Exam 3 :)

Agricultural practices and soil erosion

Impact of agricultural Practice on Soil Erosion

Disruption of natural landscapes

• The act of plowing and farming disrupts natural grasslands

• Played a crucial role in holding soil stability

• Disruption leads to significant soil loss over time

• Negatively affecting food production and causing displacement of farming communities

Dust Bowl Consequences

•  History of Unsustainable farming practice can lead to severe soil erosion

• The erosion of topsoil, essential for crop growth

• Resulted in widespread agricultural failure and migration of families

• Towards california

• Migration prompted government actions 

• Controlling the influx of displaced populations

Sustainable farming practices

• Combat soil erosion

• Sustainable farming methods being introduced

• Contour plowing: involves plowing along the natural contours of land

• Method to retain water and soil

• Reducing erosion and promoting soil health

Historical Context of Migration

The great migration

• Many families displaced due to unsustainable farming practices that led to soil erosion

• Mass migration towards california

• Significant demographic changes and prompted government interventions

• Mange the influx of migrants

Government Actions

• Implemented to control migration and support displaced families

• Established programs for sustainable farming and soil conservation

Local environmental issues and sustainability challenges

Rainfall variability

• Increased rainfall can benefit regions that require water for hydroelectric power

• Areas experiencing prolonged droughts face significant sustainability challenges in agriculture

Soil Management Practices

• Ensure food security while maintaining ecological balances

• Soil management practices evolve 

• Address the dual needs of human consumption and ecological sustainability

• Agricultural practices do not compromise soil health and productivity 

Water Resource Challenges in California

Hydroelectric power and climate change

Dependence on River Flow

• Hydroelectric power generations relies on continuous river flow

• Increasingly uncertain due to changing climate patterns

Impact of Drought

• California has experienced prolonged periods of drought

• Directly affect the capacity for hydroelectric generation

• Leads to reservoir depletion

Reservoir management 

• Reservoirs may fill

• Subsequent dry seasons raise concerns about the reliability of energy source

Population pressure

• Increased consumption from a growing population

• Raising sustainability questions regarding hydroelectric power generation

Groundwater depletion in southern california

Reliance on groundwater

• Relies on groundwater

• Recharged from rainfall and stored underground

• Major agricultural regions: Central valley and imperial valley

• Depend heavily on this resource for irrigation

Overdrafting Aquifers

• Arise when aquifers are overdrawn

• Leading issues such as salinization: accumulated salts make soil toxic for crops

Ground Subsidence

• Excessive water pumping causes ground subsidence in areas like Salinas Valley

• Leads to uneven surfaces, building damage and cracked roads

Management challenges

• Lack of comprehensive regulatory body to manage groundwater use efficiently

• Complicating efforts to ensure sustainability

Agricultural Irrigation and Water Management

Irrigation Needs

• Regions require extensive irrigation to support crop production

• Areas where natural water sources are scarce

Impact of irrigation

• Transformed unusable land into productive agricultural areas

• Management to maintain soil fertility and prevent degradation

Salinization Issues

• Over-reliance on irrigation can lead to salinization

• Salts accumulate in the soil, makes it less productive and toxic for crops

California’s Water Supply and infrastructure

Water sources

• Does not naturally receive enough water in the regions where most people live

• Rainfall and snowpack occur in the Sierra Nevada and northern regions

• Southern and central parts are drier

Water transportation systems

• States built an extensive water transportation system

Includes

• Dams: to collect and store water

• Aqueducts: Man-made channels or pipelines to carry water to arid regions

• Pumps: used to move water uphill when necessary

• Groundwater: water is pumped from underground aquifers

• Desalination: converting ocean water into fresh water, rare due to high costs

• Water recycling : cleaning and reusing wastewater to supplement water supply

Wetland loss and ecological impact

Overview of wetlands

Wetlands are vital ecosystems that include both coastal and inland types

Coastal wetlands

• Such as sand dunes,beaches,tidal flats and salt marshes

Inland wetlands

• Including swamps,marshes,bogs and fens

• More common and diverse than coastal ones

• Plays a crucial role in maintaining ecological balance

Extent of wetland loss in california

• Experienced a dramatic loss of wetlands

• Over 90% of its wetlands disappeared due to human activities

Urbanization: expansion of cities and infrastructure

Agriculture: conversion of wetland areas for farming and agricultural practices

• Many midwestern states have lost around 90% of their wetlands

• Average national wetland loss in the US is about 50%

• Alaska has preserved nearly all it wetlands due to its low population density and vast wet areas

