NN31811.127

INSTITOOT VOUK CULTUURTECHNIEK EN WATERHUISHOUDING INSTITUTE FOR LAND AND WATER MANAGEMENT RESEARCH P.O. BOX 35, WAGENINGEN, THE NETHERLANDS

Buried channel aquifers and present open drainage system of East Gelderland, the Netherlands

J. J. de Vries and E. van Rees Veilinga

Verspreide overdrukken Miscellaneous Reprints Uit: Geologie en Mijnbouw 127 From: 51 (1), 1972 Nog te verkriigen Verspreide Overdrukken: 26. VISSER, W. C. 1965. Een zelfregistrerende water­ Still available Miscallaneous Reprmts: standsmeTer voor verscn111enae meeropdrachten. 27. POST, C. J. VAN DER, en J.C. VAN LEEUWEN. 1965. Vergelijking van enkele grondbewerkingswerktuigen (Summary: Camparisen of various soil cultivation 5. VISSER, W. C. 1962. Wie beeinflusst das Speiche­ methode;); MEYS, M. Q. VAN DER, en C. J. VAN DER rungsvermögen den Dränab~tand (Summary: How POST. 1965. Wortelontwikkeling bij herfsttomaten does moisture starage capecity influence drain spa­ (Summary: Root development of autumn tomatoes). cing). 28. BIJKERK, C. en J. PIETERS. 1965. Techniek en econo­ 6. SCHOTHORST, C. J. 1963. Herontginningsresultaten mie van het onderhoud van enkele Drentse water­ onder de loep (Summary: Opinion of farmers on schappen (Summary: Technica! and economical as­ the effect of improving cut-over high moor peat pects of the maintenance of open watercourses). soils). 29. WIEBING, R. 1965. Het grondverbeteringsproefveld 7. WIND, G. P. en D. J. PATIJE. 1963. De opbrengsten te De Krim (Ov.). op de proefboerderij voor machinale bodemverbete­ 31. TOUSSAINT, C. G. en D. HETIINGA. 1966. Effect ring te Borgercompagnie in 1962 (Summary: The van rijenafstond en beregening bij zomertarwe op yields of on experimental farm soil impravement on zandgrond (Summary: Effects of row spacing and cut-over high moor peat soils). sprinkling irrigation of spring wheat on sandy soils). 8. Verbetering van Ploatgronden. 1963. WIND, G. P. 32. POST, C. J. VAN DER, en J.C. VAN LEEUWEN. 1966. Het theoretisch te verwachten effect van plaatgrond­ De waterlozing in glasgebieden (Summary: Water verbetering. HIDDING, A. P. Resultaten van het ver­ discharge in glasshouse regions). diepen van de doorwortelbare zone van plaatgron­ 33. HAAN, F. A. M. DE, en G. P. WIND. 1966. Bodem­ den. verdichting als gevolg van de wijze van uitvoering 9. DUIN, R. H. A. VAN. 1963. Problemen van platte­ van grondverbeteringswerkzaamheden. landsinrichting. 34. WEERD, B. VAN DER, en W. C. VISSER. 1966. Een 10. WIEBING, R. en G. P. WIND. 1964; Verbetering van apparaat voor het meten van draindebieten onder veenkoloniale grond. water en enkele op deze meting steunende resul­ 11. BIERHUIZEN, J. F. 1964. Growth and water use of taten. vegetobles in a greenhouse. 35. GELDEREN, C. VAN. 1966. Bepaling en gebruik van 12. VISSER, W. C. 1964. Formulae for the ecological re­ de minimale gemiddelde kavelafstand (Summary: action of erop yields. Determination and use of the minimum mean lot 13. VISSER, W. C. 1964. Cropping pattern and water re­ distance). lotions. 36. BIJKERK, C. 1966. Landinrichting in gebieden met 18. VISSER, W. C. 1964. De stikstofvorming in de grond verouderde structuur (Summary: Physical planning en de ontwatering (Summary: The formation of ni­ of agricultural areas with on out-of-date structure). trogen in the soil and the depth of yield drainage). 37. VISSER, W. C. 1966. De wijdte van de perforatiesJeu­ 20. SLATYER, R. 0. and J. F. BIERHUIZEN. 1964. A dif­ ven in plastiek drainbuizen in verband met opdrij­ ferentiel psychrometer for continuous measurements ven. of transpiration. 38. SCHOTHORST, C. J. 1966. Klink van veengrond na 21. HIDDING, A. P. 1965. Resultaten van een aantal be­ diepere ontwatering. zandingsproeven. 39. VISSER, W. C. 1966. Ober die Weiterentwicklung der 22. TOUSSAINT, C. G. 1965. Het effect V'an water en Auffassungen hinsichtlich der Dränung van Obstan­ stikstof op al dan niet met chloorcholinchloride be· lagen in den Niederlanden. spoten wintertarwe. 40. FLACH, A. J. en J. PIETERS. 1966. Veranderingen in 23. HIDDING, A. P. 1965. Untersuchungen zur Beein­ de wandruwheidsfactor van open waterlopen tijdens flussing schwerer Tonböden durch kulturtechnische heT groeise1zoen. Masznahmen. 41. SPIJK, P. 1967. Invloed van de situering van boerde­ 24. BERG, C. VAN DEN, en l. J. LOCHT. 1965. Overzicht rijen op de investeringen in openbare nutsvoorzie­ van het economisch onderzoek in de cultuurtechniek. ningen (Summary: The effect of the settiement pat­ 25. VISSER, W. C. 1965. A methad of determining evapo­ tarn of farm buildings on the investments in utility transpiration in soil monoliths. works). Zie achterkaft See back cover GEOLOGIE EN MIJNBOUW VOLUME 51 (1), p .. 45-52 1972

