Sampling design for compliance monitoring of surface water quality: A case study in a Polder area

International agreements such as the EU Water Framework Directive (WFD) ask for efficient sampling methods for monitoring natural resources. In this paper a general methodology for designing efficient, statistically sound monitoring schemes is described. An important decision is the choice between a design-based and a model-based method, implying the choice between probability (random) sampling and purposive sampling. For mapping purposes, model-based methods are more appropriate, whereas to obtain valid results for the universe as a whole, such as in testing water quality standards against legal standards, we generally prefer a design-based method. Four basic sampling patterns in space-time universe are described: static, synchronous, static-synchronous, and rotational. A case study is carried out for monitoring the quality of surface water at two farms in western Netherlands, wherein a synchronous sampling design is applied, with stratified simple random sampling in both space and time. To reduce laboratory costs the aliquots taken at the locations of a given sampling round are bulked to form a composite. To test the spatiotemporal mean N-total concentration during the summer half-year against the MAR standard with a power of 80% at a concentration 15% below the MAR standard and with a confidence of 95%, six to nine sampling rounds are needed with 50 to 75 locations per sampling round. For P-total the required number of sampling rounds differs strongly between the two farms, but is for both farms much larger than for N-total

Estimating space-time mean concentrations of nutrients in surface waters of variable depth

A monitoring scheme has been designed to test whether the space-time mean concentration total Nitrogen (N-total) in the surface water in the Northern Frisian Woodlands (NFW, The Netherlands) complies with standards of the European Water Framework directive. Since in statistical testing for compliance monitoring valid estimators for the mean and its variance are important, a design-based method is preferred above a model-based method. In the NFW-area the surface water depth varies in both space and time and can periodically equal zero, due to variation in precipitation and evapotranspiration. To account for this, space-time mean concentrations are estimated by the ratio of the estimated total mass of nutrient and the estimated total volume of water. The method is applied in the period from 1 April to 30 September 2008 to four hydrologically different subareas. Besides, the aim was to use the information on the spatial and temporal variance of N-total concentrations to optimize the numbers of sampling rounds and sampling locations per sampling round in future monitoring campaigns, given budgetary constraints. A bootstrap procedure was applied to account for uncertainty about the temporal and spatial variances in estimating the optimal number of sampling rounds and sampling locations. For two subareas the accuracy of the estimated space-time means can be improved by sampling more frequently at less locations (compared to the design applied in 2008), whereas for one subarea sampling less frequently at more locations increases the precision. For one subarea the sample data were rather inconclusive about the optimal sample sizes

Towards a Soil Information System with quantified accuracy : a prototype for mapping continuous soil properties

This report describes the potential and functionality of software for spatial analysis, prediction and stochastic simulation of continuous soil properties using data from the Dutch Soil Information System (BIS). A geostatistical framework and R codes were developed. The geostatistical model of a soil property has a deterministic component representing the mean value within a soil category, and a stochastic component of standardized residuals. The standardized residuals are interpolated or simulated based on the simple kriging system. The software was tested in four case studies: exchangeable soil pH, clay content, organic matter content and Mean Spring Water table depth (MSW). It is concluded that the geostatistical framework and R codes developed in this study enable to predict values of continuous soil properties spatially, and to quantify the inaccuracy of these predictions. The inaccuracy of a spatial prediction at a certain location is quantified by the kriging variance, which can be interpreted as an indication of the uncertainty about the true value

Systems Analysis of International Law: An Inquiry into its Application

This report investigates the usefulness of systems analysis as a methodological tool for the analysis of the world legal system. Due to increasingly complex relations between states, traditional methods for legal analysis are no longer sufficient to provide adequate explanations of the changing features of international legal regulation. Systems analysis offers the opportunity to combine methods used in legal and social sciences and, moreover, to focus on the dynamics of international law development. The development of a regime for the prevention of long range transboundary air pollution in Europe serves as a case study. In the report three levels of analyses are distinguished: (a) a theoretical level concerned with the general legal and political theories explaining the international behavior of states; (b) a policy making level dealing with international (legal) cooperation in practice, i.e. the process of acceptance of specific international rules; and (c) an instrumental level which deals with specific techniques and technologies used to facilitate the policy and law making process and, for example, to supervise the behavior of states and to enforce international agreements. Examples are (satellite) monitoring techniques and the use of integrated computer models like the RAINS model developed at IIASA. The first two levels of analyses receive most attention in this report. The main conclusion is that systems analysis forms a promising methodology to be used in legal science. However, more extensive research remains necessary

