Introduction

As many planning problems focus on processes that evolve over time in a complex environment, it is often difficult to evaluate the long term implications of a planning decision. Computer simulations have long been used as a method for evaluating proposed future scenarios in planning (Timmermans, 2003). However, most simulation efforts in spatial planning have focused on large spatial scales (such as at the city and regional levels) and on relatively abstract concepts (such as land use patterns, traffic and economic development), while one can argue that the planning decisions that have the most impact on individual citizens tend to be either at a relatively small scale or have very local impacts.

At these small scales (such as the sub-watershed or village), visual elements and the overall visual quality of the proposed planning intervention are extremely important. This is particularly true with areas dependent on tourism, which are often promoted based on their scenic qualities. Aesthetics are hard to quantify and therefore hard to integrate into a computer model. Because of the persisting perception that visual quality is too subjective a concept, it has largely been ignored in planning models and simulation. This is, in our opinion, a large oversight, as there is a whole class of planning problems where aesthetics are important, yet visual quality questions are largely left to designers at the individual project scale, with little consideration for how individual aesthetic choices combine to impact the larger landscape.

Our project integrates these aesthetic qualities with other factors such as availability of recreational opportunities, congestion and service levels using an agent based approach. We focus on their impacts on tourism, in particular summer hikers. Others (Gimblett, 2002) have used agent-based approaches to model tourists, but their focus has been primarily been on congestion issues. While congestion is a problem for the busiest and most famous tourism areas, it our contention that the encroachment of development and changes to the management of the landscape have the potential for far greater impacts on the attractiveness of a given area for tourists.

The specific test site is a valley in the Gstaad-Saanenland region of south-western Switzerland. The communities of Schönried and Saanenmöser are at the two ends of the site; their economies are highly tourism dependent. While the primary tourism draw to the area used to be winter skiing, long term climate change is forcing the community to focus its efforts on building up a more diversified tourism economy. This includes capitalizing on its already strong reputation for summer hiking. The landscape is a mixture of pasture and coniferous forests, dominated by Norway Spruce (Picea abies). The test site is characterized by significant topography and is considered ideal for walking and hiking (see figure 1). The trails are very accessible to a wide range of hiking abilities due to the summer operation of one chair-lift and two gondolas. In the high season, the area is busy with hikers and walkers who easily fill the two main parking lots in Schönried.

Figure 1: The landscape is a mixture of pasture and coniferous forests, dominated by Norway Spruce (Picea abies). The test site is characterized by significant topography and is considered ideal for walking and hiking.

A recent study in the area (Müller and Landes, 2001) identified that the biggest attraction for summer tourists are the area's scenic qualities. Hiking and walking is the primary recreational activity in the summer months. The focus on views was confirmed by our own study in 2002 (Cavens and Lange, 2003), which confirmed that views and landscape variety are the most important factors that influence hikers in their choice of hiking routes.

In addition to the community's desire to diversify its recreational economy, there are landscape policy issues that have the potential to change the desirability of the area for summer tourism. These issues include changes to the pattern of the landscape due to changing agricultural policy, shifts in forestry practices, closing of the gondolas and/or chairlifts, and increased holiday home construction. Any of these changes would have complex repercussions for the tourism industry: future scenarios to test the agent model will be selected from them.