Keywords

1 Introduction

Since its adoption in 1972, the World Heritage Convention has faced continuous evolution. The first inscribed cultural properties had an iconic monumental character, were supposed to be conserved in a certain historic state, and were mainly managed without the participation of local communities. The decision of the UNESCO World Heritage Committee in 1992 to include cultural landscapes as a separate category of cultural sites representing the “combined works of nature and of man” designated in Article 1 of the Convention contributed significantly to altering this situation since it influenced several other strategic decisions of the World Heritage Committee. This resulted in a major paradigm shift with regard to the Convention’s implementation. In the beginning, cultural World Heritage properties were considered mainly as isolated “islands” regarding their conservation. Meanwhile, due to the Convention’s evolution and due to the introduction of cultural landscapes, many “living” World Heritage properties were inscribed on the World Heritage List that are supposed to be managed with the integration of local communities. However, such properties on a large scale mostly have a high degree of complexity and are vulnerable to pressure to change, thus requiring integrated management strategies. Using the World Heritage cultural landscape Upper Middle Rhine Valley as a case study, it will be argued in this paper that both the abovementioned paradigm shift and the increasing challenges to manage complex World Heritage properties cause the need for new proactive instruments to assess transformations. Such new instruments should combine innovative technical solutions with a systematic approach to using attributes and values conveying their Outstanding Universal Value and must be thoroughly embedded in local social, political and legislative frameworks.

2 World Heritage Landscapes and Pressure to Change

Acknowledging cultural landscapes as cultural heritage had a decisive influence on the evolution of the World Heritage Convention. This step enabled underrepresented State Parties to suggest cultural sites without a monumental character for inscription in the World Heritage List and can be seen as a precursor of both the Global Strategy adopted in 1994 by the World Heritage Committee and the so-called Gap Report published by ICOMOS in 2004 (ICOMOS, 2004). It was also an important step towards the Committee’s decision to approve the 2011 Recommendation on the Historic Urban Landscape as an “holistic and interdisciplinary” approach addressing the “inclusive management of heritage resources” (WHITRAP, 2016, 11), thus leading to an integrated approach to urban management, which should support the integration of urban conservation in broader urban development considerations (Bandarin & van Oers, 2015). Meanwhile, many cultural and urban landscapes on a large scale, conveying both tangible and intangible values, have been inscribed on the World Heritage List. Mostly, such properties are embedded in or related to “living” urban agglomerations, and a considerable number of them are transboundary or serial transnational properties.

In contradiction to properties with a monumental character, such complex landscapes require strategies for integrated management combining preservation and sustainable development (Rössler, 2012; Kloos, 2017). Besides, after the turn of the millennium, due to many discussions with regard to their visual, structural and functional integrity, it became obvious that such complex World Heritage cultural and urban landscapes easily can get affected by pressure to change. Common questions are related to management problems and pressure due to development, inter alia, caused by planned high-rise tower blocks, traffic and service infrastructure, as well as socio-economic transformations (Veillon, 2014; van Oers, 2010; Bandarin & van Oers, 2015). At the latest, after the Committee’s decision to withdraw the cultural landscape Dresden Elbe Valley from the World Heritage List due to the realisation of the so-called Waldschlößchen Bridge in 2009, it became obvious that the increasing size and complexity of cultural properties inscribed on the World Heritage List cause new challenges concerning their management (Ringbeck & Rössler, 2011). As a consequence, the World Heritage Committee successively adapted the regulations to manage World Heritage properties. The Operational Guidelines state, since 2005, that nomination proposals for the World Heritage List have to contain management plans explaining how the OUV and attributes conveying tangible and intangible values of potential World Heritage properties can be maintained, how this can be combined with their sustainable development and how such strategies will be organised and coordinated with the integration of relevant stakeholders, especially local communities. Besides, it was decided that properties inscribed earlier on the World Heritage List should also be provided with management plans as soon as possible.

