Hydro-ecological relations in the Delta Waters

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Of course. tke environmental changes have not only influenced the vegetatian but also the fauna. Figure 5 gives an idea of the dynamics of the breeding bird populations on pne of the newly emergod islands in Lake Grevelingen. &er the constmction of the dam in the Broursershaveuse Gat some 400 hectares of tidal flats and a wll salt marsh were exposed to the air and wind. &specially the species of sandy beaches and pebble coasts (We the Kentish Plover) began to breed on the new land. The population of Bedshank, also a coastal bird, did not increase before some vegetation was existing. airily because the h- needed this vegetation to hide their nests. At that time the species of bare beaches were alrea* deelinhlg. The fimt breeding birds of shrlibs have colonized the island only recently and a common species like the Villow Warbler is still increasing. Woodland species do not breed on the island, because vegetation structure has not yet been dfiferentiated enough and there are no nestiag sites for these birds. It will take at least some 50-1Wl years before the bird communities begin to stabilfae. G-rally speaking the foll4ng factors influence the developnent of vegetation and animal wildlLfe an the former dt marshes and tidal f late : * the initial ecosystem present at the moment of dw constrnctiod; * processes of adaption ta the newly created situation; * mahagement of water and Land by m=. 3.1 Initial ecosystems The newly developed ecosystems have their starting point in the old estuadne waters. These Mtial ecosystems are strongly influcn-d by the origins1 waterrepime. This Fs illustrated by the distribution of the vegetation series qf Figure l in relation to height and tidal floo6ing (see Fig. 6). p e vegetation types inasated hy an open rectangle died within rwo or three years &ter embanlaaent was finished
and this resulted in an almost complete ba~e soil. The hatched vegetation types changed much more gradually, without dying off totally. After the enclesure in most areas %he water was pemnently fixed more or lee$ at mean sea-level (%L). The following aifferences occuted. In the fresh and brackish tidal areas the orisinal marsh vegetation c m at a mu& MLW) lower level (on certain places even below than in the saline systems. Coneequently a larger area of here soils eraerged after the completion af the dams in the ffaltwater systems in comparison to the upstream tidalwaters. This difference is enlarged bp the dying off 09 the lower saltmarsh species in the first years after the enclosure. Vegetation development on the former salt marshes and tide1 flats uas dominated by colonisation of the new habitets by mnual pionier species. On the contrary, in the fresh and brackish areas the new species (that had to invade existing vegetatians) were m&dy tall peremial herbs and grasses, shrubs and trees. 3.2 Processes abimie eavironntent After the welesure ~.f an estsarg a nlrmber of precesnes started thanging ahiotic environment of the new tcrrestr-ial environments (e..g. A PERtOUTINB SOIL -- B YllL WITH IMRRWE8BLE M W Figure 7 Twa main groundwater regimes on the newly emerged land in the former estnaries (after Drost and Visser, 1981)
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Netherlands organkation fw applied
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TNO Commlitee on Hydrological Resea
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2 RIVER WATER AM) THE QPALITH OF TB
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B.J.M. Baptist BIJkswaterstaat. Tid
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This approach will put to use what
Page 13 and 14:
Estuaries that have not been influe
Page 15 and 16:
2 CHIWGES XN TEE DELTA The Delta ar
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area decltned cnnside~ably, leadins
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Plan, then it is apparent tbt the s
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Tiddl flats df the Eastem Seheldt v
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tracefore possible to convert the a
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Figsrlre 7 Changes in the cadrnrum
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prevention measures are desirable h
