scholarly journals Nonflood Flow May Be Major Driver of Delta Growth

Eos ◽  
2017 ◽  
Author(s):  
Sarah Stanley

Plants and fluctuating river flow work together to balance vertical sediment buildup with sediment delivery to the delta’s edge.


2021 ◽  
Vol 925 (1) ◽  
pp. 012029
Author(s):  
E Djunarsjah ◽  
M M Julian ◽  
N R Alfandi ◽  
A A Baskoro

Abstract The watershed is an area above or higher than a river whose topographical boundaries cause water to flow into the same river. The river flow carries sediment particles that potentially cause silting of the estuary area. The sediment carried by the river flows from the erosion process that occurs in the watershed. Changes in land cover potentially affect the rate of sediment export to rivers due to changes in surface roughness and water infiltration rate to the ground. This study aims to identify the effect of the land cover change on the total sediment yield from the Peusangan Watershed, Aceh Province. The sediment yield is calculated from the erosion rate and the sediment delivery ratio. The erosion rate is modeled using the revised universal soil loss equation, while the sediment delivery ratio is calculated based on the function of the watershed area. From the results of the calculation, in general, the rate of erosion is at a very level where the average erosion rate in 1995 is 26,715 tons/ha/year, in 2005 it is 26,886 tons/ha/year, in 2015 it is 24,959 tons/ha/year and in 2018 amounted to 26,771 tons/ha/year. With a sediment delivery ratio value of 0.180, The total sediment yield was 1,083,148.20 tons in 1995, 1,090,047.94 tons in 2005, 1,011,920.71 tons in 2015, and 1,085,398.35 tons in 2018. The identification results show that the changes in land cover affect the total sediment yield that comes out of the watershed.



2018 ◽  
Vol 6 (2) ◽  
pp. 161
Author(s):  
Beny Tribiyono ◽  
S. B. Yuwono ◽  
I. S. Banuwa

Watershed The process of River Flow (DAS) conducted by humans is incorrect, causing damage and bad conditions to the environment on the downstream. Unregulated land use with land and air formulations in the Upper DAS section contains the amount of erosion. One of the main problems occurring in the Sekampung Hulu Basin is the magnitude of erosion. The erosion will increase the rate of erosion and the amount of sediment entering the river. The study aims to (1) estimate sediment potential in DAM Batutegi and (2) estimate erosion in Sekampung Hulu Basin with SDR method (Sediment Delivery Ratio). Based on the analysis result, the total value of sediment potential in DAM Batutegi is 83.478,74 ton/year or equivalent with sediment thickness of 5.04 mm/year and the average value obtained by SDR method in Sekampung Hulu Basin is on average 140,31 ton/ha/year.Proses perlakuan pemanfaatanDaerah Aliran Sungai (DAS) yang dilakukan oleh manusia secara tidak benar, menimbulkan kerusakan dan kondisiyang buruk terhadap lingkungan pada bagian hilir. Pemakaian pada lahan yang tidak setaraf dengan rumusan-rumusan konservasi tanah dan air di bagian hulu DAS menimbulkanbesarnya erosi. Salah satu permasalahan utama yang sering terjadi di DAS Sekampung Hulu adalah besarnya erosi. Erosi yang terjadi akan meningkatkan laju erosi dan jumlah sedimen yang masuk ke sungai. Penelitian bertujuan (1) memperkirakan besarnya potensi sedimen di DAM Batutegi dan (2) memperkirakan erosi di DAS Sekampung Hulu dengan metode SDR (Sediment Delivery Ratio). Diketahui berdasarkan hasil analisis, nilai total potensisedimen di DAM Batutegi sebesar 83.478,74 ton/tahun atau sepadan dengan ketebalan sedimen sebesar 5,04 mm/tahun dan nilai estimasierosi yang didapatkan dengan metode SDR di DAS Sekampung Hulu rata-rata sebesar 140,31 ton/ha/tahun.



