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Trabancos River

2007 Schools Wikipedia Selection. Related subjects: European Geography


                             Trabancos River

                                        .
                             State

                                   España (Spain)—>

                            Length          85,860 meters
               Elevation at Source           1,120 meters
                         Provinces       Ávila and Valladolid
                       River Mouth   Duero River near the Village
                                   of Pollos ( Valladolid province)
                Elevation at Mouth            657 meters
                                River - Hydrology

   The Trabancos is a river in Spain which flows between the Zapardiel and
   the Guareña rivers and is a tributary of the Duero river. The source of
   the Trabancos is in Moraña, a region in the north of the province of
   Ávila, near Blascomillán. The Trabancos is at an elevation of
   approximately 1,100 meters, is approximately 85 kilometers long and,
   although its river bed is stable, only has a constant water flow during
   torrential rains.

Fluvial Geomorphology

   From its source in the province of Ávila, to its mouth in the village
   of Pollos ("Village of Chickens" in Spanish) in the Vallisoletana
   ("confluence of waters") region, the course of the Trabancos is
   markedly affected by a geologic fault originating in the Tertiary
   era—likely pre-Pliocene which, like most of the observed faults of that
   geological era, follows a NNE-SSW direction. As shown in the graph
   below, the fault separates material laid down during the Oligocene
   epoch on the right margin, from material laid down during the Miocene
   epoch on the left margin. The surface level represents material
   deposited during the Quaternary period.

   Archeological research in areas surrounding the Trabancos River,
   between the villages of Castrejón and Pollos ( Valladolid province)
   have been compared with the specialized bibliography and the published
   geological charts (infra), as a result of which a sequence of river
   terraces have been designated as follows, appearing on the left hand
   margin of the chart: TT-1 platform (the most ancient, at +35/40 meters
   over the flood plain); the TT-2 platform (the second one at +25/30
   meters); the TT-3 platform (at +15 meters over the floodplain); and the
   TT-4 platform (at +10 meters, the last and most recent).

   The right hand margin of the designated chart depicts a gravel plateau
   present along the middle and final courses of the Trabancos River. The
   scientist Alfredo Pérez-Gonzalez named this formation "Superficie de
   Alaejos" ("The Plateau of Alaejos", after a nearby village). The
   Alaejos Plateau incorporates a number of different types of materials,
   including, among others: red argillic soil and a colluvium build up of
   gravels with rounded stones of quartz and quartzite.

   The Quaternary terrace deposits of the Trabancos River only appear on
   the left hand side of the valley, over the Miocene sediments. This is
   the result of a hard slope in the opposite margin, where the terrain is
   heavily eroded, which renders the formation and maintenance of river
   terraces impossible.
   Cross section, depicting the fault that affects the middle and final
   courses of the Trabancos Riveras well as the sequence of its river
   terraces
   Enlarge

    Cross section, depicting the fault that affects the middle and final
                       courses of the Trabancos River
                as well as the sequence of its river terraces

   Of the previously mentioned river terraces, the one known as TT-4 is
   only visible near Narros del Castillo ( Ávila). Terrace TT-3 is the
   best preserved of the lot; although its height on the bed of the stream
   is not constant, it clearly stands out on the floodplain. Terrace TT-2
   is quite well preserved as well, although it has been more heavily
   sculptured by other small tributaries of the Trabancos River. By
   contrast, terrace TT-1 is greatly eroded; although some sections
   survive to the south of the municipality of Alaejos ( Valladolid), they
   are very difficult to differentiate from the colluvium floor that
   covers the Superficie de Alaejos. Entering into land in the
   municipality of Pollos, the stream stops to form river terraces,
   cutting traversely and lowering enough (between 40 and 60 meters) to
   meet the terrace deposits of the Duero River.

