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  1. 1. Ecological models • are important for environmental decision support because they allow the consequences of alternative policies and management scenarios to be explored. • An early critical element in the definition of the ecological model is experience. It highlights peoples interaction with their physical and sociocultural environment. • Ecological model also recognize multiple levels on influence on health behaviors including intrapersonal/individual factor. • The term is used to indicate that the scientifically relevant features of any environment for human development include not only its objective properties but also the way in which these properties are subjectively experienced by the persons
  2. • Abasic grouping shows that ecological models in general belong to three areas:biodemographic ,bioenergetics and biogeovisual models include: • flowcharts,graphs ,diagram and 3D model. • Aecological models of health behavior emphasize the environmental and policy contexts of behavior, while incorporating social and psychological influences (Gruenewald et al., 2014). • It focuses on the linkages and relationships among multiple factors (or determinants) affecting health. • The core concept of ecological model is that behavior has influences from multiple scales including:individual,interpersonal, institutional, and community used to design and evaluate environmental interventions. White aComiskey2007.
  3. • 1.1 Levels of ecological Modeles • the Ecological Model provides a framework for identifying reasons for public health problems as well as for planning interventions. • The basis of the model is the recognition, that public health problems are rarely caused only by wrong individual behaviour but rather by a combination of factors from five different levels: • (1) Intrapersonal factors-Characteritcs of the individual such as knowledge,attitudes, behavier ,self concept ,skills and developmental history. Include gender, values,goals,expectation,age,genetics,coping skill,management skill,health literacy and counseling servece.
  4. • (2) Interpersonal factors – social network level: Who makes family or household decisions? How much money is availably in households and families and how are spending decisions reached? • (3) Institutional factors – organizational level: Who has real influence in the community? Are there organizations that prevent positive changes or that could help bring about those changes? How do the local marketing and distribution systems work? • (4) Community factors – community level: Is there any institutional support for solutions to public health problems? Have public health problems even been identified as problems for the community by the formal and informal leadership? What roles are played by local businesses, schools, clinics, NGOs and other associations? • (5) Policy factors – national level: What influence do national policies (e.g. laws,
  5. • tariffs, grants, taxes) have on the public health? Which parties and interests are involved in the policy-making process? • The Ecological Model is not just used to identify problems but also to identify key people, groups and resources that can help bring about positive chain.
  6. 1.2The importance of ecological model • Allow integration between behavioral and environmental change. • It allows for attention to be given the interaction between personal and environmental factors. • The model also can assist those in need with education of how different factors can play a role in their over all health.
  7. • 2 . Invasive Species • an "invasive species" is a species that is: • non-native (or alien) to the ecosystem under consideration and,whose introduction causes or is likely to cause economic or environmental harm or harm to human health. • .It can out compete native species for resources and cause native species to go extinict or become endanger. • they typically do not have natural killer to keep their population in check and they usually can reproduce quickly.
  8. 2 .1. How do Invasive Species Spread? • by human activities: People, and goods transported, travel quickly around the world, and often carry uninvited species with them. • can be introduced to an area by ship ,water, firewood, accidental release, and by people. • Insects can be transported easily in wood, shipping palettes, and crates shipped across the globe. • Human activities, such as those involved in global commerce and the pet trade, , such as those involved in global commerce and the pet trade, are considered to be the most common ways invasive plants, animals, microbes, and other organisms are transported to new habitats.
  9. • 2.2 Impacts of Invasive Species. • Invasive species can lead to the extinction of native plants and animals. • destroy biodiversity, and permanently alter habitats. • the various impacts of invasive species -- economic and social, environmental and ecological, and human health. • invasive species,modifies or disrupts the ecosystems it colonizes. • reduce water quality. • Damage recrational opportunties.
  10. invasive species: Burmese python
  11. • 2.2.1Controlling mechanisms are: • Mechanical: physical removing plant from environment through cutting or pulling. • Chemical: uses herbicides to kill plant. • Biological: use plant diseases or insect predictor. natural enemies • Cultural:selection of pest-resistant crops,winter cover crops,changing planting dates.
  12. • 3. The desert locust (Schistocerca gregaria ) is a species of locust, a periodically swarming, short- horned grasshopper in the family Acrididae. • They are found primarily in the deserts and dry areas of northern and eastern Africa, Arabia, and southwest Asia. • During population surge years, they may extend north into parts of western Spain and southern Italy, south into Eastern Africa, and east • It is the most destructive migratory pest in the world.
  13. • In response to environmental stimuli dense and highly mobile.. • They are ravenous eaters who consume their own weight per day, targeting food crops and forage. • a single square kilometer of swarm can contain up to 80 million adults, with the capacity to consume the same amount of food in one day as 35,000 people.. 3.1 Desert locust crisis 2020-2021 • Starting in early 2020, a massive desert locust upsurge broke out across greater Eastern Africa, Southwest Asia, and the area around the Red Sea, as favourable climatic conditions allowed widespread breeding of the pest.
  14. 3.1.2 Causes of desert locust • Arises from an increase population density which cause the locust to aggregate. • Locust need to multiply, concentrated and aggregate for swarms to form • The gregarious form undergo color change • A behavior change which make them band toget
  15. • 3.1.3 Consequence of desert locust • Deterioration to vegetation and crops in the infested areas • Major agricultural damage. • Lead to famine and starvation. • Eat every thing green and destroy crops • Eating large quantity of food • 3.1.4 Management of desert locust • Techniques for managing locust swarms include: • Cultural control: digging ,burning and bating[scattering locust food with insecticides]. • Chemical or biological: dusting with insecticides and spraying liquid insecticides. • Chemical pesticides have been the only effective method to control extreme locust infestations.
  16. • 3.1.5 Where are Desert Locust found? • Desert Locusts are usually restricted to the semi-arid and arid deserts of Africa • , the Near East and South-West Asia that receive less than 200 mm of rain annually. • African Migratory Locust (Locusta migratoria migratorioides) - Africa; • Oriental Migratory Locust (Locusta migratoria manilensis) - South-East Asia; • Red Locust (Nomadacris septemfasciata) - Eastern Africa; • Brown Locust (Locustana pardalina) - Southern Africa;