What Is the Impact of Tectonic Plate Movement on Country Size? A Long-Term Forecast

The Earth’s surface is under permanent alteration with the area of some nations growing or shrinking due to natural or man-made processes, for example sea level change. Here, based on the NUVEL 1A model, we forecast (in 10, 25, and 50 years) the changes in area for countries that are located on the border of the major tectonic plates. In the analysis we identify countries that are projected to gain or lose land due to the tectonic plate movement only. Over the next 50 years, the global balance of area gains (0.4 km2) and losses (12.7 km2) is negative. Thus, due to the movements of lithospheric plates, the land surface of the Earth will decrease by 12 km2 in 50 years. Overall, the changes are not that spectacular, as in the case of changes in sea/water levels, but in some smaller countries, projected losses exceed a few thousand square metres a year, e.g., in Nepal the losses exceed 10,000 m2 year−1. Methodologically, this paper finds itself between metric analysis and essay, trying to provoke useful academic discussion and incite educators’ interests to illustrate to students the tectonic movement and its force. Limitations of the used model have been discussed in the methodology section.

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Modeling the impact of oceanic circulation and marine productivity on Cretaceous seafloor anoxia

10.5194/egusphere-egu2020-20746 ◽

2020 ◽

Author(s):

Yannick Donnadieu ◽

Marie Laugie ◽

Jean-Baptiste Ladant ◽

François Raisson ◽

Laurent Bopp

Keyword(s):

Land Surface ◽

Oceanic Circulation ◽

Equatorial Pacific Ocean ◽

Oxygen Minimum Zones ◽

Tethys Sea ◽

Marine Biogeochemistry ◽

Anoxic Events ◽

Marine Productivity ◽

The Impact

Oceanic anoxic events (OAEs) are abrupt events of widespread deposition of organic-rich sediments and extensive seafloor anoxia. Mechanisms usually invoked as drivers of oceanic anoxia are various and still debated today. They include a rise of the CO2 atmospheric level due to increased volcanic activity, a control by the paleogeography, changes in oceanic circulation or enhanced marine productivity. In order to assess the role of these mechanisms, we use an IPCC-class model, the IPSL-CM5A2 Earth System Model, which couples the atmosphere, land surface, and ocean components, this last one including sea ice, physical oceanography and marine biogeochemistry which allows to simulate oceanic oxygen.We focus here on OAE2, which occurs during the Cretaceous at the Cenomanian-Turonian boundary (93.5 Ma), and is identified as a global event with evidence for seafloor anoxia in the Atlantic and Indian Oceans, the Southwest Tethys Sea and the Equatorial Pacific Ocean. Using a set of simulations from 115 to 70 Ma, we analyze the long-term paleogeographic control on oceanic circulation and consequences on oceanic oxygen concentration and anoxia spreading. Short-term controls such as an increase of pCO2, nutrients, or orbital configurations are also studied with a second set of simulations with a Cenomano-Turonian (90 Ma) paleogeographic configuration. The different simulated maps of oxygen are used to study the evolution of marine productivity and oxygen minimum zones as well as the spreading of seafloor anoxia, in order to unravel the interlocking of the different mechanisms and their specific impact on anoxia through space and time.

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Evaluation of 2018 drought and effectiveness of adaptation measures in the Netherlands

10.5194/egusphere-egu2020-9166 ◽

2020 ◽

Author(s):

Marjolein H.J. van Huijgevoort ◽

Janine A. de Wit ◽

Ruud P. Bartholomeus

Keyword(s):

