scholarly journals Trends in the Maximum, Mean, and Low Flows of Turkish Rivers

2005 ◽  
Vol 6 (3) ◽  
pp. 280-290 ◽  
Author(s):  
H. K. Cigizoglu ◽  
M. Bayazit ◽  
B. Önöz
Keyword(s):  
Trend Analysis ◽  
Kendall Test ◽  
T Test ◽  
Precipitation Trend ◽  
Annual Maximum ◽  
Low Flows ◽  
Time Period ◽  
Southern Turkey ◽  
The Mean ◽  
Maximum Flows

Abstract In this study the existence of trend in maximum, mean, and low flows of Turkish rivers has been investigated. The data consisted of the daily mean flows of nearly 100 flow stations in 24 hydrological regions of Turkey. Trend analysis has been carried out using the parametric t test and nonparametric τ (Mann–Kendall) test. Both tests have been applied to annual maximum, mean, 1-day, and 7-day low flows. Trend existence was detected in the majority of rivers in western and southern Turkey and in some parts of central and eastern Turkey. Trends in mean and low flows were more common compared with maximum flows. Except at a few stations, flows showed a decreasing trend. In the time period of the last 30–60 yr, statistically significant decrease was found especially in the mean and low flows (and in some of the maximum flows) in western, central, and southern parts of Turkey. Such trends were not observed in other regions. These results are in agreement with those of the precipitation trend studies in Turkey.

scholarly journals A comparison between orthodontic model analysis using conventional methods and iModelAnalysis

2018 ◽  
Vol 51 (4) ◽  
pp. 173
Author(s):  
Vita Previa Indirayana ◽  
Gita Gayatri ◽  
N. R. Yuliawati Zenab
Keyword(s):  
Sampling Method ◽  
Model Analysis ◽  
T Test ◽  
Normality Test ◽  
Time Period ◽  
Significant Difference ◽  
The Mean ◽  
Conventional Methods ◽  
Paired T Test ◽  
Dental Casts

Background: Model analysis constitutes an essential aspect of orthodontic diagnostic practice. Pavan has developed an application to simplify the mathematical calculations employed in orthodontic model analysis. Purpose: This study was conducted to obtain the differences in results and time periods of model analysis using conventional means and iModelAnalysis. Methods: The research represented a comparative analytic study. The populations comprised dental casts dating from 2014 in the Orthodontics Laboratory of Padjadjaran University. The samples comprised 31 dental casts which were subjected to a total sampling method consisting of two treatments; a conventional method calculation and one using iModelAnalysis. A normality test was conducted and processed using a paired t-test with α=0.05. Results: The means of arch length discrepancies were 1.64±2.63 mm and 1.37±3.07 mm for the conventional methods and 1.65±2.43mm and 1.42±3.04mm for iModelAnalysis. The results of a Bolton analysis for conventional methods were 78.05±2.69% and 91.93±1.29%, while those for iModelAnalysis were 77.91±2.70% and 91.96±2.13%. A Howes analysis of conventional methods produced a result of 45.56±2.83%, while for an iModelAnalysis one of 45.56±2.85%. Pont analysis for conventional methods was 39.35±0.04 mm and 49.17±2.55 mm, while for iModelAnalysis it was 39.35±0.07 mm and 49.19±2.57mm. The mean of the duration of analysis using conventional methods was 1703.81±56.46 seconds, while for iModelAnalysis it was 990.06±34.87 seconds. A normality test confirmed that the data was normally distributed (p>0.05). The results of a paired sample t-test with p>0.05 showed that there was no significant difference between the results of each analysis, while there was significant difference in the time period of analysis. Conclusion: There was no difference in the analysis results. However, there was difference in the time period of analysis between conventional methods and that of iModelAnalysis.

scholarly journals Evolution of low flows in Czechia revisited

2015 ◽  
Vol 369 ◽  
pp. 87-95 ◽  
Author(s):  
O. Ledvinka
Keyword(s):  
Trend Analysis ◽  
Autoregressive Process ◽  
Kendall Test ◽  
Test Statistic ◽  
Memory Processes ◽  
Low Flows ◽  
Long Memory Processes ◽  
In Series ◽  
Short Memory ◽  
First Time

