1 Introduction

Topographic cartography, which is usually carried out by state authorities, is known to have the task of representing material objects of relevance that are permanently found on the earth's surface in plan view, as true to scale as possible, with recourse to a largely standardized signature language, also internationally (see, for example: Dickmann 2018; Field 2018; Grünreich 2006). This entails a threefold challenge. The first arises from the objects to be represented, here in the divergent combination of relevance and permanence. The second two have been discussed at length in the past by Critical Cartography, which has been developing since the 1980s: Second, then, the question of expert interpretive sovereignty of government agencies regarding the topographic-cartographic record of the earth's surface. Thirdly, the question of relevance, which is an expression of the social construction of the world, which in turn is not sufficiently reflected in view of the positivist paradigm of cartography. The last two points are—according to the protagonists of Critical Cartography—characterized by at least an implicit exercise of power, from which the consequence is drawn that cartography should be participatory or artistic as far as possible (see among many: Crampton und Krygier 2005; Glasze 2014; Harley 1989; Kim 2015; Wood und Fels 1986).

With our contribution, we take the concerns of Critical Cartography seriously but do not follow its rigorous conclusions. Accordingly, we follow the approach of post-critical cartography, which, following a neopragmatic logic, does not refer to fundamental moral questions of cartography, but links cartography-making to questions of usefulness, suitability, and usability for gaining knowledge (finding one's way in the world is also a form of knowledge; see in more detail: Kühne 2021a, b; Kühne und Jenal 2020b). Thereby, we draw on the understanding of 'deviant cartographies' (Edler und Kühne 2022) by asking whether (new) cartographic representations could have a functional, afunctional, dysfunctional, or meta-functional effect on cartography in particular and for society in general. In doing so, we set ourselves apart from the notion of a general paradigm shift (Kuhn 1970) since we assume a productive potential of different perspectives of and on cartography, which is by all means context-dependent.

This paper addresses the possibilities of a cartographic representation of complex developments in the physical space that is sensitive to contingencies. Here, complexity denotes the diversity of functions of a system (while complicatedness denotes the diversity of structures), 'contingency' is a label of what is neither necessary nor impossible (Müller 2013; Papadimitriou 2021; Ropohl 2012). The study area, based on which we want to deal with the question of the representation and representability of material objects that have a great relevance but a manageable permanence, is a part of the south coast of the US state of Louisiana, namely that part located between the Mississippi River delta and the mouth of the Atchafalaya River into the Gulf of Mexico, an area thus characterized by a great dynamic, whereby the dynamic is dominated in large parts by the loss of land. For this purpose, eight topographic representations from the period of 1814 to 2022, as well as a recent satellite photo from NASA, are examined. Therefore, following the neopragmatic basic idea of the article, with the aim of comparability of the representations of the coastal course, these representations were transferred into their own map representations made especially for this purpose. These form the basis for further reflections on the expansion of boundaries of standardized representations (based on the three challenges mentioned at the beginning).

The reasons why Louisiana is particularly suited for the reflection of the cartographic representation of coastal land loss (rather than other spaces where comparable things are happening) are many: first, detailed cartographic records go back a long way (more than two centuries). Second, the Louisiana coast has been the subject of numerous cartographic images, so processes of change are particularly well documented—and different interpretations of water and land. Third, the processes underlying coastal loss are characterized by a high degree of complexity, in which natural and natural-cultural hybrid developments can be found. Fourth, the processes of coastal land loss are subject to very intensive study. Thus, fifth, the Louisiana coast is particularly well suited to demonstrate how the land loss will also occur in other regions of the world as a consequence of continuing climate change.

Our paper first briefly introduces the theoretical background of postcritical and deviant cartographies and, following that, briefly addresses the multiple causes and consequences of land loss in southern Louisiana. This is followed by a presentation of the results of the study of the topographical representations and, subsequently, a reflection on the basis of these on questions of normalization and deviance, of dichotomization and hybridity before we proceed to a conclusion in which the three challenges formulated at the beginning are revisited.