In parallel, new monitoring mechanisms were adopted by the Committee. The so-called Periodic Reporting serves as a regular monitoring system for World Heritage properties; State Parties have to submit State of Conservation (SOC) Reports every 6 years. In parallel, Reactive Monitoring was introduced as a mechanism of: “reporting by the Secretariat, other sectors of UNESCO and the Advisory Bodies to the Committee on the state of conservation of specific World Heritage properties that are under threat.” (UNESCO World Heritage Centre, 2019, para 169) Meanwhile, the Operational Guidelines also state that: “to this end, the States Parties shall submit specific reports and impact studies each time exceptional circumstances occur, or work is undertaken which may have an impact on the Outstanding Universal Value (OUV) of the property or its state of conservation.” (UNESCO World Heritage Centre, 2019, para 169) Hence, the introduction of Reactive Monitoring is closely related to a third monitoring instrument, the aforementioned impact studies. As a reaction to a growing number of properties affected by pressure to change, an increasing number of Heritage Impact Assessments (HIAs) has been requested by the Committee in recent years. Due to the publication of the so-called ICOMOS Guidance on Heritage Impact Assessments for Cultural World Heritage Properties 2011, which is planned to be updated soon, HIAs meanwhile can be considered as a standardised instrument to identify and assess positive and negative impacts of planned or cumulative transformations with regard to the OUV and integrity of World Heritage properties (ICOMOS, 2011; Kloos, 2017).

Additionally, the Convention’s evolution during the last 50 years resulted in a second major change concerning its implementation. While the first iconic monuments were chosen as the “best of the best”(Cameron, 2008, 71–79) and entered on the World Heritage List as their “global significance was beyond question”(Ringbeck, 2021, 117–130) the inscription of the “new generation” of more complex World Heritage properties caused a need for a more systematic approach to justify their OUV. As such sites consist of a large range of different attributes conveying tangible and intangible values, a new systematic approach to identify the potential OUV during nomination processes was defined in 2005. Since then, so-called Statements of Outstanding Universal Value (SOUV) serve “as the central reference document for justifying inscription and assessing developments, risks and threats following recognition as a World Heritage property” (Ringbeck, 2021, 117–130) . As an essential tool for describing the attributes and values, SOUVs define “the thinking at the time of inscription on the basis of the criteria in force at the time” so as to provide “a clear, shared understanding of the reasons for inscription”. Besides, requirements for the management to sustain the Outstanding Universal Value for the long-term should be mentioned. (Ringbeck, 2021, 117–130). Formally, SOUVs consist of a Brief Synthesis, the Justification of Criteria, a Statement of Integrity and Authenticity (only cultural sites), as well as Requirements for Protection and Management (UNESCO World Heritage Centre, 2019, Annex 10). For earlier inscribed properties, so-called Retrospective Statements of Outstanding Universal Value (RSOUV) have to be compiled, which also must be adopted by the Committee.

In conclusion, the Convention’s evolution during the last 50 years resulted in four major consequences with regard to its implementation:

  1. (a)

    In general, the shift to larger and more complex World Heritage properties increased the risk of pressure to change.

  2. (b)

    World Heritage management became far more challenging than it used to be as management strategies have to address, inter alia, preservation and sustainable development of inhabited areas on a wider scale with a high degree of complexity, as well as a wide range of different stakeholders.

  3. (c)

    Such management strategies also have to respond to more refined monitoring mechanisms, including Periodic Reporting and Reactive Monitoring, as well as HIAs as additional assessment instruments.

  4. (d)

    Nominations, management and monitoring of World Heritage properties have to be handled in line with (R)SOUVs, and the attributes and values described thereby. Hence, the identification and listing of attributes and values became far more important than it used to be in the beginning of the Convention’s implementation.

In the following, the World Heritage property Upper Middle Rhine Valley will be used as an example to demonstrate that these consequences of the Convention’s evolution result in a need for more systematic instruments to monitor transformations and to assess their impact on the OUV and integrity of UNESCO World Heritage properties. Thereby, such instruments should address and activate a clear understanding of the OUV, as well as attributes and values of such complex World Heritage properties, so as to support UNESCO’s overall strategy to use cultural heritage as a pillar of sustainable development.

3 Pressure to Change and Present Monitoring Activities in the World Heritage Property Upper Middle Rhine Valley

The Upper Middle Rhine Valley was inscribed on the World Heritage List in 2002. The property, located in southwest Germany, was inscribed according to the Operational Guidelines as a so-called “organically evolved landscape”, sub-category “continuing landscape” (UNESCO World Heritage Centre, 2019, Annex 3). It stretches 67 kilometres from the two towns Bingen and Rüdesheim in the south to the city of Koblenz in the north. The cultural landscape of the Upper Middle Rhine Valley is characterised by both its spectacular scenery characterised by River Rhine, which formed a canyon in the Rhenish Slate Mountains, and by its rich cultural heritage. Moreover, its particular geomorphological setting consisting of about 60 towns and villages, as well as numberless castles and steep vineyards terraced by dry stone walls, characterise the valley. Besides its size and these various attributes, the political landscape of the area is also complex. The site is located in the two federal states Rhineland-Palatinate and Hesse, which, according to the legislation of the Federal Republic of Germany, have full and sovereign rights concerning cultural affairs. Hence, both federal states are jointly responsible for the upkeep of the OUV of the site. Additionally, the World Heritage cultural landscape consists of 59 municipalities. To coordinate and manage the property, the so-called Upper Middle Rhine Valley World Heritage Association (Zweckverband Oberes Mittelrheintal) was established. This administrative institution comprises representatives from all the local and “county” authorities in the World Heritage area and its buffer zone, as well as the federal states of Hesse and Rhineland-Palatinate.