Abstract. Although a nationwide study focusing on the evolution of low flows in Czechia was conducted in the past, a need for the revision of the results has arisen. By means of the trend analysis, which specifically considers the presence of significant serial correlation at the first lag, the former study highlighted areas where 7-day low flows increase or decrease. However, taking into account only the lag-one autoregressive process might still have led to the detection of so-called pseudo-trends because, besides short-term persistence, also long-term persistence may adversely influence the variance of the test statistic when the independence among data is required. Therefore, one should carefully investigate the presence of persistence in time series. Before the trend analysis itself, the authors' previous studies aimed at the discrimination between short memory processes and long memory processes employing jointly the Phillips–Perron test and the Kwiatkowski–Phillips–Schmidt–Shin test. This analysis was accompanied by the Hurst exponent estimation. Here, the subsequent identification of trends is carried out using three modifications of the Mann–Kendall test that allow different kinds of persistence. These include the Bayley–Hammersley–Matalas–Langbein–Lettenmaier equivalent sample size approach, the trend-free pre-whitening approach and a block bootstrap with automatic selection of the block length, which was applied for the first time in hydrology. The general results are similar to those presented in the former study on trends. Nevertheless, the divergent minimum discharges evolution in the western part of Czechia is now much clear. Moreover, no significant increasing trend in series incorporating Julian days was found.

scholarly journals Trend  Analysis of Climate variables, Stream flow and their Linkage at Modjo River Watershed, Central Ethiopia

2020 ◽  
Author(s):  
Kokeb Zena ◽  
Tamene Adugna ◽  
Fekadu Fufa
Keyword(s):  
Climate Variability ◽  
Trend Analysis ◽  
Stream Flow ◽  
Management Practices ◽  
River Flow ◽  
Pearson Correlation ◽  
Kendall Test ◽  
Precipitation Series ◽  
River Watershed ◽  
The Mean

Abstract Background: Trend and variability analysis of precipitation and stream flow series provides valuable information to understand hydrological changes associated with climate variability. In this study, annual and seasonal trends of precipitation and stream flow series and their relationship was investigated over the Modjo river watershed. The Mann-Kendall test and Sen’s slope estimator were used for trend analysis and evaluation of its magnitude respectively, with an approach that corrects the serial correlation. The Pearson correlation analysis was also applied to evaluate the relationships between river flow and precipitation series.Results: the mean and maximum stream flow series showed downward trends at the annual and kiremt time series, whereas no significant trend was observed for the minimum flow over the Modjo watershed. The study indicated that the mean annual and kiremt (monsoon) stream flow decreased significantly at a rate of 8.262 and 6.528 m3s-1per year respectively. In contrary to the river flow, there is no positive or negative trend in the annual and seasonal precipitation series although the tendency was towards increasing trends. It was evidenced that the annual, and kiremt season river flow series was affected abruptly since 2000, however for the same analysis period there was no evidence of changes in precipitation events, which is also not related significantly with the variability of river flow during the analysis period.Conclusions: the river flow decreased dramatically in the Modjo watershed during the analysis period (1981-2015), however it was not primarily associated significantly with climate variability (precipitation & temperature). The result suggests the need of considering the unplanned water extraction and the poor land use management practices to sustain and restore river flow trend observed in the watershed.

scholarly journals Statistical Trend Analysis of Rainfall in Amaravathi River Basin using Mann-Kendall Test

2017 ◽  
Vol 12 (1) ◽  
pp. 89-96 ◽  
Author(s):  
S.I Sridhar ◽  
A Raviraj
Keyword(s):  
Trend Analysis ◽  
Tamil Nadu ◽  
Monsoon Season ◽  
Kendall Test ◽  
Rain Gauge ◽  
Seasonal Rainfall ◽  
North East ◽  
Increasing Trend ◽  
The Mean ◽  
Slope Estimator

The present study aims to detect the trends in annual and seasonal rainfall and its magnitude in Amaravathi basin, Tamil Nadu. In this study, the mean annual and seasonal rainfall in 10 rain gauge stations of Amaravathi basin have been analysed to determine the trend and its magnitude for the period of 1982-2014. The trend analysis is done using Mann-Kendall and Sen’s slope estimator. The trend analysis results showed wide variations during all the seasons. The increasing trend of rainfall is found to be dominant during north-east monsoon season when compared to other seasons.

scholarly journals Long-term changes in the water temperature of rivers in Latvia

