Climate Change Impact on Flood Control Measures for Highly Populated Urban Watershed

Flooding and overflows are recurring problems in several Brazilian cities, which usually undergo disorderly development. Their causes vary from increased impervious surface areas, deficiency/inefficiency of drainage structures and their maintenance, siltation of rivers, channel obstructions, and climatic factors. This situation is aggravated in the major cities. The Anhangabau watershed lies in the central portion of the city of Sao Paulo – Brazil and covers a drainage area of 5.4 km². The region is highly urbanized and crossed by a major north-south road connection. During heavy rain events, portions of this interconnection passage become compromised, disrupting the flow of vehicles, creating a chaotic situation for the population, as well as losses to the national economy. Observed rainfall records and an existing IDF (intensity duration frequency) curve for the region are used to obtain design storms. To account for climate change, a well know procedure, the equidistance quantile matching method for updating IDF curves under climate change, was applied to the existing historical data. Several different global climate models (GCM) and one regional model were applied to obtain and update rainfall design storm. The GCMs and future scenarios used were from the IPCC Assessment Report 5 (AR5) and two future projections: RCP (representative concentration pathway) 4.5 and 8.5. Alternatives previously proposed to solve to flooding issue are briefly reviewed. On one of the latest studies [1], a few modern concepts of water resources management are presented, and the linear retention measure was found to offer higher potential to mitigate the flooding problem in the lower valley of the watershed. Therefore, this alternative was used to evaluate different design storms scenarios combined with return periods of 25 and 100-years as well as the updated IDF under climate change for RCP 4.5 and RCP 8.5. To model the complex network, representing both road and drainage systems and their interconnections, PCSWMM/SWMM software was applied. Results are presented as flooding maps and show the impacts of the proposed linear retention measure based on the existing IDF curves and the updated IDF curves under climate change for two different drainage system conditions, current and improved with the use of linear retention reservoirs. Results show that the prosed changes on the drainage system help reduce the risk and damage to flooding. The climate change scenarios, however, impose a significant threat and need immediate attention from city planners and stakeholders.

Additional Leave as the Determinant of Retirement Timing—Retaining Older Workers in Norway

Faced with a rapidly aging labor force, increasing the labor supply of older workers has become an important goal for European countries. Offering additional leave to older workers with the option of withdrawing a contractual pension (contractual early retirement pension AFP) has become a widespread retention measure in Norwegian companies. Thus far, no studies documenting the effects of individual retention measures on early retirement behavior have been published. The aim of this article is to examine whether offering additional leave impacts the relative risk of withdrawal of a contractual pension. The analysis uses a difference-in-differences approach and examines whether offering additional leave to counteract early retirement impacts the retirement decisions of 61- and 62-year-olds within the next two years of their employment, controlling for a range of different individual and company characteristics. This is achieved by comparing changes and differences in the individual relative risk of retiring early on the contractual pension (AFP scheme) in the period 2001–2010 among older workers in companies with and without the retention measure. The analysis shows an overall average increase in the relative risk of a 61- or 62-year-old worker retiring on the contractual pension between 2001 and 2010; however, among older workers employed in companies offering additional leave there has been a decrease in the relative risk. The effect of additional leave is evident both before and after controlling for the selected individual and company characteristics. Thus, the analysis shows that offering additional leave as a retention measure reduces the individual relative risk of withdrawing a contractual pension (AFP) in the next two years of employment among older workers between the age of 61 and 62 years.

Item Selection and Picture-Word Differences in Recognition and Recall

The hypothesis that word superiority at an associative stage of paired-associate recall reflected differential item selection was examined. Indices of item difficulty were related to picture-word differences for each retention measure, but the word superiority effect appeared independent of item selection.

Discovery Learning in Kindergarten Mathematics

Non-cued Discovery (NCD), Perceptual Cue Guided Discovery (PCG), and Verbal Didactic (VDI) instructional procedures for teaching number conservation were compared with each other and with a control to evaluate the discovery learning hypothesis for immediate learning, retention, and transfer in a sample of 120 kindergarten subjects. The VDI group was found superior to either discovery treatment (p=.05) on immediate learning. On the retention measure both the PCG and VDI treatments were superior to the NCD and Controls (p=.05). Although some transfer value of the training was apparent, no treatment differences emerged. The results are interpreted as providing little support for employing unaided discovery learning methods for teaching the studied beginning mathematical concepts to kindergarten subjects. Guided discovery and verbal didactic methods of instruction are seen as providing attention directing cues necessary in learning

Delayed Feedback Effects on Learning and Retention of Morse Code Symbols

In five experimental comparisons of delayed and immediate feedback on the learning of visually presented Morse Code by adult Ss, no effect on learning was shown. Four studies employing recall as the retention measure also yielded no influences of delay on retention. The fifth comparison employed relearning as the retention measure and found superior retention for Ss receiving immediate feedback during learning. These findings contrast with those of a good number of studies with children in which learning under delay produced superior relearning, i.e., the Delay Retention Effect. Hypotheses concerning the different influences of delay on children vs adults and on learning vs retention are put forward.