**1. Introduction**

74 Cartography – A Tool for Spatial Analysis

111(1-2): 48-60.

1531-2009.

385.

354-374.

2: 1-4. Doi:10.1109/IEEC.2010.5533250.

integrazione. Geomedia 3: 14-22.

System Sciences 5: 143-153.

lgs\_5574.htm. Accessed 2011 Apr 22.

Seminarului Geografic "Dimitrie Cantemir" 19-20: 211-226.

Western Iowa. Soil Science Society of America Journal 42(2): 323-328.

Paulo, Brazil. Zeitschrift. für Geomorphology N.F. 34(4): 423-434.

geomorphology. Earth Surface Processes and Landforms 32: 66-74.

conditions for ephemeral gully incision. Geomorphology 16(2): 161-173.

gully. Journal of the Hydraulics Division 101(1): 65-80.

[69] Xie H, Jia H (2010) The Development of 3D Laser Scanning Technique and Its Applications in Land Reclamation. Information Engineering and Electronic Commerce

[70] Rinaudo F, Nex F (2011) LIDAR e Fotogrammetria Digitale verso una nuova

[71] Lee I, Schenk T (2001) 3D Perceptual Organization of Laser Altimetry Data. International Archives of Photogrammetry and Remote Sensing 34(3/W4): 119-127. [72] Marzolff I, Poesen J (2009) The potential of 3D gully monitoring with GIS using highresolution aerial photography and a digital photogrammetry system. Geomorphology

[73] Mikoš M, Vidmar A, Brilly M (2005) Using a laser measurement sydtem for monitoring morphological changes on the Strug rock fall, Slovenia. Natural Hazards and Earth

[74] Bretar F, Chauve A, Bailly J-S, Mallet C, Jacome A (2009) Terrain surfaces and 3-D land10 cover classification from small footprint full-waveform lidar data: application to badlands. Hydrology and Earth System Science 13: 1531–1544. Ddoi:10.5194/hess-13-

[75] Leica HDS3000 data sheet. 2006. Available: http://www.leica-geosystems.com/hds/en/

[76] James T D, Carbonneau P E, Lane S N (2007) Investigating the effects of DEM error in scaling analysis. Photogrammetric engineering and remote sensing 73(1): 67–78. [77] Erhan E (2001) Consideratii privind resursele climatice ale Moldovei. Lucrarile

[78] Blong R J, Graham O P, Veness J A (1982) The role of side wall processes in gully development; some N.S.W. examples. Earth Surface Processes and Landforms 7: 381-

[79] Bradford J M, Piest R F, Spomer R G (1978) Failure sequence of gully headwalls in

[80] Bull W B (1997) Gully processes and modeling. Progress in Physical Geography 21(3):

[81] De Oliveira M A T (1990) Slope geometry and gully erosion development: Bananal, Sao

[82] Harvey A M (1992) Process interactions, temporal scales and the development of hillslope gully system: Howgill Fells, northwest England. Geomorphology 5: 323-344. [83] Heede, B.H. 1976. Gully development and Control: The Status of our Knowledge. Fort

[84] Heritage G, Hetherington D (2007) Towards a protocol for laser scanning in fluvial

[85] Piest R F, Bradford J M, Wyatt G M (1975) Soil Erosion and Sediment transport from

[86] Vandaele K, Poesen J, Govers G, Wesenael van B (1996) Geomorphic threshold

[87] Ursulescu N (2006) Donées récentes concernant l'histoire des communautés énéolithique de la civilisation Cucuteni. Acta Terrae Septemcastrensis 5: 79-113.

Collins, Colo.: Rocky Mountain Forest and Range Experiment Station. 42 p.

Cartographic Heritage consists in the whole amount of ancient cartographic documents (not only maps, but also atlas, planispheres, globes, ...) the history has brought us, today perceived as a cultural value to be necessarily preserved due to its historical and geographical content as well as its artistic value. It is a great but often poorly known heritage, because usually ancient cartographic documents are kept in places closed to the public, and only occasionally they are proved valuable outside of specific research activities.

