scholarly journals A State-Of-The-Art Perspective on the Characterization of Subterranean Estuaries at the Regional Scale

2021 ◽  
Vol 9 ◽  
Author(s):  
Nils Moosdorf ◽  
Michael Ernst Böttcher ◽  
Dini Adyasari ◽  
Ercan Erkul ◽  
Benjamin S. Gilfedder ◽  
...  
Keyword(s):  
Temporal Dynamics ◽  
Regional Scale ◽  
Geophysical Methods ◽  
Coastal Ocean ◽  
Coastal Sediments ◽  
Solute Fluxes ◽  
Spatio Temporal ◽  
Biogeochemical Transformations ◽  
The Impact ◽  
Subterranean Estuaries

Subterranean estuaries the, subsurface mixing zones of terrestrial groundwater and seawater, substantially influence solute fluxes to the oceans. Solutes brought by groundwater from land and solutes brought from the sea can undergo biogeochemical reactions. These are often mediated by microbes and controlled by reactions with coastal sediments, and determine the composition of fluids discharging from STEs (i.e., submarine groundwater discharge), which may have consequences showing in coastal ecosystems. While at the local scale (meters), processes have been intensively studied, the impact of subterranean estuary processes on solute fluxes to the coastal ocean remains poorly constrained at the regional scale (kilometers). In the present communication, we review the processes that occur in STEs, focusing mainly on fluid flow and biogeochemical transformations of nitrogen, phosphorus, carbon, sulfur and trace metals. We highlight the spatio-temporal dynamics and measurable manifestations of those processes. The objective of this contribution is to provide a perspective on how tracer studies, geophysical methods, remote sensing and hydrogeological modeling could exploit such manifestations to estimate the regional-scale impact of processes in STEs on solute fluxes to the coastal ocean.

scholarly journals Investigating the Spatio-Temporal Variation of Soil Moisture and Agricultural Drought towards Supporting Water Resources Management in the Red River Basin of Vietnam

2021 ◽  
Vol 13 (9) ◽  
pp. 4926
Author(s):  
Nguyen Duc Luong ◽  
Nguyen Hoang Hiep ◽  
Thi Hieu Bui
Keyword(s):  
Soil Moisture ◽  
River Basin ◽  
Temporal Dynamics ◽  
Regional Scale ◽  
Dry Season ◽  
Red River ◽  
Agricultural Drought ◽  
Severe Drought ◽  
Red River Basin ◽  
Spatio Temporal

The increasing serious droughts recently might have significant impacts on socioeconomic development in the Red River basin (RRB). This study applied the variable infiltration capacity (VIC) model to investigate spatio-temporal dynamics of soil moisture in the northeast, northwest, and Red River Delta (RRD) regions of the RRB part belongs to territory of Vietnam. The soil moisture dataset simulated for 10 years (2005–2014) was utilized to establish the soil moisture anomaly percentage index (SMAPI) for assessing intensity of agricultural drought. Soil moisture appeared to co-vary with precipitation, air temperature, evapotranspiration, and various features of land cover, topography, and soil type in three regions of the RRB. SMAPI analysis revealed that more areas in the northeast experienced severe droughts compared to those in other regions, especially in the dry season and transitional months. Meanwhile, the northwest mainly suffered from mild drought and a slightly wet condition during the dry season. Different from that, the RRD mainly had moderately to very wet conditions throughout the year. The areas of both agricultural and forested lands associated with severe drought in the dry season were larger than those in the wet season. Generally, VIC-based soil moisture approach offered a feasible solution for improving soil moisture and agricultural drought monitoring capabilities at the regional scale.

scholarly journals Spatio-temporal dynamics of schistosomiasis in Rwanda between 2001 and 2012: impact of the national Neglected Tropical Disease control programme

2017 ◽  
Vol 12 (1) ◽  
Author(s):  
Elias Nyandwi ◽  
Tom Veldkamp ◽  
Frank Badu Osei ◽  
Sherif Amer
Keyword(s):  
Temporal Dynamics ◽  
Public Health Problem ◽  
Incidence Rates ◽  
Control Programme ◽  
Scan Statistics ◽  
Major Public Health Problem ◽  
Implementation Phase ◽  
Incidence Data ◽  
Spatio Temporal ◽  
The Impact