   The TT-3 platform features a very compact and thick Miocene epoch
   conglomerate formed of river-smoothed pebbles of quartzite, most likely
   cut by the Trabancos River ages ago, and cemented together by chalk and
   sandstone materials. While this Miocene conglomerate emerges from the
   banks of each river terrace, the quartzite in the conglomerate on the
   TT-2 platform, just northwest of the municipality of Siete Iglesias de
   Trabancos, likely derives from the action of the Duero River rather
   than the Trabancos River, as a slope in the terrain is thought to have
   caused the formation of an alluvial fan which deposited quartzite on
   the fluvial fossil river bed of the Trabancos.

   The fact that the river terraces of the Trabancos River cut and cross
   some terraces of the Duero River, leads to the conclusion that the
   affected Duero River terraces are younger than those which were not
   formed as a result of the activity of the waters of this river. The
   "superficie de Alaejos" carve-out intrudes 4 to 6 meters into the Duero
   River terrace designated TD-7 (+74/80 m) to the northwest of Siete
   Iglesias de Trabancos village. Likewise, the TT-2 fluvial terrace of
   Trabancos cuts some Duero River terraces. Since the previously
   mentioned Duero River terrace named TD-7 has been dated by Alfredo
   Pérez-González (op.cit.) to the beginning of the Middle Pleistocene,
   meaning the river terraces of Trabancos River are younger than the
   "Superficie de Alaejos", it appears plausible that this postdates the
   creation of Trabancos valley: the proposed date could, thus, be halfway
   through the Middle Pleistocene or later.

History of the Trabancos region

   Although the eastern portion of the river is of insignificant
   hydrographic importance, at least until the 13th century, it played an
   important role in the history of the North Spanish Plateau.

Prehistoric era

   Evidence of prehistoric human habitation has been unearthed in
   hillsides in some areas of Narros del Castillo ( Ávila), and in Siete
   Iglesias de Trabancos ( Valladolid), dating from the Quaternary period,
   and have been further pinpointed as originating in the lower
   Paleolithic era. At both sites, collections of lithic stone artifacts
   knapped during the Acheulean period are found on the surface (not as a
   result of archeological excavation), including among others:
   centripetally knapped lithic cores, others displaying non-arranged
   lithic reduction, as well as lithic flakes characteristic of both the
   Levallois and Kombewa techniques, chopping tools and handaxes.

  Centripetal lithic core

                         Lithic flake Handaxe

                                             Chopper

                                                    Another lithic flake handaxe

     Lithic artifacts and tools from the Acheulean culture found in the
                  fluvial quaternary terraces of Trabancos

   Only ambiguous archaeological evidence has been found dating from the
   late Roman period. It has been suggested by some that this is a result
   of the severity of the land and weather in the Trabancos valley and its
   surrounding regions. Possibly, during the pre-Roman period the
   territory was a no-man's-land between the Hispanic tribes of the Vaccei
   and Vettoni.

   Some archaeological remains have been found in the municipality of
   Siete iglesias de Trabancos ( Valladolid), but they are not
   well-preserved, having been situated on the surface of the terrain.
   Such remains consist of, for instance, broken pieces of comb-decorated
   pottery which appear to date from Spain's Iron Age. There are few other
   examples of prehistoric findings directly along the Trabancos river.
   However, in the surrounding regions, such as the municipality of
   Alaejos ( Valladolid), archaeological investigation has unearthed
   several human burials sites that have been dated to the Bronze Age. In
   addition, some prehistoric remains have been found near the mouth of
   the Trabancos River, in Pollos village, but which originated from the
   Duero River. These include relics of the Spanish Bronze age classified
   as Cogotas pottery, as well as Proto-Cogotas pottery, both featuring
   incised decoration.