The recovery of ancient cartography is intended to save, and possibly to spread throughout a wide public, Cartographic Heritage, making use of the potential it offers. Unfortunately, ancient cartographic documents often suffer from preservation problems of their analogue support (an organic material, thus subject to wear), mostly due to aging. Therefore, the recovery of ancient cartography firstly consists in traditional restoration, intended to safeguard the analogue support against the damaging effects of time. Beside this, a recovery of the content of historical documents is also possible, carrying the cartographic document to a different support, usually a digital one. In such a way, regeneration of ancient cartography in a digital environment is an interesting way of Cultural Heritage preservation and valorisation.

Digital regeneration is not exhaust by the digitization step: modern digital techniques allow new chances of using the map information, which would be unachievable on an analogue support. In particular, georeferencing and analysis of map deformations help in metric analysis of ancient cartography. In fact, usually the metric precision of an ancient cartographic document can be very different from that of a present map, due to an amount of deformations and errors that can be very high with respect to our standards. For example, graphical deformations can be induced by the old type of cartographic transformation (if one exists, it can be different from the modern ones), whereas other deformations can be due

© 2012 Cremonini et al., licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2012 Cremonini et al., licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

to an alteration in the analogue support; other errors can be recorded in the cartographic document, for instance errors that were made by the cartographer during survey or draft steps, or errors inherent to the surveying instruments at that time. In order to compare an ancient cartographic document to a modern one (usually a modern map used as reference), a georeferencing process is performed in a digital environment, assigning cartographic coordinates to a number of still existing and recognizable Ground Control Points (GCPs). This way, the native metric content of the map can be reproduced in the digital image, and furthermore an analysis of the existing map deformations is allowed. Thus, it becomes possible to understand the characteristics of metric precision of the original product (e.g. the projection type) in respect to the present reference cartographic base, as well as to evaluate and represent the degree of deformation recorded in the ancient document. The historical map, now in digital form, can be easily exploited and compared with other cartographic databases, thanks also to current web services; change analysis and analytical procedures can be performed through GIS applications.

Analysis of Pre-Geodetic Maps in Search of Construction Steps Details 77

documents are kept today in the Venice National Archive (ASVe), and two of them (F and L maps) have been examined on site. The original documents are drawn on several watercolor papers stuck on canvas supports. For the aim of the present study, digital copies of the originals, made by ASVe, were used: high resolution (300-400 dpi) copies were derived from high quality scanning (F and L maps), and a lower quality copy was derived from digitization of photographic images (P map), the original paper support being afflicted by wear problems. No images may be reproduced, in any form or by any means, without permission of the Venice National Archive; it is necessary to apply to the Photoreproduction Section of the Venice State Archive in order to obtain the release of copies.

A further fundamental tool of analysis was the book edited by the main author, Fabri, containing the description of the so called *squadra zoppa* (or *squadra mobile*, i.e. mobile square), a new topographical instrument probably invented and used by Fabri himself (Panepinto, 2009). That instrument was useful for performing every type of topographic measurement (i.e. heights, distances, depths) in urban and land surveying, and also for map drawing (reporting the measurements on the paper). Surprisingly, the handbook seems to be a powerful record of the author's whole technical experience originated by the surveying operations performed in the geographical areas depicted in the maps here studied (Figure 2). A copy of the book, today preserved at the *Dore* Library of the Engineering Faculty of the

Even if the above mentioned existence of a textbook probably related to the chosen maps would not be taken into account, other strong motivations appear to exist to focus our