2 Theoretical Derivation: From Operationalizing Postcritical to Deviant Cartographies

The neopragmatic approach assumes that there should be no exclusion of methods or theories based on ideological settlements or moral constrictions. Similarly, neopragmatism rejects a predetermined subordination of certain theoretical approaches to others (on neopragmatic geographies, see: Chilla et al. 2015; Kühne 2018; Kühne und Jenal 2021; on neopragmatism, fundamentally: Rorty 1997, 1998; on postcritical cartography, also in the following: Edler et al. 2019; Kühne 2021a). With the development of postcritical cartographies, the approach of 'deviant cartographies' has emerged. Their development started, first of all, in Karl Popper's consideration that scientific progress takes place by setting up 'bold' hypotheses and theories, which would then have to prove themselves scientifically (Popper 1959). Second, they are based on the critical distance to the idea that one paradigm would be completely replaced by another paradigm (Kuhn 1970). This leads, thirdly, to the consideration that scientific progress arises from deviance (a term borrowed from sociology), i.e. from a surpassing of theories (Becker 1963; Durkheim 1994 [1912]), that is, through a transgression of the status quo. Deviance, in relation to cartography in particular, science in general, can act in four ways (Edler und Kühne 2022):

  • Functional deviance generates scientific progress, so it is capable, useful and usable in relation to scientific questions. It can also affect society in this way. One example is the development of zoomable cartographic representations that facilitate orientation on the earth's surface.

  • A-functional deviance produces no effect on science or society because it produces no resonance. For example, the development of a cartographic representation, which is ignored in the professional world and beyond.

  • Dysfunctional deviance occurs when deviations from a norm tend to impede scientific progress, contingencies arbitrarily constrain. For example, when cartographic representations are used to manipulate constructions of the world, to incite ill will and hatred (cf: Monmonier 2018).

  • Meta-functional deviance enables reflection on the operation of science and its effects. In relation to cartography, this means that meta-functional deviance provides insights into the contingency of world interpretations and forms of complexity reduction of the world through maps (Kühne et al. 2022).

We will revisit these considerations after introducing the spatial context of the cartographic representations, and the loss of land in southern Louisiana.

3 Land Loss in Southern Louisiana—An Outline of Causes and Consequences

The causes of land loss in southern Louisiana are diverse. Some are human-caused, while others elude human influence. For example, the glacial isostatic subsidence of large portions of the U.S. Gulf Coast is beyond human influence. This is a consequence of the melting of the North American ice sheet after the last glacial period. As a result of this melting, the lithosphere, which was formerly burdened by ice, is uplifted, and the lithosphere, which was not burdened by ice and was formerly uplifted, e.g. in today's Louisiana, is subsided (Molnar 2015). This subsidence is enhanced by the additional loading of sediment that the Mississippi River discharges (550 million tons per year before 1950; 220 million tons per year today), which regionally pushes the lithosphere deeper into the asthenosphere (Dokka 2011; Olea and Coleman 2014). Sediments undergo compaction and are mobile in parts under surcharge. This, in turn, results in the formation of salt diapirs, but also downthrow towards the Gulf of Mexico (Dokka 2006, 2011; Rogers et al. 2006). Other processes leading to land loss in southern Louisiana, on the other hand, are secondary consequences of human actions: The construction of levees along the Mississippi River for flood control, however, also prevented sediments from settling over a wide area, which meant that there was no compensation for the subsidence of the regional earth's surface (Beatley 2009). In addition, drainage of land for agricultural, infrastructure, and residential use contributes to land subsidence: It accelerates subsidence in mineral soils, and organic soils are exposed to oxidation (Kolb and Saucier 1982; Rogers et al. 2006). Subsidence is also further intensified in the relatively loosely bedded sediments of southern Louisiana by high surcharge loads (such as large buildings as in downtown New Orleans) (Dokka 2011; Rogers et al. 2006). The widespread withdrawal of oil and gas, as well as water, reduces the pressure in the pores of the sediments, often resulting in subsidence of the overlying material. Withdrawal of liquid and gaseous substances modifies the structures of the sedimentary material, which may result in penetration of water into salt diapirs, salt is dissolved, which in turn leads to subsidence of the overlying material (Heinrich et al. 2020; Rogers et al. 2006). These are not the only influences of oil and gas extraction on coastal land loss: With the aim of extracting and transporting oil and gas, Louisiana's coastal region has been crisscrossed by countless pipelines and canals; it is precisely through these canals that seawater penetrates far inland and damages the autochthonous vegetation, reducing its erosion-protective effect. In parts, this vegetation is already in a state of considerable stress from invasive species (such as Roseau scale insects; Barras 2009; Swenson 2021). These processes increase the vulnerability of coastal Louisiana to the impacts of anthropogenic climate change. This is true not only for sea level rise but also for projected increases in extreme weather events, most notably: hurricanes (Olea and Coleman 2014; see Figs. 1 and 2).