                     Sieteiglesias de Trabancos pottery

                Bronze age pottery from the Village of Pollos

          Roman pottery ( Terra sigillata) found in Pollos village

             Roman plate found near the Village of Nava del Rey

   Archaeological remains of pottery found on the surface of the Trabancos
                                 river basin

Roman times

   The Romans likely came to the Trabancos region in the 2nd century,
   during the campaigns of Lucius Licinius Lucullus ( 152 BC), but the
   area was peripheral to the regions of principal occupation, as well as
   to the creation of early towns and more importantly, trade routes: most
   travel routes were in the east of this region, which followed the river
   Eresma from the town of Coca (Cauca, in Roman times) and Matapozuelos
   village (Nivaria in Roman times), up to Simancas (Septimanca); and at
   the west, for the " Vía de la Plata" ("silver road"), the most
   important Roman route in Lusitania Province. Nevertheless, it is known
   that in the Vallisoletan area, there was several villages that probably
   are of pre-Roman origin. In fact, the etymology of the word 'Trabancos'
   suggests a name originating before the Roman occupation.

   At the Lavachicha site (municipality of Castrejón, Valladolid) several
   pieces of typical Roman pottery named terra sigillata hispanica have
   been unearthed and there was also an archaeological excavation in the
   1980s that revealed a necropolis from late Roman times or, perhaps,
   from Visigothic times. Similar remains of late Roman pottery, have been
   found in Carpio ( Valladolid), but only at ground level, and not from
   archaeological excavation. Another municipality crossed by the
   Trabancos River is Nava del Rey (a small town located in Valladolid),
   where, once again, are found superficial pieces of terra sigillata
   hispanica and a striking plate fragment with red gloss, resembling
   those that were carried by Roman legionaries on military campaigns.

The Middle Ages

   In the Middle Ages, the area remained a zone of little interest. No
   written documents exist prior to the 12th century that mention the
   region. It is known, however, that between 711 and 740 AD the Berbers
   had stationed troops in the valley of the Duero, but the majority of
   these peoples left the area because of a severe drought that occurred
   sometime between 750 and 753 AD. Only the most important centers of
   habitation survived ( Medina del Campo, Olmedo, Alcazarén, Tordesillas,
   etc.).

   During the Christian conquest, little emphasis was placed on resettling
   the region, as it was essential for the sovereigns of the time to
   consolidate more strategic zones (in the 11th century, priority was
   placed on the south of the Sistema Central, a mountain range located in
   the centre of the Iberian peninsula), which is why Medina del Campo
   remained intact into the 12th century.

   Nevertheless, Tomas Mañanes, a professor at the University of
   Valladolid, who investigated the Trabancos valley and Guareña area,
   found numerous defensive turrets or "Torrejones" (according to the
   local dialect) that were dated to the 11th century; that is to say,
   previous to any official resettlement. Specifically, more than ten
   defensive structures of various sizes were verified along the course of
   the Trabancos River in the province of Valladolid.
   Aerial photo showing the ruins of one of the defensive 'torrejones' on
   the borders of the river Trabancos near Medina del Campo
   Enlarge

   Aerial photo showing the ruins of one of the defensive 'torrejones' on
          the borders of the river Trabancos near Medina del Campo

   Map showing distribution of medieval forts in the border region between
   the Kingdoms of Castile and León in the 12th century
   Enlarge

   Map showing distribution of medieval forts in the border region between
            the Kingdoms of Castile and León in the 12th century

Character and purpose of the Torrejones

   Almost all the torrejones are in areas which are now uninhabited
   (except those in Castrejón and Alaejos, both of which were turned into
   castles, in later history). The torrejones were relatively simple
   square or egg-shaped structures, with several floors, built of
   limestone or brick. At least two categories of torrejones can be
   identified: The first have small peepholes in their walls and are built
   in regions that were in isolated areas at the time of use, and the
   other are small castles located in what were rural farming villages
   (though today they are deserted).

