The effects of large wood (LW) on water and sediment connectivity in river systems: a new LW dis-connectivity index and its application in sediment management contexts

2021 ◽  
Author(s):  
Ronald E. Pöppl ◽  
Hannah Fergg ◽  
Maria T. Wurster ◽  
Anne Schuchardt ◽  
David Morche
Keyword(s):  
Sediment Management ◽  
Connectivity Index ◽  
Large Wood ◽  
Transport Capacity ◽  
Water And Sediment ◽  
Channel Blockage ◽  
Sediment Connectivity ◽  
Channel Hydraulics ◽  
The Relationship ◽  
Mixed Load

<p>It is well known that in-stream large wood (LW) can have significant effects on channel hydraulics and thus water and sediment connectivity, i.e. by creating hydraulic resistance that decreases flow velocity and transport capacity. The relationship between an in-stream LW structure and its hydraulic function (incl. the related effects on water and sediment connectivity) is generally quantified through drag force. Drag analyses, however, are data-demanding and often not straightforward - especially in complex debris jam settings where LW accumulations consist of wood pieces of widely variable sizes. Here, we introduce a simple LW dis-connectivity index (calculated based on visually estimated, field-derived LW parameters such as the degree of channel blockage), which has been applied in different sediment management contexts in medium-sized mixed-load streams in Austria.</p><p> </p>

Spatial-temporal assessment of water and sediment connectivity through a modified connectivity index in a subtropical mountainous catchment

CATENA ◽  
2021 ◽  
Vol 204 ◽  
pp. 105380
Author(s):  
Franciele Zanandrea ◽  
Gean Paulo Michel ◽  
Masato Kobiyama ◽  
Guilherme Censi ◽  
Bruno Henrique Abatti
Keyword(s):  
Connectivity Index ◽  
Mountainous Catchment ◽  
Water And Sediment ◽  
Sediment Connectivity ◽  
Temporal Assessment

Development and application of a sediment connectivity index to small fluvial catchments: a case study in Arenoso stream, Córdoba, Argentina

2021 ◽  
Vol 80 (8) ◽  
Author(s):  
María Jimena Andreazzini ◽  
Susana Beatriz Degiovanni ◽  
María Eugenia Benito ◽  
Karina Vanesa Echevarria
Keyword(s):  
Connectivity Index ◽  
Sediment Connectivity

scholarly journals Flume Experiments Evaluating the Efficacy of a Large Wood Trap Featuring Horizontal Rods

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1837
Author(s):  
Mayuko Furukawa ◽  
Daizo Tsutsumi ◽  
Hironori Muto ◽  
Taro Uchida ◽  
Takuro Suzuki ◽  
...  
Keyword(s):  
Relative Length ◽  
Large Wood ◽  
Basic Information ◽  
Trapping Rate ◽  
Supply Rate ◽  
Flume Experiments ◽  
Water And Sediment ◽  
Constant Rate

Large wood (LW) disasters, which often accompany sediment-related disasters, occur worldwide. To prevent and mitigate such disasters, we developed a unique LW trap featuring horizontal rods aligned with the flow. When LW enters the trap, it is scooped up by the rods and thus separated from water and sediment. We explored trapping efficacy using a flume of slope 0.087. Water circulated at a constant rate of 1.8 L/s, LW was added to the flow, and the trapping rates were measured. We focused on the relative wood length (Lw) with respect to the horizontal rod spacing (Sr), the number of LW units supplied, and the supply rate. A longer relative length (Lw/Sr) of LW was associated with a higher trapping rate. The trapping rate was also high when the LW number or supply rate was high. The critical Lw/Sr value was 1.5; below this value, LW was not trapped. This study yields the basic information needed to design traps featuring horizontal rods to mitigate LW-related disasters.

scholarly journals Response of Variation of Water and Sediment to Landscape Pattern in the Dapoling Watershed