2016 ◽  
Vol 70 (2) ◽  
pp. 78-87 ◽  
Author(s):  
Inese Latkovska ◽  
Elga Apsīte
Keyword(s):  
Water Temperature ◽  
Kendall Test ◽  
Maximum Temperature ◽  
Small Rivers ◽  
Positive Trend ◽  
Annual Maximum ◽  
Monitoring Period ◽  
Time Period ◽  
Maximum Water Temperature ◽  
Maximum Water

Abstract The study describes the trends of monthly mean water temperature (from May to October) and the annual maximum water temperature of the rivers in Latvia during the time period from 1945 to 2000. The results demonstrated that the mean water temperatures during the monitoring period from May to October were higher in the largest rivers (from 13.6 °C to 16.1 °C) compared to those in the smallest rivers (from 11.5 °C to 15.7 °C). Similar patterns were seen for the maximum water temperature: in large rivers from 22.9 °C to 25.7 °C, and in small rivers from 20.8 °C to 25.8 °C. Generally, lower water temperatures occurred in rivers with a high groundwater inflow rate, for example, in rivers of the Gauja basin, in particular, in the Amata River. Mann-Kendall test results demonstrated that during the monitoring period from May to October, mean water temperatures had a positive trend. However, the annual maximum temperature had a negative trend.

scholarly journals Climate Change Impact on the Magnitude and Timing of Hydrological Extremes Across Great Britain

2021 ◽  
Vol 3 ◽  
Author(s):  
Rosanna A. Lane ◽  
Alison L. Kay
Keyword(s):  
Climate Change ◽  
Great Britain ◽  
Return Period ◽  
Climate Change Impact ◽  
Annual Maximum ◽  
Low Flows ◽  
Hydrological Extremes ◽  
Change Impact ◽  
High Flows ◽  
Maximum Flows

Climate change could intensify hydrological extremes, changing not just the magnitude but also the timing of flood and drought events. Understanding these potential future changes to hydrological extremes at the national level is critical to guide policy decisions and ensure adequate adaptation measures are put in place. Here, climate change impact on the magnitude and timing of extreme flows is modelled across Great Britain (GB), using an ensemble of climate data from the latest UK Climate Projections product (UKCP18) and a national grid-based hydrological model. All ensemble members show large reductions in low flows, of around −90 to −25% for 10-year return period low flows by 2050–2080. The direction of change for high flows is uncertain, but increases in 10-year return period high flows of over 9% are possible across most of the country. Simultaneous worsening of both extremes (i.e., a reduction in low flows combined with an increase in high flows) are projected in the west. Changes to flow timing are also projected; with mostly earlier annual maximum flows across Scotland, later annual maximum flows across England and Wales, and later low flows across GB. However, these changes are generally not statistically significant due to the high interannual variability of annual maximum/minimum flow timing. These results highlight the need for adaptation strategies that can cope with a wide range of future changes in hydrological extremes, and consider changes in the timing as well as magnitude.

scholarly journals Input Availability and Use under Poultry Import Prohibition: A study of Southeast Nigeria

2015 ◽  
Vol 48 (1-2) ◽  
pp. 18-23
Author(s):  
Jane Munonye ◽  
Chinedum Nwajiuba ◽  
Christopher Eze
Keyword(s):  
Standard Deviation ◽  
Trend Analysis ◽  
Significant Variation ◽  
Mean Value ◽  
Poultry Feed ◽  
Poultry Production ◽  
Major Constraint ◽  
Time Period ◽  
The Mean ◽  
Broad Objective

Abstract The broad objective of the study is to examine input availability and use under poultry import prohibition in southeast Nigeria from 1994-2009. The specific objectives include: to determine whether there is increased demand for poultry feed, drugs and day old chicks before and since the ban; to determine the effect of input supplied on domestic poultry production. The study adopted trend analysis of before (1994-2001) and since (2002-2009) the ban to examine the variations in poultry input and supply. Three states were sampled out of the five states that made up the zone. Data were collected through the use of a questionnaire. A total of sixty respondents were used, 20 persons each from the three states selected. The results showed that feed demanded has a mean value of 141.75 tons before the ban and 82.19 tons since the ban indicated a decrease in demand for feed. While day-old chicks demanded has a mean value of 310.47 birds before the ban and 466.3 birds since the ban indicated an increase in the demand for day-old chicks. The mean value of Drugs was 266.7 grams before the ban and 299.3 grams since the ban, indicating an increase in demand for drugs. There was also a significant variation in the standard deviation and also in both maximum and minimum values over the time period in feed, day-old chicks and drugs. The major constraint is input availability. The study concluded that there was an increase in demand for day old chicks since the ban.

