Visual Controls in Landscape Planning

Seventh Section in Litton's Article: Descriptive Approaches to Landscape Analysis

 

Visual Controls in Landscape Planning, Design, Goals, and Policies:

Litton explains that “In a longer term view of the landscape and sustaining its varied qualities, landscape inventories and assessments of region and locality are tools to affect visual controls in landscape planning and design” (pg. 84).  He also suggests that monitoring and revisions to plans are necessary, and that landscape analyses should be maintained to keep track of the dynamics of the change, including outside influences such as fire, natural disasters, and insect infestation.  The author discusses the need for landscape planning that protects all scenic resources, not just the spectacular.  Litton acknowledges that it is important to maintain an interdependent relationship between visual controls and landscape planning and design, as one is just as important as the other.

The author expresses general goals in protecting visual qualities in a regional landscape.  He emphasizes that “To address the visual integrity…means to account for the landscape management intentions within a set of identified” areas or units (pg. 84).  Litton suggests the following terms to express the degree of changes between natural between man-made domination.

• Preservation
• Protection/Retention/Maintenance
• Alteration/Modification
• Rehabilitation/Restoration
• Degradation/Deterioration/Destruction

These terms use landscape examples or displays as a graphic explanation.  The National Forest Service has adopted these terms as “visual quality objectives”.

Design policies are founded on design solutions that appear appropriate for each specific site within unit scale.  Litton explains that further study needs to be conducted on the visual interrelationships between individual projects or changes and the surrounding landscape. He argues that visual relationships need critical analysis if there are to be improvements in visual management.

Visual Controls in Landscape Planning, Design, Goals, and Policies applied to Vistas:

The long term goals of vista management are to create places for people to observe, interpret, and enjoy iconic natural landscapes.  These areas must also be maintained in a way that is beneficial to the Park, its visitors, and the surrounding flora and fauna.  Even though these areas are considered by Litton to be alterations or modifications of the landscape, they will encourage native plants to reclaim and dominate these clearings.  Within a relatively short time, these vista clearings should be nearly self-sustaining, requiring minimal vegetation removal every seven years.  

Typical Park vista management planning only focuses on removing vegetation, and does not address additional ways to manage the clearing in the future.  By adding the use of herbicide and encouraging low growing shrubs to maintain the clearing, future re-clearing work will be minimal and require a small crew.  My vista management recommendations offer a solution that financially beneficial for the Park, provides visitors with long term vista opportunities, and allows new ecosystems mimicking naturally occurring clearings of desirable native plants to flourish.

Visual Impact Prediction

Sixth Section in Litton's Article: Descriptive Approaches to Landscape Analysis
 

Visual Impact Prediction:

According to Litton, there are four criteria used in determining aesthetic values, visual values, and relationships in a landscape. 

•  vividness (memorability),
• intactness (relative apparent naturalness),
• encroachment (presence of degradation), and 
• uniqueness (relative scarcity)

A report of these criteria also serves as an indicator of the landscape’s environmental aesthetics which can be clearly and tangibly established through visual landscape analysis.  The author explains that visual impact predictions address the landscape’s visual vulnerability or sensitivity to change.  Visual simulations identify special landscape compositions, expose surrounding influences, conditions, and reveal the unit’s context and location in a larger environment  and possible impacts to the adjacent landscapes, both positive and negative (“red flags”).  These impact predictions can also be valuable tools for landscape architects to use to show the proposed changes to the public and become review material for resource management.  Litton argues that since these representations are developed by professionals that the results should be reasonably accurate.  He goes on to explain that several alternatives must be prepared to display a difference in changes and impacts.

A visual absorption capability study by Jacobs and Way (1969) describes an alternative way of considering relative visual impacts.  Similar to visual vulnerability, visual absorption is the “potential for developmental changes to be absorbed or screened by vegetation or topography” (pg. 84).

Visual Impact Prediction applied to Vista Management:

Numerous vistas within Great Smoky Mountains National Park exhibit all of the aesthetic value criteria listed by Litton.  Many of the most memorable, unique views can be seen from Newfound Gap Road.  Visual impact predictions were developed for Campbell Overlook and Newfound Gap Parking Area, because they demonstration two considerably different management methods, topography, and vegetation.  Even though both vistas have not been formally managed in decades, Campbell Overlook is significantly more obstructed by encroaching vegetation. 