Schistosomiasis is recognised as a major public health problem in Rwanda. We aimed to identify the spatio-temporal dynamics of its distribution at a fine-scale spatial resolution and to explore the impact of control programme interventions. Incidence data of Schistosoma mansoni infection at 367 health facilities were obtained for the period 2001-2012. Disease cluster analyses were conducted using spatial scan statistics and geographic information systems. The impact of control interventions was assessed for three distinct sub-periods. Findings demonstrated persisting, emerging and re-emerging clusters of schistosomiasis infection across space and time. The control programme initially caused an abrupt increase in incidence rates during its implementation phase. However, this was followed by declining and disappearing clusters when the programme was fully in place. The findings presented should contribute to a better understanding of the dynamics of schistosomiasis distribution to be used when implementing future control activities, including prevention and elimination efforts.

Predicting change in biogeochemical potential of subsurface systems with changing hydrogeological conditions

2021 ◽  
Author(s):  
Swamini Khurana ◽  
Falk Heße ◽  
Martin Thullner
Keyword(s):  
Water Quality ◽  
Preferential Flow ◽  
Nutrient Loading ◽  
Temporal Dynamics ◽  
Reaction Network ◽  
Climate Scenario ◽  
Ecosystem Functions ◽  
External Forcing ◽  
Spatio Temporal ◽  
The Impact

<p>In a changing climate scenario, we expect weather event patterns to change, both in frequency and in intensity. The subsequent impacts of these changing patterns on ecosystem functions are of great interest. Water quality particularly is critical due to public health concerns. Already, seasonal variation of water quality has been attributed to varying microbial community assemblages and nutrient loading in the corresponding water body but the contribution of the variations in the quantity of groundwater recharge is a missing link. It is thus beneficial to establish links between external forcing such as changing infiltration rate or recharge on nutrient cycling in the subsurface. We undertake this study to investigate the impact of temporal variation in external forcing on the biogeochemical potential of spatially heterogeneous subsurface systems using a numerical modeling approach. We used geostatistical tools to generate spatial random fields by considering difference combinations of the variance in the log conductivity field and the anisotropy of the domain. Tuning these two parameters assists in effective representation of a wide variety of geologic materials with varying intensity of preferential flow paths in the heterogeneous domain. We ran simulations using OGS#BRNS that enables us to combine a flexibly defined microbial mediated reaction network with the mentioned spatially heterogeneous domains in transient conditions. We propose that a combination of estimated field indicators of Damköhler number, Peclet number (transformed Damköhler number: Da<sub>t</sub>), and projected temporal dynamics in surface conditions can assist us in predicting the change in biogeochemical potential of the subsurface system. Preliminary results indicate that we miss potentially critical variations in reactive species concentration if we neglect spatio-temporal heterogeneities for regimes where 1<Da<sub>t</sub><40. For regimes characterized by values outside this range, we propose that spatio-temporal heterogeneities due to subsurface structure and changing hydrological forcing may not be relevant.</p>

scholarly journals Regional Public Stock Reductions in Spain: Estimations from a Multiregional Spatial Vector Autorregressive Model

REGION ◽  
2017 ◽  
Vol 4 (1) ◽  
pp. 129 ◽  
Author(s):  
Miguel A Márquez ◽  
Julian Ramajo ◽  
Geoffrey Hewings
Keyword(s):  
Economic Growth ◽  
Temporal Dynamics ◽  
Public Investment ◽  
Public Capital ◽  
Regional Economic Growth ◽  
State Variables ◽  
Regional System ◽  
Negative Effect ◽  
Spatio Temporal ◽  
The Impact

The estimation of the impact of public investment on regional economic growth requires consideration of the spatio-temporal dynamics among the state variables of each region.  Recent austerity policies in Spain that feature temporary decreases in the accumulation of regional public capital should thus be evaluated in terms of their impact on the economy as a whole, on specific regions together with the spillovers effects from one region to the rest of the regional system.  Applying a multiregional integrated specification to model interdependencies across regions, our results indicate that, while global decreases in public investment have a homogenously negative effect on the output of all the regions, the Spanish regions portray heterogeneous responses from localized public capital stock reductions over the simulation period considered.

