Trends in rainfall intensity for stormwater designs in Ontario

2012 ◽  
Vol 3 (1) ◽  
pp. 1-10 ◽  
Author(s):  
B. Vasiljevic ◽  
E. McBean ◽  
B. Gharabaghi
Keyword(s):  
Rainfall Intensity ◽  
Statistical Significance ◽  
Sewer Pipes ◽  
Rainfall Events ◽  
Rain Gauges ◽  
Long Term Trends ◽  
Using Data ◽  
Storm Sewer

The intensities of short-duration rainfall events are fundamental inputs to the design of stormwater management infrastructure. However, since stormwater infrastructure must function as designed for many decades, if there are long-term trends in rainfall intensities, design storms need to be modified. Evidence demonstrates, using data from 13 rain gauges in Ontario, that storm intensities relevant to urban stormwater (5 year) appear to have changed over the last 30 years. The results show, for example, statistical significance at 80% confidence that the 5-year storm has increased, and 85% that the 2-year storm has increased, for the 1 h storm in Waterloo, using partial duration series (PDS) data. The PDS data indicate intensities are increasing at a rate of 1–3% per year. Results show, for example, that a 5-year recurrence storm for PDS for the period 1970–1984 is now very close in magnitude to a 2-year recurrence storm for the period 1985–2003 for Waterloo, Ontario. The implications for a case study demonstrate that 5 out of 12 storm sewer pipes in a subdivision would need to be increased in diameter to obtain the same level of stormwater performance.

scholarly journals How Do Trade-Offs and Synergies between Ecosystem Services Change in the Long Period? The Case Study of Uxin, Inner Mongolia, China

2019 ◽  
Vol 11 (21) ◽  
pp. 6041 ◽  
Author(s):  
Zhang ◽  
Li ◽  
Buyantuev ◽  
Bao ◽  
Zhang
Keyword(s):  
Ecosystem Services ◽  
Inner Mongolia ◽  
Stepwise Regression ◽  
Driving Forces ◽  
Extended Period ◽  
Trade Offs ◽  
Development And Utilization ◽  
Long Term Trends

Ecosystem services management should often expect to deal with non-linearities due to trade-offs and synergies between ecosystem services (ES). Therefore, it is important to analyze long-term trends in ES development and utilization to understand their responses to climate change and intensification of human activities. In this paper, the region of Uxin in Inner Mongolia, China, was chosen as a case study area to describe the spatial distribution and trends of 5 ES indicators. Changes in relationships between ES and driving forces of dynamics of ES relationships were analyzed for the period 1979–2016 using a stepwise regression. We found that: the magnitude and directions in ES relationships changed during this extended period; those changes are influenced by climate factors, land use change, technological progress, and population growth.

scholarly journals Trends in the Frequency of Intense Precipitation Events in Southern and Southeastern Brazil during 1960–2004

2011 ◽  
Vol 24 (7) ◽  
pp. 1913-1921 ◽  
Author(s):  
Mateus da Silva Teixeira ◽  
Prakki Satyamurty
Keyword(s):  
Extreme Rainfall ◽  
Southeastern Brazil ◽  
Extreme Rainfall Event ◽  
Southern Brazil ◽  
Extreme Rainfall Events ◽  
Rainfall Events ◽  
Annual Frequency ◽  
Long Term Trends ◽  
Increasing Trends

Abstract A new approach to define heavy and extreme rainfall events based on cluster analysis and area-average rainfall series is presented. The annual frequency of the heavy and extreme rainfall events is obtained for the southeastern and southern Brazil regions. In the 1960–2004 period, 510 (98) and 466 (77) heavy (extreme) rainfall events are identified in the two regions. Monthly distributions of the events closely follow the monthly climatological rainfall in the two regions. In both regions, annual heavy and extreme rainfall event frequencies present increasing trends in the 45-yr period. However, only in southern Brazil is the trend statistically significant. Although longer time series are necessary to ensure the existence of long-term trends, the positive trends are somewhat alarming since they indicate that climate changes, in terms of rainfall regimes, are possibly under way in Brazil.

scholarly journals Kia kaua te reo e rite ki te moa, ka ngaro: do not let the language suffer the same fate as the moa

2020 ◽  
Vol 17 (162) ◽  
pp. 20190526
Author(s):  
Tessa Barrett-Walker ◽  
Michael J. Plank ◽  
Rachael Ka'ai-Mahuta ◽  
Daniel Hikuroa ◽  
Alex James
Keyword(s):  
New Zealand ◽  
Census Data ◽  
Initial Conditions ◽  
Endangered Languages ◽  
Endangered Language ◽  
Learning Rates ◽  
Welsh Language ◽  
Using Data

