Answer 1:
I'm not sure that wind erosion is a very
significant problem in the Ventura/Santa Barbara
area since this region is well sheltered from
prevailing winds in the area. We are protected
from south winds by the Channel Islands,from north
winds by the Santa Inez Mountains, and from
northwest coastal winds by Point Conception. We are only exposed to the west and to the east or
southeast, which is where the seasonal Santa Ana winds come from.
Additionally, for an arid (dry) climate, this area is fairly well vegetated with trees and brush that serve as a windbreak to absorb and diminish the strength of the winds, and to hold moisture and stabilize the soil against potential wind erosion. As a result, most of the Ventura/Santa Barbara area rarely experiences strong enough winds that would cause damage due to wind erosion.
However, in areas of Santa Barbara or Ventura where cover vegetation and windbreak-forming trees have been removed, the soil may be very exposed to any winds and suffer topsoil loss due to wind (or water) erosion. This may especially be a problem in areas where ranching and livestock grazing have damaged surface vegetation and denuded the surface; where farming has replaced perennial brush and trees that are present year round with low-lying annual crops that leave the soil bare during the non-growing season; or in locations where forest fires or clear cuts have exposed previously forested areas.
Topsoil loss is a serious problem for some agriculture because it removes the surface levels of the soil that contain the most nutrient-rich organic matter and sustain the microbial communities that plants require surviving and growing. Additionally, the soil that is blown into the atmosphere can create dust storms that contribute to air pollution,
harm human and animal health through respiratory
stress, and harm vegetation in a number of ways, including enhancing the transmission of diseases and susceptibility of plants to diseases.
Wind and water erosion together enhance the potential for watershed destruction, flooding,
sedimentation, landslides, and fugitive dust
storms resulting from the loss of native ground cover and grading on steep slopes.
As an aside, sometimes wind erosion in distant parts of the world cause dust and sand storms that carry particulate matter along with pathogens
(diseases) and other chemicals thousands of miles to distant, remote ecosystems where they may have a tremendous impact. For instance, sand storms from wind erosion in the Sahara Desert carry sand along with a pathogen across the Atlantic Ocean to the Caribbean Sea, which subsequently causes a
disease epidemic in sea fans (a type of soft coral) on coral reefs throughout the Caribbean.
Additionally, the Gobi Desert in north central
China and Mongolia produces large dust storms
from wind erosion. These dust storms occasionally
sweep eastward and transport iron-rich dust into
the North Pacific Ocean. Since iron is a
limiting nutrient for primary producers in the North Pacific, these iron deposits from wind erosion can cause large phytoplankton blooms. In both cases, the wind erosion problem is originating in very arid (dry) desert areas with little moisture or cover vegetation to stabilize and shield the soil.
Wind erosion is primarily a problem
for plant and animal life in the following types
of areas:
1) Wind-exposed areas.
2) Areas where windbreak vegetation has been removed, degraded, or replaced with lower-lying
vegetation.
3) Arid (dry) areas, especially
deserts where scarce water has been depleted or
diverted for other uses (e.g., agriculture, urban
consumption.
4) Arid areas where droughts have
dried up previously existing water sources
In arid regions, existing water
sources are important to alleviate the effects of
wind erosion because water helps to bind and
stabilize soil. Wind erosion is especially a
problem in the dry southwestern U.S. as increasing
numbers of people are diverting lakes, streams,
and rivers and depleting groundwater stores for
irrigation and other human uses.
Here is an excerpt from the website, click
here
"Populations are growing
rapidly in large parts of the semi-arid to arid regions of the southwestern United States. As a result, stresses are increasing on fragile desert
surfaces and on water supplies in an area where water is a precious commodity. Nearly all of the available surface water has already been claimed and diverted for human use, and ground water is now tapped for new water supplies. As surface and ground water diversion increases, arid-land surfaces that were previously wet or stabilized by vegetation are increasingly susceptible to deflation by wind. |