WAVELET TRANSFORM FOR MEDIUM-RANGE STREAMFLOWS PROJECTIONS IN NATIONAL INTERCONNECTED SYSTEM

This work aims to analyze the variability of average annual streamflow time series of the SIN (Brazil) and create a projection model of future streamflow scenarios from 3 to 10 years using wavelet transform. The streamflow time series were used divided into two periods: 1931 to 2005 and 2006 to 2017, for calibration and verification, respectively. The annual series was standardized, and by the wavelet transform, it was decomposed into two bands plus the residue for each Base Posts (BP) for later reconstruction. Then an autoregressive model per band and residue was made. The projection was obtained by adding the autoregressive models. For performance evaluation, a qualitative analysis of the cumulative probability distribution of the projected years and the likelihood were made. The model identified the probability distribution function of the projected years and obtained likelihood greater than 1 in most of the SIN regions, indicating that this methodology can capture the medium-range variability.

Systemy umożliwiające identyfikację upadku z wysokości

The article discusses two types of systems developed at CIOP-PIB, which enable the identification of human falls from a height. The operation of the first system is based on an accelerometric measuring system implemented in the hip belt, which is an element of the equipment protecting against falls from a height. The operation of the second system is based on the analysis of the recorded video. The methods and results of calibration and verification tests of both designed systems, which were used for the preliminary tests, were presented. During these tests, the participant performed specific exercises: sitting down and simulating falling. The comparison of the test results showed a high convergence between the values measured with the acceleration sensors and the values obtained on the basis of the image analysis. The described systems can therefore be used for fall dentification and as initiators of devices for dynamic shortening of the fall path, which will reduce the forces acting on a person during restraining his fall from a height.

Measuring the diameter of a cylinder with automatic calibration

The work aims at developing a method for measuring the diameter of cylindrical objects, eliminating the need for calibration and verification of the measurement system during operation. The system for measuring the diameter of cylindrical objects contains a photodetector and a light source located on opposite sides of the measured object to implement the shadow method. The proposed method is based on the measurement of two reference cylinders located in the measuring area for automatic calibration of the system at each measurement. It is shown that the proposed method provides stable reliable measurements with an error of less than 2 μm for the diameter of the measured cylindrical objects of up to 10 mm.

On the selection of precipitation products for the regionalisation of hydrological model parameters

Over the past years, novel parameter regionalisation techniques have been developed to predict streamflow in data-scarce regions. In this paper, we examined how the choice of gridded daily precipitation (P) products affects individual catchment calibration and verification, as well as the relative performance of three well-known regionalisation techniques (spatial proximity, feature similarity, and parameter regression) over 100 near-natural catchments with diverse hydrological regimes across Chile. We configured and calibrated a conceptual semi-distributed HBV-like hydrological model for each catchment, using four P products (ERA5, MSWEPv2.8, RF-MEPv2, and CR2MET), and two objective functions. The three regionalisation techniques were applied and evaluated for each combination of P product and objective function, using a leave-one-out cross-validation procedure. Despite differences in the spatio-temporal distribution of P quantities, all P products provided good performance during calibration (median KGE's > 0.77), two independent verification periods (median KGE's > 0.70 and 0.61, for near normal and dry conditions, respectively), and regionalisation results (with median KGE's for the best method ranging from 0.56 to 0.63). Our results suggest that model calibration is able to compensate, to some extent, differences between forcing datasets, and that the spatial resolution of P products does not substantially affect the regionalisation performance. Overall, feature similarity provided the best results, followed closely by spatial proximity, while parameter regression performed the worst, thus reinforcing the importance of transferring complete parameter sets to ungauged catchments. Our results suggest that: i) merging P products and ground-based measurements does not necessarily translate into an improved hydrological modelling performance; ii) a P product that provides the best individual model performance during calibration and verification does not necessarily provide the best performance in terms of parameter regionalisation; and iii) the hydrological regime affects the performance of regionalisation methods, with rain-dominated catchments with a snow component performing the best over Chile for spatial proximity and feature similarity.

Application of Xin'anjiang Model and Wetspa Model in the Inflow Forecasting of Shiquan Reservoir

<p>In order to improve the accuracy of the inflow forecasting of Shiquan Reservoir in the Han River Basin, this paper compared the application effects of Xin'anjing model and Wetspa model. The study collected the rainfall and runoff data from 2009 to 2015, as well as the DEM, land use and soil data with 1000´1000m grid size. The model calibration and verification periods were from 2009 to 2012 and from 2013 to 2015, respectively. In addition to using the runoff depth and the determination coefficient to evaluate the accuracy of the two models, the flow relative error CR1, model confidence coefficient CR2, Nash-Sutcliffe efficiency CR3, logarithmic version of Nash-Sutcliffe efficiency CR4 for low flow, improved Nash-Sutcliffe efficiency CR5 for high flow were adopted to analyze the simulation results of the two models. The results showed that the simulation results of the Wetspa model could be used as a supplement to the simulation results of the Xin'anjiang model, providing high-precision flood forecasting results for the scheduling decisions of Shiquan Reservoir in terms of time and space.</p>