   

Visual simulations revealed the pros and cons of three clearing alternatives for Campbell Overlook.  Positive impacts include removing encroaching vegetation to reveal the opposing peaks and valley, view of the river, increased sunlight for lower growing flowering shrubs, and an increased food supply for animals by encouraging fruiting plants.  Negative impacts include the disturbance of a natural ecosystem and temporary unpleasant appearance of the clearing until a new ecosystem could be established.  Potential impacts could be erosion, accidental release of chemicals into waterways (herbicide, gas, geological disturbance), and more invasive plants with the increase of sunlight.

Newfound Gap Parking Area requires significantly less clearing, and visual simulations only revealed one practical alternative.  By selectively removing trees that are obstructing the view and treating the stump with herbicide, the view should be preserved for years to come.  Minimal work will be needed cyclically to maintain this clearing.  Positive impacts include a panoramic view of mountain ranges to the horizon.  Negative impacts include loss of possible flying squirrel habitat, although the amount of possible habitat to be removed is so small, this impact is negligible.  Since the clearing will be done at the top of Newfound Gap and herbicide will be used in such small amounts, it doubtful chemicals will enter the waterways.

Landscape Inventories for Research and Monitoring

Fifth Section of Litton's Article: Descriptive Approaches to Landscape Analysis

Landscape Inventories for Research and Monitoring:

Litton explains that if professionally prepared landscape inventories and their supporting elements are prepared using the proper criteria, it also considered an expert’s document.  Such criteria include Litton’s concepts of using landform features or spatial enclosures as inventory elements.  An evaluation of these concepts (Chaik 1972, Zube et. al. 1974) noted 

 

…a high level of agreement between the visual perception of lay persons and that of the professional.  In another example of psychological research directed toward landscape displays, visual relationships of elements found …in the environment…are subjects of perceptual response and evaluation (pg. 82).

Since the criteria used is also utilized by practicing professionals who are trained in aesthetic evaluation and have an understanding of visual values and opinions identified by the public, it can be assumed that the inventory’s results would be agreeable with the needs of the majority of people. 

In a study on the Connecticut River Valley, Litton developed landscape prescriptions to manipulate visual relationships between silvicultural techniques and roadside forest land.  Inventories of existing vegetation were conducted and sample plots of visual landscape “before” and “after” prescriptions were developed.  The author describes how landscape inventory with visual samples serve as devices for “monitoring the appearance of natural and man-made changes over time” (pg. 83).  He goes on to add that even though some changes may appear to be insignificant, they may accumulate over time and become seriously degrading.  Litton also argues that “no judgment about shifting changes in scenic quality is possible without the visual base line of how the landscape looked at a specific time in the past” (pg. 83).

Landscape Inventories for Research and Monitoring applied to Vista Management:

Guided by Litton’s approach and using his terminology, I was able to properly evaluate and inventory landscape elements.  I was able to inventory existing vegetation and develop visual simulations that would depict the results of selected treatments such as “windowing”, “layering”, and “clearing”.   Then I would create a visual simulation of what changes might occur over the next several years.  If a majority of changes were beneficial, and there were no significant negative impacts, then the treatment would become a practical alternative to the exciting condition.  From these results, a preferred alternative was agreed upon by the Park team, and then further developed into a detailed landscape prescriptions or recommendations for vista management.

 Litton’s suggestion of using past landscape conditions as a visual base line was also incorporated, because it is important to understand the original intent of the vista.  However, many vistas were previously managed as panoramic views without regard for plant communities who might inhabit the clearing as a part of natural succession.  Successful vista management must protect the integrity of the view and while still encouraging desired native plants to dominate the vista clearing.  The clearings would continue to be monitored to ensure that no further changes needed to be made to the management plan and that any unforeseen impacts would be resolved.  According to research of other national park vista management plans, vista management should be cyclic to prevent large re-clearings from being necessary.  By monitoring these clearings over a period of seven years (it is assumed it will take seven years for tree species to grow tall enough impact the view), I will be able to track the rate of regrowth of both desired and undesired plants within the clearing and alter or confirm the suggested cyclic vista management frequency.