2017 ◽  
Vol 3 (2) ◽  
pp. 451-474 ◽  
Author(s):  
Maxime Jolivel ◽  
Michel Allard

In order to assess the impact of seasonal active layer thaw and thermokarst on river flow and turbidity, a gauging station was installed near the mouth of the Sheldrake River in the discontinuous permafrost zone of northern Quebec. The station provided 5 years of water level data and 3 years of turbidity data. The hydrological data for the river showed the usual high water stage occurring at spring snowmelt, with smaller peaks related to rain events in summer. Larger and longer turbidity peaks also occurred in summer in response to warm air temperature spells, suggesting that a large part of the annual suspension load was carried during midsummer turbidity peaks. Supported by geomorphological observations across the catchment area, the most plausible interpretation is that the rapid thawing of the active layer during warm conditions in July led to the activation of frostboils and triggered landslides throughout the river catchment, thus increasing soil erosion and raising sediment delivery into the hydrological network. These results indicate that maximum sediment discharge in a thermokarst-affected region may be predominantly driven by the rate of summer thawing and associated activation of erosion features in the catchment.



2018 ◽  
Vol 4 (1) ◽  
pp. 32-38
Author(s):  
Bhimo Rizky Samudro ◽  
Yogi Pasca Pratama

This paper will describe the function of water resources to support business activities in Surakarta regency, Central Java province. Surakarta is a business city in Central Java province with small business enterprises and specific culture. This city has a famous river with the name is Bengawan Solo. Bengawan Solo is a River Flow Regional (RFR) to support business activities in Surakarta regency. Concious with the function, societies and local government in Surakarta must to manage the sustainability of River Flow Regional (RFR) Bengawan Solo. It is important to manage the sustainability of business activity in Surakarta regency.   According to the condition in Surakarta regency, this paper will explain how the simulation of Low Impact Development Model in Surakarta regency. Low Impact Development is a model that can manage and evaluate sustainability of water resources in River Flow Regional (RFR). Low Impact Development can analys goals, structures, and process water resources management. The system can also evaluate results and impacts of water resources management. From this study, we hope that Low Impact Development can manage water resources in River Flow Regional (RFR) Bengawan Solo.  



2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Raka Maulana ◽  
Yulianti Pratama ◽  
Lina Apriyanti

<p>Some areas in the city of Bandung is an area that dilitasi by the flow of the river, to prevent the introduction of garbage into the river basin is necessary to note the waste management systems in residential areas along the river. Cidurian river has a length of 24.86 Km along the river flow. Consists of the city of Bandung and Bandung regency. Administrative regions Cidurian River past eight (8) districts, from the region in the District Kiaracondong precisely Village Babakan Babakan Sari and Surabaya populous and the most densely populated. Thus, there should be community-based waste management in the form of a reduction in resources to prevent potential entry of waste into the river basin. Planning waste reduction will be divided into two, namely the reduction of inorganic waste with waste bank then the reduction of organic waste with absorption holes biopori, and bio reactor mini determination of the reduction is determined by the results of the analysis of the sampling covers the composition and garbage, then the result of the measurement characteristics test and analysis results questionnaire.</p>



2019 ◽  
Vol 7 (2) ◽  
pp. 100-111
Author(s):  
Miskar Maini ◽  
Junita Eka Susanti