Spatio-Temporal Dynamics of Sociology in Post-1990 Turkey

2019 ◽  
Vol 24 (4) ◽  
pp. 598-616
Author(s):  
Canan Neşe Kınıkoğlu
Keyword(s):  
Temporal Dynamics ◽  
Sociological Research ◽  
Sociological Knowledge ◽  
Social Foundations ◽  
Methodological Nationalism ◽  
Turkish Nationalism ◽  
Spatial Differences ◽  
Phd Theses ◽  
Spatio Temporal ◽  
The Impact

This study explores the spatio-temporal conditions of producing sociological knowledge at universities at a time of transformation in post-1990 (1990–2017) Turkey. Through a content analysis of the sociology PhD theses submitted in this period, it investigates the questions of where, when, and how sociological knowledge is institutionalized in Turkey. The study has two main findings. First, spatial distribution of sociology PhD theses highlights the ensuing centre–periphery relationships inside Turkey, a country itself located in the periphery. Endowed with better resources, the centre (mainly Ankara and Istanbul) focuses on macro solutions to the problems faced by Turkey and other countries, whereas the rest of the country produces knowledge about their immediate surroundings, that is, particular regions/cities/towns of Turkey. This difference illustrates the degrees to which sociological research in post-1990 Turkey is territorially limited by (Turkish) national borders. Second, temporally speaking, the sociological interest in domestic issues revolves mainly around ‘politics’ and ‘economy’, insofar as they relate to the economic crises, neoliberalism, globalization, and democratization attempts Turkey experienced in the post-1990 period. A closer reading of this spatio-temporality may suggest that Turkish sociology is susceptible to methodological nationalism that downplays the impact of nationalism, conforms to the nation-state and nations, and territorially limits the unit of analysis. Despite the transformations brought about by the period and the spatial differences in knowledge production between the centre and the periphery, sociology in Turkey is bound by the national territorial and ideational boundaries, reproducing the ethnic, political, cultural, and social foundations of Turkish nationalism. This study argues that although Turkish sociology stands on the periphery within the non-Western context, it is nonetheless formalized around its own centre–periphery relationship within the country itself, and that its spatio-temporal institutionalization in the post-1990 period has reproduced an implicit methodological nationalism that relies on Turkish nationalism.

An exact solution of a diffusive predator–prey system

2005 ◽  
Vol 461 (2056) ◽  
pp. 1029-1053 ◽  
Author(s):  
Sergei Petrovskii ◽  
Horst Malchow ◽  
Bai-Lian Li
Keyword(s):  
Exact Solution ◽  
Large Time ◽  
Temporal Dynamics ◽  
Nonlinear Partial Differential Equations ◽  
Predator Prey ◽  
Change Of Variables ◽  
Spatio Temporal ◽  
Parameter Values ◽  
The Impact ◽  
Large Time Limit

We consider a system of two nonlinear partial differential equations describing the spatio-temporal dynamics of a predator–prey community where the prey per capita growth rate is damped by the Allee effect. Using an appropriate change of variables, we obtain an exact solution of the system, which appears to be related to the issue of biological invasion. In the large-time limit, or for appropriate parameter values, this solution describes the propagation of a travelling population front. We show that the properties of the solution exhibit biologically reasonable dependence on the parameter values; in particular, it predicts that the travelling front of invasive species can be stopped or reversed owing to the impact of predation.

Spatio Temporal Variability of Rainfall Across Western Libya from 1979 to 2009

2020 ◽  
Vol 6 (3) ◽  
pp. 235-244
Author(s):  
Ali Salem Eddenjal
Keyword(s):  
Time Series ◽  
Rainfall Variability ◽  
Statistical Significance ◽  
Regional Scale ◽  
Policy Makers ◽  
Rain Gauges ◽  
Spatio Temporal ◽  
Annual Scale ◽  
Increasing Trends ◽  
The Impact