USPOREDBA DOBROBITI KRAVA MUZARA U VEZANOM I SLOBODNOM UZGOJU

Milk production on Slovenian farms is an important economic activity that underwent essential changes after the introduction of the European Union standards. Sound state of health and welfare of dairy cows remain the essential conditions for the quality of milk and dairy products, as well as important public health aspects. This paper presents the currently applicable welfare standards for farm animals, the European priority activities in the field of welfare of farm animals, and the results of inquiry into the state of play in dairy cow housing systems in the narrower north-eastern territory of Slovenia. Ten free housing system dairy farms and ten tether system dairy farms were inspected, compared and assessed according to the Austrian method of the Animal Needs Index (ANI) for cattle. ANI is a relevant criterion for assessing the adequacy of husbandry systems, based on graded point system. The five areas of influence impacting animal welfare were assessed, including: affording movement (‘Locomotion’), affording social interaction (‘Social interaction’), type and condition of flooring (‘Flooring’), light and air conditions (‘Light and Air’), including ventilation and noise level, and quality of care for the animals (‘Stockmanship’). Adequacy of housing conditions was evaluated and compared between the free housing and tether systems for dairy cows. The paper further presents the state of health of animals examined and the scope of diseases detected, including technopathies and injuries, reasons for culling dairy cows and herd structure by the end of 2009, in either of the two husbandry systems. The advantages and disadvantages of the method used for assessing the adequacy of each husbandry system are presented as well.Proizvodnja mlijeka na privatnim farmama goveda u Sloveniji je značajna gospodarska djelatnost, koja je zbog uvođenja evropskih propisa doživjela značajne promijene. Zdravlje i dobrobit krava predstavljaju osnovne uvjete za kakvoću mlijeka i mliječnih proizvoda a uz to su i značajni činjenici zdravlja čovjeka. U radu su predstavljeni aktualni standardi o dobrobiti domaćih životinja, značajne europske aktivnosti na području dobrobiti i rezultati analiziranog stanja na užem području sjeverno-istočne Slovenije. Praćeno je i analizirano 10 privatnih farmi sa slobodnim uzgojem krava muzara i 10 s uzgojem na vezu. Ocijenjena je kvaliteta uzgoja prema austrijskoj metodi ANI, koja predstavlja mjerilo za ocjenu primjerenosti uzgoja na temelju sustava bodova. Ocijenjeno je svih pet utjecajnih područja značajnih za dobrobit životinja i to: sloboda kretanja, socijalni kontakti, stanje podova, osvjetljenje, ventilacija, buka te kvaliteta skrbi za životinje. Ocijenjena je adekvatnost uzgoja i napravljena usporedba između slobodnog i vezanog načina uzgoja. Analizirano je zdravstveno stanje pregledanih životinja i predstavljen opseg bolesti, tehnopatija i ozljeda, uzroci za izlučivanje krava muzara i sastav stada na istraživanim farmama krajem 2009 godine. Predstavljene su prednosti i nedostaci metode za ocjenjivanje kvalitete uzgoja životinja

Hoezo representatief? : over de betekenissen van representatief in de KRW literatuur

We gaan in op de selectie van representatieve locaties en representatieve tijdstippen bij monitoring voor de Europese Kaderrichtlijn Water. Het blijkt dat 'representatief' veel kan betekenen, wat niet altijd bijdraagt aan duidelijkheid over de steekproef opzet. Wij pleiten er daarom voor om het woord 'representatief' niet te gebruiken, maar de opzet en het doel van de steekproef gedetailleerd te beschrijven. 'Representatief' wordt wel eens in verband gebracht met kanssteekproeven, waarbij de eenheden aselect, at rondom, worden gekozen. Wij benadrukken dat, afhankelijk van het doel, in het ene geval een gerichte steekproef beter is en in het andere geval een kanssteekproef

Increased susceptibility to proactive interference in adults with dyslexia?

Recent findings show that people with dyslexia have an impairment in serial-order memory. Based on these findings, the present study aimed to test the hypothesis that people with dyslexia have difficulties dealing with proactive interference (PI) in recognition memory. A group of 25 adults with dyslexia and a group of matched controls were subjected to a 2-back recognition task, which required participants to indicate whether an item (mis)matched the item that had been presented 2 trials before. PI was elicited using lure trials in which the item matched the item in the 3-back position instead of the targeted 2-back position. Our results demonstrate that the introduction of lure trials affected 2-back recognition performance more severely in the dyslexic group than in the control group, suggesting greater difficulty in resisting PI in dyslexia.Peer reviewedFinal Accepted Versio