BURIED CHANNEL AOUIFERS AND PRESENT OPEN DRAINAGE SYSTEM OF EAST GELDERLAND, THE NETHERLANDS

1 2 J.J. DE VRIES ) and E. VAN REES VELLINGA )

ABSTRACT formations that were known to occur in this region. The buried channel aquifers are of great im­ In the eastern part of the province of Gelderland, two portance for the water supply of municipalities and buried valley systems have been traced. Orte system is filled industries. · with fluvioglacial deposits dating from the Saalian lee Age, the other with preglacial fluvial sediments which are remarkable The age and course of these old valley systems in rich in vulcanic minerals. relation to the geomorphologic developments of the Both systems have a course which is almost perpendicular area is discussed in this paper. to the present drainage system. This change in stream direction is explained by postglacial reptacement of the main drainage channel in the area, teetonic movement perpendi­ cular to the old channels, and postglacial filling of the old GENERAL GEOLOGY OF THE AREA channels with wind blown sand. From a geological point of view, two different areas may he distinguished in Eastern Gelderland: the INTRODUCTION East Netherlands plateau and the Pleistocene basin (see fig. 2). In the eastern part of Gelderland Pleistocene The East Netherlands plateau extends from the buried valleys occur. The presence of an old buried German frontier to the line Groenlo-Aalten. Here channel system near Winterwijk and Aalten was thick layèrs of marine clays and clayey sands of mentioned by F a b e r (1960) and is shown in fig. 1. mainly Oligocene and Miocene age are found at the From the results of more recent investigatiom by land surface or at shallow depth. At many places W a 1 ter (1965), Cs on ka (1965), Romein these Tertiary deposits are covered by a thin layer of (1967) and de Ridder (1966) the course and wind-blown sands. Locally, however, coarse, gravel­ depth of the valley system have been traced. hearing layers of fluvial Middle-Pleistocene (Sterk­ Another buried valley system . was traeed west of sel/Enschede Formation) and fluvioglacial origin, as the former {de Ridder, 1966; and Ernst, de wellas boulder clay (Drente Formation), occur. R i d d e r and d e V r i e s, 1970). The channels of In westerly direction the Tertiary deposits dip this system are filled with very coarse sand. The rather abruptly under the Pleistocene basin. The heavy mineral content of these channel deposits transition from the plateau to the Pleistocene basin is differs significantly from the composition of the marked by a terrace . escarpmènt along the line

1 Groenlo-Aalten which at several places · reaches an ) Institute of Earth Sciences, Free University, Amsterdam. 2 ) Institute for Land and Water Management Research, elevation of several meters. Wageningen. The Pleistocene basin is filled with predominantly

~ ti SEP. 1973 46

-1- -1- -1- + ~ preglacial channels + +++++. younger channels "f.-"f.--f-. )(')(. ')(.')(.