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elationships between different spec
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Bio-essay Weriments with polluted s
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considerable thought to drawing up
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ShLOUONS, W. and BYSINK, W.D., 1981
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are taken. The first year after the
Page 39 and 40:
The Hollands DiepJnaringpllet is pa
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In 1976 the determination of chlozo
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, 0.66 m 0,s - 0.02 1989 I 0.86 - 0
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Table 3 Eutrophication of the Volke
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Laks Volkarek ---- Lake Zoom 0.40 0
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4 WAGBEET MEdSIIRaS TO PEEVBT OR LT
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Table 5 gives estimtes of the phosp
Page 53 and 54: In principle, two states of equilib
Page 55 and 56: Zooplankton (Alma affinis) Pike (Es
Page 58 and 59: EUTROPHICATION OF ESTUAAIES AND BRA
Page 60 and 61: The average discharge of Xhine and
Page 62 and 63: and only l-2% cows frm the aive Sch
Page 64 and 65: highest trophic potential: nutrient
Page 66 and 67: period 1980-19$3 in an increase of
Page 68 and 69: model calculations reveal that a ni
Page 70 and 71: Table 3 PreUmInary carbon budget of
Page 72 and 73: Water life of Lake Grevelingen
Page 74 and 75: macrophytes livkg on or rooting in
Page 76 and 77: less predictable for water managers
Page 78 and 79: ILWNEWIJK, A.. KEIP, C., 1988. De v
Page 80 and 81: XBE CHANGING TmAL LAMXiCAPE I N TEE
Page 82 and 83: The storm surke of L&Z1 A.D., knorm
Page 84 and 85: osi* rn@8IOIP m .SL 4 Has F~~ULB 3
Page 86 and 87: During the 19th century man starts
Page 88 and 89: mudflats have retreated some 100-20
Page 90 and 91: aq811~33a.e~ pue 3pTatlJS uxaJsafi
Page 92 and 93: Erosion by waves of sandy shoals (c
Page 94 and 95: Lt has been estimated that the sedi
Page 96 and 97: Implementafion of the Delta Project
Page 98 and 99: ECOLOGICAL DEVELOWdENT OF SALT MAKS
Page 100 and 101: fn tidal water systems sedimentatio
Page 102 and 103: hierarchical position. Tn the egtua
Page 106 and 107: wind erasson, desaliuation, aeratio
Page 108 and 109: Fonner tirtal flats with saltmarsh
Page 110 and 111: Grevelingen. Lake Veere and Krammer
Page 112 and 113: As mentioned above aa important que
Page 114 and 115: A seaond important perspective for
Page 116: BEEEXNX, W.D. and 80ZBf&. J. L9M. T
Page 119 and 120: are determining the dfstrlbution af
Page 121 and 122: this volume or in Duutsaa, et aL, 1
Page 123 and 124: artificial waterflow was created af
Page 125 and 126: of waterbirds occur regulsrly. The
Page 127 and 128: . DISTRIBUXIOBI OF WATEJBIRoS OVER
Page 129 and 130: small bird$ extludiag them vill net
Page 131 and 132: In order to lsok for relatiouehips
Page 133 and 134: Table 3 Biomass of macroroobenthos
Page 135 and 136: freshwater basins. Clearly the pres
Page 137 and 138: scmthem bottueary o-f the winter di
Page 139 and 140: OCLURRENCE AND DIET QF B ~T .tUQ 80
Page 141 and 142: 5.2 H- factors Next to all fartors
Page 143 and 144: Bewick's Swans (Cygnus columbariusl
Page 145 and 146: m's activiries do not always have t
Page 147 and 148: measure affecting food supply or av
Page 149 and 150: DOQiWT$QS, G. 4 TWISK, F., 1987. De
Page 151 and 152: MEININGEB, P.L. and HAPEREX, A.M.M.
Page 153 and 154: PISCIVORES Litfle Grebe Great Crest
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IPYBRO-EGOLOOIOAL BELATIONB ZN THE
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apart from upstream purification; -
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Storm surge barrier Eastern Scheldt
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- In addition to existing managemen
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Nature is pliable. Belattvely young
Page 166 and 167:
Ro. 1. No. 2. SQ. 3. Investigations
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25. The relation between water quan
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Hydro-ecological relations in the Delta Waters

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