scholarly journals High resolution bed level change and synchronized biophysical data from 10 tidal flats in northwestern Europe

2020 ◽  
Author(s):  
Zhan Hu ◽  
Pim W. J. M. Willemsen ◽  
Bas W. Borsje ◽  
Chen Wang ◽  
Heng Wang ◽  
...  

Abstract. Tidal flats provide valuable ecosystem services such as flood protection and carbon sequestration. Erosion and accretion processes govern the eco-geomorphic evolution of intertidal ecosystems (marshes and bare flats), and hence substantially affect their valuable ecosystem services. To understand the intertidal ecosystem development, high-frequency bed-level change data are thus needed. However, such datasets are scarce due to the lack of suitable methods that do not involve excessive labour and/or instrument cost. By applying newly-developed Surface Elevation Dynamics sensors (SED-sensors), we obtained unique high-resolution daily bed-level change data sets in the period 2013–2017 from 10 salt marsh sites situated in the Netherlands, Belgium and Britain in contrasting physical and biological settings. At each site, multiple sensors were deployed for 9–20 months to ensure sufficient spatial and temporal coverage of highly variable bed level change processes. The bed level change data are provided with synchronized hydrodynamic data, i.e. water level, wave height, tidal current velocity, and medium grain size (D50) as well as (for some sites) chlorophyll-a level and organic matter content of the surface sediment. This dataset has revealed diverse spatial morphodynamic patterns over daily to seasonal scales, which are valuable to theoretical and model development. On the daily scale, this dataset is particularly instructive as it includes a number of storm events, the response to which can be detected in the bed level change observations. Such data are rare but useful to study tidal flat response to highly energetic conditions. The dataset is available from the 4TU.Centre for Research Data (https://doi.org/10.4121/uuid:4830dbc2-84b8-46f9-99a3- 90f01ab5b923, Hu et al., 2020), which is expected to expand with additional SED-sensor data from ongoing and planned surveys.

2021 ◽  
Vol 13 (2) ◽  
pp. 405-416
Author(s):  
Zhan Hu ◽  
Pim W. J. M. Willemsen ◽  
Bas W. Borsje ◽  
Chen Wang ◽  
Heng Wang ◽  
...  

Abstract. Tidal flats provide valuable ecosystem services such as flood protection and carbon sequestration. Erosion and accretion processes govern the ecogeomorphic evolution of intertidal ecosystems (marshes and bare flats) and, hence, substantially affect their valuable ecosystem services. To understand the intertidal ecosystem development, high-frequency bed-level change data are thus needed. However, such datasets are scarce due to the lack of suitable methods that do not involve excessive labour and/or costly instruments. By applying newly developed surface elevation dynamics (SED) sensors, we obtained unique high-resolution daily bed-level change datasets in the period 2013–2017 from 10 marsh–mudflat sites situated in the Netherlands, Belgium, and the United Kingdom in contrasting physical and biological settings. At each site, multiple sensors were deployed for 9–20 months to ensure sufficient spatial and temporal coverage of highly variable bed-level change processes. The bed-level change data are provided with synchronized hydrodynamic data, i.e. water level, wave height, tidal current velocity, medium sediment grain size (D50), and chlorophyll a level at four sites. This dataset has revealed diverse spatial morphodynamics patterns over daily to seasonal scales, which are valuable to theoretical and model development. On the daily scale, this dataset is particularly instructive, as it includes a number of storm events, the response to which can be detected in the bed-level change observations. Such data are rare but useful to study tidal flat response to highly energetic conditions. The dataset is available from 4TU.ResearchData (https://doi.org/10.4121/12693254.v4; Hu et al., 2020), which is expected to expand with additional SED sensor data from ongoing and planned surveys.


Water ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1640
Author(s):  
John Robotham ◽  
Gareth Old ◽  
Ponnambalam Rameshwaran ◽  
David Sear ◽  
David Gasca-Tucker ◽  
...  

The creation of ponds and wetlands has the potential to alleviate stream water quality impairment in catchments affected by diffuse agricultural pollution. Understanding the hydrological and biogeochemical functioning of these features is important in determining their effectiveness at mitigating pollution. This study investigated sediment and nutrient retention in three connected (on-line) ponds on a lowland headwater stream by sampling inflowing and outflowing concentrations during base and storm flows. Sediment trapping devices were used to quantify sediment and phosphorus accumulations within ponds over approximately monthly periods. The organic matter content and particle size composition of accumulated sediment were also measured. The ponds retained dissolved nitrate, soluble reactive phosphorus and suspended solids during baseflows. During small to moderate storm events, some ponds were able to reduce peak concentrations and loads of suspended solids and phosphorus; however, during large magnitude events, resuspension of deposited sediment resulted in net loss. Ponds filtered out larger particles most effectively. Between August 2019 and March 2020, the ponds accumulated 0.306 t ha−1 sediment from the 30 ha contributing area. During this period, total sediment accumulations in ponds were estimated to equal 7.6% of the suspended flux leaving the 340 ha catchment downstream. This study demonstrates the complexity of pollutant retention dynamics in on-line ponds and highlights how their effectiveness can be influenced by the timing and magnitude of events.