Importance of wetlands

Reasons:

Biodiversity: they provide habitat for endemic species and migratory birds

• Serves as critical stopovers during migration

Water supply: wetlands act as natural filters

• Improving water quality by trapping pollutants and sediments

Flood control: they help in flood management by absorbing excess water and reducing runoff

Storm protection: wetlands can buffer coastal areas against storm surges and erosion

Ecological consequences of wetland loss

Loss of habitat: disappearance of wetlands leads to decline of species that depend on these ecosystems

Altered water cycles: wetland loss disrupts natural water cycles

• Affecting local hydrology and increasing the risk of flooding

Decreased water quality: without wetlands to filter pollutants, water quality in surrounding areas can deteriorate (disappear or decline)

Increased urban runoff: urbanization without wetlands can lead to increased runoff

• Causes erosion and sedimentation in rivers and lakes (breaking down or moving earth materials like soil and rock by wind,water or ice)

Legal framework and restoration efforts

• To address wetland loss, several legal frameworks and restoration efforts 

Not net loss policy: requires that any wetland destruction must be mitigated

• Typically a 1:1 replacement ratio, higher in california

Enforcement: the U.S Army Corps of Engineers oversees wetland impacts restoration efforts

• Ensures compliance with regulations

Local restoration projects

 Los Cerritos Wetlands: near long beach, undergoing restoration and conservation efforts

Bolsa Chica Restoration: a collaborative effort aimed at restoring a historical inlet and promoting ecological sustainability

Biodiversity and Human threats

Importance of biodiversity

• Refers to the variety of life on earth

• Encompassing different species (species diversity)

• Ecosystems and genetic diversity is crucial for

Ecosystem stability: high biodiversity creates stable and productive ecosystems

Essential for

• Clean air

• Clean water 

• Soil fertility 

• pollination

Human survival: Humans rely on biodiversity for

• Food 

• Medicine

• Ecological stability

 Loss of biodiversity threatens human existence

• Disrupts the balance of ecosystems that support life on earth

Threats to biodiversity

• Human activities pose threats to biodiversity

• Deforestation: the destruction of forests (Amazon rainforest)

• Urbanization: the process of making an area more urban

• Agriculture: practice of cultivating the soil, producing crops and raising livestock 

• Infrastructure development: Highways, creating,improving and maintaining essential facilities and systems that support economic activity and improve quality of life

overharvesting/overfishing: unsustainable practices lead to the depletion of species

Pollution: contamination of air,water,soil adversely affects wildlife and ecosystems

Climate change: alters habitats and migration patterns

• Makes it difficult for species to adapt

Invasive species: non-native species can outcompete or prey on native species

• Disrupts local ecosystems

• Human activity over the last century is comparable to the mass extinction event that wiped out the dinosaurs 65 millions years ago

• Undergoing a mass extinction event

• The loss of over 50% of biodiversity, is unprecedented 

Conservation Efforts

• Combat biodiversity loss

• Conservation strategies are being implemented

• The construction of wildlife bridges, near los angeles

• Aims to reduce habitat fragmentation and allow wildlife movement between ecosystems

• Human-engineered solution supports trees and ecosystems, making an proactive approach towards biodiversity conservation 

Biofuel production and environmental impact

Biodiesel and ethanol production: processes and applications

Biodiesel

• Heavy,oil fuel that can be produced from vegetable oil

• Inventor of diesel, mr diesel, intended his engine to run on vegetable oil

• Leftover oil from mcdonalds can be reproduced to create biodiesel

Ethanol

• A fuel made by crushing crops rich in sugar and adding yeast

• Metabolizes sugar into carbon dioxide (CO2) and alcohol

• Ethyl alcohol is commonly referred as ethanol

• Chemically the same as beverage alcohol

Yeast metabolism

• Metabolizes sugar into CO2 and alcohol

• Utilization of these byproducts varies based on the application 

Baking: The CO2 is used to aerate the dough, while the alcohol evaporates during cooking

