scholarly journals New Methods for the Assessment of Flow Regime Alteration under Climate Change and Human Disturbance

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2435
Author(s):  
Pengfei Shi ◽  
Jiahong Liu ◽  
Tao Yang ◽  
Chong-Yu Xu ◽  
Jie Feng ◽  
...  
Keyword(s):  
Climate Change ◽  
Flow Regime ◽  
Yellow River ◽  
Anthropogenic Activities ◽  
Great Influence ◽  
Time Warping ◽  
New Methods ◽  
Range Of Variability Approach ◽  
Dynamic Time ◽  
High Level

Climate change and anthropogenic activities do collectively lead to an alteration of the flow regime, posing a great influence upon the structure and persistence of native biotic communities within river ecosystems. The range of variability approach (RVA) method is commonly used to evaluate the flow regime alteration. However, it was reported to underestimate the degree of flow regime potentially. In this study, two new assessment methods/metrics for evaluating the process behaviors of the flow regime are developed based on Euclidean distance and dynamic time warping (DTW) distance. They are then integrated with the metric of RVA, generating two composite metrics that represent both frequency and process changes of the flow regime. The new methods/metrics were applied to identify the flow regime alteration in a typical basin in the middle reaches of the Yellow River, China. The results show that the composite metrics consistently reveal a high alteration degree of flow regime in the basin. The decreased biological integrity of fish demonstrates the reasonability of the high-level overall alteration to some degree. The updated methods enable more scientific evaluation for the complex hydrologic alteration under a changing environment.

scholarly journals Anthropogenic and Climate Effects on a Free Dam Tropical River: Measuring the Contributions on Flow Regime

2020 ◽  
Vol 12 (23) ◽  
pp. 10030
Author(s):  
Verônica Léo ◽  
Hersília Santos ◽  
Letícia Pereira ◽  
Lilia Oliveira
Keyword(s):  
Climate Change ◽  
Flow Regime ◽  
River Flow ◽  
Human Impacts ◽  
Global Climate ◽  
Rate Of Change ◽  
Hydrologic Alteration ◽  
Tropical River ◽  
Range Of Variability Approach ◽  
Flow Components

The demand for freshwater resources and climate change pose a simultaneous threat to rivers. Those impacts are often analyzed separately, and some human impacts are widely evaluated in river dynamics—especially in downstream areas rather than the consequences of land cover changes in headwater reaches. The distinction between anthropogenic and climate on the components of the flow regime is proposed here for an upstream free dam reach whose watershed is responsible for the water supply in Rio de Janeiro. Indicators of hydrologic alteration (IHA) and the range of variability approach (RVA) combined with statistical analyses of anthropogenic and climate parameters indicated that (1) four river flow components (magnitude, frequency, duration, and rate of change) were greatly altered from the previous period (1947 to 1967) and the actual (1994 to 2014); (2) shifts in the sea surface temperature of the Atlantic correlated with flow magnitude; (3) the cattle activity effects on the flow regime of the studied area decreased 42.6% of superficial discharge; global climate change led to a 10.8% reduction in the same river component. This research indicated that climate change will impact the intensification of human actions on rivers in the southeast Brazilian headwaters.

scholarly journals Exploring climate change impacts during first half of the 21st century on flow regime of the transboundary Kabul River in the Hindukush region

2019 ◽  
Vol 11 (4) ◽  
pp. 1521-1538
Author(s):  
Muhammad Zia ur Rahman Hashmi ◽  
Amjad Masood ◽  
Haris Mushtaq ◽  
Syed Ahsan Ali Bukhari ◽  
Burhan Ahmad ◽  
...  
Keyword(s):  
Climate Change ◽  
Flow Regime ◽  
Climate Change Impacts ◽  
River System ◽  
Joint Strategy ◽  
Rcp 8.5 ◽  
High Level ◽  
Flooding Events ◽  
Kabul River ◽  
Far Future