Landscape Evaluations

Fourth Section in Litton's Article: Descriptive Approaches to Landscape Analysis

Landscape Evaluations:

Litton suggests that there are two kinds of evaluations in visual inventorying: professional judgment and the perceptions of the public.  In the first evaluation, the criteria used for professional judgments by landscape architects and environmental planners are essentially derived from design.  Written guidelines include the Visual Management System (USFS 1974) and the Visual Resource Management guides (USBLM 1976).  Both documents outline the fundamental ideas of “line, form, color, and texture as criteria; but they are exemplified but occurrences and relationships found in nature” (pg. 81).  Litton’s preference has been the aesthetic criteria of vividness, unity, form, space, color, and variety (1972), but he has tied these abstract terms to landscapes that express these values in tangible ways.  

•  Line – edge, silhouette, or contour
• Form – space and shape
• Color – hue, chroma, brilliance, and value
• Texture – part of surface variance and patterns

These visual assessment associate aesthetic criteria terms with basic physical elements of visual landscape (vegetation, landforms, water, and land use patterns) to create assessments of the landscape that clear to the observer.  The author also describes how “the sequential movement of an observer through the landscape, both in time and space, may profoundly alter a person’s sense of scenic values” (81).  

Visual inventory units are intended to reveal the characteristics of a landscape within its regional context.  Not only are these units part of an inventory, but they are essential in creating “comparative qualitative assessments among units” (pg. 81).  By viewing the landscape in “more tangible” units and sub-units instead of as a whole, it allows the observer and the professional to create a more detailed description and assessment of the landscape.  Litton explains that overall, the landscape evaluation is a sum of all the tangible units that emerge in a whole area.  He adds even though professional evaluations are primarily qualitative judgments; they still have quantitative procedures that must be applied.

• Qualitative judgments – “express the results of using criteria which are not themselves readily reduced to simple or precise numerical values” (pg. 81).

•  Quantitative procedures – applied to different visual units, these procedures can “systematically measure such things as relative relief, mosaic unit areas of various vegetation types, or numbers and coverage of water bodies” (pg. 81). 

The results from these measurements and assessments are useful in creating systematic comparisons between differing components in different units, however the ranking of their visual value still demands qualitative judgment.

Litton explains that “community participation in identification of perceived values of the landscape requires psychological or sociological analysis” (pg. 82).  However, he acknowledges that “Because of conflicting political views and administrative/legal restrictions, it is virtually impossible for public agencies to conduct social response studies on public land” (pg. 82).  Consequently, most public agencies use academic research as insight.  The author explains how workshops conducted by the National Park Service in 1978 revealed that preferences are generalized judgments that include “a complex of variables in which visual elements are elusive” (pg. 82).  Litton notes that more work is needed to develop workshops that better correlate physical-visual landscape criteria utilized by professionals with perceptual values identified by the public.  

Even with local values described in research and participatory evaluations, current opinions about landscape values should not restrict or solely dictate future landscape choices.  The author argues that “after evaluations are made, whatever their origin, the question remains about what decisions are most appropriate for landscape units of different value.  Where high quality is identified –as it is apt to be a rare thing – it is clear enough that special planning and design efforts  are called for…Otherwise the landscape falls apart, losing overall aesthetic quality” (pg. 82).  Litton believes that even though appropriate management should be given to regionally typical landscapes, special attention must be given to protect the landscapes that exhibit the highest level of regional scenic beauty and characteristics.

Landscape Evaluations applied to Vistas:

Vistas, like many landscapes, are affected by time and space.  Examples of this are viewing the landscape as you transcend from one forest type to the next; associating color and texture changes to the seasonal aspects of the landscape; and revealing how sunlight effects the observer’s impressions of the landscape as it shifts between sunrise to sunset.  Many of the Park’s vistas display extraordinary examples of the scenic quality that can be found in this region. 

