Rock fragments and soil hydrological processes: Significance and progress

It was not until the late Middle Ages that the sea penetrated far into the interior of The Netherlands, thus flooding three quarters of a million hectares of land. Since then half a million hectares have been reclaimed from the sea. The Dutch Government chose to preserve the remaining quarter of a million hectares of shallow sea with mudflats of the Waddensea as a nature reserve. The management objectives are at one hand to preserve all characteristic habitats and species with a minimal interference by human activities in geomorphological and hydrological processes, and at the other hand to guarantee the safety against the sea of the inhabitants of the adjacent mainland and islands and to facilitate certain economic and recreational uses of the Waddensea without jeopardizing the natural qualities. These objectives are being elaborated in managementplans.

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A STELLA-Based Model to Simultaneously Predict Hydrological Processes, N Uptake and Biomass Production in a Eucalyptus Plantation

Forests ◽

10.3390/f12050515 ◽

2021 ◽

Vol 12 (5) ◽

pp. 515

Author(s):

Ying Ouyang ◽

Gary Feng ◽

Heidi Renninger ◽

Theodor D. Leininger ◽

Prem Parajuli ◽

...

Keyword(s):

Water Use ◽

Biomass Production ◽

Net Primary Production ◽

N Uptake ◽

Hydrological Processes ◽

Modeling Tools ◽

Eucalyptus Plantation ◽

Simulation Scenario ◽

Use Efficiency ◽

N Use

Eucalyptus is one of the fastest growing hardwoods for bioenergy production. Currently, few modeling tools exist to simultaneously estimate soil hydrological processes, nitrogen (N) uptake, and biomass production in a eucalyptus plantation. In this study, a STELLA (Structural Thinking and Experiential Learning Laboratory with Animation)-based model was developed to meet this need. After the model calibration and validation, a simulation scenario was developed to assess eucalyptus (E. grandis × urophylla) annual net primary production (ANPP), woody biomass production (WBP), water use efficiency (WUE), and N use efficiency (NUE) for a simulation period of 20 years. Simulation results showed that a typical annual variation pattern was predicted for water use, N uptake, and ANPP, increasing from spring to fall and decreasing from fall to the following winter. Overall, the average NUE during the growth stage was 700 kg/kg. To produce 1000 kg eucalyptus biomass, it required 114.84 m3 of water and 0.92 kg of N. This study suggests that the STELLA-based model is a useful tool to estimate ANPP, WBP, WUE, and NUE in a eucalyptus plantation.

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The use of mineral interfaces in sand-sized volcanic rock fragments to infer mechanical durability

Journal of Palaeogeography ◽

10.1186/s42501-020-00068-8 ◽

2020 ◽

Vol 9 (1) ◽

Author(s):

Emilia Le Pera ◽

Consuele Morrone

Keyword(s):

Volcanic Rock ◽

Rock Fragments ◽

Mechanical Durability ◽

Mineral Interfaces

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Quantifying organic carbon stocks using a stereological profile imaging method to account for rock fragments in stony soils

Geoderma ◽

10.1016/j.geoderma.2020.114837 ◽

2021 ◽

Vol 385 ◽

pp. 114837

Author(s):

Zhuo-Dong Jiang ◽

Qiu-Bing Wang ◽

Kristofor R. Brye ◽

Kabindra Adhikari ◽

Fu-Jun Sun ◽

...

Keyword(s):

Organic Carbon ◽

Carbon Stocks ◽

Imaging Method ◽

Rock Fragments

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Women Advancing Research on Hydrological Processes: Preface

Hydrological Processes ◽

10.1002/hyp.14267 ◽

2021 ◽

Author(s):

Doerthe Tetzlaff ◽

Elizabeth Boyer ◽

Tanya Doody ◽

Anne Jefferson ◽

Annalisa Molini

Keyword(s):

Hydrological Processes

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Stress level effect on mobility of dry granular flows of angular rock fragments

Landslides ◽

10.1007/s10346-021-01687-5 ◽

2021 ◽

Author(s):

B. Cagnoli

Keyword(s):