2022 ◽  
Vol 14 (2) ◽  
pp. 678
Author(s):  
Chong Wei ◽  
Zhiqiang Zhang ◽  
Zhiguo Wang ◽  
Lianhai Cao ◽  
Yichang Wei ◽  
...  
Keyword(s):  
Landscape Pattern ◽  
Sediment Yield ◽  
Landscape Heterogeneity ◽  
Swat Model ◽  
Landscape Patterns ◽  
Land Resource ◽  
Low Carbon ◽  
Water And Sediment ◽  
The Relationship ◽  
Runoff And Sediment Yield

The relationship between water-sediment processes and landscape pattern changes has currently become a research hotspot in low-carbon water and land resource optimization research. The SWAT-VRR model is a distributed hydrological model which better shows the effect of land use landscape change on hydrological processes in the watershed. In this paper, the hydrological models of the Dapoling watershed were built, the runoff and sediment yield from 2006 to 2011 were simulated, and the relationship between landscape patterns and water-sediment yield was analyzed. The results show that the SWAT-VRR model is more accurate and reasonable in describing runoff and sediment yield than the SWAT model. The sub-basins whose soil erosion is relatively light are mostly concentrated in the middle reaches with a slope mainly between 0–5°. The NP, PD, ED, SPIIT, SHEI, and SHDI of the watershed increased slightly, and the COHESION, AI, CONTAG, and LPI showed a certain decrease. The landscape pattern is further fragmented, with the degree of landscape heterogeneity increasing and the connection reducing. The runoff, sediment yield and surface runoff are all extremely significantly negatively correlated with forest, which implies that for more complicated patch shapes of forest which have longer boundaries connecting with the patches of other landscape types, the water and sediment processes are regulated more effectively. Therefore, it can be more productive to carry out research on the optimization of water and soil resources under the constraint of carbon emission based on the SWAT-VRR model.

scholarly journals ANALISIS KECEPATAN JATUH SEDIMEN PADA SUNGAI CIBEET, JAWA BARAT

2021 ◽  
Vol 5 (1) ◽  
pp. 45
Author(s):  
Kevin Wijaya Warsito ◽  
Wati Astriningsih Pranoto
Keyword(s):  
Conceptual Understanding ◽  
Settling Velocity ◽  
Soil Mechanics ◽  
River Estuary ◽  
Sediment Concentration ◽  
Water And Sediment ◽  
Sediment Research ◽  
Hydraulics Laboratory ◽  
The Relationship ◽  
Optimum Salinity

Cibeet River is one of the branch of the Citarum river in West Java province with a length of 101 km. Cibeet River is one of the rivers supplying water and sediment to the West Tarum irrigation channel or known as the Kalimalang. In this research, the sample used was in the form of mud taken at the Cibeet River Estuary. This research is focused on settling velocity which is a parameter for sedimentation in order to improve numerical modeling and conceptual understanding of sediment dynamics, especially mud. Sediment research is carried out in the Soil Mechanics laboratory and Hydraulics laboratory. Bottom withdrawal tube experiments were carried out using 5 types of salinity and 6 kinds of sediment concentrations. The purpose of the study was to obtain settling velocity and compare laboratory results with the Stokes law approach and compare the relationship between settling velocity with sediment concentration and salinity. The optimum salinity is obtained at 15 ‰, and the optimum sediment concentration at 4700 ppm with an average fall speed of 37,28 mm / s. The results from the laboratory are not in accordance with the Stokes law due to the influence of flocculation from the cohesive nature of the mud sediment, so that using the Stokes law approach cannot calculate the velocity of falling sediment on the mud. Keywords: concentration; salinity; sediment; settling velocity AbstrakSungai Cibeet merupakan salah satu anak sungai dari sungai Citarum di provinsi Jawa Barat dengan panjang 101 km. Sungai Cibeet merupakan salah satu sungai pemasok air dan sedimen ke saluran irigasi Tarum Barat atau dikenal sebagai Kalimalang. Pada penelitian ini, sampel yang digunakan berupa lumpur yang diambil di Muara Sungai Cibeet. Penelitian ini difokuskan pada kecepatan jatuh sedimen yang merupakan parameter untuk sedimentasi demi meningkatkan permodelan numerik dan pemahaman konsep dari dinamika sedimen terutama lumpur.  Penelitian ini dilakukan di laboratorium Mekanika Tanah dan laboratorium Hidrolika, memakai bottom withdrawal tube, dilakukan dengan menggunakan 5 macam jenis salinitas dan 6 macam konsentrasi sedimen.  Penelitian ini membandingkan antara hasil laboratorium dengan pendekatan yaitu hukum Stokes serta membandingkan hubungan antara konsentrasi sedimen dengan salinitas. Untuk salinitas didapat optimum pada saat 15‰, dan konsentrasi sedimen yang optimum pada saat 4700 ppm dengan kecepatan jatuh rata-rata 37,28 mm/s. Hasil dari laboratorium tidak sesuai dengan pendekatan hukum stokes dikarenakan adanya pengaruh flokulasi dari sifat sedimen lumpur yang kohesif, sehingga menggunakan pendekatan hukum stokes tidak bisa untuk menghitung kecepatan jatuh sedimen pada lumpur.

