Did you think of this...?

HUMAN INFLUENCES on geology

The term "human influences" is the central theme for the second part of
GPRA goal Ib4. The term has purposefully been selected in order to
explore the full breath of human activities, both inside national parks
and external to the park boundaries. Adjacent land use, consumptive
activities, administrative practices, and visitor use can all influence
earth surface processes. An effective way to illustrate human influences
on earth surface processes is to go through some examples. This is not a
comprehensive treatment, and these examples do [not]{.underline} occur
in all parks. These examples are provided to raise awareness, stimulate
the reader's thinking, and perhaps cause the reader to contemplate
additional cases from his or her own experience.

[Land Use]{.underline}

-   Agriculture -- Intense use can cause loss of soil, erosion, and dust
    storms. Use of pesticides can affect both surface water and
    groundwater quality.

-   Grazing -- Overgrazing can cause loss of vegetation, invasion of
    exotic species, soil erosion, and nutrient loss.

-   Forestry -- Intense logging or clear cutting creates conditions for
    increased erosion; eroded and transported sediment can cause
    increased sediment loading in streams, which could affect fluvial
    habitat.

-   Water impoundment -- This has the potential to affect one segment of
    a stream or river or an entire watershed. Controlled volume of flow
    does not duplicate natural events, such as floods and drought. It
    can affect the sediment load, change the stream morphology, and
    alter the habitat that is dependent on a fluvial system.

-   Urbanization -- This can cause a host of impacts, but a few stand
    outs are: change in drainage patterns because of impervious surfaces
    (streets, parking lots, pavement, buildings), increased erosion,
    affects on surface and groundwater quality and quantity, release of
    toxins into the air, increased humidity in arid regions.

-   Alterations to shorelines -- Dredging, beach mining, river
    modification, installation of protective structures, and removal of
    back-shore vegetation can potentially alter shoreline processes,
    position, and morphology by changing the sediment supply, transport,
    and erosion.

# Consumptive Use

-   Groundwater withdrawal --This sustainable, renewable resource can
    become a non-renewable, mined one, if groundwater withdrawal exceeds
    recharge. Mining groundwater is terminal and affects and entire
    ecosystem (both living and non-living components). Where withdrawal
    has been intense for decades, the surface has been known to collapse
    (subside) over many acres to depths of over ten feet.

-   Oil and gas production -- This can cause surface subsidence and
    cause contamination of water aquifers and cave & karst systems. Oil
    and gas operations can leave a considerable "footprint" on the land,
    such as roads (created during seismic tests and well operation),
    pipelines, facilities, storage tanks, and well pads.

-   Mining (open pit and underground) -- It can reconfigure the
    landscape over large areas bringing significant and permanent change
    to the landscape. It can affect groundwater by releasing heavy
    metals or other chemicals into the system.

-   Mineral Materials Mining -- If performed in sensitive ecosystems or
    with respect to volume of material removed, the quarrying of stone,
    mining of gravel, and borrowing of soil can impact geologic process.

-   Extirpation of species -- This can affect both the living and
    non-living components of an ecosystem. Take the elimination of
    beaver from an ecosystem, for example. This can alter water
    impoundment, sediment load, timing of sediment release, and stream
    channel morphology.

## Administrative Use

-   Roads & bridges -- Often these have been constructed with little or
    no consideration for natural processes. Roads can disrupt drainage,
    cause erosion, and create hillslope instability. The abutments for
    bridges can change the flow and morphology of streams and rivers.

-   Parking lots -- Construction, location, and drainage off parking
    lots can cause harm. Large paved areas (acres) deprive the surface
    of an opportunity to absorb precipitation. Water flowing from the
    parking lots can cause erosion and gullying if not properly
    directed. Runoff pollution affects surface water and groundwater.

-   Facilities placed over karst and caves -- Contaminants and runoff
    from restrooms and other water usage can reach cave and karst
    systems below Earth's surface and cause damage to the fragile
    subterranean ecosystem.

-   Water consumption -- Parks located in arid environments need special
    consideration for all aspects of water usage (restrooms, watering
    lawns, domestic use for staff, maintenance shops, etc.)

-   Trails -- If they are poorly located with respect to soil,
    rockwalls, wetlands, and sensitive vegetation, they have the
    potential to exacerbate erosion, rock falls, and slope instability.
    The placement of snowmobile trails can influence slope stability and
    cause avalanches.

-   Armoring -- Through engineering efforts, humans have attempted to
    impose stability on naturally dynamic and ever-changing environments
    along streams, rivers, coastlines, and shorelines. Structures
    interfere with the transport of sand and sediment and aggravate
    erosion over the long-term.

-   Planting exotic species -- Planting non-native species on sand dunes
    to hold them in place disrupts eolian processes that drive an
    ecosystem.

-   Fire -- Fires directly affect slope stability and can cause debris
    flows on steep slopes.

## Visitor Use

-   Compaction of soils -- Over use by recreationists (hiking, horseback
    riding, mountain biking, OHV's) can compact soil, which diminishes
    its capability to function and maintain itself as a viable part of
    the ecosystem.

-   Social trails -- Depending on the fragile nature of the environment,
    wandering off-trail can seriously damage fragile resources (caves,
    wetlands, soil crusts, cinder cones, tundra, etc.)

-   Touching fragile features -- A number of geologic features have
    taken years to form through geologic processes, and although
    seemingly rock-hard, they may be fragile. Examples include
    stalactites and stalagmites in caves. Also included are erosional
    features, such as arches, bridges, hoodoos, and badlands. Crystals
    are another example. Visitors touching or climbing on all these
    features can cause irreparable damage.

-   Power boating -- Over a period of time, wakes from small and large
    boats alike can contribute to shoreline erosion. Fuel contamination
    can affect water quality.