Brewing: the alcohol is retained for the alcoholic beverage, while the CO2 escapes

• Alcohol concentration becomes too high, it can inhibit yeast activity

Impact of Biofuels on carbon emission and food supply:focus on corn production

• Significant impact on carbon emissions

• Comparison to fossil fuels

• Unlike fossil fuels. Extract carbon from the ground and release it into the atmosphere

• Biofuels can improve the carbon cycle by being a domestic product

• Shift not only boosts the economy but enhances national security by reducing dependence on foreign oil

Corn as biofuel

• Corm is the primary crop used for biofuel production

• Corn is rich in sugar and the government subsidizes its production for biofuel

• Subsides incentivises farmers to grow corn for biofuel

• Leads to shortages and rising prices of corn as a food source 

Due to the focus on biofuel production

• U.S. shifted from providing international aid in the form of corn to countries experiencing famines

• Amount of corn required to fill a car’s gas tank with biofuel could feed a family for a year

• Highlights the ethical implication of using food crops for fuel

Comparison of corn-based and sugar cane biofuel production:Challenges and successes

The problem with corn-based biofuel production

• U.S agriculture is highly mechanized

• Relies on heavy machinery that burns fossil fuels to plow ,plant, spray and harvest corn

• Amount of fossil fuel burned to produce biofuel is roughly equivalent to the energy obtained from the biofuel itself

• Inefficiency turns the process into unproductive “busy work”

• Does Not save on imports, promote energy independence, or help with global warming

Biofuel success in brazil

• Producing biofuel for years using sugarcane

• A fast-growing tropical grass that yields a significant amount of sugar

• More abundant than needed for sugar production

• Does not disrupt the food supply

Brazilian agriculture is more manual

• Workers planting,tending, and harvesting sugarcane by hand

• Results in a better balance between fossil fuel input and biofuel output

• Making sugar cane more sustainable option for biofuel production

Deforestation and corporate agriculture

Impact of deforestation in tropical regions

• Driven by several factors, including urbanization and agricultural practices

Urbanization

• Urban areas expend,people often move into forested regions to build homes

• They cannot afford housing in cities

• Migration is facilitated by the construction of roads 

• Lead to further development and forest cleaning

Road Construction: initial roads through forests lead to the creation of side roads and dwellings

Agricultural expansion: people clear forests for vegetable gardens, leading to more deforestation as the soil depletes

Urban development: process contributes to the development of cities and suburban areas resulting in significant habitat loss

Consequences of deforestation

• Impacting biodiversity and contributing to climate change

• Release of greenhouse gases like methane from rotting vegetation

Corporate Agriculture and deforestation

• Corporate agriculture is a major driver of deforestation, in tropical regions

Cash crops

• Portions of the amazon rainforest

• Cleared for soybean production

• Used in various food products and biofuels

Palm Oil plantations

• Forests in countries like Malaysia and Indonesia

• Replaced with palm oil plantations, exacerbating deforestation

Degradation resources occur

• Exceed the environment's ability to replenish itself

• Leads to long-term ecological damage

Biofuel production and its impact

• Deforestation is linked to biofuel production

• Derived from crops that require significant land use

Definition of biofuel

• Liquid fuel made from living organisms

• Intended to replace fossil fuels like gasoline and diesel

Types of biofuel

• Include those made from sugar-rich crops

Process of making biofuel

Crushing the crop: Start with a crop that contains a high sugar content

Adding yeast: added to metabolize the sugar, producing carbon dioxide and alcohol

• Used as fuel

Biofuels promote

• Renewable energy sources

• Production leads to significant deforestation

• Land is cleared to grow the necessary crops

Groundwater Management in California

Supply of groundwater in California

• Crucial resource for california

• Provides a significant portion of the state’s water supply

• In long beach, half of the water comes from groundwater sources

• Approximately 20 water wells in the area

• Located near Long beach City College

Reliance on groundwater with challenges

• In coastal areas where seawater intrusion poses a significant threat

Challenges of Seawater intrusion

Seawater intrusion occurs

• When over-pumping of groundwater leads to a drop in aquifer pressure

• Drop allows seawater to seep into freshwater aquifers

• Contaminating the water supply

• Salt levels in the aquifer rises too high

• Affected wells must be abandoned

• Leads to a loss of freshwater resources

In long beach

• Several wells near the coast lost due to this issue

• Urgent need for effective groundwater management strategies to combat seawater 

intrusion

Groundwater management solutions

Problem of seawater intrusion

• Long beach has implemented the Alamitos Barrier Project

• Project involves injecting water into the ground through wells to maintain aquifer pressure and push seawater back into the ocean

