scholarly journals Sediment export in marly badland catchments modulated by frost-cracking intensity, Draix-Bléone Critical Zone Observatory, SE France

2021 ◽  
Author(s):  
Coline Ariagno ◽  
Caroline Le Bouteiller ◽  
Peter van der Beek ◽  
Sébastien Klotz
Keyword(s):  
Predictive Model ◽  
Field Data ◽  
Rainfall Variability ◽  
Critical Zone ◽  
Annual Rainfall ◽  
Weathering Processes ◽  
Frost Weathering ◽  
Critical Zone Observatory ◽  
Sediment Export ◽  
Se France

Abstract. At the interface between the lithosphere and the atmosphere, the critical zone records the complex interactions between erosion, climate, geologic substrate and life, and can be directly monitored. Long data records collected in the sparsely vegetated, steep marly badland catchments of the Draix-Bléone Critical Zone Observatory (CZO), SE France, allow analysing potential climatic controls on long-term regolith dynamics and sediment export. Although widely accepted as a first-order control, rainfall variability does not fully explain the observed inter-annual variability in sediment export, suggesting that regolith production and its controls may modulate the observed pattern of sediment export. Here, we define sediment-export anomalies as the residuals from a predictive model with annual rainfall intensity above a threshold as the control. We then use continuous soil-temperature data, recorded at different locations over multiple years, to highlight the role of frost weathering in regolith production. Several proxies for different frost-weathering processes have been calculated from these data and compared to the sediment-export anomalies, with careful consideration of field data quality. Our results suggest that frost-cracking intensity (linked to ice segregation) can explain about half (47–64 %) of the sediment-export anomalies. In contrast, the number of freeze-thaw cycles (linked to volumetric expansion) has only a minor impact on catchment sediment response. The time spent below 0 °C also correlates well with the sediment-export anomalies and requires fewer field data to be calculated than the frost-cracking intensity. Thus, frost-weathering processes modulate sediment export by controlling regolith production in these catchments and should be taken into account when building a predictive model of sediment export from these badlands under a changing climate.

Sediment export in marly badland catchments controlled by frost cracking intensity, Draix-Bléone CZO, SE France

2021 ◽  
Author(s):  
Coline Ariagno ◽  
Caroline Le Bouteiller ◽  
Peter Van der Beek ◽  
Sébastien Klotz
Keyword(s):  
Chemical Weathering ◽  
Rainfall Variability ◽  
Critical Zone ◽  
Careful Consideration ◽  
Sediment Flux ◽  
Climate Conditions ◽  
Physical Weathering ◽  
Changing Climate ◽  
Sediment Export ◽  
Se France

<p>At the interface between the lithosphere and the atmosphere, the critical zone records the complex interactions between erosion, climate, geologic substrate and life, and can be directly monitored. The sparsely vegetated, steep marly badland catchments of the Draix-Bléone Critical Zone Observatory (CZO), SE France are characterised by high quantities of exported sediment and rapid morphologic changes. Characterizing and understanding the physical weathering processes in this area are key to predict the temporal variability of regolith production and sediment flux, as well as their evolution under changing climate conditions.</p><p>Long data records collected in the Draix-Bléone CZO allow analysing long-term regolith dynamics and climatic control on sediment export. Although widely accepted as the first order control, rainfall variability does not fully explain the observed yearly variability in sediment export, suggesting that regolith production and its controls may contribute to the observed pattern of sediment export. Within the several factors that can influence marls weathering (soil moisture, density, chemical weathering), this study focuses on continuous temperature data, recorded at different locations over multiple years, and aims to highlight the role of frost cracking in regolith production. Several proxies for frost cracking intensity have been calculated from these data and compared to the sediment export anomalies, with careful consideration of field data quality. Our initial results suggest that frost-cracking processes have a significant impact on catchment sediment response and should be taken into account when building a predictive model of sediment export from these catchments under a changing climate.</p>

Landscape response to tipping points in granite weathering: The case of stepped topography in the Southern Sierra Critical Zone Observatory

2011 ◽  
Vol 26 ◽  
pp. S48-S50 ◽  
Author(s):  
Barbara S. Jessup ◽  
W. Jesse Hahm ◽  
Scott N. Miller ◽  
James W. Kirchner ◽  
Clifford S. Riebe
Keyword(s):  
Critical Zone ◽  
Tipping Points ◽  
Critical Zone Observatory ◽  
Landscape Response ◽  
Granite Weathering

scholarly journals China's water sustainability in the 21st century: a climate-informed water risk assessment covering multi-sector water demands

