Nigeria's free digital learning hub. Videos, lecture notes, practice questions and leaderboards aligned with CCMAS, NBTE, NCCE, WAEC, NECO, IJMB and JAMB curricula.
Loading
Nigeria's free digital learning hub. Videos, lecture notes, practice questions and leaderboards aligned with CCMAS, NBTE, NCCE, WAEC, NECO, IJMB and JAMB curricula.
Environmental Health Science · 100 Level
This is the complete lecture note for EVM 102 Introduction of Natural environment, prepared for Environmental Health Science students at 100 Level. You can read it online below, open it in the full viewer, or download the PDF for offline study. It pairs with the course's video lectures, so you can read and watch together.
LA-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS
LA-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS Series 1 Course code: EVM102 Course title: Introduction to Natural Environment Course credit load: 2 Units List of Series: Series 1: Foundations of the Natural Environment Series 2: Land and Its Components Series 3: Water Systems and Aquatic Life Series 4: Atmosphere, Climate, and Circulation Series 5: Human Impacts and Environmental Challenges Series Outline for Series 1: Foundations of the Natural Environment Part 1 (1.1): Concept of the Natural Environment o Sub-Part 1.1.1: Definition and scope of the natural environment o Sub-Part 1.1.2: Components of the natural environment Part 2 (1.2): Interrelationships within the Natural Environment o Sub-Part 1.2.1: Interaction between land, water, and atmosphere o Sub-Part 1.2.2: Natural cycles and balance Part 3 (1.3): Factors Affecting the Natural Environment o Sub-Part 1.3.1: Physical factors (climate, geology, topography) o Sub-Part 1.3.2: Biological factors (species interactions, vegetation cover) Part 4 (1.4): Issues and Challenges of the Natural Environment o Sub-Part 1.4.1: Human activities and environmental change o Sub-Part 1.4.2: Global environmental challenges Introduction
LA-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS The natural environment forms the foundation of life on Earth, shaping the conditions under which humans, animals, and plants exist. It encompasses land, water, and the atmosphere, all of which interact to sustain ecosystems and regulate climate. Understanding these components is essential, as they provide the resources and services upon which societies depend. The aim of this Series is to introduce you to the concept of the natural environment, its components, and the factors that influence it, while also highlighting the challenges that arise from human interaction with nature. We shall commence this Series by defining the natural environment and identifying its major components. Next, we will examine how these components interact and maintain balance through natural cycles. Subsequently, we will analyse the physical and biological factors that affect the environment. Finally, we will conclude by evaluating the issues and challenges that arise from human activities and global environmental changes. Series Learning Outcomes Upon completing this Series, you should be able to: SLO 1.1 define the concept of the natural environment, SLO 1.2 identify and explain the components of the natural environment, SLO 1.3 analyse the interrelationships among land, water, and atmosphere, SLO 1.4 evaluate the physical and biological factors influencing the natural environment, and SLO 1.5 assess the issues and challenges facing the natural environment due to human activities and global changes.
LA-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS 1.1 Concept Of The Natural Environment 1.1.1 Definition and scope of the natural environment The natural environment refers to all living and non-living things that occur naturally on Earth. It includes physical elements such as landforms, water bodies, soil, and the atmosphere, as well as biological elements such as plants, animals, and microorganisms. Together, these components form the conditions that sustain life. The scope of the natural environment is broad, ranging from the smallest organisms in the soil to the vast climatic systems that regulate global weather. Fill in the blank: The __________ environment includes both living and non-living things occurring naturally on Earth. 1.1.2 Components of the natural environment The components of the natural environment can be grouped into three broad categories: land, water, and atmosphere. Land includes soil, vegetation, and animals that inhabit terrestrial ecosystems. Water covers both freshwater and marine systems, supporting aquatic organisms. The atmosphere is the layer of gases surrounding the Earth, which regulates temperature and provides oxygen for living organisms. These components are interconnected, and changes in one often affect the others. Fill in the blank: The three broad categories of the natural environment are land, __________, and atmosphere. Short description: A landscape image showing land, water, vegetation, and sky to represent the natural environment. Plate 1.1 Components of the natural environment