As these maps were made during the very short period between the years 1592 and 1599, i.e. the lapse of time immediately forerunning a series of very important works aiming at the Po river channel diversion, they stimulate a compelling geomorphological analysis (Cremonini 2007a; Cremonini & Samonati 2009) focused on the easternmost peripheral areas that today no longer exist, due to erosional dynamics of seashore evolution developed during the last four centuries (Cremonini 2007b; Cremonini 2010). A further problem arises, due to the fact that the maps depict in a quite different manner the same landforms, although they appear to have been drawn in the same years by the same author or co-author (Ottavio Fabri). For these reasons the maps have already been studied from various viewpoints and metrically analysed in a digital environment (Bitelli et al. 2009, 2010), to try to overcome the merely

Although the modern digital techniques, in particular georeferencing of the cartographic samples coupled with a study of the map deformations, help in metric analysis of ancient cartography, in pre-geodetic cartography studies specific analytical tools need to be used,

Granted for these reproductions: n. 81/2010.

analysis on those cartographic samples.

qualitative comparison between the available maps.

e.g. in the step-by-step solution here proposed.

University of Bologna, has been examined on site (Fabri 1673).

**3. The reasons of the choice and the previous studies** 

This way, regeneration of ancient maps in digital form appears to be useful for many users: not only the public and institutions who collect them, but also experts who exploit this kind of documents to derive information for their studies, ranging from urban development to geomorphological or environmental topics. Many institutions today are digitalizing their cartographic heritage, in order to preserve and catalogue it and give online access to it (Adcock et al., 2004). On the evidence of growing interest in the argument, the International Cartographic Association (ICA) instituted in 2007 the "Commission on Digital Technologies in Cartographic Heritage", whose aim is to encourage digital approaches to cartographic heritage.

The present research would demonstrate the usefulness of the digital regeneration of ancient cartography; it provides an example of studies that can be performed after digital regeneration of ancient cartography, with a non-conventional approach mainly focused on technical considerations about the map-making procedures.

## **2. Materials**

In this study, a set of three maps, depicting the northern coast of the Adriatic Sea along the Po river delta (South of Venice, Italy) at the end of the 16th century, is analysed (Figure 1). The first two maps were both drafted in the year 1592, whereas the third one was drafted few years later (1599).

The maps represent a rare case where the authors of documents are known. The same cartographer, Ottavio Fabri, was author of the first map (hereinafter "F map") and co-author in the other two (hereinafter "P map" and "L map"), in which the main authors were Gerolamo Pontara and Bonaiuto Lorini, respectively. All of them were very famous landsurveyors in Renaissance Venice (*Savi ed Esecutori delle Acque della Serenissima Repubblica*).

The dimensions of these documents are very large, and their average scales range between about 1:12,000 and 1:13,000, not being constant throughout the entire maps. The original documents are kept today in the Venice National Archive (ASVe), and two of them (F and L maps) have been examined on site. The original documents are drawn on several watercolor papers stuck on canvas supports. For the aim of the present study, digital copies of the originals, made by ASVe, were used: high resolution (300-400 dpi) copies were derived from high quality scanning (F and L maps), and a lower quality copy was derived from digitization of photographic images (P map), the original paper support being afflicted by wear problems. No images may be reproduced, in any form or by any means, without permission of the Venice National Archive; it is necessary to apply to the Photoreproduction Section of the Venice State Archive in order to obtain the release of copies. Granted for these reproductions: n. 81/2010.

A further fundamental tool of analysis was the book edited by the main author, Fabri, containing the description of the so called *squadra zoppa* (or *squadra mobile*, i.e. mobile square), a new topographical instrument probably invented and used by Fabri himself (Panepinto, 2009). That instrument was useful for performing every type of topographic measurement (i.e. heights, distances, depths) in urban and land surveying, and also for map drawing (reporting the measurements on the paper). Surprisingly, the handbook seems to be a powerful record of the author's whole technical experience originated by the surveying operations performed in the geographical areas depicted in the maps here studied (Figure 2). A copy of the book, today preserved at the *Dore* Library of the Engineering Faculty of the University of Bologna, has been examined on site (Fabri 1673).