• City has used recycled water to supply the barrier for irrigation purposes

• Recycled water goes under three-level treatment process:

Primary treatment: removes solids but leaves the water foul and unsafe

Secondary treatment: bacteria to break down organic matter

• Water remains cloudy containing pathogens

Tertiary treatment: purifies the water through clarification,disinfection,filtration and chemical treatment

• Results in a safe and usable product

Impact of water overuse

• Lead to several environmental issues

Groundwater overdraft

• Excessive pumping

• Cause land subsidences, where the ground sinks due to the loss of water in aquifers

Saltwater intrusion

• Over-extraction near coastal areas

• Allows ocean water to infiltrate freshwater aquifers

• Rendering them salty and unusable

Salinization of farmland

• Continuous irrigation can lead to salt buildup in the soil

• Making it infertile over time

• Not caused by seawater bur can result from freshwater carrying small amounts of salt

Impacts

• Underscore the importance of sustainable groundwater management practices

• Protect both water quality and agricultural productivity

Urbanization and resource management

Impact of urbanization on natural resources

urbanization significantly affects natural resources in ways:

Loss of wetlands 

• Over 90% of wetlands in california have been lost

• Wetlands play crucial role in cleaning water and supporting wildlife

Groundwater depletion

• Urbanization leads to increased demand for water

• Results in groundwater depletion

• Causes land subsidence and saltwater intrusion

• Contaminated aquifers near the ocean

Salinization of farmland

• Urban development leads to increased irrigation

• Causes salinization, repeated leaves salt in the soil

• Unusable for crops

Paving and water absorption

• Paving of surfaces prevents water from soaking into the ground

• Makes it hard to recharge aquifers

• Exacerbates the issues of groundwater depletion and salinization

Factors of critical need

• Sustainable urban planning to mitigate the negative impacts of urbanization on natural resources 

Sustainable Urban planning Strategies

• Effective sustainable urban planning strategies essential to manager the impact of urbanization on natural resources

Water management

• Implementing strategies such as recycled systems and desalination

• Help alleviate water scarcity

• Recycled water involves cleaning wastewater for reuse

• Desalination removes salt from seawater

Green infrastructure

• Incorporating green spaces and permeable surfaces in urban design 

• Enhance water absorption and reduce runoff

• Helps recharge aquifers and mitigate flooding

Soil management

• Utilizing sustainable agricultural practices

• Rain-fed agriculture, can prevent salinization and maintain soil health

Perennial crops: stabilize soil with deep root systems, can be more sustainable than annual crops

Regulatory Measures

• Enforcing regulations that protect wetlands

• Promote sustainable land use that helps preserve critical natural resources

Adopting these strategies

• Urban planners can create more sustainable cities

• Minimize the adverse effects of urbanization on natural resources

Challenges in Water Management

-water management in urban areas face several challenges

Groundwater management

• Over-extraction of groundwater leads to serious issues

• Such as land subsidence and saltwater intrusion

• Sustainable practices are crucial mange to resources

Salinization

• A significant problem in areas with heavy irrigation

• Reduces agricultural productivity

• Leads to irreversible damage to soil health

Urban development impacts

• Poor planning leads to permanent loss of critical resources 

• Like farmland and groundwater

• Essential to integrate sustainable practices into urban development

• Prevent these losses

Addressing challenges

• Requires a comprehensive approach

• Combine effective water management strategies with sustainable urban planning

Conservation strategies and endangered species

Overview of the Endangered Species Act (ESA)

• Enacted in 1973

• Protects species that are in danger of being extinction

• Aims to prevent extinction of these species and promote their recovery

Key provisions of the ESA include (aka illegal to)

• Take (kill)

• Harm (damage)

