The assessment of visual quality as a tool for the conservation of rural landscape diversity

ssessmentof visualqualityas a tool for the conservation ral landscapediversity V. Angileri’, A. Toccolini lst~utodi hgegneria Agraria, Via Celoria, 2, 20133 Milan, (Accepted 8 January

Italy

I993 )

e visual componentsofa landscape not only represent an aesthetic value but also testify to the interrelation ofcultural. economic and biological phenomena. In fact it is often possible to find a relation between the beauty of landscape and its richness in terms ofbio-ecoiogical factors. Though it is not always easy to apply techniques for the assessment of landscape visual quality. this quality can be reasonably considered as a resource which has to be preserved in order to protect rural landscape diversity. The paper describes ‘he drawing up and the application of a new and operative technique for the assessme.at of landscape quality of a rural area between the city of Milan and the Ticino river. This technique derives from previous British and American experiences, which have been adapted to the Italian context ( in terms of landscape character. survey techniques and available databases); it is based on the identification of landscape units by field survey and photo-interpretation of aerial photographs and on the preparation of a scale of landscape values (this is done by interviewing a sample of people who gave numerical assessment to photographs of typical landscape units of the area). Finally five classes of different landscape quality values were found and a landscape evaluation map for the area was drawn up. The five landscape classes differ in relief, vegetation, density of built-up areas, size of cultivated fields and presence of character elements such as hedgerows, small woods, canals, lines of poplars or willows.

Introduction

The visu4 component of a landscape does not merely have an aesthetic value, but often bears witness to deep-seated dynamics deriving from cultural, economic and biological phenomena. It is in fact often possible to find a correlation between the beauty of a landscape and its richness in Go-ecological terms (Nassauer, 1988 ). In the PO Valley, for example, the elements which visually characterise the landscape, amongst which are hedges, springs, rows of poplars and willows, are not only left-overs from the traditional rural landscape, but also provide important habitats which can contribute to the heterogeneity and therefore the ecological quality of the agricultural land. *Corresponding

author.

0 1993 Elsevier Science Publishers

Moreover, the degree of appreciation of a landscape, as it is expressed by the local inhabitants in particular, is often the sum result of a collection of values based on the time of perception: besides the formal beauty, which is the result of the composition of lines, colours and the structures in the landscape, other important criteria appear to be the productivity and naturalness of the landscape, these being connected with the ecological qualities of the land (in practice, the most beautiful landscapes are often perceived as biologically rich and vice versa). On the basis of these considerations and in order to encourage the study, conservation and reasoned development of the most significant landscapes still existing in the Milan metropolitan area, an original, practical technique was used to analyse the visual quality of the landscape in an area of West Milan. It was devel-

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out from a critical analysis of ies, especially those of English 1987 ). adapted so as to make it atible both with the characteristics of the al landscape, and with the tools and analysing the land and currently available data banks.

Bearing in mind the difficulty of dexloping a tool able to evaluate as objectively as possible an inherently subjective resource such as the visual quality of the iandscape (Fabos, 1978; Falini et al., i ?M; Zube et a;., ! 982 ), it was considered that the analysis technique to be developed should have t’ne following requisites: ( 1) a certain level of objectivitv (at least as far as the surveyors’ work was concerned ): ( 2 ) ease of application; (3) use of currently available tools for surveying and analysing the land (not only on-thespot measurement. but also use of aerial photointerpretation techniques ): (4) representation of final results compatible with those usua1?y ~~~3~~~ of other land resources; ( 5 ) limited costs. The technique proposed (schematically represented in Fig. 1) is based on the well-known technique of visual analysis used by Fines ( 1973 ) for the county of East Sussex f UK), to which important changes have been made to make it applicable to the type of the land in our study. The technique developed thus anticipates the determination of a scale of values relating to the visual quality of the various landscape units recognised in the study area, using the judgements given by a selected sample bf interviewees of a series of photographs shown to them. On the basis of this scale it is therefore possible to assign the various views of which the land is made u,- to various quality

---/ landscape units In the study area , ______ _____ - _

. ____.__--. ---- - --take pcctures of IandsLaoe types

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___ --_______ _________ lanJsc3oe .yocs bv atr-ohc!o;rach / _-_-_______ __--_____ ______~

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levels, producing. as a final result, a map of the visual quality of the landscape on a suitable scale. The study area to which the technique was applied is situated to the west of iian and covers approximately 8000 ha.