Soil Moisture ◽

The Netherlands ◽

Capillary Rise ◽

Hydrological Drought ◽

Water Levels ◽

Severe Drought ◽

Drought Event ◽

Groundwater Levels ◽

The Impact

Extreme dry conditions occurred over the summer of 2018 in the Netherlands. This severe drought event led to very low groundwater &#160;and surface water levels. These impacted several sectors like navigation, agriculture, nature and drinking water supply. Especially in the Pleistocene uplands of the Netherlands, the low groundwater levels had a large impact on crop yields and biodiversity in nature areas. Projections show that droughts with this severity will occur more often in the future due to changes in climate. To mitigate the impact of these drought events, water management needs to be altered.In this study, we evaluated the 2018 drought event in the sandy regions of the Netherlands and studied which measures could be most effective to mitigate drought impact. We have included meteorological, soil moisture and hydrological drought and the propagation of the drought through these types. Droughts were determined with standardized indices (e.g. Standardized Precipitation Index) and the variable threshold level method. Investigated measures were, for example, higher water levels in ditches, reduced irrigation from groundwater, and increased water conservation in winter. We also studied the timing of these measures to determine the potential for mitigating effects during a drought versus the effectiveness of long term adaptation. The measures were simulated with the agro-hydrological Soil&#8211;Water&#8211;Atmosphere&#8211;Plant (SWAP) model for several areas across the Netherlands for both agricultural fields and nature sites.As expected, decreasing irrigation from groundwater reduced the severity of the hydrological drought in the region. Severity of the soil moisture drought also decreased in fields that were never irrigated due to the effects of capillary rise from the groundwater, but, as expected, increased in currently irrigated fields. Increasing the level of a weir in ditches had a relatively small effect on the hydrological drought, provided water was available to sustain higher water levels. This measure is, therefore, better suited as a long term change than as ad hoc measure during a drought. The effectiveness of the measures depended on the characteristics of the regions; for some regions small changes led to increases in groundwater levels for several months, whereas in other regions effects were lost after a few weeks. This study gives insight into the most effective measures to mitigate drought impacts in low-lying sandy regions like the Netherlands.

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Seawater Intrusion on the Arctic Coast (Svalbard): The Concept of Onshore-Permafrost Wedge

Geosciences ◽

10.3390/geosciences10090349 ◽

2020 ◽

Vol 10 (9) ◽

pp. 349

Author(s):

Marek Kasprzak

Keyword(s):

Electrical Resistivity ◽

Coastal Zone ◽

Seawater Intrusion ◽

Land Surface ◽

Sea Water ◽

Thermal State ◽

Spring Tide ◽

The Arctic ◽

Short Article ◽

The Impact

Numerous hydrogeological studies on the coastal zone describe the intrusion of sea water inland, salting underground aquifers. The phenomenon is commonly observed in the coasts outside polar areas. However, the impact of sea water has so far not been an object of detailed investigation in a periglacial environment devoid of subsea permafrost. Geophysical measurements at the west coast of the Wedel-Jarlsberg Land in Svalbard indicate that the border between the unfrozen seabed and the frozen ground onshore is not delimited by the shoreline. A zone of coastal unfrozen ground is located under a thin layer of permafrost reaching toward the sea. This state was observed with the use of electrical resistivity tomography under rocky headlands and capes, uplifted marine terraces located at the foot of mountain massifs and valley mouths as well as in the marginal zone of the Werenskiold Glacier. This short article presents the results of such a measurement, supplemented with electromagnetic detection. The measurements are unique in that they were conducted not only on the land surface, but also at the floor of the sea bay during the low water spring tide. The author proposes name structures detected in the coastal zone as a “permafrost wedge”, extending an identification of the permafrost base between the coast and the glaciers of Svalbard. However, in the absence of boreholes that would allow determining the thermal state of the ground in the study sites, the concept is based only on the interpretation of the geophysical imaging. Therefore, further discussion is required on whether the identified contrasts in electrical resistivity indeed result from thermal differences between the rocks or if they only indicate the cryotic state of the ground (saline cryopeg) within the range of seawater intrusion.

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Using Satellite Remote Sensing to Study the Impact of Climate and Anthropogenic Changes in the Mesopotamian Marshlands, Iraq

Remote Sensing ◽

10.3390/rs10101524 ◽

2018 ◽

Vol 10 (10) ◽

pp. 1524 ◽

Cited By ~ 3

Author(s):

Reyadh Albarakat ◽

Venkat Lakshmi ◽

Compton Tucker

Keyword(s):