Fig. 1
figure 1

Damage and makeshift protection to the technical flood protection measures (levee reinforced with fiberglass) on Barrier Island Grand Isle after Hurricane Ida in the summer of 2021, here a photograph was taken in May 2022. Large parts of the buildings on the island are destroyed or severely damaged (photograph by Olaf Kühne 2022)

Full size image
Fig. 2
figure 2

Hurricanes, which are increasing in intensity and number as a result of climate change, threaten human dwellings not only on the coast: Here, the wreckage of a houseboat on Bayou Lafourche, highlighting the small vertical distance between populated land and the surface of the bayou (photograph by Lara Koegst 2022)

Full size image

Measures to address land loss in southern Louisiana are diverse, ranging from individual protective measures such as elevation of buildings, preparation of evacuation plans, engineered coastal protection measures (construction of levees, of particular importance in this regard are the barrier islands as they protect the material space behind them from the direct impact of floodwaters, see Fig. 1) to the resettlement of entire settlements. Renaturalization to reduce the loss of land is meanwhile also taking place. But the measures also have significant social impacts; for example, the construction of the 98-mile Morganza to the Gulf Risk Reduction System levee is designed to protect larger settlements in particular (Fig. 3). Smaller settlements, often inhabited by Native Americans, are prominent for example on Isle de Jean Charles, are left with relocation as the only option (see Fig. 4). Whereas coastal protection and resettlement were previously top-down decisions (or subject to individual initiative), the competencies of the region's inhabitants are now being integrated into the planning process. Resettlement is sought in such a way that social networks are affected as little as possible by the change of location (Baum 2021; Colten 2015, 2021a, b; Hemmerling et al. 2020, 2022).

Fig. 3
figure 3

The Morganza to the Gulf Risk Reduction System levee (Own illustration according to Schleifstein 2021)

Full size image
Fig. 4
figure 4

View from Island Road to Isle de Jean Charles looking northeast, outside the Morganza to the Gulf protection system. Here it becomes clear what danger of flooding the road, as well as the island at a similar level above sea level are exposed to. The road is provisionally protected by boulder levees, but what is interesting here is that the part to the right of the road that can be seen here as a water area is still intersected by areas classified as land on Google Maps (in June 2022), whilst on the Bing map service (June 2022) this very area is even still classified as a land area (photograph by Olaf Kühne 2022)

Full size image

After this classification of the causes and consequences of land loss in southern Louisiana, we turn to the topographic-cartographic representation of central coastal Louisiana.

4 Louisiana's Coastline in the Course of Time—Illustrated on the Basis of Topographic-Cartographic Representations

The analysis of eight topographic-cartographic representations from 1814 to 2022 has a dual objective of documenting coastal land loss and examining cartographic approaches to hybridity, complexity, and contingency. In this section, we address the first of these two questions and in the next section the second.

The cartographic representations of the central section of the coast in southern Louisiana were translated into a uniform signature language with the goal of better comparability, generalized in the same way, and—in accordance with the (neo)pragmatic approach—designed with the expressive goal in mind, namely the representation of the coast or the construction of a coastline. To clarify the constructed character of the created maps, the signature of the coastline was deliberately not subjected to any smoothing. Historical maps were georeferenced prior to digitization during map creation. The selection of maps firstly pursued the goal of covering as large a time period as possible, whereby the oldest available map (from 1814) was used. Second, we wanted to map the period between 1814 and 2022 (here: 1897, 1924 and 1980). Third, we pursue the goal of comparing current representations of different provenance among themselves and, fourth, with a current NASA satellite image.