The OUV of the property was justified as follows (UNESCO World Heritage Centre, 2021):

  • Criterion ii: As one of the most important transport routes in Europe, the Middle Rhine Valley has for two millennia facilitated the exchange of culture between the Mediterranean region and the north;

  • Criterion iv: As an outstanding organic cultural landscape, the present-day character of which is determined both by its geomorphological and geological setting and by the human interventions, such as settlements, transport infrastructure, and land use, that it has undergone over two thousand years;

  • Criterion v: As an outstanding example of an evolving traditional way of life and means of communication in a narrow river valley. The terracing of its steep slopes in particular has shaped the landscape in many ways for more than two millennia. However, this form of land use is under threat from the socio-economic pressures of the present day.

Justification criterion (v), where it is stated that the characteristic vineyards terraced by dry stone walls as the traditional way of land use are under threat, shows that the property faces pressure to change. Many of these steep vineyards were neglected in recent years and, therefore, have been transformed into a forested landscape (Ministerium für Wirtschaft, Klimaschutz, Energie und Landesplanung Rheinland-Pfalz, 2013). However, other socio-economic factors also affect the property. Currently, the valley serves as the main transport corridor for freight traffic between main ports located in Northern Italy and Northern Europe. Approximately 130,000 trains passed through the valley in the year 2019 (Ministerium für Wirtschaft, Klimaschutz, Energie und Landesplanung Rheinland-Pfalz, 2013), thus, leading to an enormous amount of noise and considerable air pollution. Younger inhabitants also frequently move to the higher parts or leave the valley, which leads to demographical imbalances of the population (Ministerium für Wirtschaft, Klimaschutz, Energie und Landesplanung Rheinland-Pfalz, 2013). Besides, numberless planned infrastructure projects document the current pressure to change in the valley. Issues during recent years included, inter alia, plans for new wind turbines, alternative railway tracks due to the need to replace existing tunnels (Goedkoop et al., 2014) and a new railroad crossing at the town of Rüdesheim (Kloos et.al., 2021). Additionally, to facilitate the crossing of the River Rhine, a new bridge between the towns of St Goar and St Goarshausen is currently conceived (Kloos et al., 2009), and a new ropeway was installed in Koblenz.

Most of the abovementioned projects were mentioned in the various SOC Reports submitted by the State Party of Germany. Due to the large number of such issues, the Committee has started a Reactive-Monitoring process and requested the State Party to submit SOC Reports every 2 years (instead of 6 years normally). Frequently, the planned projects led to lengthy and partly controversial discussions with the UNESCO World Committee and its Advisory Body, ICOMOS. Consequently, when the Committee requested that the State Party update the property’s management plan in 2018, the idea arose to conceive a more systematic approach to submit information about planned projects, which could possibly affect the OUV of the property. Up until now, the various planned projects were separately submitted to the Committee. Frequently, the Committee recommended compiling additional studies such as Heritage Impact Assessments to assess these projects. With the goal to accelerate this process and to avoid unnecessary communication, the new system should provide a more unified and proactive assessment methodology, which should allow the evaluation of planned projects prior to the information of the Committee concerning their compatibility with the OUV of the World Heritage property.

4 Cultural Landscape Compatibility Study (CLCS) as a New Proactive Approach to Monitor Change

Against this background, it was decided by the Upper Middle Rhine Valley World Heritage Association and the responsible ministries in Rhineland-Palatinate and Hesse to set up both the new management plan and this new systematic approach to assess planned projects in parallel. The general starting point of this new approach, called Cultural Landscape Compatibility Study (CLCS), is a simple idea. Visualisations of planned projects, generated on the basis of superimpositions of a 3D computer model and GPS-related digital photographs, should serve as a means to assess the potential impact of planned projects on the OUV and integrity of the World Heritage property. Such a methodology has already proven to be useful in numberless HIAs both in the Upper Middle Rhine Valley and other World Heritage properties, as it can show and evaluate planned transformations transparently from an independent point of view (Kloos, 2015, 2017).