• Harass (disturb) endangered species

• Harass includes indirect action such as lights or noise that can affect the behavior of species

Challenges with the ESA

• Often criticized for being reactive rather than proactive 

• Species must be in “imminent danger” before they can be listed for protection

• Listing process can be lengthy

• Means species may go extinct before they receive any protection

• Has limited success in practice

Example: california condor

• A large vulture with a wingspan of up to 10 feet

• Native to california

• Plays a role in the ecosystem by consuming carrion (Dead animals)

Is endangered due to

• Habitat loss from farmland and ranching in the central valley

• Other pressures that are not yet fully detailed in this context

Example illustrates the importance of the ESA and the challenges it faces in effectively protecting endangered species

Primary causes of species endangerment

Species become endangered due to several primary factors:

• Overharvesting/overconsumption (eg overfishing)

• Poaching (illegal hunting)

• Pollution (creating toxic environments)

• Habitat loss (the most significant factor)

• Habitat loss does not directly kill species but destroys the ecosystems they depend on

Understanding these causes is essential

• Developing effective conservation strategies 

Ecological importance of endangered species

• Plays critical roles in their ecosystem

• Bengal tiger is a top predator that helps control the populations of lower predators

• Loss leads to ecological imbalances such as overpopulation of species like hyenas

• Insignificant species can have a profound impact

• A small plantain in Southern California

• Supports a specific caterpillar that feeds on it

• Plantain goes extinct creates a trigger of a cascade of biodiversity loss

• Affects many species, including butterflies that pollinate other plants

Interconnectedness of species within ecosystems and the importance of protecting all species regardless of their perceived significance 

California Condor Recovery efforts

• Faced near extinction with fewer than 20 individuals

Recovery efforts included 

Captive Breeding: condors were taken into zoos to prevent human imprinting

Raising chicks: hand-raised using condor puppets to avoid human contact

Current status: the population has increased to over 200 condors today

• Successful conservation strategies when proactive measures are taken

Water Acquisition and Environmental consequences 

Overview of water acquisition in los angeles

Major incentives for its growth

• Railroad companies promoting tourism and settlement

• State and city governments aiming for population growth to boost tax revenue

Significant problem arose

• The limited water supply threatened continued expansion

• Address issue by several aqueducts constructed to transport water from distant sources to the city

Major Aqueducts in Southern California

Los angeles Aqueduct

• First major aqueduct

• Constructed to bring water from the owens Valley

•  Built in the early 1900s

Colorado River Aqueduct

• Built about 20 years after the L.A Aqueduct (1930s)

• Starts at the Lake Havasu near Parker Dam on the California-Arizona border crosses the desert

California Aqueduct

• Constructed in the 1950s

• Transport water from the Bay Area down the Central Valley into Southern California

The Los Angeles Aqueduct and its environmental impact

• Los angeles aqueduct is an engineering marvel

• Contoured to run along mountain faces and using siphons to cross valleys

• Built manually without heavy machinery and includes hydroelectric stations

• To generate electricity from the water’s descent

Environmental consequences of the aqueduct

• Diversion of the Owens River: diverted in the aqueduct, leading to significant environmental consequences

• Owens lake dried up, becoming an dust bowl of toxic salts

• Local agriculture in owens valley collapsed

• Health hazards emerged due to toxic dust storms

Local Resistance

• Local residents of owens valley resisted the diversion

• Dynamited the aqueduct multiples times

• Los angeles respond with armed guards, leading to gun battles

• Los angeles prevailed, owens valley remains dry and arid today

Legal and ethical considerations

• Actions taken by los angeles were technically legal but raised significant ethical questions:

• Deception and lack of transparency in the process

• Highlights the conflict between urban growth and resource exploitation,

• As well as the water rights and ethics involved in development

Key Themes in Water Acquisition and Environmental Consequences

Construction of aqueducts in los angeles reflects broader themes:

• Urban growth and resource exploitation: need for water drove the expansion of the city

• Often at the expense of surrounding areas

• Water rights and ethics in development: the diversion of water from owens valley raises questions about the rights of local communities versus the needs of urban centers

Long-term environmental and social impacts: consequences of large-scale engineering projects, have lasting efforts on both the environmental and local populations