Hydrogeomorphology as a Tool in the Evolutionary Analysis of the Dynamic Landscape—Application to Larrodrigo, Salamanca, Spain

Evolutionary analysis of the fluvial landscape provides relevant inputs for the environmental management of a territory, in such a way that the understanding of the dynamics of fluvial spaces becomes a preponderant factor in the definition of protection and management strategies. Although the development of geographic information systems is a step forward in the study of the landscape, it is necessary to establish methodological frameworks that make remote sensing techniques available at multiple spatio-temporal scales, especially in basins with high levels of intervention. In the present study, we develop a methodology for the analysis of the fluvial landscape development in the last century of a highly modified water body, through the detailed study of hydrogeomorphic elements, using remote sensing techniques including high-density surface data (LiDAR) and historical aerial imageries; when supported by fieldwork, these allow for the identification of the sequence of sedimentation–erosion zones, differentiating in detail the zones denominated as areas of current erosion, accretion zones, and historical erosion zones. An application of the methodology was carried out in the Larrodrigo stream, located in Salamanca, Spain.

Shipyards

This chapter provides a history of the Ottoman naval fleet in the Tigris-Euphrates basin, referred to as the Shatt River Fleet in Ottoman bureaucratic parlance. In the sixteenth century, the Ottomans established two shipyards at the two ends of the river basin—Birecik in the north and Basra in the south. Both shipyards became the administrative centers for the Ottoman navy operating on the Tigris and Euphrates. Boats of the Shatt River Fleet were fitted with light cannon pieces and played a combat and support role in Ottoman military operations. They cooperated with land forces based in the fortresses to strengthen the Ottoman presence along the eastern frontier. While the literature on naval warfare in the early modern Military Revolution has largely focused on developments taking place at sea, this chapter shows how the Ottoman Empire adapted the latest naval technologies to a fluvial landscape.

Fluvial landscape evolution controlled by the sediment deposition coefficient: Estimation from experimental and natural landscapes

The evolution of a fluvial landscape is a balance between tectonic uplift, fluvial erosion, and sediment deposition. The erosion term can be expressed according to the stream power model, stating that fluvial incision is proportional to powers of river slope and discharge. The deposition term can be expressed as proportional to the sediment flux divided by a transport length. This length can be defined as the water flux times a scaling factor ζ. This factor exerts a major control on the river dynamics, on the spacing between sedimentary bedforms, or on the overall landscape erosional behavior. Yet, this factor is difficult to measure either in the lab or in the field. Here, we propose a new formulation for the deposition term based on a dimensionless coefficient, G, which can be estimated at the scale of a landscape from the slopes of rivers at the transition between a catchment and its fan. We estimate this deposition coefficient from 29 experimental catchment–alluvial fan systems and 68 natural examples. Based on our data set, we support the idea of Davy and Lague (2009) that G is a relevant parameter to characterize the erosional and transport mode of a fluvial landscape, which can be field calibrated, with a continuum from detachment-limited (G = 0) to transport-limited behavior (G >0.4 from the studied examples).

ESTRUTURA E FRAGMENTAÇÃO GEOECOLÓGICA DE PAISAGEM FLUVIAL NO BAIXO RIO XINGU – AMAZÔNIA CENTRO-ORIENTAL (STRUCTURE AND GEOECOLOGICAL FRAGMENTATION OF THE RIVER LANDSCAPE IN THE LOWER XINGU RIVER - CENTRAL-EASTERN AMAZON)

RESUMO:A análise geoecológica busca subsidiar o planejamento dos usos e da ocupação da paisagem em acordo com seus limites e potencialidades. A área de estudo é uma paisagem fluvial localizada a jusante da Usina Hidrelétrica de Belo Monte, no Baixo Rio Xingu, a qual promove modificações no contexto geoecológico regional e local. O objetivo da pesquisa é entender a estrutura geoecológica de paisagem fluvial no Baixo Rio Xingu, incluindo análise das métricas dos fragmentos que compõem as unidades paisagísticas. Analisou-se a paisagem através de estudo sistêmico e holístico de dados produzidos em atividades de campo, pesquisas bibliográficas e utilizando-se técnicas de sensoriamento remoto e geoprocessamento. O entendimento das inter-relações entre os componentes da paisagem permitiu a identificação e caracterização das unidades de paisagem fluvial e identificou-se que a transgressão do Oceano Atlântico sobre o Rio Amazonas possibilita o aumento e redução diária e pode aumentar ou diminuir sazonalmente as cotas fluviométricas do Rio Xingu, antecipando ou perdurando cheias.Palavras-chave: Fragmentação da Paisagem; Geomorfologia Fluvial; Análise Geoambiental. ABSTRACT:The geoecological analysis seeks to subsidize the planning of the uses and occupation of the landscape in accordance with its limits and potentialities. The study area is river landscape located downstream of the Hydroelectric of Belo Monte on the lower Xingu River, which promotes modifications in the regional geoecological context. In order to understand the geoecological structure of the fluvial landscape in the lower Xingu River, including the analysis of the metrics and fragments that compose it's units. The landscape was analyzed through a systemic and holistic study of data produced in field activities, bibliographical and using remote sensing and geoprocessing techniques. The understanding of the interrelations between the components of the landscape allowed the identification and characterization of the fluvial landscape units. The transgression of the Atlantic Ocean over the Amazon River makes it possible to increase and reduce daily, and may increase or decrease seasonally the Xingu River.Keywords: Landscape Fragmentation; River Geomorphology; Geoenvironmental Analysis.