Selectie van inwinningstechnieken voor bodemdata : Selecteren vanuit de (onderzoeks)vraag

A procedure has been developed to establish whether or not area-wide soil information in the Key Register of the Subsurface (BRO) meets the requirements of the user with regard to accuracy and spatial detail, and to select the most efficient additional mapping method to meet these requirements. A trade-off between costs and accuracy appears to be easier in simple applications than in multiple applications. In the latter case, accuracy is often assumed to be 70% map purity. However, this criterion needs to be more accurately defined and substantiated and, if necessary, adjusted on the basis of the results of risk analyses. Furthermore, it is necessary to monitor where and for which soil characteristics the Soil Map of the Netherlands, scale 1 : 50,000, meets this quality criterion

A selection of sensing techniques for mapping soil hydraulic properties

Data on soil hydraulic properties are needed as input for many models, such as models to predict unsaturated water movement and crop growth, and models to predict leaching of nutrients and pesticides to groundwater. The soil physics database of the Netherlands shows several lacunae, and a substantial part of the data were collected more than thirty years ago and thus might not represent actual soil hydraulic conditions

Selectie van inwinningstechnieken voor bodemdata : Selecteren vanuit de (onderzoeks)vraag

A procedure has been developed to establish whether or not area-wide soil information in the Key Register of the Subsurface (BRO) meets the requirements of the user with regard to accuracy and spatial detail, and to select the most efficient additional mapping method to meet these requirements. A trade-off between costs and accuracy appears to be easier in simple applications than in multiple applications. In the latter case, accuracy is often assumed to be 70% map purity. However, this criterion needs to be more accurately defined and substantiated and, if necessary, adjusted on the basis of the results of risk analyses. Furthermore, it is necessary to monitor where and for which soil characteristics the Soil Map of the Netherlands, scale 1 : 50,000, meets this quality criterion

Archeologie op de kop : Het archeologisch potentieel van het Maasterras tussen Well en Aijen slim en snel in kaart gebracht door een combinatie van onderzoekstechnieken

Het Maasdal is archeologisch veel rijker dan twintig jaar geleden werd vermoed. Uit verschillende grootschalige archeologische onderzoeken is gebleken dat het landschap en de archeologische vindplaatsen daarin veel diverser zijn dan lange tijd is aangenomen. In opdracht van de Provincie Limburg is in het plangebied Vergrote Voorhaven (onderdeel van het Maaspark Well) door RAAP een innovatieve onderzoekssystematiek toegepast, waarbij eerst het landschap gedetailleerd in kaart wordt gebracht en vervolgens voorkeurslocaties van vindplaatsen gericht worden onderzocht. Bovendien is een systematiek uitgedacht om te komen tot een objectievere waardestelling van de vindplaatsen

Interpolatie, aggregatie en desaggregatie van ruimtelijke bodemgegevens in de Basisregistratie Ondergrond (BRO)

Soil data in the Key Register of the Subsurface (Basisregistratie Ondergrond – BRO) are not always in a form appropriate for specific uses. This is true for all sectors and uses for which soil information is relevant, such as agriculture, nature conservation, land use planning, water management, infrastructure and climate mitigation. This report sets out a number of methods for converting soil data to spatial resolutions and levels of accuracy more appropriate for the uses in question

Kartering van fosfaatbeschikbaarheid in de bodem met behulp van natuurlijke radioactiviteit

De mogelijkheden voor natuurontwikkeling op voormalige landbouwgronden worden sterk bepaald door de fosfaatbeschikbaarheid. In een case study is de zogeheten GM Soil Meter gebruikt om de bodem vlakdekkend te scannen op de fosfaatbeschikbaarheid. Deze Soil Meter bevat een sensor waarmee natuurlijke radioactiviteit uit de bodem in de vorm van gammastraling wordt gemeten. Gammaspectra worden gekalibreerd aan chemische bodemeigenschappen. Door proceskennis over P-adsorptie- en -desorptie te koppelen aan verzamelde ruimtelijke informatie kon vlakdekkende informatie met een hoge resolutie worden verkregen over gebiedsdelen waar een te hoge fosfaatbeschikbaarheid is te verwachten. De verkregen kaartinformatie is veelbelovend: de patronen zijn met gebiedskennis te interpreteren. Een validatiestudie verdient aanbeveling om de betrouwbaarheid te kwantificere