PENINGKATAN KUALITAS HIDUP MELALUI LOGOTERAPI PADA KLIEN YANG MENJALANI HEMODIALISIS

2019 ◽  
Vol 11 (1) ◽  
pp. 9-18
Author(s):  
Abdul Wakhid ◽  
Ana Puji Astuti ◽  
Maya Kurnia Dewi
Keyword(s):  
Quality Of Life ◽  
Renal Failure ◽  
Test Group ◽  
Sampling Technique ◽  
T Test ◽  
P Value ◽  
Number Of Patients ◽  
Post Test ◽  
The Mean

Logoterapi merupakan terapi untuk menemukan makna positif dibalik sebuah kejadian yang tidak diharapkan. Logoterapi dilaksanakan secara individu maupun berkelompok dalam bentuk konseling dan berorientasi pada pencarian makna hidup individu. Tujuan logoterapi meningkatkan makna pengalaman hidup individu yang diarahkan kepada pengambilan keputusan yang bertanggung jawab. Penelitian ini dilakukan dengan menggunakan rancangan pre-experiment dengan metode pre and post test group, artinya pengumpulan data dilakukan terhadap responden untuk membandingkan kualitas hidup sebelum dan sesudah dilakukan intervensi. Teknik pengambilan sampel dilakukan dengan metode total sampling yaitu pengambilan seluruh sampel dengan tetap memperhatikan kriteria yang telah ditetapkan. Jumlah pasien yang menjalani hemodialisis di RSUD Ungaran sebanyak 21 orang dan di RSUD Ambarawa sebanyak 25 pasien. Analisis data dilakukan dengan menggunakan uji t test dependent. Hasil penelitian didapatkan bahwa dari 46 responden didapatkan rata-rata skor kualitas hidup pasien yang mejalani hemodialisis sebesar 60.22 dengan skor terrendah 55 dan skor tertinggi 69. Bahwa dari 46 responden didapatkan rata-rata skor kualitas hidup pasien yang mejalani hemodialisis sebesar 88.72 dengan skor terrendah 79 dan skor tertinggi 103. Hasil uji statistik dengan uji t test dependent diketahui ada pengaruh logoterapi terhadap kemampuan memaknai hidup pada klien yang menjalani hemodialisis di RSUD Kabupaten Semarang (p value: 0,0001). Saran perlunya peningkatan kemampuan perawat dalam memberikan layanan kesehatan termasuk pemberian atau pemanduan penemuan makna hidup bagi pasien hemodialysis, agar selain dengan hemodialysis, ada faktor internal dari pasien yang dapat dijadikan sebagai motivasi untuk sembuh dari penyakit.   Kata Kunci: Logoterapi, kualitas hidup   IMPROVE THE QUALITY OF LIFE OF PATIENTS WITH RENAL FAILURE WHO UNDERWENT HEMODIALYSIS   ABSTRACT Logotherapy is a therapy to discover the positive meaning behind an unexpected event. Logotherapy is carried out individually or in groups in the form of counseling and oriented to the search for the meaning of individual life. This study aims to improve the quality of life of patients with renal failure who underwent hemodialysis. This research was conducted by using pre-experiment with pre-post test study. The sampling technique was done by the convenience sampling. The number of patients undergoing hemodialysis as many as 46 respondents. Data analysis was done by using test t test dependent. The result showed that from 46 respondents got the mean of quality of life of patients who had hemodialysis 60.22 with lowest score 55 and highest score 69. Whereas from 46 respondents got the mean score of life quality of patients who had hemodialysis 88.72 with score the lowest score 79 and the highest score 103. The result of statistical test with t test dependent is known there is influence of logoterapi to the ability of meaningful life on client who undergo hemodialysis at Semarang Regency hospitals (p value: 0.0001). Advice on the need to improve the nurse's ability to provide health services, including the provision or guidance of the discovery of the meaning of life for hemodialysis patients, in addition to hemodialysis, there are internal factors of the patient that can be used as a motivation to recover from illness.   Keywords: Logotherapy, quality of life, kidney failure.  