Fig. 1 Preglacial and younger buried channels in East Gelderland (after Faber, 1960). gravel-hearing coarse sands of fluvial and fluvioglacial hardly be traced. Near ·Dinxperlo where the older origin, alternated by locally occurring boulder clay, system passes the German frontier, it reaches a depth fine sands and clayey deposits of the Eemian (Saale­ of more than 100 meters below land surface or more Weichsel Interglacial). The youngest of these layers than 70 m below sea level. In northeasterly direction · belong the the Kreftenheye Formation, the fluvio­ the channel becomes less deep and near the river glacial and boulder clay are indicative of the Drente Berkel the bottorn comes v'ery near to the land Formation; their total thickness is from 20 to 40 Surface. This deeply eroded valley has been gradually meters. Windblown sands of the Twente Formation filled with coarse and gravel-hearing fluvio-glacial (Weichselian) cover these coarse sediments and vary deposits, as shown in the geological section north of in thickness from 0 to 10 meters. Bredevoort (fig. 3, section A-A'). Most likely this former drainage system was a tributary of the preglacial or glacial Rhine which was BURIED CHANNELS OF THE deeply incised as a result of the drop of the sea level BAST-NETHERLANDS PLATEAU with the advancing land ice during the Saalian. Underlying the present valley of the river IJ ssel ~ Buried channels are found carved in the Tertiary · (running, some 10 to 15 km west of the region deposits of the plateau as well as in the Tertiary discussed), relics of this Saalian Rhine have been deposits underlying the coarse sediments of the found to a depth of more than 70 meters below sea Pleistocene basin. The valley system of the plateau level. Probably this deeply • carved Rhine valley runs from the north and northeast towards Dinxperlo extended south-eastward meeting the present Rhine in the south (fig. 2) and agrees with the direction of valley near Wesel in Germany (Th o rri é, 1954). the preglacial valleys given on Faber's map (fig. 1). The old valley system seems to have developed The younger systems given on Faber's map seem to along the boundaries of tlie geological formations be more shallow and less pronounced and could which were apparently the zones of least resistance in 47

•?

,~ - --~------,I I

z

.· . .·:· ·.. ... :>···

.·. .· ·······.···············.··/~··< ~ _____ // ,.,-_". / A-o------o--/1. geological cross-sectien A-/J/. .__ ,.,,., / /f terrace escarpment 1!I~f!!!!!!!!i!!1!!1!!M!! buried channel with Urk FormatJon preglacial burled channel ····-·.. ······-- formation boundaries ~ teetonic fault :::f::=:f::=::=::=:=:::: moors 0 5 ~Okm ~======~======~

Fig. 2 Map showing the buried channels, the present river courses, the ter~ace escarpment, and the teetonic faults. the area (fig. 2). In the adjacent area of Germany, tions of deR i d der (1966) revealed a buried valley comparable buried channels were found in the system of the preglacial Rhine. This system consists valleys of the Bocholter Aa, the Lippe and the Stever of deep channels in the underlying Tertiary deposits (B o I s e n k ö t t e r and H i I d e n, 1969). to a depth of more than 70 meters b~low sea level or more than 80 meters beneath the land surface. BURIED CHANNELS WEST OF THE Although these channels are also filled with gravel­ EAST NETHERLANDS PLATEAU hearing and very coarse sands, the deposits differ mineralogically from the material found in the West of the present terrace escarpment investiga- channels on the Tertiary plateau. 48

A m M148 M147 I 70 64 73 76 40 c c'

30 93 M71 83 82

10

10

20

30

0 2 4 km 1..... 1.....

HHJ Twentè Formation B B' nm~m~m~1~1 Kreftenheye Form. proj. m RY W M143 M 144 M145 M146 78 llllJIIIIIIl Continental Eemian 40 E:;:;:;:j Drente Formation 30 ..beulder clay 20 ~ Urk Formation 10 ~ Sterksei/Ensch. Form.

0 ~ Continental Pliocene

10 ~Mar. Middle Miocene ·

20 ~ Mar. Midd. Oligocene peat 30 E::::J

Fig. 3 Geologie cross-sections A-A', B-B I, c-e'. The first indications of this buried valley system beleng to the Urk Formation. were obtained from some borings near the villages of Other deposits· of the Rhine with high contents of Haarlo and Beltrum (fig. 2). Here very coarse gravel­ augite have been found at various sites in the west hearing sands, with a very high content of volcanic and north of the Netherlands (Z o n n e v e 1 d, heavy minerals (sometimes 80% to 90% augite ), are 1958). · These sediments probably belong to the directly overlying the Miocene deposits or occur in Vianen Formation which was deposited during the narrow channels incised into these deposits. These Holstein Interglacial and the early Saalian lee Age augite bearing sands, varying in thickness from 1 to (see fig. 5). Investigations ofTe r Wee (1966) have 10 meters, are overlain by fluvioglacial deposits of the made clear that a division of the various augite­ Drente Promation of which the augite content is bearing deposits is not yet possible, so for the time considerably lower. These augite sands were later also being we will regard the augite-rich deposits, as found in some borings near Lichtenvoorde and near belonging to the Urk Formation. Dinxperlo (fig. 4). It is remarkable that the augite­ In East Gelderland clayey deposits overlying the rich deposits seem to occur in a narrow zone only, augite sands are only found in one boring (M 71 near extending from Dinxperlo in the south via Varsseveld Beltrum, fig. 3, section C-C' and fig. 4). Here several and Lichtenvoorde to Haarlo in the north. meters of boulder clay (Z a g w i in, 1961) overly the Elsewhere in the Netherlands, for instanee in the augite-bearing layers filling a narrow channel, cut into Northeastpolder (in the former Zuiderzee), augite­ the underlying marine Miocene. bearing sands have been found in the subsurface by From .the obtained evidence it can be taken that Wiggers (1955). These sands are overlain by this valley system was filled before the deposition of clayey deposits of the Holstein Interglacial and the Saalien fluvioglacial materiaL So the deposits jn 49