The land-sea distribution according to Carey's General Atlas of 1814 (Fig. 5). Louisiana's coastline is shown relatively irregularly, the inland area is crossed by numerous (partly unnamed) lakes and bayous (slow-flowing, partly stagnant linear inland waters), as well as the Mississippi River in the eastern third of the map. Conspicuous in comparison to later maps is a coastline that extends very far to the south, as well as the mouth of the Atchafalaya (south of the settlement name "Morgan City" which serves as orientation) via Salt Water Lake into the Gulf of Mexico.

Fig. 5
figure 5

The land-sea distribution according to Careys General Atlas (1814), the partially transparent settlements are for orientation, they are not shown in the original of the evaluated map (Own representation according to Carey 1814)

Full size image

In Rand McNally's 1897 map (Fig. 6), this area of the Atchafalaya estuary is already showing itself completely remodeled: the river now flows directly into the Gulf and has cut off part of the peninsula. This is only one element of the change: overall, the coastline shows a significantly altered representation. On the one hand, it is depicted more delicately; on the other hand, the bays of Terbonne and Timballier are not found on the 1814 map. The bay now called Barataria Bay reaches further north, and the expanse of water called ‘Isle au Breton Sound’ in 1897 reaches northwest. The location of inland waters (with the exception of the Mississippi River) is also subject to considerable change, as are their names.

Fig. 6
figure 6

The land-sea distribution according to Rand McNally's (1897) topographic map (Own illustration according to Rand, 1897)

Full size image

Not least because of the shorter period between the two Rand McNally maps (1897 and 1924; Fig. 7), the differences in the representations are less than between the two maps previously compared. The existing trend of inland bays advancing continues. In the basic map, inland waters are essentially represented only in the form of surface waters (mostly standing waters), while the representation of (partially) flowing waters was largely omitted. Therefore, the loss of permanently existing water bodies, which are interpreted as standing, is predominantly recognizable.

Fig. 7
figure 7

The land-sea distribution according to Rand McNally's (1924) topographic map (Own illustration according to Rand, 1924)

Full size image

The trend towards a decline in permanent water interpreted as standing continues in the 1968 map of the U.S. Bureau of Census on the basis of the measurements of the United States Geological Survey (USGS) base map (Fig. 8). The drawing of the shoreline is shown in very fine detail—compared to the other maps analyzed. While Terrebonne and Timballier Bay (not named in this map) are now shown as unified, and areas classified as marine also advance on both sides of the Mississippi River, the depiction of land-sea distribution in the Atchafalaya Bay area remains largely stable.

Fig. 8
figure 8

The land-sea distribution according to the United States Geological Survey base map (1968; own illustration according to U.S. Bureau Of The Census, 1968)

Full size image

The beginning of the maps interpreting the current coastline is made by the older of the maps examined, Rand McNally's 2019 map (Fig. 9). From the less detailed coastline depicted (compared to the map examined in the previous section) the familiar pattern of advancement, particularly of the bays is visible. Thus, according to this depiction, Lake Felicity now merges into Terbonne and Timballier Bay (which provides reason to certainly question the designation of this space as a lake), a process that is also depicted in a somewhat less clear manner at Barataria Bay and Little Lake.

Fig. 9
figure 9

The land-lake distribution according to Rand McNally's (2019) topographic map (Own illustration according to Rand McNally 2019)

Full size image

A different interpretation of the coastline (like inland waters) is provided by the USGS's current 2022 online map (Fig. 10). This is particularly evident between Lake Salvador and Barataria Bay (not named here). The representation of water areas here is much more extensive. Clear differences are also evident in the interpretation of the Mississippi River delta in terms of the distribution of areas classified as "land." The location and number of inland waters is also subject to other interpretations.

Fig. 10
figure 10

The land-sea distribution according to the United States Geological Survey base map (2022, own illustration according to U.S. Geological Survey 2022)

Full size image

A different interpretation of the coastline is provided by the online map from Nations Online (2022; Fig. 11). In particular, the area between Atchafalaya and Terbonne Bay is shown here as much smaller between land and sea than is the case in the USGS (2022) map. With respect to the Mississippi River delta, it provides an interpretation that has few similarities with the others presented and suggests the presence of comparatively extensive land areas, particularly in the estuarine areas, in contrast to the map discussed below (Figs. 12, 13).