Mapping water and sediment connectivity

2019 ◽  
Vol 673 ◽  
pp. 763-767 ◽  
Author(s):  
Marco Cavalli ◽  
Damià Vericat ◽  
Paulo Pereira
Keyword(s):  
Water And Sediment ◽  
Sediment Connectivity

Optimal Allocation of High-Speed Railway Mobile Equipment Based on the Passenger Flow

2014 ◽  
Vol 505-506 ◽  
pp. 471-476
Author(s):  
Qing Jie Zheng ◽  
Bao Ming Han ◽  
Hua Li
Keyword(s):  
High Speed ◽  
Optimal Allocation ◽  
Allocation Problem ◽  
Load Factor ◽  
Transport Capacity ◽  
High Speed Railway ◽  
Passenger Flow ◽  
The Relationship ◽  
Passenger Load Factor ◽  
Multiple Units

Based on the relationship between passenger flow and demand of electric multiple units (EMU), a new methodology to calculate the EMU demand and allocate the EMU is proposed, which can meet the demand of passenger as well as avoid the waste of transport capacity. An offline allocation plan of EMU is designed by analyzing the fluctuation in passenger flow, passenger average haul distance, passenger load factor and so on. Using the methodology, the EMU allocation problem is solved through program, which is used in Beijing-Shanghai High-speed Railway to obtain the EMU allocation plan.

scholarly journals Sediments as a Part of the Soil Protection Legislation

2018 ◽  
Vol 7 (1) ◽  
pp. 1-6
Author(s):  
Ľuboš Jurík ◽  
Lucia Palšová ◽  
Ľubica Kopčová
Keyword(s):  
Land Ownership ◽  
Sediment Management ◽  
Soil Protection ◽  
The European Union ◽  
European Level ◽  
Current State ◽  
Protection Legislation ◽  
European Union Legislation ◽  
The Relationship ◽  
Legal Barriers

AbstractThe soil protection has a long tradition in Slovakia. Slovakia has a good and strict legislation on the soil protection. It also includes protection against erosion and degradation. However, there is a certain gap in the legislation in addressing the relationship between the lost soil and the land ownership. It is not clear how the land ownership is changed with soil particles movement along the slope, on which erosion occurs. Even more uncertainty regarding the land ownership occurs if the soil is transferred to the watercourses or water reservoirs, where the soil is transformed into sediments. On the European level, sediment management is not covered by specific regulations. The sediment management is partially addressed in several European directives directly or indirectly. The current legislation in Slovakia is creating economic and legal barriers to the return of the soil from the rivers and the reservoir to its original owners. The paper deals with the current state of explaining the problem with the soil erosion and sediment transport in relation to the valid legislation in Slovakia and the European Union. Legislation addressing the erosion and sediment is not just based on land ownership but also on principles for protection of the environment as the transfer of harmful substances to the soil or water.