Aims: To understand the links between climate variability and hydrology in western Libya. Background: This study represents the first comprehensive assessment of rainfall variability in western Libya at a regional scale. Objective: To assess temporal and spatial variability of rainfall in western Libya, based on data (1979-2009) from 16 rain gauges. Methods: The non-parametric Mann-Kendall method and Sen’s slop estimator were used to define changes in rainfall series and their statistical significance. Results: Coastal and mountainous time series showed decreasing trends at the annual, autumn, and spring scales, with very few exceptions. Notably, winter showed increasing trends, with the significant values of 1.94 and 0.88 mm/year at Sirt and Nalut, respectively. Desert stations showed increasing trends, especially at the annual scale, with the greatest significant increase on the order of 1.19 mm/year in Ghadames. For the regional rainfall trend analysis, annual, spring and autumn rainfalls decreased in the coastal and mountainous zones, with the highest significant decrease of 1.94 mm/year. Again, winter rainfall showed increasing trend over the whole study domain. Conclusion: Although most time series showed a tendency towards more drier conditions, most of the detected trends were statistically non-significant. This study will provide guidance for policy makers in their future planning to mitigate the impact of drought.

scholarly journals Telecoupled Food Trade Affects Pericoupled Trade and Intracoupled Production

2019 ◽  
Vol 11 (10) ◽  
pp. 2908 ◽  
Author(s):  
Anna Herzberger ◽  
Min Gon Chung ◽  
Kelly Kapsar ◽  
Kenneth A. Frank ◽  
Jianguo Liu
Keyword(s):  
Temporal Dynamics ◽  
Moving Average ◽  
Trade Networks ◽  
Autoregressive Integrated Moving Average ◽  
Food Trade ◽  
Political Landscape ◽  
Moving Average Models ◽  
Trade Relationships ◽  
Spatio Temporal ◽  
The Impact

Technology, transportation and global appetites have transformed trade relationships between near and distant countries. The impact of distant food demand on local agricultural production and trade has attracted considerable scientific scrutiny, yet little is known about how distant trade affects trade relationships and production between adjacent countries. In this paper, we explore this important issue by examining international food trade and agriculture production, which represent how distant places are connected through trade networks. By analyzing patterns of soybean, corn and wheat trading between 1991–2016 under the framework of metacoupling (human-nature interactions within, as well as between adjacent and distant systems), this study provides new insights into the spatio-temporal dynamics of trade flows. Results reveal that telecoupled (between distant countries) trade interacts with the geo-political landscape to enhance or offset intracoupled (within country) production and pericoupled (between neighboring countries) trade. Evidence from the literature and the results of autoregressive integrated moving average models indicate that when restrictions are placed on distant export routes, pericoupled trade increased. The extent to which the telecoupled food trade affected the pericoupled trade and intracoupled processes holds implications for the true extent of production driven by distant demands.

Spatio-Temporal Dynamics of Soil Geochemical Anomalies in the Zone of Impact of Slag Residuals

2019 ◽  
Vol 23 (3) ◽  
pp. 44-48 ◽  
Author(s):  
L.P. Stepanova ◽  
E.V. Yakovleva ◽  
A.V. Pisareva
Keyword(s):  
Heavy Metals ◽  
Forest Soils ◽  
Temporal Dynamics ◽  
Total Content ◽  
Gray Forest Soils ◽  
Humus Layer ◽  
Spatio Temporal ◽  
Slag Dump ◽  
The Impact ◽  
The Village

The 13-year-old (from 2003 to 2016) dynamics of soil contamination for the content of heavy metals in the area of the village of Bolshoye Dumchino of the Mtsensk District in the territory adjacent to the slag dump of Mtsensk Foundry was studied. It is shown that on the territory of the placement of slag residuals a techno geochemical anomaly is formed, in which the contained heavy metals are of technogenic and genetic (natural geochemical) nature. To identify the effect of anthropogenic factor on soil pollution with heavy metals, was determined the refined enrichment factor of heavy metals (EFHM) in light gray forest soils at different distances from the slag dump, allowing to calculate the proportion of technogeneity of metals as a percentage of its total content. The technogenic origin of heavy metals as pollutants and the role of humus soil horizons in fixing these metals in the soil profile have been proven. Analysis of the results characterizing the degree of enrichment of the genetic horizons of light gray forest soils with heavy metals for the period 2003–2016 convincingly proves the effect of maximum accumulation of slag residuals in the dump on the accumulation intensity and fixation of the studied metals, both in the upper humus layer and their distribution in the profile soil. The established patterns in changing the degree of enrichment and technogenicity of heavy metals in the profile of light-gray forest soil are caused not only by the impact of the slag dump as a source of pollution, but also by the peculiarities of using the soils of the studied territories. It is shown that the toxic load for the analyzed period not only did not decrease, but even increased.

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