Fig. 11
figure 11

The land-sea distribution according to Nations Online (2022, own illustration according to Nations Online 2022)

Full size image
Fig. 12
figure 12

The land-sea distribution according to Google Maps (2022, own illustration according to Google Maps 2022)

Full size image
Fig. 13
figure 13

The land-sea distribution according to NASA's May 12, 2022 satellite image of Louisiana (NASA 2022). The map developed based on the satellite image first shows another shoreline that differs significantly from the Google maps map (Fig. 12) that deviates significantly from the coastline, which only along Atchafalaya Bay largely coincides with the coastline that results from the satellite image. Otherwise, what is clearly to be identified as mainland clearly deviates behind the construction of the coastline given by NASA in the direction of the interior. On the satellite image wide areas become clear, which can be classified neither unambiguously as permanently existing water or land area. In this respect, a signature was developed here, which on the one hand refers to the hybridity of the structures in physical space, and on the other hand makes clear in the way they are represented that no claim is made here to provide an exact representation of the material world. Thus, the complexity of the ontological basis as well as the contingency of the cartographic interpretation of the world becomes clear. In this respect, the cartographic representation claims to be meta-functional (Own illustration according to NASA 2022)

Full size image

The online map of Google maps from 2022 provides a double alternative interpretation of the distribution of water and mainland areas: On the one hand, it contains the representation of land and water areas, on the other hand, it contains the representation of a coastline. With the exception of the depictions around Atchafalaya Bay, considerable divergences can be identified between the two depictions. With few exceptions, the areas marked as mainland can be found clearly behind the coastline depicted as a line. Notable exceptions are designations of coastal courses, such as those found south of Franklin. Compared to the other maps, which refer to the current situation, there is (especially in the area signatures) a clearly more pronounced advance of water areas in Google maps, with the exception of Atchafalaya Bay, here—especially compared to the older maps—land gains at the mouths of Atchafalaya and the Yellow Bayou are showing, which flows west of it into the Gulf, as a result of a high sediment load of both waters (Colten 2018, 2021a).

From the explanations of this section, it becomes clear, on the one hand, to which extent the land loss in Louisiana has, on the other hand—this concerns, in particular, the three most recent cartographic representations—how clearly the interpretations of the land–water distribution, in particular of the course of a coastline conceived as such, differ from each other. We will deal with the problem of decomplexing a hybrid space into a line in the following section.

5 Cartographic Representations of Coastal Land Loss: Between Normalization and Deviance, Dichotomization and Hybridity

The procedures and forms of representation in cartography, especially topographic, are known to be largely standardized. Underlying this standardization is the generation of uniqueness according to binary coding, such as "here is an object, there is not" or "here it is like this, there it is different" (Kühne et al. 2021a, b; Wardenga 2001a, b, 2002, 2006). The world unambiguated in this form can then—following the positivist paradigm—be (apparently) exactly transformed into numerical values by measuring, weighing (less important for cartography) and counting (which in turn form the basis for modeling; Tilley 1997) and last but not least—as mentioned above—represent a central point of critique of Critical Cartography. Such positivist framing is also evident in the measurement of land loss in Louisiana: for example, Louisiana's net land loss in the hurricane years 2004 to 2008 is given as 849.5 square kilometers, which significantly exceeded that of 1978 to 2004 of 743.3 square kilometers (Barras 2009). Hurricanes Katrina and Rita created 217 square miles (562 square kilometers) of net new standing water area in coastal Louisiana (Barras 2007, 2009). The net area lost is consisting of the difference between land gains and land losses (where there is a result from the deposition of flotsam, the realignment of existing marshes displaced by the storm surge). The measurement of gains and losses of land makes particular use of remote sensing methods (Weißmann et al. 2022). In the positivist tradition of thought, it is assumed that there is indicative adequacy between what is depicted and what is depicting. However, these methods do not, or only to a limited extent, allow to determine whether certain aquatic vegetation, but also flotsam, can be clearly assigned to the category "land" or to the category "water". In addition, water level fluctuations due to tides and meteorological influences clearly limit the possibility of an unambiguous classification here. For example, if an area overgrown with vegetation is not classified as land until it is rooted in the soil (Barras 2007, 2009; Couvillion et al. 2011).