LA-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS Pilot questions 1.1 1. Which of the following best describes the natural environment? 2. Which of these is not a component of the natural environment? 3. The atmosphere provides which of the following essential elements for life? 4. What are the three broad categories of the natural environment? 5. Why is the natural environment considered the foundation of life on Earth? 1.2 Interrelationships Within The Natural Environment 1.2.1 Interaction between land, water, and atmosphere The natural environment is not a collection of isolated parts, but rather a system in which land, water, and atmosphere interact continuously. For example, rainfall (atmosphere) nourishes vegetation (land), while rivers (water) transport nutrients across ecosystems. These interactions maintain ecological balance and support biodiversity. Fill in the blank: Rainfall from the __________ nourishes vegetation on land and replenishes rivers and lakes. Short description: Image showing rainfall over a forest and river, illustrating the interaction of atmosphere, land, and water. Plate 1.2 Interaction of land, water, and atmosphere
LA-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS 1.2.2 Natural cycles and balance The environment operates through natural cycles, such as the water cycle, carbon cycle, and nutrient cycles. These cycles ensure the continuous renewal of resources and maintain balance in ecosystems. For instance, the water cycle circulates water between land, atmosphere, and oceans, while the carbon cycle regulates greenhouse gases. Disruption of these cycles often leads to environmental challenges such as climate change or soil degradation. Fill in the blank: The __________ cycle circulates water between land, atmosphere, and oceans. Short description: Diagram showing the water cycle and its stages (evaporation, condensation, precipitation, collection). Figure 1.1 The water cycle Pilot questions 1.2 1. Which of the following is an example of interaction between land, water, and atmosphere? 2. The water cycle involves which of the following processes? 3. Disruption of the carbon cycle can lead to which environmental challenge? 4. Why are natural cycles important for maintaining ecological balance? 5. Give one example of how human activity can disrupt a natural cycle.
LA-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS 1.3 Factors Affecting The Natural Environment 1.3.1 Physical factors (climate, geology, topography) The natural environment is shaped by several physical factors, which include climate, geology, and topography. Climate refers to the long-term patterns of temperature, rainfall, and wind in a region, and it influences vegetation growth, soil formation, and the distribution of species. Geology relates to the structure and composition of the Earth’s crust, determining the types of rocks and minerals available, which in turn affect soil fertility and landforms. Topography describes the physical features of the land, such as mountains, valleys, and plains, and it influences water flow, erosion, and settlement patterns. Fill in the blank: The physical features of the land, such as mountains and valleys, are referred to as __________. 1.3.2 Biological factors (species interactions, vegetation cover) The environment is also influenced by biological factors, which include the presence and interaction of living organisms. Species interactions such as competition, predation, and symbiosis shape ecosystems and determine which species thrive in particular areas. Vegetation cover plays a critical role in stabilising soil, regulating water cycles, and providing habitats for animals. When vegetation is removed, ecosystems become vulnerable to erosion and biodiversity loss. Fill in the blank: The removal of __________ cover often leads to soil erosion and biodiversity loss. Short description: Image showing a forest ecosystem with vegetation cover and wildlife.
LA-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS Plate 1.3 Biological factors influencing the environment Pilot questions 1.3 1. What are the three main physical factors that shape the natural environment? 2. How does geology influence soil fertility? 3. What term describes the physical features of the land such as mountains and plains? 4. Give one example of a species interaction that affects ecosystems. 5. Why is vegetation cover important for maintaining environmental stability? 1.4 Issues And Challenges Of The Natural Environment 1.4.1 Human activities and environmental change Human activities such as deforestation, industrialisation, and urbanisation have significantly altered the natural environment. These activities often lead to pollution, habitat destruction, and the depletion of natural resources. For example, deforestation reduces biodiversity and disrupts the water cycle, while industrial emissions contribute to air pollution and climate change. Fill in the blank: Cutting down forests for agriculture or industry is known as __________. 1.4.2 Global environmental challenges Beyond local impacts, there are global environmental challenges such as climate change, desertification, and loss of biodiversity. Climate change, driven largely by greenhouse gas emissions, affects weather patterns and sea levels. Desertification reduces the productivity of land, while biodiversity loss threatens the stability of ecosystems worldwide. These challenges require international cooperation and sustainable practices to mitigate their effects. Fill in the blank: Rising global temperatures caused by greenhouse gases are referred to as __________ change. Key Global Environmental Challenges Climate Change: The long-term shift in global temperatures and weather patterns,
This is the opening of the note. Read the full note or download the PDF to continue.