Land Surface ◽

Vegetation Index ◽

Anthropogenic Activities ◽

Water Levels ◽

Statistical Analyses ◽

Vegetation Coverage ◽

Spatial And Temporal Variability ◽

Landsat Images ◽

The Impact ◽

Annual Discharge

The Iraqi Marshes in Southern Iraq are considered one of the most important wetlands in the world. From 1982 to the present, their area has varied between 10,500 km2 and 20,000 km2. The marshes support a variety of plants, such as reeds and papyrus, and are home to many species of birds. These marshes are Al-Hammar, Central or Al-Amarah, and Al-Huwaiza. Freshwater supplies to the marshes come from the Tigris and Euphrates rivers in Iraq and from the Karkha River from Iran. For this analysis, we used the Land Long-Term Data Record Version 5 (LTDR V5) Normalized Difference Vegetation Index (NDVI) from the Advanced Very High Resolution Radiometer (AVHRR) sensor dataset. This dataset was recently released at a 0.05 × 0.05° spatial resolution and daily temporal resolution to monitor the spatial and temporal variability of vegetation along with other hydrological variables such as land surface temperature, precipitation, and evapotranspiration. In our analysis, we considered three time periods: 1982–1992; 1993–2003; and 2004–2017 due to anthropogenic activities and climate changes. Furthermore, we examined the relationships between various water cycle variables through the investigation of vegetation and water coverage changes, and studied the impacts of climate change and anthropogenic activities on the Iraqi Marshes and considered additional ground observations along with the satellite datasets. Statistical analyses over the last 36 years show significant deterioration in the vegetation: 68.78%, 98.73, and 83.71% of the green biomass has declined for Al-Hammar, The Central marshes, and Al-Huwaiza, respectively. The AVHRR and Landsat images illustrate a decrease in water and vegetation coverage, which in turn has led to an increase in barren lands. Unfortunately, statistical analyses show that marshland degradation is mainly induced by human actions. The shrinkage in water supplies taken by Iraq’s local neighbors (i.e., Turkey, Syria, and Iran) has had a sharp impact on water levels. The annual discharge of the Tigris declined from ~2500–3000 m3/s to ~500 m3/s, and the annual discharge of the Euphrates River declined from ~1500 m3/s to less than 500 m3/s.

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Contribution Analysis of the Spatial-Temporal Changes in Streamflow in a Typical Elevation Transitional Watershed of Southwest China over the Past Six Decades

Forests ◽

10.3390/f10060495 ◽

2019 ◽

Vol 10 (6) ◽

pp. 495 ◽

Cited By ~ 2

Author(s):

Chengcheng Meng ◽

Huilan Zhang ◽

Yujie Wang ◽

Yunqi Wang ◽

Jian Li ◽

...

Keyword(s):

Land Surface ◽

Southwest China ◽

Potential Evapotranspiration ◽

Influencing Factor ◽

Climate Impacts ◽

Spatial And Temporal Scales ◽

Attribution Analysis ◽

Land Surface Parameter ◽

The Impact

Attribution analyses on streamflow variation to changing climate and land surface characteristics are critical in studies of watershed hydrology. However, attribution results may differ greatly on different spatial and temporal scales, which has not been extensively studied previously. This study aims to investigate the spatial-temporal contributions of climate change and underlying surface variation to streamflow alteration using Budyko framework. Jiangling River Watershed (JRW), a typical landform transitional watershed in Southwest China, was chosen as the study area. The watershed was firstly divided into eight sub-basins by hydrologic stations, and hydrometeorological series (1954–2015) were divided into sub-intervals to discriminate spatial-temporal features. The results showed that long-term tendencies of hydrometeorological variables, i.e., precipitation (P), potential evapotranspiration (E0), and runoff depth (R), exhibited clear spatial patterns, which were highly related to topographic characteristics. Additionally, sensitivity analysis, which interpreted the effect of one driving factor by unit change, showed that climate factors P and E0, and catchment characteristics (land surface parameter n) played positive, negative, and negative roles in R, according to elastic coefficients (ε), respectively. The spatial distribution of ε illustrated a greater sensitivity and heterogeneity in the plateau and semi-humid regions (upstream). Moreover, the results from attribution analysis showed that the contribution of the land surface factor accounted for approximately 80% of the R change for the entire JRW, with an obvious spatial variation. Furthermore, tendencies of the contribution rates demonstrated regulations across different sub-regions: a decreasing trend of land surface impacts in trunk stream regions and increasing tendencies in tributary regions, and vice versa for climate impacts. Overall, both hydrometeorological variables and contributions of influencing factors presented regularities in long-term tendencies across different sub-regions. More particularly, the impact of the primary influencing factor on all sub-basins exhibited a decreasing trend over time. The evidence that climate and land surface change act on streamflow in a synergistic way, would complicate the attribution analysis and bring a new challenge to attribution analysis.