This challenge is not new, already early cartographers had to face it: "Rather than impressive topography, the coast is mostly a vast low-lying marsh where it is difficult to distinguish where water ends and land begins" (Colten 2018, S. 1). Even in understanding the geography of marsh, it becomes clear that it is a hybrid space that is clearly neither one nor the other. However, when translated into cartographic representations, there is invariably a unification of the areas as "land", also most cartographic representations of the coastal area refrain from classifying the area in question as Marsh. If a classification as a marsh is made, this marsh is arranged on the side of the land of the coastline.

The problematic nature of the attempt to unambiguate a hybrid space is particularly evident in light of temporality: This concerns the rhythmicity of tides, the periodicity of hurricanes, the linearity of sea level rise due to anthropogenic climate change, and also the various other cause complexes for land loss described in the foregoing. The longing for uniqueness and rejection of the hybrid (on this in detail: Latour 1996, 1998; Latour und Woolgar 2013 [1979]; Zierhofer 1999, 2002) shows itself not only on the level of ontology, i.e., wanting to recognize unambiguous boundaries in a material space characterized by hybridity, on the level of epistemology, here of (topographical) cartography as an instrument of gaining knowledge, to decomplex the material world into units dichotomously separated through lines, but also by intervening in the material world. Thus, the construction of the Morganza levee can be understood as an effort to unambiguously separate land from the sea from a not yet precisely determined point of time in the future. A striving for unification, which is bought not least with the abandonment of numerous settlements, such as the coastal master plan of the state of Louisiana (not least Venice or Grand Isle, which are shown in numerous maps listed above; Clipp et al. 2017).

At this point, we return to the notion of deviance. It has been shown that the (topographical) cartographic norm of epistemological unambiguation, which is preceded by an ontological unambiguation, is not able to adequately represent the complexity of space with partially spatially and temporally changing degrees of hybridity. It is thus understandably at this positivist understanding that the critique of Critical Cartography begins. However, instead of declaring positivist cartography with its merits (we will come back to an essential one later) as an "outdated paradigm", our hint is to map hybridities and complexities also cartographically. Thus, the goal becomes to make clear that (in some places especially) the material world is highly complex, from which contingent social (cartographic) constructions arise. In this respect, the potential for functional deviancies arises:

  1. 1.

    Thematic cartography in particular has developed a large catalog of signatures that can be used to represent hybridities, for example, using color gradients, hatches of different colors line widths, or shading (Arnberger 1993; Dickmann 2018; Olbrich et al. 2002; Witt 1970).

  2. 2.

    In turn, the use of more artistic representations (also a requirement of Critical Cartography) can be used to illustrate the contingency of the world and of cartographic representations (Rorty 1998), to symbolize ambiguity. However, the investigation shows the other way: Instead of a signature representing hybridity, in the map of the USGS from 1980 (Fig. 8) the representation of a very small coastal course is chosen.

  3. 3.

    Internet cartography (especially in the virtual reality 3D variant) offers a variety of potentials not only to represent hybridities appropriately but also to represent processes overlapping in time to achieve an intensified understanding of the complexities of Louisiana's land loss. In addition, the use of virtual reality also allows for an immersive experience of the processes, which is difficult with traditional 2D cartography.

  4. 4.

    This experience can be further integrated when augmented reality (AR) capabilities are used. AR enables the oscillation from experiencing the landscape 1 that has been overtaken by coastal land loss to cognitively engaging with the corresponding phenomena (Koegst et al. 2022; Koegst 2022).

However, a dichotomy-based representation of water encroachment based on distinct water-land boundaries also has its raison d'être: By connecting to cartographic common sense, it succeeds in highlighting the political explosiveness of the issue (Colten 2018, 2021b; Warnke 1992).