More than a third of the world's languages are currently classified as endangered and more than half are expected to go extinct by 2100. Strategies aimed at revitalizing endangered languages have been implemented in numerous countries, with varying degrees of success. Here, we develop a new model regarding language transmission by dividing the population into defined proficiency categories and dynamically quantifying transition rates between categories. The model can predict changes in proficiency levels over time and, ultimately, whether a given endangered language is on a long-term trajectory towards extinction or recovery. We calibrate the model using data from Wales and show that the model predicts that the Welsh language will thrive in the long term. We then apply the model to te reo Māori, the indigenous language of New Zealand, as a case study. Initial conditions for this model are estimated using New Zealand census data. We modify the model to describe a country, such as New Zealand, where the endangered language is associated with a particular subpopulation representing the indigenous people. We conclude that, with current learning rates, te reo Māori is on a pathway towards extinction, but identify strategies that could help restore it to an upward trajectory.

Impact of nutrient supply on the expression of genetic improvements of cereals and row crops – A case study using data from a long-term fertilization experiment in Germany

2018 ◽  
Vol 96 ◽  
pp. 34-46 ◽  
Author(s):  
Victor Rueda-Ayala ◽  
Hella Ellen Ahrends ◽  
Stefan Siebert ◽  
Thomas Gaiser ◽  
Hubert Hüging ◽  
...  
Keyword(s):  
Nutrient Supply ◽  
Row Crops ◽  
Fertilization Experiment ◽  
Using Data

scholarly journals Kia kaua te reo e rite ki te moa, ka ngaro: Do not let the language suffer the same fate as the moa

2019 ◽  
Author(s):  
Tessa Barrett-Walker ◽  
Michael J. Plank ◽  
Rachael Ka’ai-Mahuta ◽  
Daniel Hikuroa ◽  
Alex James
Keyword(s):  
New Zealand ◽  
Census Data ◽  
Initial Conditions ◽  
Endangered Languages ◽  
Endangered Language ◽  
Learning Rates ◽  
Welsh Language ◽  
Using Data

AbstractMore than a third of the world’s languages are currently classified as endangered and more than half are expected to go extinct by 2100. Strategies aimed at revitalising endangered languages have been implemented in numerous countries, with varying degrees of success. Here, we develop a new model regarding language transmission by dividing the population into defined proficiency categories and dynamically quantifying transition rates between categories. The model can predict changes in proficiency levels over time and, ultimately, whether a given endangered language is on a long-term trajectory towards extinction or recovery. We calibrate the model using data from Wales and show that the model predicts that the Welsh language will thrive in the long term. We then apply the model to te reo Māori, the Indigenous language of New Zealand, as a case study. Initial conditions for this model are estimated using New Zealand census data. We modify the model to describe a country, such as New Zealand, where the endangered language is associated with a particular subpopulation representing the Indigenous People. We conclude that, with current learning rates, te reo Māori is on a pathway towards extinction, but identify strategies that could help restore it to an upward trajectory.

scholarly journals Precipitation Estimates from Commercial Microwave Links: Practical Approaches to Wet-antenna Correction

2021 ◽  
Author(s):  
Jaroslav Pastorek ◽  
Martin Fencl ◽  
Jörg Rieckermann ◽  
Vojtěch Bareš
Keyword(s):  
Rainfall Intensity ◽  
Rain Gauge ◽  
Model Parameters ◽  
Rainfall Events ◽  
Precipitation Estimates ◽  
Attenuation Models ◽  
Using Data ◽  
Quantitative Precipitation Estimates ◽  
Rain Gauge Network ◽  
Commercial Microwave Links

An inadequate correction for wet antenna attenuation (WAA) often causes a notable bias in quantitative precipitation estimates (QPEs) from commercial microwave links (CMLs) limiting the usability of these rainfall data in hydrological applications. This paper analyzes how WAA can be corrected without dedicated rainfall monitoring for a set of 16 CMLs. Using data collected over 53 rainfall events, the performance of six empirical WAA models was studied, both when calibrated to rainfall observations from a permanent municipal rain gauge network and when using model parameters from the literature. The transferability of WAA model parameters among CMLs of various characteristics has also been addressed. The results show that high-quality QPEs with a bias below 5% and RMSE of 1 mm/h in the median could be retrieved, even from sub-kilometer CMLs where WAA is relatively large compared to raindrop attenuation. Models in which WAA is proportional to rainfall intensity provide better WAA estimates than constant and time-dependent models. It is also shown that the parameters of models deriving WAA explicitly from rainfall intensity are independent of CML frequency and path length and, thus, transferable to other locations with CMLs of similar antenna properties.

scholarly journals Automated reconstruction of rainfall events responsible for shallow landslides