The first phase of the operative approach consists in identifying the visual units present in the study area, in other words, of finding areas which are homogeneous from the point of view of visual characteristics. In the case in question, our first move was to determine which factors most influenced the degree of visual appreciation. These factors, according to their nature, determine both the more strictly forma1 features of the landscape (the combination of lines, colours and structures) and the presence of elements which are important from the historical, cultural and/or ecological point of view (rows of trees, farmhouses, springs). The following factors were taken into consideration: geomorphology, the size of the fields, character elements (those elements

se the structure of a landscape uivalent of the nance elements’) and morphology of the study area may wo basic categories: land with hology (prevailing in the study ndulating geomorpholves towards the Ticino e fields cultivated determines e rural landscape which sely connected with the heteroe landscape. In the area under ue to the requirements of mechanisation, we are witnessing the establishment of a loose-fields pattern structure (increasing numbers of fields of over 2 ha), now definitely prevailing over a close-fields pattern residue, which is, however, still common in certain districts. Agricultural dynamics have moreover also pToduced a reduction in the number of character elements present in the traditional rural landscape (rows of willows, strings of poplars, hedges etc. ), which are being progressively eliminated as their productive function is lost. Their presence, besides bearing witness to the traditional rural landscape, which is important from a historical and cultural point of view, is of great value ecologically speaking, providing a refuge for bird life and a reserve for characteristic plant life. Moreover, these elements visually character& the landscape, making it more complex and varied. Finally, land use plays a significant part in the degree of visual appreciation of the landscape. For the purposes of this study, land use has been classified under three main headings (agricultural, natural and urban ) within which further dtstinctions have been made according to visual impact (crops, rice-paddies, fruit and vegetable nurseries, woods and poplar groves as far as agricultural use is concerned, heath and riverside for natural territories, industrial areas and urban fringe for urbanised land).

The analysis and the composition of the various categories considered provided the basis for identifying the serieb of visual units distinguished in the study area. These were subsequently mapped out according to the following definitions.

-

landscapes flat geomorphologically speaking, loose-fields pattern, devoid of character elements, typical of single-crop systems or those with a restricted number of crops (cereals and forage); the paddy-fields make a special contribution to this subgroup; - landscapes flat geomorphologically speaking, loose-fields pattern, with character elements (typically strings of poplars, irrigation canals and springs) pjpical of single-crop systems or those with a restricted number of crops (cereals and forage); the paddy-fields make a special contribution; - landscapes as above, but close-fields pattern, characteristic of more varied cropping systems, with more importance given to forage crops; - !andscapes flat geomorphologically speaking, characterised by the presence of woods and poplar groves, alternating with crops (including paddy-fields) or meadow:zici; these create a landscape which is more complex in form and more closely spaced; - landscapes with undulating geomorphology, typical of the Ticino valley, generally abounding in character elements, characterised by complex cropping systems and often focussing on poplar cultivation. Natural landscapes -

heath landscapes, characterised by typical spontaneous vegetation; - Ticino fluvial landscape, with wooded areas delimiting its boundaries. Urban landscapes -

urban fringe landscapes, characterised by a generally disordered collection of structures

with a variety at uses (residential, industrial, commercial ), containing a few, residual allotments, urban vegetable gardens, or vegetable :.mdflower nurseries; - production areas (industrial and commercial), characterised by plants and factories, stores and surrounding areas (car-parks, etc. ).

