Monitoring and Projecting Land Use/Land Cover Changes of Eleven Large Deltaic Areas in Greece from 1945 Onwards

Abstract

Wetlands are areas of high biodiversity and provide many ecosystem services of high value. However, they are under constant threat from intense anthropogenic pressures, mainly agriculture intensification, urbanization, pollution, and climate change. The temporal and spatial patterns of land use/land cover (LULC) changes within eleven large wetlands in Greece were analyzed based on thematic maps generated from aerial orthophotos taken in 1945, 1975, and 2007. Socio-economic developments and the consequent need for more arable land and utilization of water resources are among the factors that mainly determine their evolution. In 2007, LULC classes related to wetland vegetation were reduced to one third as compared to 1945 and they were mainly replaced with croplands and urban infrastructures. Each of the different sub-periods that was considered (1945–1975 and 1975–2007) was distinguished by characteristic patterns of change. Agricultural land increased up to 42% from 1945 to 1975 and became the dominant LULC class in all deltaic areas but Evros. A considerable stability was observed for the period 1975–2007 for all LULC classed but it is remarkable the extent of urban areas that doubled. There is a tendency of landscape simplification and homogenization among the deltaic areas and the output of Markov chain analysis indicates that future composition of deltaic landscapes will be similar to the current one if the main driving forces remain constant. Changes in LULC composition and structure are also combined with coastal erosion in all deltaic areas. This is attributed to the modification of sedimentary deposits due to dam construction. The results summarize the change trajectories of the major deltaic areas in Greece from 1945 to 2007 thus offering a great outlook of changes that allows managers to understand how policies and socio-economic requirements affect the deltaic ecosystems and what decisions should be made to protect and enhance them.

Agricultural Land Abandonment in Bulgaria: A Long-Term Remote Sensing Perspective, 1950–1980

“…With the recent public availability of Hexagon images, reliable methodologies for the geometric correction and classification of these images and integrated usage of these images with another historical geospatial dataset became important. Although there are several studies with Corona KH-4 images, studies with Hexagon images are fairly limited [43,48,87,88]. First studies with Hexagon KH-9 images were generally conducted for glacier monitoring, archaeology, and digital surface model generation, similar to Corona images [48,[50][51][52]54,57,[89][90][91].…”

“…The archive of Corona's declassified satellite images was released and offered for public use in February 1995 [36]. The historical data obtained from the declassified archive of US satellite imageries have been useful in several remote sensing applications, including historical LULCC [37][38][39][40][41][42][43][44][45][46][47]; however, not for Southeast Europe and not in combination with aerial photographs, except for a recent example of combining 1945 aerial photographs with 1975 Hexagon imagery for deltaic areas in Greece [48]. The follow-up Hexagon reconnaissance mission's imagery was declassified in 2002 and 2011.…”

Evaluación del cambio paisajístico reciente del humedal costero Río Maipo, Chile

“…Este aspecto juega un rol relevante en preservar la homeostasis de un humedal, en tanto incrementos en la temperatura de sus aguas pueden conllevar no sólo al deterioro y pérdida de hábitats, sino también a la colonización de especies más tolerantes a este cambio, pudiendo propiciar además la eutrofización del río (Lozano-Peña et al, 2018). Además, la deforestación de esta franja puede minar la provisión de servicios ecosistémicos provistos por el humedal, como control de caudales extremos y retención de escorrentías, reducción de la erosión ribereña y regulación del ciclo de nutrientes; que cuenta con aportes provenientes de los suelos agrícolas predominantes (Engle, 2011;Taddeo y Dronova, 2019;Krina et al, 2020). Cabe señalar también, que la preservación de la franja ripariana del humedal y de su vegetación nativa en general, se ve adicionalmente amenazada por la prolongada megasequía que afecta a Chile central desde 2010 aproximadamente, la que ha aminorado el caudal de ríos exutorios de sus macrocuencas, como el Maipo, afectando consecuentemente la irrigación de sus suelos y mantención de su vegetación (Fuentealba et al 2021).…”

Vegetation Dynamics Due to Urbanization in the Coastal Cities along the Maritime Silk Road

“…Wetland vegetation declined to one-third between 1945 and 2007 [22], which was under constant threats from urbanization and other anthropogenic pressures in Greece. These results provide useful references for managers to recognize how policies and socioeconomic requirements influence ecosystems.…”