Vistas are fundamentally “units”, revealing the relationships between both atypical and typical elements for the enjoyment of the observer.  Like most landscape evaluations, vista evaluations systematically rate the scenic quality of each view.  The evaluations used the criteria mentioned above to determine the elements’ visual values and relationships within each vista.  Even though public agencies rely heavily on professional landscape criteria, Park staff was still very receptive to visitor comments regarding improvements they wanted to see along vistas.  Numerous requests have been made to restore the view to the way it was intended to be.  Visitors who remember the vistas as they were decades ago would like their family to be able to see the same magnificent landscape they once saw.  However, landscapes conditions that were desirable in the past are not always compatible with present or future Park landscapes.  With these ideas in mind, Park staff assembled a team to determine a vista management plan.

After conducting a visual inventory and evaluation, the team surmised that there are 34 vistas that should be initially reopened to restore the most important iconic views.  This rating system incorporated qualitative judgments from the evaluation and allowed the Park to prioritize vista management by assigning a view rating of “A” (most significant), “B” (significant), or “C” (least significant) for each vista.  Vistas with the “A” rating exhibited a strong aesthetic relationship between natural elements, characteristically offering views of one or more significant elements.  Vistas with a “B” rating traditionally offered views of a range of typical elements with the occasional atypical element.  Vista with a “C” rating display typical elements that represent common ecosystems in the Park.  “A” and “B” rated vistas are meant to be viewed from a set point, while “C” rated vistas that are intended to be viewed while driving.  Adequate planning is necessary to preserve the visual integrity and protection of these iconic landscapes for enjoyment present and future generations.

Descriptive Visual Inventories

Third Section in Litton's Article: Descriptive Approaches to Landscape Analysis

 

Descriptive Visual Inventories:

Sigurd F. Olson, a 20^th century ecologist and wilderness advocate, describes how “aesthetics of the landscape is a complex fabric of sight, sound, knowledge, time, and ethics” (pg. 79).  Litton explains that “landscape inventories, based on description, are rational documentations of observed landscape.  They are foundation for succeeding assessment and analytical interpretation” (pg. 80).  If these inventories are professionally developed, they can clearly identify baseline information and serve as objective representations that reveal the landscape’s condition at given point in time.  The objective representations “identify typical landform, vegetation, water, and land use elements that are characteristic for an area” (pg. 80).  Usually typical landforms are important, but several landscapes also have atypical elements, such as extraordinary examples fast moving water, or old groves of mature trees.  By visual inventorying both typical and atypical landforms, landscape architects can identify patterns and relationships between these four elements, and creates a straight forward way of describing the landscape in simple terms.  In addition to describing what the landscape looks like, it is also important to use a map to coordinate the locations inventoried.  Litton suggests that

Another way for the professional to maintain objectivity  is to consider that the integrity of the typical or ordinary landscape combined with the atypical or extraordinary landscape it is necessary  to maintain overall scenic quality (pg. 80).

This means that landscape architects must make protect the integrity of all scenic areas, not just those who exhibit the most magnificent atypical landforms.

Descriptive inventories fall into two categories: routed and areal. 

• Routed inventories use roads, trails, or other locators to orient the traveling observer, “limiting attention to the landscape within the visual corridor” (pg. 80).  Litton describes the visual corridor as a “bounded area visible to the observer”.

• Areal inventories vary in scale or extent and typically contain varied details that address broad planning issues or purposes.

Both types of inventories are useful because they divide landscape variations into visual units.  “Definitions of depend upon spatial characteristics of land forms and vegetation or upon presence of a visually consistent (or homogeneous) set of elements” (pg. 80).  The units represent topographical enclosures ‘Each with its own distinct visual character and degree of unity’ (Tetlow and Sheppard 1977)” (pg. 81). 

Descriptive Visual Inventories applied to Vistas:

National parks and other protected natural areas are usually a complex balance between typical and atypical landforms. A routed inventory was completed and each vista was located on a map of the Park and Newfound Gap Road.  The areal inventory revealed similar topography and vegetation between vistas of low elevation and those in higher elevations.  Even though several vistas revealed mountain peaks, mature forests, waterfalls, or valleys; each vista reveals these elements differently, allowing the observer to see the landscape in a unique way.