The second phase of the operative approach anticipates the determination of a scale of evaluation for the visual quality of the landscape based on interviews with a selected sample group, who was shown representative photographs of the various visual units found in the stud) I area. Interviews were carried out with 35 people, chosen using the criteria specified below, who were asked to award from 0 to 100 points to 24 colour photos of landscapes shown to them, according to how pleasing they found them. The photographs used were subdivided into two groups: a first group consistirig of 16 photographs showing views of landscapes typical of the area of Parco Sud Milan0 (Milan Southem park) and the Ticino Park. according to the classification of the visual units (macro-landscapes); a second group of eight photographs, aimed at focusing on more limited areas or features CCthe same visual units (micro-landscapes). All the photographs used were taken over a limited period of time (2 weeks), in the month of June (the period in which the parkland is most productive) in average weather conditions (sunny days). The points system was based on a scale of 100, which has the advantage of allowing precise judgements to be made without using decimals. Half of those interviewed were chosen for their experience in the agrarian field (lecturers and researchers in the faculty of agriculture, agr5nomists and others with related qualifications: the other half was chosen at random, although trying to include a variety of age ranges, types of education and residential areas - city

centre, outskirts and suburbs). The scale of landscape values was made up by analysing the points given to each photograph by the interviewees using statistical methods: arithmetical mean and root mean square. Moreover, results were also classifie by age, sex, education an level of experience in the field of The average number of points the photographs of mat 1 ), clearly shows that in detracts from the : ‘sual quality, whereas cr variation, combined with the presence o structural elements, produces a better vi impact: furthermore, rice as a single c proved to be visually appreciated. analysis of the interviewees by age an not prod?ucP c;opr;f;C.antaW l=Ps’PttC W**bal*labUU% Ua0. However, the results obtained by separate analysis of the answers of interviewees with a degree or diploma (excludLg those with agronomical experience) were more interesting, as were the results for those with agronomical experience (Table 2 ). In the first case, the scale of average points has a much wider

Ph0t0

.-lrithmctical

numbtx

mean

Root mean square

17.3 26.4 30.0

IS.0 21.7 20 ._’

4 5

47.6

s

52.2 53.3

12 9 14 13 11

60.9 61.8 bZ. 1 62.4 63.2 63.8

10 6 15 16

69.7 73.3 75. i 76.8

16.5 17.6 14.5 15.7

pertence ( M, arith-

With

RO

Table 3 reComparison between ran es of assessment of different spondent groups ( range of assessment equals arithmetical mean of the highest value photograph/arithmetical mean of the lowest value photograph )

agronomtc Respondent groups

*-

LL.

1

23.3 PO.2 22.0 21.3 24.0 21.6 23.8 19.2 i8.8 19.9 13.7 28.3 17.6 IT.4 13.2

Total With agronomic experie Ice With no agronoinic experience Graduated and post-graduated Secondary school diploma

Macro-landscapes

Micro-landscapes

4.3

1I.2

6.4

32.2

3.4

6.8

4.3

8.8

2.5

4.5

Table 4 Arithmetical mean of the root mean square for different respondent groups Respondent

range (5 othtr words, there is a much closer relations%p oetween the average number of points gken and the degree to which the landscape wa-jjudged to be ‘beautiful’ or ‘ugly’than was found in the scale of average points obtained from the answers of interviewees with levels of education below that of a diploma) a phenomenon which was still more accentuated in the case of interviewees with agronomical experience (Table 3 ). There was a correlation between this aspect and a greater ability to discriminate between landscapes, together with the greater homogeneity of judgement found amongst the so-called experts. This last finding was also supported by the analysis of the root mean square of all the photographs (Table 4) for the various subgroups (the average of the root mean square was lower for interviewees with agronomical experience). The above considerations therefore led us to adopt, as our scale of reference for landscape quality, the scale obtained on the basis of points awarded by the interviewees with agronomical experience (Table 5). It was deemed suffi-