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Development and calibration of a global hydrological model for integrated assessment modeling

10.5194/gmd-2017-216 ◽

2017 ◽

Author(s):

Tingju Zhu ◽

Petra Döll ◽

Hannes Müller Schmied ◽

Claudia Ringler ◽

Mark W. Rosegrant

Keyword(s):

Land Surface ◽

Crop Production ◽

Hydrological Model ◽

Computational Cost ◽

Base Flow ◽

Grid Cells ◽

Runoff Generation ◽

Runoff Series ◽

The Impact

Abstract. This paper describes the IMPACT Global Hydrological Model (IGHM), a component of the International Model for Policy Analysis of Agricultural Commodities and Trade (IMPACT) integrated modeling system. IMPACT has been developed in the early 1990s to identify and analyze long-term challenges and opportunities for food, agriculture, and natural resources at global and regional scales and builds on a series of previous food demand and supply projections models developed at the International Food Policy Research Institute since the early 1980s. The IGHM has been developed to assess water availability and variability as drivers of water use and irrigated crop production in IMPACT. It adopts a saturation runoff generation scheme and uses a linear groundwater reservoir to simulate base flow in 0.5º latitude by 0.5º longitude grid cells over the global land surface excluding Antarctica. The IGHM has four cell-specific calibration parameters, which are determined through maximizing the Kling–Gupta efficiency (KGE) with a genetic algorithm at the grid cell level, using gridded natural runoff series generated by the WaterGAP Global Hydrological Model (WGHM). During the calibration and validation periods, globally, the majority of grid cells attain KGE values greater than 0.50. As a meta-model of the more computationally expensive WGHM, IGHM transfers the climate-hydrology dynamics provided by WGHM into the integrated IMPACT model at a lower computational cost and enables coupling hydrology and other related processes considered in IMPACT which are important for analyzing long-term water and food security under a range of environmental and socioeconomic changes.

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Dynamics and Impacting Factors of Ice Regimes in Latvia Inland and Coastal Waters

Proceedings of the Latvian Academy of Sciences Section B Natural Exact and Applied Sciences ◽

10.1515/prolas-2016-0059 ◽

2016 ◽

Vol 70 (6) ◽

pp. 400-408 ◽

Cited By ~ 2

Author(s):

Māris Kļaviņš ◽

Zanita Avotniece ◽

Valērijs Rodinovs

Keyword(s):

Climate Change ◽

Sea Ice ◽

North Atlantic ◽

Sea Water ◽

Inland Waters ◽

The North ◽

The North Atlantic ◽

Ice Regime ◽

The Impact

Abstract The sea ice regime is considered to be a sensitive indicator of climate change. This study investigates long-term changes in the ice regimes of the Gulf of Riga along the coast of Latvia in comparison with those of inland waters. The ice regime of the studied region indicates the impact of climate change related to increasing air and sea water temperatures. Ice cover duration on both the sea and inland waters has decreased during recent decades. In addition, long-term records on ice break in the studied region exhibit a pattern of periodic changes in the intensity of ice regime, while trends of the sea ice regime are not consistent between periods of time. Alternating mild and severe winters also occur. The ice regime was shown to be strongly influenced by large-scale atmospheric circulation processes over the North Atlantic, as indicated by close correlation with the North Atlantic Oscillation index.

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Increased vulnerability of European ecosystems to two consecutive extreme summers

10.5194/egusphere-egu21-1964 ◽

2021 ◽

Author(s):

Ana Bastos ◽

René Orth ◽

Markus Reichstein ◽

Philippe Ciais ◽

Nicolas Viovy ◽

...

Keyword(s):

Central Europe ◽

Land Surface ◽

Vegetation Index ◽

Legacy Effects ◽

The Past ◽

Surface Models ◽

Summer Temperatures ◽

The Impact ◽

Observational Record

Extreme summer temperatures in western and central Europe have become more frequent and heatwaves more prolonged over the past decades. The summer of 2018 was one of the driest and hottest in the observational record and led to losses in vegetation productivity in central Europe by up to 50%. Legacy effects from such extreme summers can affect ecosystem functioning over several years, as vegetation slowly recovers. In 2019 an extremely dry and hot summer was registered again in the region, imposing stress conditions at a time when ecosystems were still recovering from summer 2018.Using Enhanced Vegetation Index (EVI) fields from MODIS, we evaluate how ecosystems in central Europe responded to the occurrence of two consecutive extreme summers. We find that only ca. 21% of the area negatively impacted by drought in summer 2018 fully recovered in 2019.We find that the strongest EVI anomalies in 2018/19 diverge from the long-term relationships between EVI and climate, indicating an increase in ecosystem vulnerability to heat and drought events. Furthermore, 18% of the area showed a worsening of plant status during summer 2019 in spite of drought alleviation, which could be explained by interannual legacy effects from 2018, such as impaired growth and increased biotic disturbances.Land-surface models do not simulate interannual legacy effects from summer 2018 and thereby underestimate the impact of drought in 2019 on ecosystems. The poor representation of drought-induced damage and mortality and lack of biotic disturbances in these models may result in an overestimation of the resilience and stability of temperate ecosystems in the future.