The processes around land loss illustrate the dynamics of shifting portions of physical space formerly uniquely classified as 'land' to hybrid spaces, but also from hybrid spaces to water spaces. This trend is partially slowed down with coastal protection measures, which leads to a further differentiation of spatial development, for instance through the successive abandonment of settlements. Thus, a spatial pastiche is created (Hoesterey 2001; Kühne et al. 2020): Areas of different land–water hybridity, different intensity of use, and different intensity of settlement (from expansion to abandonment). The concept of space-pastiche can be used to describe spaces whose compartments are characterized by different degrees of hybridity, but also different overlapping hybridities (see in this context, for example: Birnbacher 2006; Heiland 1999; Kazig 2016; Kühne 2012; see Fig. 14), i.e. ambiguity (in detail on this concept: Aitken und Zonn 1994; Kühne 2012; Kühne und Jenal 2020a), because "pastiche does not simply mean de-differentiation, but presupposes difference formation to then lead to hybrid crossings, recombinations, reintegrations" (Vester 1993, p. 29).

Fig. 14
figure 14

View towards Port Fourchon from the new elevated Highway 1 en route to Grand Isle: view across the spatial pastiche in the Barrier Islands area, formed by a mishmash of land-sea hybrids and land-use hybrids ranging from unused space to intensive industrial use (photograph by Lara Koegst 2022)

Full size image

6 Conclusion

A task for cartography arises from the representation of spatial pastiches, in the sense of functional deviance. This does not mean eliminate traditional ways of seeing the world, as critical cartography demands, but to value them as 'classical' and to complement them by new representations, to do justice to the changing physical-spatial conditions on the one hand, to take hybridities (which already existed before) more seriously and, last but not least, to stimulate reflection on (cartographic) representations of the world (in the sense of meta-functional deviance).

The critique of critical cartography with regard to the dominance of expert-like spatial construction offers reason to reflect on power processes in spatial constructions. In this sense, they have a meta-functional effect, but the exclusivity of the rejection of expertise that has been put forward makes them impractical. Their dysfunctionality becomes especially clear in the example of land loss in Louisiana: Expert access is relevant not least because, on the one hand, underlying processes of land loss would not be ascertainable and assessable in terms of their significance without specialization, and, on the other hand, translation into maps is not trivial but requires innovative cartographic representations. This requirement arises not least from a (mentioned in the beginning of the paper) diverging combination of relevance and permanence, as essential criteria of the representation of topographic contents. Land loss, as a combination of different interlocking processes (which also include countermeasures), has a high degree of not least social (and thus cartographic) relevance. At the same time, it has a high degree of dynamism. Both stimulate the development of new forms of representation (whether 2D, 3D, analog, augmented or virtual). Cartographic deviance is here predefined, so to speak, by the material space to be represented. The basis for this is a careful recording, including historical conditions, even if the type of cartographic representation has proven to reduce complexity excessively in the face of hybridities. This careful recording was done in particular by government agencies that today make both historical imagery and current geospatial data available to the general public free of charge (in this case, the USGS), which is why the criticisms of critical cartography in this regard have become devoid of object. The neopragmatic approach taken in this paper takes up the critique of critical cartography and understands maps as results of social (and individual) construction processes. In this respect, we have chosen forms for our cartographic representations that illustrate the awareness of constructedness in the related language of signatures.

Understanding complex relations also requires heuristics that get rid of outdated notions of theoretical and methodological unambiguity (up to orthodoxy) and allow (neopragmatically) different perspectives on the world. On the basis of this essay we have shown that, for example, a positivist understanding of cartography (if it is not presented in an exclusivist way) can be combined quite profitably with constructivist considerations of cartographic world-making—in the sense of a functional deviance.

The paper was devoted to questions of cartographic theory using the example of a concrete section of the material world, southern Louisiana. Here it became clear that land loss with its manifold complex of causes is taking place at great speed—with considerable social side-effects, which are expressed not least in resettlements. But the question of defining coastlines also has political and legal implications. The definition of the different zones with differentiated sovereign claims of coastal waters (such as the 12 nautical mile zone) is based on the definition of a baseline from which measurements are taken. This baseline is aligned with the course of the coast. In the wake of land loss in Louisiana (in the context of global sea level rise due to climate change elsewhere as well), the question is becoming quite virulent as to whether seaward spheres of influence are also shifting as a result, or does it remain—regardless of the coast in physical space—with a baseline once defined? In view of the oil production in the Gulf of Mexico, this question is not only of academic interest.