AALTEN m m 25 50 75

MINERALS ~garnet I; ; ; ; ; ; ; I topaz t..:.:..:.:..Jep idote c=J other minera Is [U[::!!] ~?t~~~f~ite/ ~ stJ;~uro l ite ~m~tamorph i c E3 rg~~eb~~b~~~n.alka li ) ~mtnerals f/lllll chloritoid ~ tour maline - volcanic mlnerals

LITHOLOGY

[IJ] heavy clay ..peat [IJ sandy clay ~plant remains I H>=~>J fine sand c:::::J humus I:::::;:Jcoarse sand ~wood ~gravel ~shell n~mains

Fig. 4 Heavy mineral analysis of the borings M 71, M 201, Aalten lil. For location see fig. 2 (for M 71, alsotig. 3 section c-c'). TWE: Twente Forniation; KRE: Kreftenheye Formation; DRE: Drente Formation; URK: Urk Formation; CON PLI: Con­ tinental Pliocene; MAR MlO: Marine Miocene. 50

CHRONOLOGY DE POSlTS OF MARINE AND LOCAL PROVENANCE COASTAL

TEGELEN

KIESELOOLI TE FORMATION (R+M) MERKSEM (in part) FORMATION (in part)

R = RHINE ~ GLACIAL (COLD) STAGE M = MEUSE · ~ INTERGLACIAL (WARM) STAGE P = PERIGLACIAL 0 = ORGANOGENOUS m~t~~~~~t~t~l ~~~~E:A06 1~~ KNOWN IN B = BROOKDEPOSITS E= EASTERN PROVENANCE (WESER, ELBE)

Fig. 5 Stratigraphic division after Zagwijn, 1967. the fill are older than those found in the valley stream system need not have any relation to the old system on the East Netherlands plateau which have a valley system; being tributaries of the river IJssel they melt water origin. An early Saalien age of these are running almost perpendicular to the old valley deposits is therefore likely. system. On the East Netherlands plateau the course of the buried valley system is traceable as depressions in the THE OLD AND PRESENT STREAM SYSTEMS present land surface and the channels of this system still be considered as a natural subsurface drainage After the Saalian Glacial the preglacial valley system. It is remarkable, however, that the main system west of the terraée escarpment was overlain streams (Slingebeek, Groenlqsche Slinge and Berkel) by fluvioglacial deposits (Drente Formation), partly are almost perpendicular to the old- channel system. by Eemian sediments and by layers of fluvial origin This difference in stream direction may be explained (Kreftenheye Formation). The Drente and Kreften­ by the following processes. heye Formations consist of coarse sands, the latter deposited by braided rivers. Therefore the present A. Teetonic movements 51

