Drought and desertification are closely related phenomena. Persisting over months or years, drought can affect large areas and may have serious environmental, social and economic impacts. While drought is a natural phenomenon, whose impacts can be exacerbated by human activities that are not adapted to the local climate, land degradation is the process of turning fertile land into less or non-productive land. In extreme cases in drylands this is called desertification. Land degradation and desertification are complex phenomena driven by un-adapted human activity in combination with land and climatic constraints. Inappropriate land use, such as monocultures, and unsustainable land management practices, such as deforestation, unsuitable agricultural practices and overexploitation of water resources), can cause land degradation that can be further aggravated by drought.
The light spreads on the earth unevenly due to It's tilt. The position
of the earth changes in orbit, and the earth either becomes tilted
towards or away from the sun. This is why seasons happen.
Groundwater Storage, Porosity, and Specific Yield: Groundwater occupies the cracks and pore spaces between rocks and mineral grains below the land surface. In the saturated zone, essentially all of the pores are filled with water. If a volume of saturated aquifer material is completely dried, the water volume removed reflects the total porosity of the material, or the fraction of pore space within the total volume of solids plus open spaces. This number can be surprisingly large; some minerals and rock formations can have total porosities in excess of 50%. In the unsaturated, or vadose, zone there can be significant amounts of water present, but the voids are not completely filled (see appendix on saturated thickness).
However, some of the pore spaces may be too small or too poorly connected to permit the water they contain to flow out easily. The effective porosity can be thought of as the volume of pore space that will drain in a reasonable period of time under the influence of gravity. Effective porosity is always less than total porosity, sometimes (as in the case of clays) much less. "Good aquifers" tend to have values of effective porosity in the range of 10-30%, although examples of higher and lower values can be found. Figure 1 illustrates the relationship among the types of porosity and the volume of water in storage.
Answer:
Answer:
Explanation:
2 marker.
Most of the deserts appear to be near the Tropic of Capricorn and the Equator because the suns energy is concentrated the most there, i.e the best place for a desert.
Answer:
La opción correcta es C. Los lagos son ideales para la construcción de centrales hidroeléctricas.
Explanation:
Una central hidroeléctrica es una central eléctrica que utiliza agua corriente o que cae para poner una turbina en movimiento y generar electricidad a través de este. El uso de energía hidroeléctrica no produce contaminación ni residuos radiactivos peligrosos. Por eso se considera que las centrales hidroeléctricas generan energía verde.
En este contexto, los lagos son fundamentales para la construcción de las represas que almacenan el agua que se utiliza para hacer funcionar las centrales hidroeléctricas, ya que en el caso de los ríos, muchas veces ocurre que el ancho del caudal no es suficiente para poder realizar una construcción efectiva, con lo cual se construyen embalses artificiales que son un gasto extra de tiempo y dinero.