Mapping soil clay contents in Dutch marine districts using gamma-ray spectrometry

Conventional soil sampling methods to obtain high-resolution soil data are labour intensive and costly. Recently, gamma ray spectrometry has emerged as a promising technique to overcome these obstacles. The objective of our study was to investigate the prediction of soil clay contents using gamma-ray spectrometry in three marine clay districts in the Netherlands: the southwestern marine district (SMD), the IJsselmeerpolder district (IJPD) and the northern marine district (NMD). The performance of linear regression models was investigated at field (1000 km2) scales and for all the Dutch marine districts together. For this study, a database was available with 1371 gamma-ray spectra measured on arable fields in marine clay districts during the period 2005–2008 and these were all linked to laboratory analyses of clay contents. At the field scale, linear regression models based on 40K, 232Th, or a combination of these revealed much smaller root mean squared error (RMSE) values (2–3%) compared with a model based on the field mean (8–10%). At the district scale, the regression models for the SMD and IJPD, which have comparable sediments, performed better than for the NMD. This indicates that the prediction of clay contents in late Holocene marine sediments may be made with gamma-ray spectrometry provided that the origin of the parent material results in a unique fingerprint. Because of the heterogeneous parent material of all marine districts taken together, our study shows that no unique and precise fingerprint exists, and the RMSE of 6% between clay contents and gamma-ray spectra is not much different from the RMSE of 7% when using the overall mean as a predictor

Mapping soil clay contents in Dutch marine districts using gamma-ray spectrometry

Conventional soil sampling methods to obtain high-resolution soil data are labour intensive and costly. Recently, gamma ray spectrometry has emerged as a promising technique to overcome these obstacles. The objective of our study was to investigate the prediction of soil clay contents using gamma-ray spectrometry in three marine clay districts in the Netherlands: the southwestern marine district (SMD), the IJsselmeerpolder district (IJPD) and the northern marine district (NMD). The performance of linear regression models was investigated at field (1000 km2) scales and for all the Dutch marine districts together. For this study, a database was available with 1371 gamma-ray spectra measured on arable fields in marine clay districts during the period 2005–2008 and these were all linked to laboratory analyses of clay contents. At the field scale, linear regression models based on 40K, 232Th, or a combination of these revealed much smaller root mean squared error (RMSE) values (2–3%) compared with a model based on the field mean (8–10%). At the district scale, the regression models for the SMD and IJPD, which have comparable sediments, performed better than for the NMD. This indicates that the prediction of clay contents in late Holocene marine sediments may be made with gamma-ray spectrometry provided that the origin of the parent material results in a unique fingerprint. Because of the heterogeneous parent material of all marine districts taken together, our study shows that no unique and precise fingerprint exists, and the RMSE of 6% between clay contents and gamma-ray spectra is not much different from the RMSE of 7% when using the overall mean as a predictor

Kartering van fosfaatbeschikbaarheid in de bodem met behulp van natuurlijke radioactiviteit

De mogelijkheden voor natuurontwikkeling op voormalige landbouwgronden worden sterk bepaald door de fosfaatbeschikbaarheid. In een case study is de zogeheten GM Soil Meter gebruikt om de bodem vlakdekkend te scannen op de fosfaatbeschikbaarheid. Deze Soil Meter bevat een sensor waarmee natuurlijke radioactiviteit uit de bodem in de vorm van gammastraling wordt gemeten. Gammaspectra worden gekalibreerd aan chemische bodemeigenschappen. Door proceskennis over P-adsorptie- en -desorptie te koppelen aan verzamelde ruimtelijke informatie kon vlakdekkende informatie met een hoge resolutie worden verkregen over gebiedsdelen waar een te hoge fosfaatbeschikbaarheid is te verwachten. De verkregen kaartinformatie is veelbelovend: de patronen zijn met gebiedskennis te interpreteren. Een validatiestudie verdient aanbeveling om de betrouwbaarheid te kwantificere