The. geological structure of the East Netherlands system. plateau is governed by the high elevation of the Trias. At the end of the Weichselian glaciation the Rhine South of Winterswijk several Cretaceous and J urassic abandoned this branch. Later on the present river blocks are thrusted against these formations and erop IJ ssel running southwest to northeast some 10 to out (fault of Plantengaarde ). Aside from the com­ 20 km east of the area considered became a branch of plicated situation south and southeast of Winterswijk, the Rhine. The present drainage system of East the graben of Code, Groenlo and Eibergen are the Gelderland then became tributary to the river IJssel. main teetonic structures on this plateau (fig. 2). This would explain the southeast to northwest These graben are characterised by the preserree of direction of the present streams in the western part of Cretaceous and J urassic rock below the Tertiary East Gelderland. They probably captured the deposits while in the horsts in between them, the drainage system on the Tertiary plateau by headward Tertiary deposits are directly underlain by Trias migrating erosion, a drainage system which probably (Harsveldt, 1963). already had a southwest to northwest course deter­ Camparing the~ present drainage system with the mined by the teetonic structure of that region. teetonic structure, it can be seen that these features In the adjacent German area present streams are are partly related: the Slingebeek, the Groenlosche still tributaries to the rivers Rhine and Oude IJssel, Slinge and the Berkel are flowing in the teetonic and also follow old drainage system (B o 1 sen k ö t­ graben (fig. 2). ter and H i 1 den, 1969). An example of a more recent change in stream direction by teetonic influence is present southeast of c. The deposition of wind-blown sands Winterswijk. Here, as mentioned by F a b e r (1948) the Slingebeek has captured part of the Groenlosche · Towards the end of the WeichseÜan glaciation and Slinge. 1t is noteworthy that this event may be after the deposition of the Kreftenheye Formation, associated with the location of the Plantengaarde the wind was the principal depositing agent. In the fa ult. western Pleistocene basin the fluvial coarse sands The Schaarsbeek, the Wissinkbeek and the Beurser-· were overlain by a thick layer of fine wind-blown beek can be considered as the relics of the former sands, the Twente Formation. On the East Nether­ drainage system of glacial channels captured by the lands plateau, ho wever, only in the old channels and Groenlosche Slinge (fig. 2). A cross section of the other depressions some meters of this material was valley of the Groenlosche Slinge (see fig. 3 section l~id down. Considering the depth of the va,lleys B-B') showshow a rather shallow depression is filled before they were filled with wind-blown sands, they with fluvioglacial deposits. Possibly an incision was must have been· acting as drainage courses. The filling already present at the end of the Saalian glaciation, of these valleys with eolian deposits may have made by a tributary of the river scouring the deep initiated the change in stream direction. The develop­ preglacial channel indicated on the map. ment of peat in some of the old valleys (Koren burger Veen and Meddosche Veen, see fig. 2) is an indication of a stagnating drainage. b. Shift of the Rhine Valley The preglacial Rhine running from southeast to northwest flowed approximately perpendicular to the SUMMARY AND CONCLUSIONS Pleistocene valley system. At the retreating of the land ice the Rhine shifted its main course to an area Relics of buried channels occur in many places in south of the ice-pushed hills of Montferland (some the eastern part of the province of Gelderland. On the 15 km west of Dinxperlo) to a region where it now East Netherlands plateau the depth of one buried flows. An important branch, however, flowed to the channel is locally at least 100 meters and its course if western part of East Gelderland and deposited the from the north and northeast towards the southwest. coarse sands of the Kreftenheye Formation (Pons, · In the Pleistocene basin the depth of one buried 19 57). The downstream part of the river Oude IJ ssel channel is at least 80 meters and its course runs from can be considered as a relic of this former stream south to north. 