scholarly journals HUBUNGAN KANDUNGAN NITRAT DAN FOSFAT PADA AIR DAN SEDIMEN TERHADAP KERAPATAN LAMUN DI PANTAI PRAWEAN BANDENGAN, JEPARA Relationship The Content of Nitrates and Phosphates in Water and Sediment to The Density Seagrass at Prawean Bandengan Beach, Jepara

2020 ◽  
Vol 8 (4) ◽  
pp. 291-299
Author(s):  
Heny Setiani ◽  
Anhar Solichin ◽  
Norma Afiati
Keyword(s):  
Organic Matter ◽  
Growth And Development ◽  
Chemical Elements ◽  
Sampling Technique ◽  
Correlation Factor ◽  
Survey Method ◽  
Purposive Sampling ◽  
Water And Sediment ◽  
The Relationship ◽  
Seagrass Density

Zat hara nitrat dan fosfat merupakan unsur kimia yang sangat penting untuk mendukung pertumbuhan dan perkembangan lamun. Penyerapan nutrien pada kolom air dilakukan oleh daun sedangkan penyerapan nutrien dari sedimen dilakukan oleh akar. Ketersediaan nitrat dan fosfat pada air dan sedimen dipengaruhi oleh ketersediaan bahan organik yang berasal dari aktivitas manusia maupun dari perairan itu sendiri. Penelitian ini dilaksanakan pada bulan Mei 2019. Tujuan dari penelitian ini adalah untuk mengetahui jenis dan kerapatan lamun, kandungan nitrat dan fosfat pada air dan sedimen serta hubungannya terhadap kerapatan lamun. Metode yang digunakan yaitu metode survei dengan teknik purposive sampling. Analisis data menggunakan IBM SPSS Statistics 23. Hasil dari penelitian ini adalah terdapat 5 jenis lamun di Pantai Prawean dengan kerapatan berkisar antara 277 – 421 tegakan/m2 yang masuk dalam kategori sedang hingga rapat. DO berkisar 3,4-5,8 mg/l dan rata-rata bahan organik berkisar 6,34-6,64 mg/l. Rata-rata kandungan nitrat dan fosfat sedimen lebih tinggi dibanding pada air yakni masing-masing berkisar 0,43-0,88 mg/l dan 0,12-0,27 mg/l. Kandungan nitrat dan fosfat pada sedimen memiliki korelasi kuat terhadap kerapatan lamun dengan angka korelasi masing-masing sebesar 0,875 dan 0,718. Hubungan antara nitrat dan fosfat sedimen dengan kerapatan lamun mempunyai angka determinansi regresi (R2) sebesar 0,767 yang berarti kedua nutrien mempunyai pengaruh sebesar 76,7 % terhadap kerapatan lamun. ABSTRACT Nitrate and phosphate are very important chemical elements to support the growth and development of seagrass. Nutrient absorption in the water column is carried out by leaves while absorption of nutrients from sediments is carried out by the roots. The availability of nitrate and phosphate in the water and sediments is influenced by the availability of organic materials derived from human activities as well as from the waters themselves. The research was conducted in May 2019. The purpose of this study was to determine the type and density of seagrass, the content of nitrate and phosphate in water and sediments and their relationship to seagrass density. Survey method with purposive sampling technique were used. Data analysis using IBM SPSS Statistics 23. The results of this study are that there are 5 types of seagrasses on Prawean Beach with densities ranging from 277 - 421 ind/m2 in the medium to tight category. DO ranges from 3.4-5.8 mg/l and the average organic matter ranges from 6.34 to 6.64 mg/l. The average sediment content of nitrate and phosphate is higher than in water, each of which ranges from 0.43-0.88 mg/l and 0.12-0.27 mg/l. The content of nitrate and phosphate in sediments has a strong correlation with seagrass density with correlation factor of 0.875 and 0.718 respectively.  The relationship between nitrate and phosphate sediment with seagrass density has a regression determinant (R2) of 0.767 which means that both nutrients have an effect of 76.7% on seagrass density. 

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