Abstract In transboundary river basins, climate change is being considered as a concern of higher degree than it is in other parts of the world. The Kabul River Basin, a sub-basin of the Indus River system shared by Pakistan and Afghanistan, is no exception. High level of sensitivity of its flow to temperature makes it imperative to analyse climate change impacts on the flow regime of this important river for efficient water resources management on both sides of the border. The snowmelt runoff model integrated with remote sensing snow cover product MODIS was selected to simulate daily discharges. Future projections were generated for two selected time slices, 2011–2030 (near future) and 2031–2050 (far future), based on output of an ensemble of four GCMs' RCP 4.5 and RCP 8.5 scenarios. Analysis shows a significant temperature increase under both scenarios in the near and far future at a high-altitude region of the basin which mostly receives snowfall that is also found increasing over time. Consequently, it causes a change in the flow regime and more frequent and heavier flooding events, thus calling for a joint strategy of the two riparian countries to mitigate the anticipated impacts in the basin for safety of people and overall prosperity.

scholarly journals Analysis of Shooting Consistency in Archers: A Dynamic Time Warping Algorithm-Based Approach

2017 ◽  
Vol 2017 ◽  
pp. 1-6
Author(s):  
Cheng-Hao Quan ◽  
Zia Mohy-Ud-Din ◽  
Sangmin Lee
Keyword(s):  
Dynamic Time Warping ◽  
Important Determinant ◽  
Small Distance ◽  
Elementary Level ◽  
Time Warping ◽  
Acceleration Data ◽  
Dynamic Time ◽  
High Level ◽  
The Relationship ◽  
Inertia Sensor

The shooting consistency of an archer is commonly perceived to be an important determinant of successful scores. Four (n=4) elementary level archers from a middle school in Korea participated in this study. In order to quantify shooting consistency, movement of the bow forearm was measured with an inertia sensor during archery shooting. The shooting consistency was calculated and defined by the dynamic time warping (DTW) algorithm as the distance between two time sequences of acceleration data. Small distance values indicate that the archer has maintained high-level shooting consistency while archery shooting repetitively. To verify the shooting consistency metric, the relationship between scores and shooting consistency is evaluated. The results show that the higher the scores achieved by the archer, the higher is the level of shooting consistency demonstrated.

scholarly journals ROBOT LEARNING OF OBJECT MANIPULATION TASK ACTIONS FROM HUMAN DEMONSTRATIONS

2017 ◽  
Vol 15 (2) ◽  
pp. 217 ◽  
Author(s):  
Maria Kyrarini ◽  
Muhammad Abdul Haseeb ◽  
Danijela Ristić-Durrant ◽  
Axel Gräser
Keyword(s):  
Gaussian Mixture Model ◽  
Mixture Model ◽  
Object Manipulation ◽  
Gaussian Mixture ◽  
Robot Learning ◽  
Time Warping ◽  
Mixture Regression ◽  
Manipulation Task ◽  
Dynamic Time ◽  
High Level

Robot learning from demonstration is a method which enables robots to learn in a similar way as humans. In this paper, a framework that enables robots to learn from multiple human demonstrations via kinesthetic teaching is presented. The subject of learning is a high-level sequence of actions, as well as the low-level trajectories necessary to be followed by the robot to perform the object manipulation task. The multiple human demonstrations are recorded and only the most similar demonstrations are selected for robot learning. The high-level learning module identifies the sequence of actions of the demonstrated task. Using Dynamic Time Warping (DTW) and Gaussian Mixture Model (GMM), the model of demonstrated trajectories is learned. The learned trajectory is generated by Gaussian mixture regression (GMR) from the learned Gaussian mixture model.  In online working phase, the sequence of actions is identified and experimental results show that the robot performs the learned task successfully.

Flow regime variation in Arctic rivers

2020 ◽  
Author(s):  
Nasim Fazel ◽  
Ali Torabi Haghighi ◽  
Kabir Rasouli ◽  
Bjørn Kløve
Keyword(s):  
Climate Change ◽  
Flow Regime ◽  
Anthropogenic Activities ◽  
Flow Regimes ◽  
The Arctic ◽  
Hydro Power ◽  
Stream Flows ◽  
Arctic Rivers ◽  
Thawing Permafrost ◽  
The Impact