Range of assessment

groups

Total With ag: 3nnmic experience With no agronomic experience

Arithmetical mean of root mean square 20.1 17.7 21.1

cient, and coherent with the type of analysis and with the use of aerial photographs in the following phase, to divide this scale into only five different quality levels for the visual units previously identified. Although this classification is the result of judgements given by experts, it has the advantage of not deviating too much from the scale of points obtained from the whole sample group interviewed. As already shown, interviewees with experience in the agronomical field did however prove to have finer judgement than the others, combined with a greater ability to abstract from the photographic context. The analysis of the points awarded to the micro-landscapes led to the same conclusions. Finally, it should be stressed that, despite its limitations, the photographic test carried out seems, on the whole, to be a valid tool for the

I IO

h9or

IiltldS~i~pCS

(<‘lass

E ). scow

O-30

--

urban frlngc

landscapes, characterrsed by a gencraIly disordered collection of structures with a varict: of uses (residential. industrial, commercial i containing a fei\ residual allotments, urban vcgctablc yrdcns. or vegetable and flower nurseries; indu-: I ml and conmcrcial arcas; uncultiv;~tcd lane! Neutral landscapes (Class D ). score 3 I- :$OI_ landscape flat gt‘omorphologically speaking, loose-t”L4dspattern. dcb*oidof character elements. typica! 11‘single-crop system< or those with a rcstrictcd nur:I)cr of crops (cereals and forage ); quarries Good landscapes (Class C ), score 6 I --t‘ - landscnpcs ilat gcomorpholog~cslly speaking. loose-f1~4dspattern. \k ith character clcmcnts (11p~call> strings \k: poplars, irrigation canals and springs) and pnxnce ofwoods and poplar groves; close-fields pattern IxAscapcs characteristic of more vxi~d zopply $ystcms, if ~.mpared with those in Class D Very good landscape (Class B ). score 7 1-W - landscape as in Class C. but with more contrast bcrx+actnhigh and flat dcmcnts due to a higher density of poplar gro\‘cs and woods; singe-crop systems landscapes among poplar gmvcs and woods Evccllcnt landscape (Ciass .A). score S I- 100 - t‘lu~ ial and heath landscapes; rural landscspcs uith undulating gcomorpholog~. t!,pical of the Tlcino 1,W!. gcncrall> abounding in character cicmcnts and \.\n‘lctimcs characterised by the presence of historibuildings

analysis of the visual quality of helping those concerned to take into account the preferences of possible users the land and allowing the establishment of a ale of visual quality for the landscape not based solely on the judgement of surveyors and planners, which is all too often subjective. In view of its nature, the test c precise. detai!ed information, but only useful indications for a general classification (which is, however, as objective as it can be) of the degree of visual appreciaijon c .*the landscape, to support the irreplaceable experience of the planner and/or landscape planner.

Once the scale of the visual quality of the landscapes in the Parco Su obtained, it was possible to trace, itself, the various types of landsc and map them out in a fina a scale of 125 000. For this tion to on-the-spot surveys o cerned, colour aerial phot from the Regione Lombardia, were us were on a sca\e of 1:X 000 and had been taken on a flight made in June 1980. Consideratidn of the size of the fields proved to be of great importance. This is, moreover. evident from the aerial photographs, as it can be seen that the presence of a close-knit land structure in the study area is associated with greater preservation of charactt;r elements (a situation which may well be expected considering the dynamics of the transformations which have occurred in the rural landscape). In the analysis, urban landscapes, in the true sense of the term, were net considered. These were therefore assigned to the lowest class of visual quality. To judge the validity of the assignment of the views to the various classes an on-the-spot test was carried out. The views were found to have been classified with a high degree of precision, seeing that a change in category was required for only 10% of the surface analysed. fn the light of the results obtained and of the corresponding map (Fig. 2 ), we may conclude that the rural landscape in the study area is of relatively high visual quality. A certain amount resistance to rapid transformations have chz?acterised metropolitan area Milan over last few has helped preserve the character of rural more than the north in other of south The rural characterised by activity companies mainly in the growing and spheres, is guished by presence of expanses of