2014 ◽  
Vol 18 (5) ◽  
pp. 1653-1662 ◽  
Author(s):  
X. Chen ◽  
D. Naresh ◽  
L. Upmanu ◽  
Z. Hao ◽  
L. Dong ◽  
...  
Keyword(s):  
Water Stress ◽  
Risk Measures ◽  
Rainfall Variability ◽  
Political Process ◽  
Temporal Distribution ◽  
High Water ◽  
Annual Rainfall ◽  
Water Sustainability ◽  
Domestic Water ◽  
Water Demands

Abstract. China is facing a water resources crisis with growing concerns as to the reliable supply of water for agricultural, industrial and domestic needs. High inter-annual rainfall variability and increasing consumptive use across the country exacerbates the situation further and is a constraint on future development. For water sustainability, it is necessary to examine the differences in water demand and supply and their spatio-temporal distribution in order to quantify the dimensions of the water risk. Here, a detailed quantitative assessment of water risk as measured by the spatial distribution of cumulated deficits for China is presented. Considering daily precipitation and temperature variability over fifty years and the current water demands, risk measures are developed to inform county level water deficits that account for both within-year and across-year variations in climate. We choose political rather than watershed boundaries since economic activity and water use are organized by county and the political process is best informed through that unit. As expected, the risk measures highlight North China Plain counties as highly water stressed. Regions with high water stress have high inter-annual variability in rainfall and now have depleted groundwater aquifers. The stress components due to agricultural, industrial and domestic water demands are illustrated separately to assess the vulnerability of particular sectors within the country to provide a basis for targeted policy analysis for reducing water stress.

No bush foods without people: the essential human dimension to the sustainability of trade in native plant products from desert Australia

2011 ◽  
Vol 33 (4) ◽  
pp. 395 ◽  
Author(s):  
Fiona Walsh ◽  
Josie Douglas
Keyword(s):  
Research And Development ◽  
Reference Group ◽  
Rainfall Variability ◽  
Forest Products ◽  
Annual Rainfall ◽  
Ecological Sustainability ◽  
Small Scale ◽  
Native Plant ◽  
Plant Products ◽  
Trade Offs

Improvement in Aboriginal people’s livelihoods and economic opportunities has been a major aim of increased research and development on bush foods over the past decade. But worldwide the development of trade in non-timber forest products from natural populations has raised questions about the ecological sustainability of harvest. Trade-offs and tensions between commercialisation and cultural values have also been found. We investigated the sustainability of the small-scale commercial harvest and trade in native plant products sourced from central Australian rangelands (including Solanum centrale J.M. Black, Acacia Mill. spp.). We used semi-structured interviews with traders and Aboriginal harvesters, participant observation of trading and harvesting trips, and analysis of species and trader records. An expert Aboriginal reference group guided the project. We found no evidence of either taxa being vulnerable to over-harvest. S. centrale production is enhanced by harvesting when it co-occurs with patch-burning. Extreme fluctuations in productivity of both taxa, due to inter-annual rainfall variability, have a much greater impact on supply than harvest effects. Landscape-scale degradation (including cattle grazing and wildfire) affected ecological sustainability according to participants. By contrast, we found that sustainability of bush food trade is more strongly impacted by social and economic factors. The relationship-based links between harvesters and traders are critical to monetary trade. Harvesters and traders identified access to productive lands and narrow economic margins between costs and returns as issues for the future sustainability of harvest and trade. Harvesters and the reference group emphasised that sustaining bush harvest relies on future generations having necessary knowledge and skills; these are extremely vulnerable to loss. Aboriginal people derive multiple livelihood benefits from harvest and trade. Aboriginal custodians and harvester groups involved in recent trade are more likely to benefit from research and development investment to inter-generational knowledge and skill transfer than from investments in plant breeding and commercial horticultural development. In an inductive comparison, our study found there to be strong alignment between key findings about the strategies used by harvesters and traders in bush produce and the ‘desert system’..

scholarly journals Climatologia da pluviometria do município de Teresina, Piauí, Brasil