<p>Arctic rivers’ flow regime has changed under climate change and its consequences on melting glaciers, thawing permafrost, and precipitation patterns. Reservoirs, hydro-power sites, and water diversions have also changed flow regimes in the Arctic. The flow regime alteration in the Arctic rivers has a strong influence on the conservation and sustainability of the native biodiversity of the riverine ecosystem. The main objective of this paper is to evaluate changes in the (1) magnitude of monthly stream flows, (2) magnitude and duration of annual maxima and minima flows, (3) timing of annual maxima and minima, (4) frequency and duration of high and low pulses, and (5) rate and frequency of daily flows in seven major Arctic Rivers. The analyses provide an important basis to characterize and understand the influence of climate change and anthropogenic activities on the flow regimes in the Arctic. Streamflow observations were obtained from the outlet of the Lena, Yenisei, Kolyma, Ob (Russia), Yukon (USA and Canada), Mackenzie (Canada), and Tana (Norway and Finland) rivers in this study. These rivers are main freshwater suppliers for Arctic Ocean. Of these, five have been regulated and two are considered pristine rivers. In addition, the impact of 16 reservoirs on flow regime in the headwaters and tributaries of Lena, Yenisei, Mackenzie, and Kolyma were evaluated. The annual flow showed an increasing trend in all rivers and with a statistically significant level in Yenisei, Lena, and Mackenzie. Our results also indicated that changes in the observed flow regimes at the outlet stations vary from low to incipient level. Out of 16 reservoirs that were analyzed for flow regimes changes, construction of Krasnoyarsk and Shushenskaya dams on the Yenisei River showed the highest impact on flow regime and flow regime alteration was classified as severe in this river.</p>

scholarly journals Turnout Fault Diagnosis through Dynamic Time Warping and Signal Normalization

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Shize Huang ◽  
Fan Zhang ◽  
Rongjie Yu ◽  
Wei Chen ◽  
Fei Hu ◽  
...  
Keyword(s):  
Dynamic Time Warping ◽  
Great Influence ◽  
Future Research ◽  
Time Warping ◽  
Railway Systems ◽  
Current Curve ◽  
Diagnosis Method ◽  
Reference Curves ◽  
Dynamic Time ◽  
Signal Normalization

Turnout is one key fundamental infrastructure in the railway signal system, which has great influence on the safety of railway systems. Currently, turnout fault diagnoses are conducted manually in China; engineers are obliged to observe the signals and make problem solving decisions. Thus, the accuracies of fault diagnoses totally depend on the engineers’ experience although massive data are produced in real time by the turnout microcomputer-based monitoring systems. This paper aims to develop an intelligent diagnosis method for railway turnout through Dynamic Time Warping (DTW). We firstly extract the features of normal turnout operation current curve and normalize the collected turnout current curves. Then, five typical fault reference curves are ascertained through the microcomputer-based monitoring system, and DTW is used to identify the turnout current curve fault through test data. The analysis results based on the similarity data indicate that the analyzed five turnout fault types can be diagnosed automatically with 100% accuracy. Finally, the benefits of the proposed method and future research directions were discussed.

Emergence of New Potential Insect Pests of Date Palm: Could Climate Change Be the Reason?

2019 ◽  
Vol 30 (6) ◽  
pp. 242-245
Author(s):  
Hamadttu A. F. El-Shafie
Keyword(s):  
Climate Change ◽  
Date Palm ◽  
Insect Pests ◽  
Anthropogenic Activities ◽  
Economic Damage ◽  
South American ◽  
Palm Fruit ◽  
The Family ◽  
American Palm ◽  
Sorghum Chafer

Four insect species were reported as new potential pests of date palm in recent years. They are sorghum chafer (Pachnoda interrupta), the rose chafer (Potosia opaca), the sericine chafer beetle (Maladera insanablis), and the South American palm borer (Pysandisia archon). The first three species belong to the order Coleoptera and the family Scarabaeidae, while the fourth species is a lepidopteran of the family Castniidae. The injury as well as the economic damage caused by the four species on date palm need to be quantified. Due to climate change and anthropogenic activities, the date palm pest complex is expected to change in the future. To the author's knowledge, this article provides the first report of sorghum chafer as a pest damaging date palm fruit.

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