Ill

IUI class

D

class

E

q Fig. 2. Visual quality assessment map for a part of the study area.

land under cereals (especially maize), which are increasingly taking precedence over forage crops and, in particular. over meadowland. Nevertheless, the presence of large numbers of canals of various dimensions, of springs, with the typical vegetation which surrounds them, of strings of poplars and rows of willows, helps to interrupt the monotony of the single-cr?p landscape, enriching it with the contrast these make against the profile of the flat land. Conclusions

The illustrated technique of visual analysis proves to be most interesting for application within land-use planning processes in order to obtain a less subjective consideration of the visual elements of the landscape. This technique moreover proves to be quick and easy to use and, consequently, low in cost (the calculated cost was approximately 95-130 ECU kmB2 for studies on level ground over areas

comprising over 10 km” and 225-320 ECU km-” for surveys on areas of limited dimensions or for particularly complex areas ) . The technique applied anticipates, as we have seen, the use of aerial photographs; this tool does, however, pose the problem of finding up-to-date sources. I;, this respect the prospect of using satellite images appears interesting (Crawford, 1991); these have the significant advantage of contimlity and, therefore, of always being up to date. Problems here are related to image definition and costs, which are very high when one must purchase images especially for the study. The application of the visual analysis technique illustrated may provide useful indications for subsequent land operations, amongst which are the setting up of a scale of comparisons to show the visual quality of different areas, the streamlining of studies or plans designed to make the best use of the land and the identification of areas which require preserva-

thn or r~~l~mati~n 0 crations on the land-

hesc interventions may also provide an mes or for re-inttoduci n must be aimed, on the one hand, at visual and ecological factors, the evaluation phase, in orefine an overall landscape evaluation

Fabos, .S,, 1978. The METLAND

Landscape cess: Composite Landscape Assessment. Al Formulation and Evaluation: Part 3 of the Landscape Planning Model, Research Buktin No. 653, Massachusetts Agriculture Experimental Statmn. Amherst MA, pp. 37-46.

Falini, P. and Ciardini. F.. 1985. La qua’lita’ visiva del pae= saggio: metodi e tecniche di valutazione.. Ambiente. Vol. 25. iTPA, Rome, pp. 23Fines, K.D., 1973. dscape Evaluation: a ional Studies. Vol. 2, Litton, R.B., 1974. The Visual Ma~a~erne~t System. I

hand at making this methodology compatible with the use of GIS (Geographical Information Systems), powerful tools which, if well designed, can really extend the possibilities of land surveys and operations. References Beer, A.R., 1987. Landscape Conservation: Design in the Rural Landscape. In: People. Land and Nature Series, Paper 2, Department of Landscape .4rchitecture. Unkcrsity of Sheft’ield. Z I pp. Crawford. D., 199 1%Assessing Visual Quality from Satellite Data. In: Landscape and Land ‘CJsePlanning ASL.4 Open Committee Letter. No. 18. University of Massachusetts. Amherst. pp, 38-43.

tional Forest Landscape Management. Vol. 2 .4gric.. ,4griculture Handbook 462. Washingto PP. Nassauer. .!.I., 1988. Landscape Care: Perceptions of Lc~all People in Landscape Ecology, and Sustainabk Develop mew. In: Landscape/Land LJse Pknning. Prweedings of the 19S8 .4nnual Meeting. 4merican Society of Landscape .4rchitccts. Seattle. pp. 27-4 1.

Steimtz, U., 1988. Toward a Sustainable Law where Visual Preference and Ecological

De t 3’

Congruent. and What to DC when They Are Not. In: Landscape/Land Use Plaaaning Proceedings of the I Annuai Meeting. .4merican Soviet) of Landscape Architects. Seattle. pp. 43-56. 2ubc. E.H.. Sell, J.L. and Taylor, G.. 1982. Landscape perception: Research Appkation and Theory. Landsc. Plann. .I