Geophysics ◽  
2016 ◽  
Vol 81 (1) ◽  
pp. WA247-WA263 ◽  
Author(s):  
Baptiste Dafflon ◽  
Susan Hubbard ◽  
Craig Ulrich ◽  
John Peterson ◽  
Yuxin Wu ◽  
...  

Shallow permafrost distribution and characteristics are important for predicting ecosystem feedbacks to a changing climate over decadal to century timescales because they can drive active layer deepening and land surface deformation, which in turn can significantly affect hydrologic and biogeochemical responses, including greenhouse gas dynamics. As part of the U.S. Department of Energy Next-Generation Ecosystem Experiments-Arctic, we have investigated shallow Arctic permafrost characteristics at a site in Barrow, Alaska, with the objective of improving our understanding of the spatial distribution of shallow permafrost, its associated properties, and its links with landscape microtopography. To meet this objective, we have acquired and integrated a variety of information, including electric resistance tomography data, frequency-domain electromagnetic induction data, laboratory core analysis, petrophysical studies, high-resolution digital surface models, and color mosaics inferred from kite-based landscape imaging. The results of our study provide a comprehensive and high-resolution examination of the distribution and nature of shallow permafrost in the Arctic tundra, including the estimation of ice content, porosity, and salinity. Among other results, porosity in the top 2 m varied between 85% (besides ice wedges) and 40%, and was negatively correlated with fluid salinity. Salinity directly influenced ice and unfrozen water content and indirectly influenced the soil organic matter content. A relatively continuous but depth-variable increase in salinity led to a partially unfrozen saline layer (cryopeg) located below the top of the permafrost. The cryopeg environment could lead to year-round microbial production of greenhouse gases. Results also indicated a covariability between topography and permafrost characteristics including ice-wedge and salinity distribution. In addition to providing insight about the Arctic ecosystem, through integration of lab-based petrophysical results with field data, this study also quantified the key controls on electric resistivity at this Arctic permafrost site, including salinity, porosity, water content, ice content, soil organic matter content, and lithologic properties.


2021 ◽  
Vol 8 ◽  
Author(s):  
Wei-Jen Lin ◽  
Ming-Chih Chiu ◽  
Chiao-Wen Lin ◽  
Hsing-Juh Lin

The contribution of unvegetated tidal flats to global net primary production is comparable to that of some vegetated coastal habitats. However, compared to carbon flux regulating factors in vegetated habitats, those in unvegetated tidal flats are not well understood, particularly in terms of their cause-effect relationships. Maximum gross primary production (GPPm), net primary production (NPP) and total respiration (TR) during emersion at noon when the irradiance level was at the saturation level for photosynthesis in nine unvegetated tidal flats across the Taiwan Strait in tropical and subtropical regions were determined in winter and summer from 2011 to 2016 to examine the direct and indirect relationships between sediment characteristics and carbon fluxes by using structural equation models (SEM). Most of the GPPm and NPP values were higher in winter than in summer. Conversely, the TR values were higher in summer than in winter. The NPP values at some sites shifted to negative values in summer, indicating the sites were carbon sources. The values of GPPm, TR and NPP for the tidal flats all increased significantly with increasing sediment mud content. The SEM results showed that the sediment mud content directly increased GPPm or indirectly increased GPPm via a compositional shift in benthic microalgae. The sediment mud content also directly increased TR or indirectly increased TR via increased organic matter content. The contribution of benthic microalgal and macrofaunal biomass to TR was relatively minor. This result suggests that primary production was stimulated mainly by the organic matter content rather than by increased microalgal biomass. With the integrated SEM framework, our results showed mechanistic evidence of how sediment mud content acted as a critical factor regulating carbon fluxes in unvegetated tidal flats.