Standar permintaan engineering pesawat agar desain bangunan infrastruktur di area Air Strip Runway 2600 yang ada dapat mempunyai fungsi lain. Sedangkan kondisi lain sangat menentukan keselamatan karena lahan di sekitar Air Strip Runway 2600 Bandara Depati Amir (PGK) jika tidak ditutupi vegetasi seperti rumput, kondisi lain lahan yang belum ditutupi vegetasi di sekitar Air Strip Runway 2600 berpotensi akan mengalami erosi lahan, kemudian hasil erosi lahan ini akan terbawa oleh aliran air sehingga akan masuk ke saluran drainase yang akan menyebabkan sedimentasi pada saluran drainase tersebut, akhirnya akan berkurang efektifitas kinerja saluran drainase tersebut. Metode yang digunakan untuk memprediksi laju rata-rata erosi di area Air Strip Runway 2600 dengan memperhitungkan faktor erosivitas hujan, erodibilitas tanah, kemiringan lereng atau panjang lereng, pengelolaan tanaman dan konservasi tanah, yang masing masing tata guna lahan tersebut mengacu pada Masterplan Ultimate Bandara Depati Amir (PGK). Perhitungan dilakukan menggunakan persamaan USLE (Universal Soil Loss Equation) yang dikembangkan oleh Wischmeier dan Smith (1965, 1978), kemudian Sediment Delivery Ratio (SDR) dan Sediment Yield.Hasil penelitian ini, prediksi laju erosi permukaan pada area Air Strip Runway 2600 Bandara Depati Amir (PGK) tahun pertama yang mencapai 5,60 mm/tahun atau 100,76 Ton/Ha/tahun, laju erosi tahun kedua mencapai 3,38 mm/tahun atau 60,84 Ton/Ha/tahun dapat diklasifikasikan ke dalam kelas bahaya erosi sedang (kelas III) dan nilai SDR adalah sebesar 56,3%, nilai sediment yield (SR) pada tahun pertama sebesar 5.887,59 Ton/Tahun, pada tahun kedua ketika rumput pada area Air Strip telah tumbuh dengan sempurna terjadi penurunan hasil sediment yield yaitu nilai SR sebesar 3.554,85 Ton/Tahun.



Author(s):  
D., A., L., A. Putri

Tectonic activity in an area could result in various impacts such as changes in elevation, level of slope percentages, river flow patterns and systems, and the formation of geological structures both locally and regionally, which will form a new landscape. The tectonic activity also affects the stratigraphic sequences of the area. Therefore, it is necessary to study morphotectonic or landscape forms that are influenced by active tectonic activities, both those occur recently and in the past. These geological results help provide information of the potential of natural resources in and around Tanjung Bungo area. Morphological data are based on three main aspects including morphogenesis, morphometry, and morphography. The data are collected in two ways, the first is field survey by directly observing and taking field data such as measuring geological structures, rock positions, and outcrop profiles. The second way is to interpret them through Digital Elevation Model (DEM) and aerial photographs by analyzing river flow patterns and lineament analysis. The field measurement data are processed using WinTensor, Dips, and SedLog Software. The supporting data such as Topographic Maps, Morphological Elevation Maps, Slope Maps, Flow Pattern Maps, and Lineament Maps are based on DEM data and are processed using ArcGis Software 10.6.1 and PCI Geomatica. Morphotectonically, the Tanjung Bungo area is at a moderate to high-class level of tectonic activity taken place actively resulted in several joints, faults, and folds. The formation of geological structures has affected the morphological conditions of the area as seen from the development of steep slopes, structural flow patterns such as radial, rectangular, and dendritic, as well as illustrated by rough surface relief in Tanjung Bungo area. This area has the potential for oil and gas resources as indicated by the Telisa Formation, consisting of calcareous silts rich in planktonic and benthonic fossils, which may be source rocks and its contact with the Menggala Formation which is braided river system deposits that could be good reservoirs. Further research needs to be done since current research is only an interpretation of surface data. Current natural resources being exploited in Tanjung Bungo region are coals. The coals have thicknesses of 5-7 cm and are classified as bituminous coals.



Author(s):  
Matheus Souisa ◽  
Paulus R. Atihuta ◽  
Josephus R. Kelibulin

Ambon City is a region consisting of hilly areas and steep slopes with diverse river characteristics. Research has been carried out in the Wae Ruhu watershed in Ambon City which starts from upstream (water catchment) to downstream. This study aims to determine the magnitude of river discharge and sediment discharge in the Wae Ruhu watershed. This research was conducted in several stages including, secondary data collection, research location survey, preparation of research tools and materials as well as field data retrieval processes which included tracking coordinates at each station point and entire watershed, calculation of river flow velocity, river geometry measurements, and sampling sediment. The results showed that the average river discharge in the Wae watershed in the year 2018 was 1.24 m3 / s, and the average sediment discharge was 6.27 kg / s. From the results of this study and the field observations proposed for flood prevention and the rate of sediment movement are the construction of cliffs with sheet pile and gabions.





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