However, generating such visualisations can be complex because they are based on 3D models of the planned projects, which have to be shown in their environmental surroundings. Normally, such models have to be built up from scratch by combining and elaborating LiDAR laser measurements (so-called point clouds) with high-resolution aerial photographs, which is a time-consuming process. An additional requirement is that according to the ICOMOS Guidance 2011, the OUV of World Heritage properties and the attributes and values conveying this OUV should serve as a starting point for the assessments (ICOMOS, 2011). However, as SOUVs mostly provide only relatively general criteria, which cannot be used directly for assessments, consultants frequently have to set up separate analytic studies during the assessment process to identify relevant attributes and values. Additionally, HIAs, other than Strategic Impact Assessments (SEAs) and Environmental Impact Assessments (EIAs), are anchored neither in German nor in EU legislation at present. Frequently, this leads to long political decision processes about which institutions are responsible for conducting and financing HIAs. Due to these time-consuming factors, HIAs are often only commissioned in a late stage of planning processes or even when projects have already been realised, and they are seldomly compiled as a proactive and process-related instrument to generate a basis for bottom-up, cultural heritage-led planning processes (Kloos, 2017).

To avoid these problems, the systematic approach of the new instrument CLCS is based on the following three interrelated elements so as to accelerate assessment processes of planned projects in the Upper Middle Rhine Valley:

  1. 1.

    First, a 3D model of the entire World Heritage property should serve as the basis of the assessment of planned projects in order to save time concerning the generation of visualisations. This integrated 3D computer model of the entire Upper Middle Rhine Valley was generated from LiDAR laser measurement datasets, high-resolution aerial photographs (DOP 20) and City Geography Markup Language datasets (City GML);

  2. 2.

    Second, a clear and thorough understanding of OUV should be provided by a systematic and unified identification of the property’s various attributes and values;

  3. 3.

    Third, an independent Monitoring Advisory Body (MAB) consisting of several experts was established to evaluate planned projects. The MAB should also provide recommendations for which of the planned projects would probably be compatible with the World Heritage status and which ones would need a more in-depth investigation. The second task of this advisory body was to support the development of the CLCS (Fig. 26.1).

Fig. 26.1
A 3-D animated graphic of a city model.

Generation of the Integrated 3D Computer Model for CLCS. (Note. 3D models for CLCS from V-Cube, by A. Walther, [3D models], 2020)

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5 Experiences During the CLCS Development Process

During the elaboration of the CLCS, several presentations for various stakeholders revealed that many parties were interested in the 3D computer model for different reasons. Planning authorities and local municipalities wanted to use the model as a basis for planning processes, e.g. the planned garden exhibition BUGA 29 and architectural competitions. Additionally, questions appeared whether the 3D computer model could also be used to assess smaller projects conceived by private parties concerning their compatibility with the OUV of the property. As the model contained a large amount of data due to the size of the World Heritage property, it was decided to design it as user-friendly as possible in order to respond to these various requests. It is planned now to rent out separate parts of the 3D model to third parties, e.g. architectural offices, as a basis for their planning activities. After the finalisation of such planning processes, these supplemented parts can be re-integrated into the 3D model (Fig. 26.2).

Fig. 26.2
A 3-D animated graphic of a city model on the left and a photograph of a facade on the right.

Separated parts of the integrated 3D computer model. (Note. 3D computer models from Michael Kloos Planning and Heritage Consultancy and V-Cube, by P. Tebart and A. Walther [3D Models], 2020)

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In parallel to the generation of the 3D computer model, a participation process was started to provide a clear and thorough understanding of the OUV of the World Heritage property and the attributes and values conveying this OUV. In so doing, the elaboration process of the management plan was used as a unique opportunity to organise several workshops with various relevant stakeholders. A crucial idea of these workshops was to build up a broad basis for the understanding of the OUV, attributes and values, especially on the level of representatives of the various administrative institutions in the property.

Nevertheless, during the elaboration process of the CLCS, it turned out to be complicated to identify these relevant attributes. Particularly in the beginning of the process, it appeared to be an obstacle that “except for authenticity, attributes have so far only been defined outside the Operational Guidelines in the questionnaire for the third cycle of periodic reporting” (Ringbeck, 2021). In this phase, the suggestion of the Monitoring Advisory Body to carry out an in-depth landscape study covering the entire Upper Middle Rhine Valley turned out to be helpful. A second helpful element during the process was the requirement of ICOMOS within the 3rd cycle of Periodic Reporting to restrict the number of attributes. Generally, no more than 15 attributes should be mapped (Ringbeck, 2021). This restricted approach led to a compact table where both key attributes and attributes can be shown in one compressed overview. Additionally, to support clear and transparent information for all stakeholders, it was decided to also show these attributes on a set of maps (Fig. 26.3).