Author(s):  
O. A. Lipatnikova

The study of heavy metal speciation in bottom sediments of the Vyshnevolotsky water reservoir is presented in this paper. Sequential selective procedure was used to determine the heavy metal speciation in bottom sediments and thermodynamic calculation — to determine ones in interstitial water. It has been shown that Mn are mainly presented in exchangeable and carbonate forms; for Fe, Zn, Pb и Co the forms are related to iron and manganese hydroxides is played an important role; and Cu and Ni are mainly associated with organic matter. In interstitial waters the main forms of heavy metal speciation are free ions for Zn, Ni, Co and Cd, carbonate complexes for Pb, fulvate complexes for Cu. Effects of particle size and organic matter content in sediments on distribution of mobile and potentially mobile forms of toxic elements have been revealed.


Author(s):  
Amita M Watkar ◽  

Soil, itself means Soul of Infinite Life. Soil is the naturally occurring unconsolidated or loose covering on the earth’s surface. Physical properties depend upon the amount, size, shape, arrangement, and mineral composition of soil particles. It also depends on the organic matter content and pore spaces. Chemical properties depend on the Inorganic and organic matter present in the soil. Soils are the essential components of the environment and foundation resources for nearly all types of land use, besides being the most important component of sustainable agriculture. Therefore, assessment of soil quality and its direction of change with time is an ideal and primary indicator of sustainable agricultural land management. Soil quality indicators refer to measurable soil attributes that influence the capacity of a soil to function, within the limits imposed by the ecosystem, to preserve biological productivity and environmental quality and promote plant, animal and human health. The present study is to assess these soil attributes such as physical and chemical properties season-wise.


2017 ◽  
Vol 13 (2) ◽  
pp. 74-77
Author(s):  
Imelda J Lawalatta ◽  
Francina Matulessy ◽  
Meitty L Hehanussa

Chili (Capsicum annum L.) often experience the highest price fluctuations in Indonesia. This is caused by the production that is often disrupted in certain months, especially in the months in the rainy season due to flowers and fruits that fall before the harvest. Since agricultural land has changed its function for infrastructure development, marginal land (Ultisol) is used. The ultisol problem is: high acidity, low organic matter content, nutrient deficiency important for plants (eg N, P, Ca, Mg and Mo) and high solubility of Al, Fe and Mn. The provision of organic materials such as manure and marine mud will overcome the problem of acid-rich mineral soil and play an important role in improving, increased and maintaining sustainable land productivity. Research results for chili flower significantly. the highest number of flowers found in the treatment of L0P3, L1P2, L1P3 and L2P3 that is > 60 flower/plant. There was a single factor effect for the amount of fruit, mostly found in L3 treatment (600 ton/ha marine mud) that is 22.36 fruit/plant. The treatment of manure significantly influenced the formation of the most fruit set in the treatment of P0 and P2 (without manure and manure 20 ton/ha) that is 77.60% and 70.,45%. Keywords: Ultisol, Marine mud, Manure, Flowers and Fruit sets   ABSTRAK Tanaman cabai besar (Capsicum annum L.) sering mengalami fluktuasi harga paling tinggi di Indonesia. Hal tersebut disebabkan oleh produksi yang sering terganggu pada bulan tertentu terutama pada bulan-bulan di musim penghujan dikarenakan bunga dan buah yang rontok sebelum panen. Karena lahan pertanian banyak beralih fungsinya untuk pembangunan infrastuktur, maka digunakan lahan marginal (Ultisol). Masalah ultisol ialah: kemasaman tinggi, kadar bahan organik yang rendah, kekurangan unsur hara penting bagi tanaman (contoh: N, P, Ca, Mg dan Mo) serta tingginya kelarutan Al, Fe dan Mn. Pemberian bahan organik seperti pupuk kandang dan Lumpur laut akan mengatasi persoalan tanah mineral masam berkadar Al tinggi dan berperan penting dalam memperbaiki, meningkatkan serta mempertahankan produktifitas lahan secara berkelanjutan Hasil Penelitian untuk jumlah bunga cabai berpengaruh signifikan. jumlah bunga terbanyak terdapat pada perlakuan L0P3, L1P2, L1P3 dan L2P3 yaitu > 60 bunga/tanaman. Terjadi pengaruh faktor tunggal untuk jumlah buah, terbanyak terdapat pada perlakuan L3 ( 600 ton/ha lumpur laut) yaitu 22,36 buah/tanaman. Perlakuan pupuk kandang berpengaruh signifikan Pembentukan fruit set terbanyak pada perlakuan P0 dan P2 (tanpa pupuk kandang dan pupuk kandang 20 ton/ha) yaitu 77,60% dan 70,45%. Kata kunci: Ultisol, Lumpur Laut, Pupuk Kandang, Bunga dan Fruit set


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