2014 ◽  
Vol 14 (9) ◽  
pp. 2399-2408 ◽  
Author(s):  
G. Vessia ◽  
M. Parise ◽  
M. T. Brunetti ◽  
S. Peruccacci ◽  
M. Rossi ◽  
...  
Keyword(s):  
Rainfall Intensity ◽  
Shallow Landslides ◽  
Threshold Values ◽  
Rainfall Thresholds ◽  
Rainfall Events ◽  
Mean Intensity ◽  
Landslide Occurrence ◽  
R Language ◽  
Rain Gauges ◽  
Rainfall Duration

Abstract. Over the last 40 years, many contributions have identified empirical rainfall thresholds (e.g. rainfall intensity (I) vs. rainfall duration (D), cumulated rainfall vs. rainfall duration (ED), cumulated rainfall vs. rainfall intensity (EI)) for the possible initiation of shallow landslides, based on local and global inventories. Although different methods to trace the threshold curves have been proposed and discussed in literature, a systematic study to develop an automated procedure to select the rainfall event responsible for the landslide occurrence has only rarely been addressed. Objective criteria for estimating the rainfall responsible for the landslide occurrence play a prominent role on the threshold values. In this paper, two criteria for the identification of the effective rainfall events are presented. The first criterion is based on the analysis of the time series of rainfall mean intensity values over 1 month preceding the landslide occurrence. The second criterion is based on the analysis of the trend in the time function of the cumulated mean intensity series calculated from the rainfall records measured through rain gauges. The two criteria have been implemented in an automated procedure that is written in the R language. A sample of 100 shallow landslides collected in Italy from 2002 to 2012 was used to calibrate the procedure. The cumulated event rainfall (E) and duration (D) of rainfall events that triggered the documented landslides are calculated through the new procedure and are fitted with power law in the D, E diagram. The results are discussed by comparing the D, E pairs calculated by the automated procedure and the ones by the expert method.

Measurement properties of tipping bucket rain gauges and their influence on urban runoff simulation

1997 ◽  
Vol 36 (8-9) ◽  
pp. 7-12 ◽  
Author(s):  
R. Fankhauser
Keyword(s):  
Time Resolution ◽  
Rainfall Intensity ◽  
Depth Resolution ◽  
Urban Hydrology ◽  
Data Series ◽  
Runoff Simulation ◽  
Rainfall Events ◽  
Rain Gauges ◽  
Rainfall Depth ◽  
Bucket Size

Tipping bucket rain gauges (TBR) have become the most common device for measuring rainfall intensity in urban hydrology. Due to the measurement principle, the time resolution depends on rainfall intensity and bucket size. The present study investigated the influence of calibration uncertainties and bucket size on the accuracy of rainfall measurement and runoff simulation. Synthetic rainfall events with a time resolution of 6 seconds were generated from measured data. These rainfall series were taken as input to a model that simulated a TBR. Different TBR data series were produced by changing calibration parameters and bucket size of the simulated rain gauge. These data series together with the original rainfall events were used as input to a rainfall-runoff model. Computed runoff and overflow volume from a CSO weir were compared. The differences in rainfall depth, intensity peak and computed runoff due to the depth resolution of the TBR were smaller than expected. A depth resolution of the TBR of 0.2 - 0.3 mm per tip seems to fulfil the requirements in urban hydrology. Errors resulting from depth resolution are small compared to those of calibration (especially false rainfall depth per tip), site exposure, the influence of wind or disregarded areal rainfall distribution.

A case study of PavMD a new tool to identify good performing pavements in New Zealand

2021 ◽  
Author(s):  
Jacobus Daniel van der Walt ◽  
Eric Scheepbouwer ◽  
Bryan Pidwerbesky ◽  
Brian Guo ◽  
Max Ferguson ◽  
...  
Keyword(s):  
New Zealand ◽  
Performance Measures ◽  
Data Structures ◽  
Digital Technology ◽  
Data Driven ◽  
Pavement Performance ◽  
Using Data ◽  
Additional Value

With the advancement of digital technology, the collection of pavement performance data has become commonplace. The improvement of tools to extract useful information from pavement databases has become a priority to justify expenditures. This paper presents a case study of PaveMD, a tool that integrates multi-dimensional data structures with a data-driven fuzzy approach to identify good performing pavement sections. Combining this tool with an innovative paradigm where the focus is on repeating success can bring additional value to existing pavement databases. The case study shows that PaveMD can identify pavement sections that are performing well by comparing performance measures for the New Zealand context. In this paper, PaveMD's development is described, and its implementation is showcased using data from the New Zealand Long-Term Pavement Performance (LTPP) database. It is recommended that this approach be further developed and extended to other infrastructure databases internationally.

Sign in / Sign up

Export Citation Format

Share Document