DEVELOPMENT OF STREAMFLOW DROUGHT INDICES IN THE MORAVA RIVER BASIN

2020 ◽  
Author(s):  
Ondrej Ledvinka ◽  
◽  
Pavel Coufal ◽  
Keyword(s):  
Time Series ◽  
Kendall Test ◽  
Drought Indices ◽  
Drought Period ◽  
Left Hand ◽  
Low Flows ◽  
Current Period ◽  
Catchment Size ◽  
Morava River ◽  
The Stability

The territory of Czechia currently suffers from a long-lasting drought period which has been a subject of many studies, including the hydrological ones. Previous works indicated that the basin of the Morava River, a left-hand tributary of the Danube, is very prone to the occurrence of dry spells. It also applies to the development of various hydrological time series that often show decreases in the amount of available water. The purpose of this contribution is to extend the results of studies performed earlier and, using the most updated daily time series of discharge, to look at the situation of the so-called streamflow drought within the basin. 46 water-gauging stations representing the rivers of diverse catchment size were selected where no or a very weak anthropogenic influences are expected and the stability and sensitivity of profiles allow for the proper measurement of low flows. The selected series had to cover the most current period 1981-2018 but they could be much longer, which was considered beneficial for the next determination of the development direction. Various series of drought indices were derived from the original discharge series. Specifically, 7-, 15- and 30-day low flows together with deficit volumes and their durations were tested for trends using the modifications of the Mann– Kendall test that account for short-term and long-term persistence. In order to better reflect the drivers of streamflow drought, the indices were considered for summer and winter seasons separately as well. The places with the situation critical to the future water resources management were highlighted where substantial changes in river regime occur probably due to climate factors. Finally, the current drought episode that started in 2014 was put into a wider context, making use of the information obtained by the analyses.

Digital volumetric measurements based on 3D scans of the lower limb: A valid and reproducible method for evaluation in lymphedema therapy. (Preprint)

2019 ◽  
Author(s):  
Daniel Schiltz ◽  
Natalie Kiermeier ◽  
Dominik Eibl ◽  
Christoph Koch ◽  
Karolina Müller ◽  
...  
Keyword(s):  
Lower Limb ◽  
Lower Leg ◽  
T Test ◽  
Volume Changes ◽  
Quick Method ◽  
Reproducible Method ◽  
The Mean ◽  
3D Scans ◽  
Paired T Test ◽  
Volumetric Measurements

BACKGROUND Exact quantification of volumetric changes of the extremities is difficult. There are several direct and indirect methods to assess extremity volume. As water displacement volumetry is rarely viable in a clinical setting and circumference measurements are prone to errors due to poor reproducibility and high inter- and intra-observer variability, an objective and easily reproducible method is indispensable. OBJECTIVE The aim of this study was to establish a standardized method based on 3D scans with defined caudal and cranial landmarks of the lower leg which allows for measurements of exactly the same body area. Furthermore, this study tests the method in terms of reproducibility and evaluates volume changes after surgical therapy in patients suffering from lymphedema. METHODS 3D-scans of the lower limb were performed with a mobile 3D-scanner. Volumetric calculation was done digitally. “Repeatability“ and “Inter-observer reliability” of digital volumetry were tested. Furthermore, the method was applied on 31 patients suffering from chronic lymphedema. ANOVA (analyses of variance) was conducted to compare the digital volumetric measurements. To assess the sensitivity to changes in digital volumetry, the mean volume of 31 patients before and 3 months after therapy were compared by a paired t-Test. RESULTS Calculations of repeatability of the volume based on 20 3D-scans of the same lower leg showed a mean volume of 2,488 ± 0,011 liters (range: 2,470 – 2,510). The mean volume of the 7 measurements of the 3 examiners did not differ significantly (F(2,18) = 1,579, p = .233). The paired t-Test showed a significant mean volume decrease of 375ml (95% CI = 245/505ml) between pre and post treatment (t (30) =5,892, p < .001). CONCLUSIONS 3D-Volumetry is a noninvasive, easy and quick method to assess volume changes of the lower leg. Other than the costs, it is reproducible and precise and therefore ideal for evolution of therapy in lymphedema.

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