52 The former valley system have been filled with regarding the Mesosoic of the Achterhoek, with special fluvioglacial deposits and seem to have developed mention of the Triassic limestones. Verh. Kon. Nederl. along the boundaries of the geological formations. Geol. Mijnbouwk. Genootsch., Geol. Serie 21, 2, p. 109-130. The fllling of the system m the Pleistocene basin Heide, S. van der and W.H. Zagwijn (1967)- Stratigraphical corîsists of fluvial coarse and gravel-hearing .sands Nomendature of Quaternary deposits in The Nether­ wich are very rich in volcanic minerals. lands. Meded. Geol. Stichting. N. Ser. 18, p. 23-29. Both buried channel systems have a course which Pons, L.J. (1957) - De geologie, de bodemvorming en de is almost perpendicular to the present drainage waterstaatkundige ontwikkeling van het Land van Maas en Waal en een gedeelte van het Rijk van - system. For the valley system of the Pleistocene basin Nijmegen. Thesis Wageningen, 156 p. the cause of the change in stream direction has been Ridder, N.A. de (1966a) - De geohydrologische gesteldheid the postglacial replacement of the glacial river Rhine van de Gelderse Achterhoek (interim rapport). Inst. by the present IJ ssel as the main drainage channel of Land and Water Manag. Res. Nota 344. the area. On the East Netherlands plateau the change (1966b) - Hydrogeologie van het stroomgebied van de Leerinkbeek. Inst. Land and Water Manag. Res. in stream direction is most probably the .result of Nota 337, 22 p. teetonic movements, capture of the older system by Romein, B.J. (1967) - Stratigrafische interpretätîe van enige the tributaries of the river IJssel and the flllirig of the Mesozoïsche kernmonsters van Proefboring T van de old channels by wind-blown sands. R.O.V.D. Rapp. 9, MicropaL Lab. afd. Mesozoïcum, Geol. Dienst, 3 p. Thome, K.N. (1959) - Eisvorstoss und Flussregime an REPERENCES Niederrhein und Zuiderzee im Jung-pleistozän. Pliozän und Pleistozän am Mittel- und Niederrhein. Geol. Bolsenkötter, H. and H.D. Rilden (1969) - Ein Beitrag zur Landesarot Nordrhein-Westfalen, Band 4, p. 197-247. Talgeschichte der Stever und der Unteren Lippe. Walter, F. (1965) - Rapport inzake een geo-elektrisch Forthr. Geol. Rheinld. u. Westf. 17,47-54. onderzoek in de omgeving van Ruurlo, Lichtenvoorde Csonka, J. (1967)- Rapport inzake geo-elektrisch onderzoek en Aalten in ·de Gelderse Achterhoek. Werkgroep in de Gelderse Achterhoek oostelijk vim de lijn Ulft­ Geo-elektrisch Onderzoek TNO, 25 p. Zelhem - Ruurlo - Lochem. Werkgroep Geo-elek­ Wee, M.W. ter (1966) - Toelichting op de Geologische kaart trisch Onderzoek TNO. Rapp. XXXVI, 5 3 p. and van Nederland. Blad Steenwijk Oost (16 0), Geol 27 append. Stichting, afd. Geol. Dienst, Haarlem. Ernst, L.F., N.A. de Ridder and J.J. de Vries (1970) - Wiggers, A.J. (1955) -De wording van het Noordoostpolder­ Geohydrologic study of East Gelderland (Nether­ gebied. Thesis Amsterdam, 216 p. lands). Geol. en Mijnbouw 48, p. 457-488. Zagwijn, W.H. (1961) - Pollenanalytisch onderzoek van Faber, F.J. (1948) - Geologie van Nederland I, Algemene boringen bij Eibergen. Rapp. 296, Palaeobot. Lab., Geologie, 3rd edition, Gorinchem. Geol. Dienst. (1960) - Geologie van Nederland IV, Aanvullende Zonneveld, J.I.S. (1958) - Litho-stratigrafische eenheden in Hoofdstukken, Gorinchem. het Nederlandse Pleistoceen. Meded. Geol. Stichting. Harsveldt, H.M. (1963) - Older conceptions and present view N. Ser. 12, p. 31-64. 42. FONCK, H. 1966. Een vergelijking van chemische 73. WEERD, B. VAN DER. 1969. Ontwatering van boom­ slootreiniging met andere slootreinigingsmethoden gaarden. naar ervaringen in enkele Gelderse waterschappen 74. FONCK, H. 1968. Afwateringsproblemen in zandge­ in 1963-1964. bieden. 43. WIEBING, R. 1967. Het grondverbeteringsproefveld 75. BON, J. 1969. De invloed van bos in Nederland op te De Krim (Ov.). de afvoer van beekgebieden. 44. WIND, G. P. en J. R. WILLET. 