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In 1944 and 1945 large areas of the Netherlands were inundated with sea-water. After removing the flood-water the salt and moisture figures of the soil were checked, usually to a depth of 80 cm, for several winters and summers. The drying and salinization (in particular of the plough ridge) of the soil in summer and the rewetting and leaching in winter were studied. The distribution of salt through the soil was governed mainly by downward passage of precipitation and upward capillary transport of soil moisture during summerweather. Irregular distribution in short distances was primarily due to unequal rates of intake.To calculate the downward passage of water through the soil, the loss of salt from a column of soil was divided by salt concentration of the solution leaving the bottom of the column. This concentration was assumed equal to the mean concentration of the lowest part of the column during leaching. Conditions limiting this method were discussed.Capillary rise was calculated in a similar way. Rainfall, soil moisture and capillary rise were considered in calculation of evapotranspiration. Zowel in ons land als in het buitenland was reeds lang bekend dat vele cultuurgewassen sterk zoutgevoelig zijn, zodat, voor een zo goed mogelijk uitoefenen van het landbouwbedrijf op zoute gronden, kennis van het zoutgehalte van de grond zeer gewenst is. Toen de Duitse legerleiding dan ook, in het voorjaar van 1944, voor het onder water zetten van een groot aantal polders gebruik maakte van zout of brak water, stond meteen vast, dat, na de inundaties, in de weer drooggevallen gebieden een omvangrijk onderzoek naar het zoutgehalte van de grond niet zou kunnen worden gemist. Onderzoek is gedaan naar de zouthuishouding (zomer- en winterperiode) over de afzonderlijke jaren 1945-1950.

This paper deals with the hydrological properties of deltaic sediments. A detailed study was made of the geological history of part of the delta plain of the Rhine and Meuse. Such hydrological properties as thickness of aquifers and semi-permeable layers, transmissibility of the aquifers were determined.

Bodemgeschiktheid, onderzoek van Stiboka

In het kader van de werkzaamheden die door het ICW in het Deltagebied worden uitgevoerd, wordt een onderzoek ingesteld naar de frequenties van afgevoerde hoeveelheden water in oen aantal bemalingsgebioden. In deze Nota zal een overzicht worden gegeven van de tot nu toe bereikte stand van zaken bij de voorbereiding van het onderzoek.

Bodemgeschiktheid, onderzoek van Stiboka

The results were discussed of an ecological study of salt marsh vegetation along the estuaries of the rivers Scheldt, Meuse and Rhine (incl. the Eastern Scheldt) as a part of European halophytic vegetation.Communities were classified by the Swiss-French system of Braun Blanquet. Special attention was devoted to a cybernetic approach to the vegetation and its habitat as accomplished in space and time.Environmental aspects considered included the stable borders between the Arctic, Atlantic, Continental and Mediterranean climatic types along the West European coast, the ecological significance of tides, the origin of mud flats and salt marshes, physical and chemical properties of the soil and their relation to sedimentation, and biotic factors. choice between intraregional and interregional classification could be based only on floristic relationships. Existing, mostly regional systems could be combined into a single classification scheme for the whole European halophytic vegetation.Finally West European salt marsh communities, including tidal drift communities, were described, especially those of the south-west Netherlands.

Doel van dit onderzoek was de rentabiliteit van de visserij op consumptiegarnalen in 1947 alsmede de kosten per kg van consumptiegarnalen te benaderen. Dit onderzoek omvat uitsluitend de garnalenvisserij in de zeegaten en op de Noordzee.

Landbouwkundige inventarisatie Zeeuwse en Zuid-Hollandse eilanden, West-Brabant klei en zand