   Nevertheless, the typological similarity of the structures and the
   relatively short distance between them (ideal for visual
   communication), has led some to think that they were on opposite sides
   of the frontier line between the Kingdoms of León and Castile (in
   Salamanca there is a town names Zorita de la Frontera ("Zorita on the
   Border") in memory of those times). These fortresses were reinforced in
   the 12th and 13th centuries due to conflicts between the two kingdoms;
   but it appears that they are more plentiful on the Castilian side (near
   the Trabancos) than on the Leonese side (near the River Guareña). This
   has been seen as indicative of a certain independence on the part of
   the militia of the Community of Medina del Campo and surrounding areas,
   which was thereby forced to defend itself without outside help, whilst
   the Leonese side would have been able to rely on the help of Royal
   troops, and the Knights Hospitaller of the Order of Saint John of
   Jerusalem, billeted in Castronuño and Torrecilla de la Orden.

The Trabancos River area becomes strategically important

   As indicated at the start of the discussion of the area during the
   Middle Ages, despite its history as a fortified border from the tenth
   century, the area was unimportant until the thirteenth. The King of the
   (now united) Kingdom of Castile and Leon, Alphonse VII ( 1126- 1157),
   made a series of internal territorial changes which involved the
   transfer of Leonese territories to the Crown of Castille: specifically,
   The Tierra de Campos to the north of the Duero, an area which at the
   time was much valued for its riches, and the alfoz de Medina del Campo
   (to the south of the Duero), a poor and sparsely populated zone,
   although it possessed a certain strategic value in terms of the defense
   of the passes of the Duero valley. During the time of the union of the
   two crowns, the question of who owned these areas was of little
   importance; however, upon the death of Alphonse VII and the division of
   his possession amongst his sons, continuous conflicts arose over the
   control of the area, especially Tierra de Campos, but also, though less
   importantly, over the area of Medina del Campo.

   The wars over the area intensified between 1178 and 1181. The Leonese
   Alfoz de Toro was heavily defended, thanks to the Fortress of
   Castronuño, with a vicious battle taking place even on the shores of
   the Trabancos River itself. Of particular note is an encounter in 1179
   between Leonese and Castilian forces, just outside the Fortress of
   Cast'cam (Castrejón), which led to the signing of a peace treaty
   between Alphonse VIII of Castille and Ferdinand II of Leon. But in fact
   peace came to a swift end in the year 1183, when the Kings of Castille
   and Leon made camp on the outskirts of the towns of Carpio and Fresno
   el Viejo (both towns in the Province of Valladolid) respectively.

   After the death of Ferdinand II, fighting resumed (interspersed with a
   short truce in 1204 thanks to the marriage of Alphonse IX of León to
   his niece, Berenguela of Castile; but the marriage was annulled by her
   father because of the close blood-relationship of the spouses .
   Finally, the Crowns of both kingdoms were taken by King Ferdinand III
   of Castile.

   The logical conclusion of these events was that the border was heavily
   militarized, involving the building of castles and reinforcements of
   troops in the areas surrounding the Trabancos River, with some castles
   being erected in the west, such as in Alaejos. Paradoxically, the wars
   increased the value of the region, and for the first time there began
   to appear documents recording the area in the files of the cathedrals
   of Zamora, Salamanca and Segovia including documents regarding: Siete
   Iglesias de Trabancos ("Seven Churches at Trabancos") in 1178, Alaejos
   (Falafeios) in 1167, and in 1180, Eván de Arriba, Eván de Abajo,
   Valdefuentes and Pedroso (which are now deserted villages), together
   with Nava del Rey in 1265, among others.

   This last date, 1265, corresponds to a document found in the 'Book of
   Loans' of Salamanca cathedral, which records the result of a new
   conflict: the battle between the dioceses of Salamanca and Segovia for
   the possession of the parishes to the east of the Trabancos; an area
   that hitherto had been accorded little worth. Salamanca had made use of
   the frontier struggles to take possession of the towns of Medina del
   Campo, provoking a conflict of interest since the region was under
   Castilian rule, and Salamanca belonged to the crown of León. In fact,
   the Salmantinos created new parishes, like Siete Iglesias de Trabancos
   in 1167, and Alaejos in 1185.