1967. De proefboer­ 76. MEIJERMAN, G. C. 1969. Baten en kosten van cul­ derij voor machinale bodemverbetering te Borger­ tuurtechnische mvesteringen In veenkoloniale akker· compagnie. bouwbedrijven (Summary: Benefits and costs of in­ 45. KIK, R. 1967. Vergelijking van de oude en nieuwe vestments in improving the lay-out of land in the toestand van de ruilverkaveling "Buitenpolder achter Netherlands N-E Peat District). Kuinre". . 77. PERDOK, U. D., J. A. HULSHOF en Ch. Th. SCHLAN­ 46. BON, J. 1967. Hoge beekafvoeren in de Achterhoek. GEN. 1969. Grondige verandering van de bodem. 47. PLOEGER, J. 1967. Inkomstenontwikkeling in de land­ 78. VISSER, W. C. 1969. Mathematica! models in soil bouw. productivity studies, exempli'fied by the response to 48. TOUSSAINT, C. G. en R. WIEBING. 1967. Onder­ nitrogen. grondbekalking en beregening op hoge zandgrond. 79. WIND, G. P. 1969. Grondverbetering. 49. WIEBING, R. en D. VAN DER HEIJ. 1967. Resultaten 80. WIND, G. P. 1969. Capillary conductivity data esti­ van grondverbetering. mated by a simple method. 51. BIJKERK, C. 1968. Het gebruik van de grond en de 81. WESSELING, J. and K. E. WIT. 1969. An infiltration landinrichting. method for the determination of the capillary con­ 52. BON, J. 1968. Bepaling van de kM voor het ontwer· ductivity of undisturbed soil cores. pen van leidingen (Summary: Determination of the 82. VISSER, W. C. 1969. The relation between the litho­ roughness coefficient (kM) for the design of con­ log•cal propert1es and the shape of the desorption duits). curve. 54. WIEBING, R. 1968. Het grondverbeteringsproefveld 83. VISSER, W. C. 1969. An impirial expression far the te De Krim. desorption curve. 55. BE:RG, C. VAN DEN. 1968. Tuinbouw en waterver­ 84. STAK.MAN, W. P. 1969. Determination of the pore ontreiniging. size by the air bubbling pressure method. 57. HIDDING, A. P. 1968. Enkele voorlopige resultaten 85. STAKMAN, W. P. 1969. The relation between parti­ van plaatgrondverbetering ten behoeve van de fruit­ ele size, pore size and hydraulic conductivity of teelt. sand separates. 58. STOL, Ph. Th. 1968. Toepassing en gebruik van com­ 86. VISSER, W. C. 1969. Unsaturated soil moisture con­ puters. ditlens studied from field observations. 59. BERG, C. VAN DEN. 1968. Nederland-Waterland? 87. ERNST, l. F. 1969. Determination of starage coeffi­ 60. LIER, H. N. VAN. 1968. Raming van zondagbezoek cients from observation of groundwater levels. aan strandbaden in de provincie Drenthe voor de 88. TOUSSAINT, C. G. 1968. De waterbehoefte van de jaren 1980 en 2000. tumbouw in West-Nederland (Summary: Water re­ 61. BIJ KERK, C. en J. BUDDINGH. 1968. Techniek en qulrement for horticulture in the West-Netherlands). economie van het onderhoud van waterlopen. 89. STOL, Ph. Th. 1969. Use of computers for the inves­ 62. STAKMAN, W. P. en L. J. S. REINDERS. 1968. Door­ tigation of the hydrologie properties ol on area, latendheidsproblemen op enige tuinbouwpercelen in exemplified with the temporary drawdown of het ruilverkavelingsgebied Maarsseveense Plassen. ground-water levels. 63. BON, J. 1968. Gebruik van afvoerverhoudingen bij 90. SPIJK, P. 1969. Gedachten over de werkwijze ten het bepalen van de maatgevende afvoer in grotere aanzien van landinrichtingsplannen: alternatieven stroomgebieden (Summary: The use of discharge en beoordelingsaspecten. ratios for the determination of the norm discharge 91. BIJKERK, C. 1969. Recreatie-onderzoek ten behoeve in catchment areas of a fairly large size). van de landinrichting. 64. FONCK, H. 1968. Slootdichtheid en wintergrondwa­ 92. COUWENHOVEN, T. 1969. Verzilting en land- en terstand in de Gelderse Achterhoek. tuinbouw in Nederland. 65. BON, J. 1968. De minimum afvoer van de Baakse 93. VISSER, W. C. 1968. Ein Ertragsmodell für günstige beek. und schädliche Umweltfaktoren. 66. SPIJK, P. en Th. J. LINTHORST. 1968. Routedistributie VISSER, W. C. Anwendung der parametrischen bij landbouwbedrijfsverkeer (Summary: Route distri­ 94. 1968. Biologie auf praktische Probleme. bution for internol rural traffic). 67. RIJTEMA, P. E. 1969. Derived meteorological data: 95. WIEBING, R. 1970. Het grondverbeteringsproefveld transpiration. te De Krim. 69. BON, J. 1969. Topographie en vorm van het grond­ 96. LIER, H. N. VAN. 1970. Capaciteitsberekening voor watervlak als achtergrond van de te verwachten af­ nieuw te stichten strandbaden. voeren in de Gelderse Achterhoek. 