2016 ◽  
Vol 11 (4) ◽  
pp. 135
Author(s):  
Hudson Ellen Alencar Menezes ◽  
Raimundo Mainar de Medeiros ◽  
José Lucas Guilherme Santos
Keyword(s):  
Water Resources ◽  
Rainfall Variability ◽  
Intertropical Convergence Zone ◽  
Atmospheric Dynamics ◽  
Rainfall Data ◽  
Annual Rainfall ◽  
Convergence Zone ◽  
Northeast Brazil ◽  
Urban Structures ◽  
Urbanized Areas

<p>As variações nas precipitações refletem claramente a dinâmica atmosférica da região, marcada pela intensa variabilidade, onde se observa a atuação da Zona de Convergência Intertropical (ZCIT) com sua atuação entre os meses de janeiro a março, sendo esse período mais chuvoso. As variabilidades espaço temporal no comportamento das chuvas tem sido analisadas e diagnosticadas por vários autores no Nordeste do Brasil (NEB), portanto objetivou-se diagnosticar a variabilidade dos índices pluviométricos em Teresina no Estado do Piauí no período de 1913 a 2010. A análise do comportamento da precipitação nas cidades de grande e médio porte é de extrema importância para o gerenciamento dos recursos hídricos, uma vez que se trata de áreas densamente urbanizadas. Muitas vezes, sem uma estruturação urbana adequada, estas cidades se encaixam perfeitamente nesse contexto. Foram utilizados dados mensais observados e anuais de precipitação pluviométrica no período de 1913 a 2010, com 97 anos de observações. Os resultados mostraram a recorrência de valores máximos de precipitação anual dentro de um intervalo de 18, 11 e 8 anos. Na análise dos desvios-padrões, os resultados mostraram predominância dos desvios negativos em relação aos desvios positivos.</p><p align="center"><strong><em>Climatology of rainfall in the Teresina city, Piauí state, Brazil</em></strong></p><p>Variations in precipitation clearly reflect the atmospheric dynamics of the region, marked by intense variability, where we observe the performance of the Intertropical Convergence Zone (ITCZ) with his performance in the months of January-March, this being more rain tem period. The timeline of rainfall variability in behavior has been analyzed and diagnosed by several authors in Northeast Brazil (NEB), so let's study this variability between the periods 1913 to 2010 of Teresina city.  The behavior of rainfall in cities large and medium sized is of utmost importance to the managerial of water resources, since it is densely urbanized areas. Often without adequate urban structures these cities fit perfectly in this context. We used observed monthly and annual rainfall data for the period 1913-2010, 97 years of observations. The results showed recurrence of maximum values of annual precipitation an interval of 18, 11 and 8 years. In the analysis of standard deviations, the results showed a predominance of negative deviations from the positive deviations.<strong></strong></p><p align="center"><strong><em><br /></em></strong></p>

scholarly journals Rainfall trend analysis using Mann-Kendall and Sen’s slope estimator test in West Kalimantan

2021 ◽  
Vol 893 (1) ◽  
pp. 012006
Author(s):  
F Aditya ◽  
E Gusmayanti ◽  
J Sudrajat
Keyword(s):  
Climate Change ◽  
Rainfall Variability ◽  
Annual Rainfall ◽  
Sen’S Slope Estimator ◽  
West Kalimantan ◽  
Rainfall Analysis ◽  
Sen’S Slope ◽  
Rainfall Trends ◽  
Slope Estimator ◽  
The Impact

Abstract Climate change has been a prominent issue in the last decade. Climate change on a global scale does not necessarily have the same effect in different regions. Rainfall is a crucial weather element related to climate change. Rainfall trends analysis is an appropriate step in assessing the impact of climate change on water availability and food security. This study examines rainfall variations and changes at West Kalimantan, focusing on Mempawah and Kubu Raya from 2000-2019. The Mann-Kendall (MK) and Sen's Slope estimator test, which can determine rainfall variability and long-term monotonic trends, were utilized to analyze 12 rainfall stations. The findings revealed that the annual rainfall pattern prevailed in all locations. Mempawah region tends to experience a downward trend, while Kubu Raya had an upward trend. However, a significant trend (at 95% confidence level) was identified in Sungai Kunyit with a slope value of -33.20 mm/year. This trend indicates that Sungai Kunyit will become drier in the future. The results of monthly rainfall analysis showed that significant upward and downward trends were detected in eight locations. Rainfall trends indicate that climate change has occurred in this region.

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