Assessment of Reservoir Storage Capacity Loss and Investigating the Effects of Climate Variability on Reservoir Sedimentation in Italy

Author(s):  
Epari Ritesh Patro ◽  
Carlo De Michele

<p>Reservoir sedimentation has a prominent impact on the hydropower performance in the future and is a growing concern for hydropower stakeholders. Sedimentation caused by soil erosion is influenced by various parameters. Reservoir sedimentation is one of the most challenging problems that affect hydroelectric production since it overall causes a reduction of the reservoir capacity that overcomes the annual increase in storage volume and implies a dangerous net loss of energy. The first part of this study examined various Italian reservoirs (50 dams) to determine sedimentation rates and storage capacity loss based on available bathymetric surveys. All the reservoirs studied here have reached an average age of 74 years as of 2019, with the highest loss of capacity observed at 90% and the highest annual sediment yield of 2471 m<sup>3</sup>/km<sup>2</sup>/year. Out of all the reservoirs studied, 25% of them already have reached their half-life as of 2019. The second part of this study extended the work to the specific case study of the Ceppo Morelli hydropower plant. The study was carried out to analyse the water-sediment interaction, future sediment load and prioritizing of critical soil erosion areas using the Soil and Water Assessment Tool (SWAT). The distinguishing feature of this work lies in the possibility to exploit remote sensing data (i.e. actual/potential evapotranspiration) to successfully calibrate hydrological models in scarce data regions. Simulation results indicated that the discharge and sediment load entering Ceppo Morelli reservoir will decline and the rate of reduction of latter is higher than that of former for all the future climate scenarios implemented. This analysis will provide a starting point for management and prioritization of adaptation and remediation policies for addressing the issue of reservoir sedimentation. These results are part of the RELAID project funded through PRIN-Italy. The aim of this project is to integrate updated knowledge on hydrologic, hydraulics, and sedimentation processes to address the water and flood risk management of impounded Italian rivers through a holistic paradigm.</p><p>Keywords: reservoir sedimentation; hydropower; hydrological modeling; RELAID; Italy</p>

2018 ◽  
Vol 45 (1) ◽  
pp. 10-19 ◽  
Author(s):  
Caroline W. Maina ◽  
Joseph K. Sang ◽  
Benedict M. Mutua ◽  
James M. Raude

Abstract Soil erosion is one of the main soil degradation phenomena that threaten sustainable use of soil productivity thus affecting food security. In addition, it leads to reservoir storage capacity loss because of sedimentation. This not only affects water quantity but also water quality. Worldwide, annual loss in reservoir storage capacity due to sedimentation is 0.5 to 1%. Similarly, about 27% of land in Africa is largely degraded by erosion. As a result, there is need to minimize soil erosion and deposition through site specific estimation of soil erosion and deposition rates in the reservoirs. To achieve this, Fallout RadioNuclides (FRNs) are some of the methods in use. The most common radionuclides include; 137Cs, 210Pb and 7Be. Only few countries in Africa have exploited these FRNs. In these countries, 137Cs has been largely exploited but in some regions, it has been reported to be below minimum detection limit. Using 137Cs and 210Pb, maximum reference inventory in Africa is found to be 1450 and 2602 Bq/m2, respectively. However, there is minimal application of 7Be within the continent. Also, very little has been done in Africa to assess chronology and sedimentation rates of reservoirs using FRNs measured from sediment cores. In conclusion, a gap still exists on FRNs application in Africa in assessing soil erosion, deposition and reservoir sedimentation.


2020 ◽  
Author(s):  
Huilan Zhang

<p>Climate change and various human activities have resulted in noticeable changes in watershed hydrological and soil erosion regimes. In this study, a comprehensive investigation was conducted to distinguish between the effects of climate variables and those of land use and land cover change (LUCC) variables on runoff and sediment discharge in a watershed located at upper reaches of the Yangtze River. Statistical analysis results revealed significant and slight increasing trends in runoff and sediment discharge, respectively. Abrupt changes occurred in 1974 and 1995, which divided the entire time series into a decrease–increase–decrease tendency pattern; this pattern was the response to climate changes and the Reforestation and Returning Farmland to Forest project in China. In addition, redundancy analysis was used for partition statistical analyses, and the contributions of climate change and LUCC to runoff and sediment discharge were at the ratio of 4:1. Since 1990, the effect of LUCC has increased notably and its relationship with hydrological variables changed from positive to negative in approximately 1995. Finally, simulations performed using the distributed Basic Pollution Calculation Center (BPCC) model confirmed that climate and LUCC variables reduced the runoff depth and sediment load between 1980 and 2003. The contributions of climate fluctuation and LUCC to runoff depth were at the ratio of 5:1, and those to sediment load were at the ratio of 3:1, which exhibited the dominant role of climate change and the high sensitivity of sediment load to human interference. Overall, the results of distributed hydrological modeling were consistent with those of statistical analyses. The results provided detailed information and explained the mechanics underlying hydrological processes and soil erosion.</p><p> </p>