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The changing landscape of Canada's western boreal forest: the current dynamics of permafrost

Canadian Journal of Forest Research ◽

10.1139/x99-214 ◽

2000 ◽

Vol 30 (2) ◽

pp. 283-287 ◽

Cited By ~ 76

Author(s):

Dale H Vitt ◽

Linda A Halsey ◽

Stephen C Zoltai

Keyword(s):

Organic Matter ◽

Little Ice Age ◽

Water Levels ◽

Ice Age ◽

Ecosystem Change ◽

Western Canada ◽

Permafrost Degradation ◽

Organic Matter Accumulation ◽

The Impact

This paper examines the impact that climatic change over the last millennium has had on aggradation and degradation of permafrost peatlands and the associated change in organic matter accumulation. Permafrost reached its southernmost Holocene extent in boreal continental western Canada during the Little Ice Age with 28 800 km2 of permafrost peatland present within a sensitive zone demarcated by permafrost degradation. Subsequent degradation of permafrost has occurred in response to warming, with forested bogs changing to nonforested poor fens, associated with rising water levels. In conjunction with this ecosystem change, long-term net organic matter accumulation increases. As permafrost is in disequilibrium with climate, much of the permafrost that remains is in a relict state. Mapping of past and present permafrost distribution from peatland landforms indicates only 9% has degraded since the Little Ice Age, resulting in a 5% increase in long-term net organic matter accumulation. Of the permafrost that remains, 22% is in disequilibrium, located largely in the northern part of the sensitive zone. Additional loss of forested lands will occur in the future in boreal continental western Canada under present-day climatic conditions as permafrost approaches equilibrium, with a further 11% increase in long-term net organic matter accumulation predicted.

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Lake Mead and Hoover Dam monitoring in Nevada and Arizona states, USA using InSAR

10.5194/egusphere-egu2020-21582 ◽

2020 ◽

Author(s):

Mehdi Darvishi ◽

Georgia Destouni ◽

Fernando Jaramillo

Keyword(s):

Los Angeles ◽

Water Level ◽

Land Surface ◽

Ground Deformation ◽

The United States ◽

Water Levels ◽

Lake Mead ◽

Water Level Changes ◽

Hoover Dam ◽

The Impact

Man-made reservoirs and lakes are key elements in the terrestrial water system. The increased concern about the impact of anthropogenic interventions on and the dynamics of these water resources has given rise to various approaches for representing human-water interactions in land surface models. Synthetic aperture radar interferometry (InSAR) has become a powerful geodetic tool for this purpose, by evidencing changes of ground and water surfaces across time and space. In this research, the Lake Mead and associated Hoover Dam are studied using Small Baseline Subset (SBAS) technique. Lake Mead is the largest reservoir in the United States, in terms of water capacity, supplies water and hydropower for millions of people in Las Vegas, Los Angeles and southwestern part of the USA. In recent years, rising temperature, increasing evaporation and decreasing precipitation have decreased water levels substantially, and probably modified its surrounding groundwater and surface as well.This study aims to identify a hydrology-induced ground deformation around the lake Mead and a probable Hoover dam movement displacement. For the reservoir, we used the SBAS technique using 138 SAR data, including ERS1/2, Envisat, ALOS PALSAR and Sentinel-1, covering a time-spam between 1995 and 2019. For the analysis on the dam, we used the SBAS technique from 2014 to 2019 with descending and ascending modes of Sentinel-1A/B imageries. We found two main deformation patterns around the lake associated with the water level changes. Firstly, ERS and Sentinel-1 data evidenced a ground deformation that manifested itself as as a subsidence pattern in 1995 that has gradually changed into an uplift up to 2019. Secondly, the correlation trend between the deformation and water level changes has changed from negative to positive, with a transition point around March 2008. A possible interpretation for this is that the ground has initially reacted to the water fluctuations in the reservoir before March 2008 but after no longer plays a dominant role in the deformation occurring around the lake. The findings will help us to have a better understanding over the changes happened around the lake due to the water level changes and provide the valuable information for more effective management and maintenance of hydraulic structures and facilities near by the lake and water control in the future.

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