The Trabancos River area today

   Looking at the Trabancos today and at a time when it is dry, it might
   seem preposterous that at one time it held a position of strategic
   importance for the town of Medina del Campo, and also, for the
   so-called "Extremadura Catellana" (the wildest border of Castile).
   However, the area's archaeological heritage is fast disappearing, and
   it is only thanks to published research that we can catch a glimpse of
   the region's former glory.

ZEPA designation

   Map showing the ZEPA SPA designated territory. The red-colored area
   corresponds to the province of Valladolid, and the orange corresponds
   to Salamanca and Ávila.
   Enlarge

     Map showing the ZEPA SPA designated territory. The red-colored area
    corresponds to the province of Valladolid, and the orange corresponds
                          to Salamanca and Ávila.

   The middle and final course of the river Trabancos has been included in
   the ZEPA (Zona Especial de Protección para las Aves [Special Zone for
   Protection of Birds]) Tierra de Campiñas ("Land of champaigns"; Special
   Protection Area ("SPA")).

   ZEPA SPAs, are catalogued by the member states of the European Union as
   natural zones of special interest for the conservation of bird species
   threatened with extinction, in accordance with the criteria established
   by the community board Birds Directive 79/409/CEE and subsequent
   modifications by the (Directiva de Aves) "Aviary Regulation Board" of
   the EU.

   Although the designation also includes a portion of the Guareña River's
   course to the west, and the Zapardiel River's course to the east, the
   Trabancos River ZEPA SPA designated area is the largest in the
   Autonomous Community of Castile and León, since it covers almost 1,400
   square kilometres, including the Campo de Peñaranda (in Salamanca), the
   Moraña (in Ávila) and, especially, a large part of the Tierra de Medina
   del Campo. In all, 73% of the territory of the Trabancos ZEPA SPA
   corresponds to the province of Valladolid.

   The designated region is largely uninhabited —97% of the area is
   agricultural land, with an emphasis on cereal crops and other
   irrigation farming purposes. The areas of ecological interest are found
   in the remaining 3% percent of the terrain. The region is characterized
   by tilled land and pastures, small pine woods and holm oak woods, with
   interspersed wasteland areas covered in halophile bushes. There are
   also many small ephemeral ponds; a characteristic of Spanish steppes,
   which are only water-filled during the winter. From a conservation
   standpoint, such ponds, like nearby segments of the Trabancos River's
   banks, are in a precarious ecological state. Nevertheless, the areas
   are still capable of sustaining the flora and fauna commensurate with a
   natural riverside environment.

   The Trabancos region stands out for its concentration of great bustards
   (more than 2000); as well as having the largest reproductive
   concentration of black-bellied sandgrouses (Pterocles orientalis) in
   Castile and León (with more than 200 mating pairs). It is also the
   winter season nesting ground of more than 1,500 red kites (Milvus
   milvus). There are also numerous birds of prey; the most abundant are
   montagu's harriers (Circus pygargus, 50 mating pairs) and lesser
   kestrels (Falco naumanni; almost 150 mating pairs), but there are also
   hawks, goshawks, falcons, owls, and others. The region is also host to
   numerous gamebirds, including the red-legged partridge (Alectoris
   rufa).

   Despite their importance, the population of little bustard (Tetrax
   tetrax) in the region appear to be diminishing. Although not all the
   species protected in this ZEPA SPA can be listed, the protected area is
   a migratory crossing site and wintertime nesting area which, along with
   the Riberas de Castronuño (Valladolid) nature reserve, is frequented by
   many waterfowl ( cranes, geese, etc.), some of which even take
   advantage of the area ephemeral ponds for nesting during humid winters.

   Great Bustard in Alaejos
   Enlarge

                          Great Bustard in Alaejos

   Running Red-legged Partridge
   Enlarge

                        Running Red-legged Partridge

   Red Kites gathering for the winter season
   Enlarge

                  Red Kites gathering for the winter season

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