Preservation of vernacular schist masonry farm walls

Abstract

This paper complements the information presented at the CIAV2013 on vernacular buildings in northern Portugal, and addresses the topic of masonry walls in the rural areas of the northwestern Portuguese coastline. These walls are structural schist masonry constructions, built using ancient techniques and locally available resources. The result is a territory built for agricultural exploration, and a landscape imprinted with past social hierarchies and structures. Using the information gathered by the fieldwork study, the paper will present studies on masonry walls with different morphologies, construction materials and building techniques employed. The information presented aims to contribute to enlighten researchers and technicians about these building specificities, to increase the scarce available literature about schist’s potential as construction material, and to enhance the importance of the cultural value of this particular kind of heritage. 1 THE VERNACULAR MASONRY WALL The vernacular masonry walls represent one of the most characteristic and important heritage of the Portuguese rural landscape. Built since immemorial times using empirical knowledge, by local populations and using locally available resources, they were used to establish limits, do define property boundaries, but also to shape and improve the landscape, making it more suitable for agricultural and forestall production. The Portuguese northwestern countryside along the Atlantic coastline, also called riverside (Saraiva 1994), see Figure 1, is characterized by large plains, valleys and smooth elevation transitions, but also by its dense occupation marked by a past strict social and economical hierarchy. Small and medium size farms and property passed to the territory the existent social organization, by the overwhelming presence of vernacular masonry walls in the landscape. In the border between the Portuguese northeastern territory the riverside becomes the mountain (Saraiva 1994), see Figure 1, and the territory takes the shape of very steep mountains, with drastic elevation variations and very narrow and deep valleys. In this territory, fertile land is scarce and resource optimization is a priority, making collective work and the community vitals to the survival of local populations. In this territory, vernacular masonry walls are mainly used to establish areas and paths, to guard and control herds, and specially to help shaping the land in order to get more usable farmland. Figure 1. From the top: riverside rural landscape— Barqueiros, Barcelos (study area) (41°29’6.46”N, 8°43’43.43”W); mountain rural landscape—Sistelo, Arcos de Valdevez (41°58’54.88”N, 8°21’7.09”W); Study area’s limits on Portuguese military chart (C.E. Barroso et al.). Vernacu_Book.indb 117 7/31/2014 7:39:26 PM 118 2 STUDY AREA CHARATERIZATION The study area, see Figure 1, is located in the south riverside area of the Cavado river, and its characterized by abundance of fertile land and of water resources, plateaus, valleys and plains extending until the Atlantic ocean. Until the mid-20th century, this area was exclusively a rural landscape densely explored by it agricultural resources, and occupied by small settlements composed either by more concentrated groups of farmhouses around a church or monastery, or by scattered groups over the territory. In an effort to increase available resources, the farmland was prepared during centuries to increase its production capability by adding forestall materials and manures to the land, but also by the removal of natural limits by building slopes, of irrigation systems and production buildings. With the increase of agricultural production occurred over the 19th century (Ribeiro 1945), along with the economical resources brought by the brasileiros emigrants (Monteiro 2000), and the construction of new regional roads connecting major cities, this territory gained in population and in wealth. It declined again in the first decades of the 20th century, leading in the 60 s and 70 s to an exponential growth of emigration phenomenon (Saraiva 1994). This new and very different emigration phenomenon to the center of Europe, imported different ways of life and vernacular logics and hierarchies were progressively abandoned.