Stress Level ◽

Granular Flow ◽

High Stress ◽

Granular Flows ◽

Flow Dynamics ◽

Small Scale ◽

Flow Volume ◽

Rock Fragments ◽

Rock Avalanches ◽

Flow Mobility

AbstractGranular flows of angular rock fragments such as rock avalanches and dense pyroclastic flows are simulated numerically by means of the discrete element method. Since large-scale flows generate stresses that are larger than those generated by small-scale flows, the purpose of these simulations is to understand the effect that the stress level has on flow mobility. The results show that granular flows that slide en mass have a flow mobility that is not influenced by the stress level. On the contrary, the stress level governs flow mobility when granular flow dynamics is affected by clast agitation and collisions. This second case occurs on a relatively rougher subsurface where an increase of the stress level causes an increase of flow mobility. The results show also that as the stress level increases, the effect that an increase of flow volume has on flow mobility switches sign from causing a decrease of mobility at low stress level to causing an increase of mobility at high stress level. This latter volume effect corresponds to the famous Heim’s mobility increase with the increase of the volume of large rock avalanches detected so far only in the field and for this reason considered inexplicable without resorting to extraordinary mechanisms. Granular flow dynamics is described in terms of dimensionless scaling parameters in three different granular flow regimes. This paper illustrates for each regime the functional relationship of flow mobility with stress level, flow volume, grain size, channel width, and basal friction.

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Impacts of land use and land cover changes on hydrological processes and sediment yield determined using the SWAT model

International Journal of Sediment Research ◽

10.1016/j.ijsrc.2021.04.002 ◽

2021 ◽

Author(s):

Edivaldo Afonso de Oliveira Serrão ◽

Madson Tavares Silva ◽

Thomás Rocha Ferreira ◽

Lorena Conceição Paiva de Ataide ◽

Cleber Assis dos Santos ◽

...

Keyword(s):

Land Use ◽

Land Cover ◽

Sediment Yield ◽

Swat Model ◽

Hydrological Processes ◽

Land Cover Changes

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Groundwater salinity variation in Upazila Assasuni (southwestern Bangladesh), as steered by surface clay layer thickness, relative elevation and present-day land use

Hydrology and Earth System Sciences ◽

10.5194/hess-23-1431-2019 ◽

2019 ◽

Vol 23 (3) ◽

pp. 1431-1451 ◽

Cited By ~ 5

Author(s):

Floris Loys Naus ◽

Paul Schot ◽

Koos Groen ◽

Kazi Matin Ahmed ◽

Jasper Griffioen

Keyword(s):

Land Use ◽

Drinking Water ◽

Coastal Region ◽

Shallow Depth ◽

Hydrological Processes ◽

Groundwater Salinity ◽

Clay Layer ◽

Fresh Groundwater ◽

Salinity Variation ◽

Clay Layers

Abstract. In the southwestern coastal region of Bangladesh, options for drinking water are limited by groundwater salinity. To protect and improve the drinking water supply, the large variation in groundwater salinity needs to be better understood. This study identifies the palaeo and present-day hydrological processes and their geographical or geological controls that determine variation in groundwater salinity in Upazila Assasuni in southwestern Bangladesh. Our approach involved three steps: a geological reconstruction, based on the literature; fieldwork to collect high-density hydrological and lithological data; and data processing to link the collected data to the geological reconstruction in order to infer the evolution of the groundwater salinity in the study area. Groundwater freshening and salinization patterns were deduced using PHREEQC cation exchange simulations and isotope data were used to derive relevant hydrological processes and water sources. We found that the factor steering the relative importance of palaeo and present-day hydrogeological conditions was the thickness of the Holocene surface clay layer. The groundwater in aquifers under thick surface clay layers is controlled by the palaeohydrological conditions prevailing when the aquifers were buried. The groundwater in aquifers under thin surface clay layers is affected by present-day processes, which vary depending on present-day surface elevation. Slightly higher-lying areas are recharged by rain and rainfed ponds and therefore have fresh groundwater at shallow depth. In contrast, the lower-lying areas with a thin surface clay layer have brackish–saline groundwater at shallow depth because of flooding by marine-influenced water, subsequent infiltration and salinization. Recently, aquaculture ponds in areas with a thin surface clay layer have increased the salinity in the underlying shallow aquifers. We hypothesize that to understand and predict shallow groundwater salinity variation in southwestern Bangladesh, the relative elevation and land use can be used as a first estimate in areas with a thin surface clay layer, while knowledge of palaeohydrogeological conditions is needed in areas with a thick surface clay layer.

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