Fig. 26.3
A map of Upper Middle Rhine Valley with representation for various places in a legend on the top right.

Extracted map with identified attributes conveying the OUV of the World Heritage property Upper Middle Rhine Valley. (Note. Map of Upper Middle Rhine Valley from Michael Kloos Planning and Heritage Consultancy and v-cube, by P. Tebart and A. Walther [Map], 2021)

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These new tools of the CLCS approach – the 3D computer model and the unified system to map attributes – were later tested concerning their efficiency with regard to planned projects in the Upper Middle Rhine Valley. During these first test assessments, plans of various projects were inserted in the 3D computer model in order to visualise their potential impact on the OUV of the World Heritage property. In the second step, relevant attributes in the investigation areas were derived from the unified attribute table and displayed on panoramic photographs. This combined approach of visualisations and visual analysis of key attributes turned out to be very useful. As it could clearly be assessed and graded how attributes would be affected, it could also be stated which of the planned alternative projects would be compatible with the OUV and which ones not. Consequently, incompatible versions can now already be ruled out prior to the information of from the World Heritage Committee (Fig. 26.4).

Fig. 26.4
A photograph of a river valley indicates five inner investigation areas.

Visual analysis of attributes of an inner investigation area in the World Heritage property Upper Middle Rhine Valley. (Note. Colored digital photograph of an inner investigation area from Michael Kloos Planning and Heritage Consultancy, by M. Kloos and P. Tebart [Digital Photograph], 2021)

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6 Conclusion: Recommendations for Future Research Activities

The case study in the Upper Middle Rhine Valley reveals that it is possible to provide efficient tools to monitor and assess transformations caused by planned projects in complex World Heritage properties. At present, further test assessments are being carried out to elaborate the CLCS approach as a new systematic and proactive evaluating instrument. However, the development process of CLCS in the Upper Middle Rhine Valley also shows that various questions remain to be solved, both on a theoretical and practical level.

It is a crucial theoretical issue that both OUV and attributes play a very important role concerning both the assessment of changes in World Heritage properties and the identification of the OUV during nomination and management processes (Ringbeck, 2021). However, up until now, the Operational Guidelines only define how to identify attributes with regard to the authenticity of World Heritage properties. In this context, it turned out to be helpful to follow the abovementioned statement of ICOMOS within the 3rd cycle of Periodic Reporting that recommended using a limited number of approximately 5 key attributes and 10 attributes. However, further research should be carried out to determine whether this approach could serve as a general starting point to establish a unified system to identify attributes and values in World Heritage properties and their surroundings.

A second more practical issue concerning the implementation of CLCS is related to juridical and political levels. Up until now, it is unclear how initiatives of private building owners and project developers in the Upper Middle Rhine Valley will be affected. Consequently, it must be clarified how planned projects of private parties can be assessed with this new tool and who has to cover the costs for that. These questions are particularly relevant if such preliminary assessments reveal that an in-depth assessment will be necessary since HIAs are also not yet embedded into German legislation. Even though it turned out to be possible to develop a new systematic approach to evaluate transformations on a technical level, it is obvious that future research activities also have to cover such practical juridical and political questions.

Fifty years ago, the theoretical idea of sustainability of the World Heritage Convention was to safeguard the most iconic sites of Outstanding Universal Value for future generations. Today, it appears that UNESCO’s approach to considering cultural and urban landscapes as important elements to provide identity for local communities is highly dependent on efficient systematic tools that can combine the preservation of their OUV with their sustainable development on a practical level. Systematic technical approaches and instruments such as CLCS can be helpful to support the sustainable preservation of complex World Heritage properties. However, such instruments also require an in-depth theoretical knowledge of sites’ OUVs and attributes and values related thereby, as well as a sound integration in existing legislative frameworks. It should also be noted that such strategic instruments can only be helpful if they are developed with the participation of stakeholders on various levels because this is an indispensable step for their broad acceptance on local and regional levels. In other words, innovative technical instruments such as CLCS can be considered valuable to support strategies combining preservation and sustainable development, but they should not be considered as stand-alone instruments. To guarantee their full effectiveness, they should be embedded in a multidimensional management strategy.