s model is particularly useful for its simplicity and general applicability, making it a standard in hydrological studies. Philip’s equation, on the other hand, offers a more detailed, physically based approach, especially useful for understanding the early stages of infiltration. By applying these models, engineers, hydrologists, and environmental scientists can better manage water resources, design effective irrigation systems, and predict flood risks in various landscapes. IN-DETAILED DISCUSSION When reading mathematical problems, especially those involving equations like the Horton Model and Philip’s Equation, it's important to understand how to interpret the symbols, variables, CE 118-HYDROLOGY PANGASINAN STATE UNIVERSITY RIZALYN C. ILUMIN, MSME, MSCE URDANETA CAMPUS (1st Sem, AY 2024-2025) Instructor Page 19 of 24 and equations. Below is a narrative explanation to help you read and understand the symbols and signs used in the examples provided. General Guidelines for Reading Mathematical Problems 1. Understand the Context: ◦ Before diving into the equations and symbols, get a sense of what the problem is about. For example, in infiltration problems, you're dealing with how water enters the soil over time. IN LU Y.I P M C O C YN T AL EN IZ D R U ST CE 118-HYDROLOGY PANGASINAN STATE UNIVERSITY RIZALYN C. ILUMIN, MSME, MSCE URDANETA CAMPUS (1st Sem, AY 2024-2025) Instructor Page 20 of 24  IN LU Y.I P M C O C YN T AL EN IZ D R U ST CE 118-HYDROLOGY PANGASINAN STATE UNIVERSITY RIZALYN C. ILUMIN, MSME, MSCE URDANETA CAMPUS (1st Sem, AY 2024-2025) Instructor Page 21 of 24  IN LU Y.I P M C O C YN T AL EN IZ D R U ST 6. Step-by-Step Solution: Break down the problem into smaller parts. Solve each part step by step, following the mathematical operations in the correct order: parentheses, exponents, multiplication and division (from left to right), and addition and subtraction (from left to right) — often abbreviated as PEMDAS. CE 118-HYDROLOGY PANGASINAN STATE UNIVERSITY RIZALYN C. ILUMIN, MSME, MSCE URDANETA CAMPUS (1st Sem, AY 2024-2025) Instructor Page 22 of 24  IN LU Y.I P M C O C YN T AL EN IZ D R U ST CE 118-HYDROLOGY PANGASINAN STATE UNIVERSITY RIZALYN C. ILUMIN, MSME, MSCE URDANETA CAMPUS (1st Sem, AY 2024-2025) Instructor Page 23 of 24  IN LU Y.I P M C O C YN T AL EN IZ D Conclusion R U To read and understand the signs, symbols, and problems in mathematical equations: ST Recognize the variables and what they represent. Understand the mathematical operations involved. Substitute values carefully. Follow the order of operations (PEMDAS). Step through each part of the equation methodically, ensuring that each operation is performed correctly. By practicing these steps, you'll gain confidence in solving similar problems. CE 118-HYDROLOGY PANGASINAN STATE UNIVERSITY RIZALYN C. ILUMIN, MSME, MSCE URDANETA CAMPUS (1st Sem, AY 2024-2025) Instructor Page 24 of 24