2018 ◽  
Vol 40 ◽  
pp. 03042
Author(s):  
David C. Froehlich

Mathematical expressions are developed that relate the storage capacity loss of reservoirs in India to the catchment area, the reservoir surface area, the original storage volume, and the time since the first filling of the impoundment. The relations for sedimentation of reservoirs found on eastward and westward flowing rivers differ significantly, because of meteorological and geological influences on land surface runoff and sediment yield within reservoir catchments. The formulations give good fits to the assembled data and allow an uncomplicated calculation of the half-life of reservoirs (that is, the time needed for the storage capacity to be reduced by 50%), which offers a measure of when sedimentation will have a significant adverse impact on the functioning of dams.


2019 ◽  
Vol 37 (2) ◽  
pp. 206-219
Author(s):  
Meindert E. Peters

Friedrich Nietzsche's influence on Isadora Duncan's work, in particular his idea of the Dionysian, has been widely discussed, especially in regard to her later work. What has been left underdeveloped in critical examinations of her work, however, is his influence on her earlier choreographic work, which she defended in a famous speech held in 1903 called The Dance of the Future. While commentators often describe this speech as ‘Nietzschean’, Duncan's autobiography suggests that she only studied Nietzsche's work after this speech. I take this incongruity as a starting point to explore the connections between her speech and Nietzsche's work, in particular his Thus Spoke Zarathustra. I argue that in subject and language Duncan's speech resembles Nietzsche's in important ways. This article will draw attention to the ways in which Duncan takes her cues from Nietzsche in bringing together seemingly conflicting ideas of religion and an overturning of morality; Nietzsche's notion of eternal recurrence and the teleology present in his idea of the Übermensch; and a renegotiation of the body's relation to the mind. In doing so, this article contributes not only to scholarship on Duncan's early work but also to discussions of Nietzsche's reception in the early twentieth century. Moreover, the importance Duncan ascribes to the body in dance and expression also asks for a new understanding of Nietzsche's own way of expressing his philosophy.


Leadership ◽  
2021 ◽  
pp. 174271502199959
Author(s):  
Chellie Spiller
Keyword(s):  
The Past ◽  

This article encourages a move away from the excessively inward gaze of ‘to thine own self be true’ and explores ‘I AM’ consciousness as a starting point. An I AM approach encourages a move from the measurable self to the immeasurable expansiveness and mystery of our own becoming. It is to step beyond the lines drawn around the ‘true self’ or the lines that others would have us draw. I AM consciousness reflects an ancient Indigenous thread that echoes through millennia and reminds humans that we are a movement through time, and each person is a present link to the past and the future, woven into a fabric of belonging.


Land ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 650
Author(s):  
Wakjira Takala Dibaba ◽  
Tamene Adugna Demissie ◽  
Konrad Miegel

Excessive soil loss and sediment yield in the highlands of Ethiopia are the primary factors that accelerate the decline of land productivity, water resources, operation and function of existing water infrastructure, as well as soil and water management practices. This study was conducted at Finchaa catchment in the Upper Blue Nile basin of Ethiopia to estimate the rate of soil erosion and sediment loss and prioritize the most sensitive sub-watersheds using the Soil and Water Assessment Tool (SWAT) model. The SWAT model was calibrated and validated using the observed streamflow and sediment data. The average annual sediment yield (SY) in Finchaa catchment for the period 1990–2015 was 36.47 ton ha−1 yr−1 with the annual yield varying from negligible to about 107.2 ton ha−1 yr−1. Five sub-basins which account for about 24.83% of the area were predicted to suffer severely from soil erosion risks, with SY in excess of 50 ton ha−1 yr−1. Only 15.05% of the area within the tolerable rate of loss (below 11 ton ha−1yr−1) was considered as the least prioritized areas for maintenance of crop production. Despite the reasonable reduction of sediment yields by the management scenarios, the reduction by contour farming, slope terracing, zero free grazing and reforestation were still above the tolerable soil loss. Vegetative contour strips and soil bund were significant in reducing SY below the tolerable soil loss, which is equivalent to 63.9% and 64.8% reduction, respectively. In general, effective and sustainable soil erosion management requires not only prioritizations of the erosion hotspots but also prioritizations of the most effective management practices. We believe that the results provided new and updated insights that enable a proactive approach to preserve the soil and reduce land degradation risks that could allow resource regeneration.


Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1548
Author(s):  
Suresh Marahatta ◽  
Deepak Aryal ◽  
Laxmi Prasad Devkota ◽  
Utsav Bhattarai ◽  
Dibesh Shrestha

This study aims at analysing the impact of climate change (CC) on the river hydrology of a complex mountainous river basin—the Budhigandaki River Basin (BRB)—using the Soil and Water Assessment Tool (SWAT) hydrological model that was calibrated and validated in Part I of this research. A relatively new approach of selecting global climate models (GCMs) for each of the two selected RCPs, 4.5 (stabilization scenario) and 8.5 (high emission scenario), representing four extreme cases (warm-wet, cold-wet, warm-dry, and cold-dry conditions), was applied. Future climate data was bias corrected using a quantile mapping method. The bias-corrected GCM data were forced into the SWAT model one at a time to simulate the future flows of BRB for three 30-year time windows: Immediate Future (2021–2050), Mid Future (2046–2075), and Far Future (2070–2099). The projected flows were compared with the corresponding monthly, seasonal, annual, and fractional differences of extreme flows of the simulated baseline period (1983–2012). The results showed that future long-term average annual flows are expected to increase in all climatic conditions for both RCPs compared to the baseline. The range of predicted changes in future monthly, seasonal, and annual flows shows high uncertainty. The comparative frequency analysis of the annual one-day-maximum and -minimum flows shows increased high flows and decreased low flows in the future. These results imply the necessity for design modifications in hydraulic structures as well as the preference of storage over run-of-river water resources development projects in the study basin from the perspective of climate resilience.


Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1313
Author(s):  
George Akoko ◽  
Tu Hoang Le ◽  
Takashi Gomi ◽  
Tasuku Kato

The soil and water assessment tool (SWAT) is a well-known hydrological modeling tool that has been applied in various hydrologic and environmental simulations. A total of 206 studies over a 15-year period (2005–2019) were identified from various peer-reviewed scientific journals listed on the SWAT website database, which is supported by the Centre for Agricultural and Rural Development (CARD). These studies were categorized into five areas, namely applications considering: water resources and streamflow, erosion and sedimentation, land-use management and agricultural-related contexts, climate-change contexts, and model parameterization and dataset inputs. Water resources studies were applied to understand hydrological processes and responses in various river basins. Land-use and agriculture-related context studies mainly analyzed impacts and mitigation measures on the environment and provided insights into better environmental management. Erosion and sedimentation studies using the SWAT model were done to quantify sediment yield and evaluate soil conservation measures. Climate-change context studies mainly demonstrated streamflow sensitivity to weather changes. The model parameterization studies highlighted parameter selection in streamflow analysis, model improvements, and basin scale calibrations. Dataset inputs mainly compared simulations with rain-gauge and global rainfall data sources. The challenges and advantages of the SWAT model’s applications, which range from data availability and prediction uncertainties to the model’s capability in various applications, are highlighted. Discussions on considerations for future simulations such as data sharing, and potential for better future analysis are also highlighted. Increased efforts in local data availability and a multidimensional approach in future simulations are recommended.


2017 ◽  
Vol 38 (9) ◽  
pp. 1631-1641 ◽  
Author(s):  
Mayte E van Alebeek ◽  
Renate M Arntz ◽  
Merel S Ekker ◽  
Nathalie E Synhaeve ◽  
Noortje AMM Maaijwee ◽  
...  

Incidence of ischemic stroke and transient ischemic attack in young adults is rising. However, etiology remains unknown in 30–40% of these patients when current classification systems designed for the elderly are used. Our aim was to identify risk factors according to a pediatric approach, which might lead to both better identification of risk factors and provide a stepping stone for the understanding of disease mechanism, particularly in patients currently classified as “unknown etiology”. Risk factors of 656 young stroke patients (aged 18–50) of the FUTURE study were categorized according to the “International Pediatric Stroke Study” (IPSS), with stratification on gender, age and stroke of “unknown etiology”. Categorization of risk factors into ≥1 IPSS category was possible in 94% of young stroke patients. Chronic systemic conditions were more present in patients aged <35 compared to patients ≥35 (32.6% vs. 15.6%, p < 0.05). Among 226 patients classified as “stroke of unknown etiology” using TOAST, we found risk factors in 199 patients (88%) with the IPSS approach. We identified multiple risk factors linked to other mechanisms of stroke in the young than in the elderly . This can be a valuable starting point to develop an etiologic classification system specifically designed for young stroke patients.


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