97. VISSER, W. C. 1970. Kritische beschouwingen om­ 70. WIEBING, R. 1969. Het grondverbeteringsproefveld trent de grondslagen voor het ontwerpen van een te De Krim (Ov.). goed plan van waterbeheersing. 71. PERDOK, U. D. 1969. De grondlegging van de meng­ 98. VRIES, J. J. DE. 1969. Relatie tussen het sulfaat en rotor en de menggootwoeler op het veenkoloniale ijzergehalte in het diepe grondwater van de Gel­ profiel. derse Achterhoek (Summary: Relation between the 72. LIER, H. N. VAN. 1969. Onderzoek betreffende de re­ sulphate- and iron content of the deep ground­ creatie in vier strandbaden in de provincie Drenthe. water in the "Gelderse Achterhoek"). 99. LIER, H. N. VAN. 1970. Enkele aspecten van de 116. LIER, H. N. VAN. 1970. Zwemwater in stro openluchtrecreatie. 117. BIJKERK, C. 1970. Het onderzoek naar op."e·n-'ï"lu-c..-ht':------4 100. BERG, C. VAN DEN. 1970. De waterbehoefte in de recreatie. land- en tuinbouw (Summary: Water requirements 118. OOSTROM, C. G. J. VAN. 1971. Kwaliteit van glas­ of ogriculture and horticulture). opstanden in twee Westlandse h,Jinbouwgebieden. 101. TOUSSAINT, C. G. 1970. Boomteelt en waterkwali­ 119. WAARD, J. DE, en H. D. L. VAN RIJN. 1971. De teit. onderhoudskosten van plattelondswegen. 102. BIJKERK, C., TH. J. LINTHORST en C. VAN WIJK. 120. BERG, J. J. A. VAN DEN, en G. C. MEIJERMAN. 1970. Cultuurtechnische Inventarisatie Nederland. 1971. Kosten en baten van perceelsvergroting voor (Summary: A methad of a machine processed sur­ akkerbouwbedrijf van ca. 50 ha in de ruilverkave­ vey of the division of rural areas, as practised in ling 'De Marne' (Summary: Benefits ond invest­ the Ne1herlands). ments when en lorging parcel-sizes for 50 ha arabie 103. WEERD, B. VAN DER. 1969. Een grondwaterstands­ farms on heavy clay in the re-allotment area 'De afleesapparaat. Marne' (Northern Netherlands). 104. HELliNGS, A. J. 1969. Methoden voor het bepalen 121. BERG, C. VAN DEN. 1971. Cultuurtechnische as­ van het tijdstip van beregening. pecten van de bestemmingsverondering van de 105. FEDDES, R. A. 1969. Beregeningsprogramma's. grond (Summary: Land development aspects of 106. SCHOTHORST, C. J. 1969. Polderpeil en grond­ changes in land use). waterstand bij veengrasland. 122. KIK, R. 1971. Een methode voor het vervaardigen 107. lOCHT, l. J. 1970. Die Abschätzung kulturtechni­ van een voorlopig toedelingspion voor een ruil­ scher Projekte in den Niederlanden. verkaveling. 108. liER, H. N. VAN, en J. G. VAN KEULEN. 1970. Een 123. STOl, Ph. Th. 1971. Het voststellen van afvoer­ gravitatiemodel voor recreatie-verkeersstromen coëfficiënten van poldergemalen met behulp van toegepost op strondbodbezoek. (Summory: A gra­ moa lstootgegevens. vitation model for recreotionol traffic flows). 124. liER, H. N. VAN, J. G. BAKKER en H. BERGMAN. 109. MEIJERMAN, G. C. en J. J. A. VAN DEN BERG. 1971. Onderzoek ten behoeve van open luchtre­ 1970. Bedrijfseconomische mogelijkheden voor ge­ creatievoorzieningen bij de inrichting van het plat­ mengde bedrijven in het Noordelijk kleimozaiek­ teland. gebted. (Summory: Present economie possibilities 125. STOl, PH. TH. 1971. Een beschouwing over de for mixed holdings in a mosaic parcelled clay frequentie van weerkeren van hydrologische ge­ region tn the N.-Netherlands). beurtenissen. 110. WIJNSMA, M. en K. E. WIT. 1970. Het nemen van 126. WESSEliNG, J. and H. J. COlENBRANDER. 1972. ongestoorde grondkolommen. The use of geohydrology in solving water manage­ 111. DASBERG, S. and J. W. BAKKER. 1970. Character­ ment problems in agriculture. tzing soit aeration under changing soil moisture 127. VRIES, J. J. DE and E. VAN REES VElLINGA. 1972. conditions for bean growth. Buried chonnel aquifers ond present open drainage 112. liER, H. N. VAN. 1970. Strandbadrecreatie. system of east Gelderland, the Netherlands. 113. TOUSSAINT, C. G. en T. COUWENHOVEN. 1970. Interne zoutbelasting van de poldergebieden in West-Nederland. 114. BERG, C. VAN DEN. 19n. Waterhuishoudkundig onderzoek van het Instituut voor Cultuurtechniek en Waterhuishouding. 115. ERNST, L. F., N. A. DE RIDDER and J. J. DE VRIES. 1970. A geohydrologic study of East Gelderland (Netherlands).