The Coast of Belgium.-From Sangatte on the French coast to the Texel on the north of Holland, the coast consists of a low sandy shore, bordered the greater part of the distance by sanddunes, which form the principal protection from the sea of the low-lying land behind them.

Beyond Dunkirk there is very little movement of the sand, and the beach is in a more or less stable condition.

At certain parts of the coast of Belgium considerable encroachments were made at one time on the dunes during high tides and storms, but the protection works carried out about three centuries ago, and which have since been maintained and strengthened, stopped further erosion.

From a comparison of various charts and plans dating from the beginning of the present century, and of surveys made of the coast in the years 1833 and 1870, the conclusion arrived at by a commission appointed to investigate this matter was that no material alteration in the general features of the beach has taken place.1

In some parts there has been a gradual wasting of the beach, and the low-water line has approached nearer the shore.

Measurements taken, in 1870 and 1883, of the height of the beach at the groynes between Ostend and Heyst showed that, with one or two small exceptions, the beach had been neither raised nor lowered at these groynes, although during that period there had been some very heavy storms.

Near Nieuport, the sand beach is about 400 yards in width, with a slope between high and low water of 1 in 80. The dunes here are nearly a mile in width, and vary in height from 50 to 80 feet, the highest hill being 114 feet.

Both the beach and the dunes diminish in width towards Ostend, the beach being only about 330 yards wide at Middel-Kerke, the high-water line being from 15 to 30 yards from the foot of the dunes before the sea-wall was built. At Maria-Kerke, where the dunes almost disappear, the beach is flat, the average slope being 1 in 70. The whole of the coast in front of these two villages is now protected by a sea-wall and groynes.

A chart of 1725 shows that at that time the dunes were of very little width at this part, and that it had become necessary to protect the coast by the stone-pitched bank d'Albertus, and by groynes made of bricks and fascines. Beyond this to Ostend

1 De Mey, "Ports Modernes."

the dunes are about 170 yards wide, and their face is protected by brickwork and groynes. On the east side of Ostend the sand beach is about 300 yards wide between high and low water, the inclination being 1 in 60. Ostend is protected by a stone pitched sea-wall 710 yards long, built at the beginning of the last century, in front of which the beach diminishes in width to about 200 yards. The beach is protected by four low masonry groynes running out at right angles to the shore. A new wall in front of the town has recently been constructed, of which a description is given in Chapter V. The groyning is described at page 348.

Eastward of Ostend the beach widens again to 400 yards, the slope between high and low water being 1 in 77. Near Aubette, high water reaches the foot of the dunes. Beyond the Point of Wenduyne, groynes constructed of fascines and stones extend all along the frontage to Heyst, a distance of 8 miles. They extend out at right angles to the shore to low water, a length of 230 yards, and are spaced about the same distance apart. The first erection of these groynes was commenced in 1604, and they have since been slowly added to.

Near Wenduyne the dunes are protected by a brick wall 666 yards long.

Eastward of Blankenberghe, the dunes are reduced to a mere heap of sand, lying against the bank constructed by Comte Jean after the great storm of 1280, when the sea broke through the dunes and inundated the country. The bank, with a short break at Heyst, continues to Knocke, a length of over 2 miles, and is the principal defence of the country. This bank is 23 feet above low water; the top is 15 feet and the base 55 feet wide, the slope on the sea side being 4 to 1.

The bank consists of clay backed by the sand-dunes.

Near the lighthouse at Blankenberghe the dunes are protected for about 11⁄2 miles with a pitching of random stone. The top of the bank is paved with bricks for a width of 76 feet, forming a roadway.

During a great storm and high tide in 1788, nearly half the dunes at Blankenberghe were cut away and their height greatly reduced, after which the sea-face was protected for a length of 300 yards by "a bank of precaution," which is protected by stone pitching.

Between Blankenberghe and Heyst the dunes are only from 35 to 55 yards wide, and even less in some places.

Beyond Heyst the dunes increase in width to about 300 yards, and at Knocke, on the west side of the entrance to the Scheldt, are about three-quarters of a mile wide, and from 50 to 80 feet high; the beach in front being 360 yards wide, with an inclination of 1 in 50 between high and low water.

East of Heyst the dunes divide into three separate ranges, with "pannes or cultivated land lying between.

At Zwyn a new dune is forming across the site of the old creek, which extends for 550 yards in length by 27 yards wide and 20 feet high.

A large tract of land, formerly part of an arm of the sea, has been reclaimed between Zwyn and the Scheldt, a bank for protecting the land having been built in 1240. The last embankment was made in 1872.

On the low shores of the north coast of Belgium and Holland, dykes have been constructed for the reclamation and protection of the land on a grander and more imposing scale than in any other part of the world.

The islands of Walcheren and Beveland, at the mouth of the Scheldt, suffered constant inundations from the sea between the fourteenth and eighteenth centuries. Walcheren is protected by dunes along the greater part of its coast-line, but on the most exposed part on the north-west side the dunes are wanting, and this part in the ninth century was protected by the West Kapelle bank. This bank was breached in 1808, and the island inundated. It has more recently been reconstructed. A description of this sea-wall is given in Chapter V. (page 111).

Originally the alluvial land at the mouth of the Scheldt consisted of a number of separate islands. Walcheren contains ten of these islands united into one between the end of the fourteenth century and the middle of the fifteenth century. Goepee and Overflakkee were also separate islands, covering about 10,000 acres. By means of sixty successive advances of the banks, these separate enclosures have been brought into a single island containing 60,000 acres.1

Along the shore to Cadzand, at the entrance to the Scheldt, the coast has been protected by fascine groynes for about 3 miles. This part suffered severely from the inroads of the sea in 1658.

The Coast of Holland.-From the Scheldt to the Texel the

1 1 Conrad, Address International Navigation Congress at the Hague, 1898.

Dutch coast continues much of the same character as that already described, but is more exposed.

Holland is surrounded by the sea on three sides, and depends either on natural dunes or artificial banks for its preservation from the sea. Altogether there are 1550 miles of dykes or seawalls to maintain on the coasts of the North Sea and on the Zuyder Zee.

Careful measurements of this part of the coast have been made by the Dutch Government during the last half-century.

Between the years 1843 and 1846, they caused to be placed all along the Dutch coast, extending from the Helder to the Hook of Holland, a distance of 75 miles, at the foot of the sand-hills, oak posts at intervals of one kilometre (0.62 mile) to form a permanent base line; and from these, at regular intervals, measurements have been periodically taken to the foot of the dunes on the land side, and to the low-water line on the sea side.

1

The results are recorded in the Proceedings of the Dutch Institution of Civil Engineers. They are also set out in considerable detail, and tables given for the different periods, in the report of a Commission appointed to investigate the shell fishery of the coast, issued in 1896.2

The coast between the two parts named forms the arc of a very large circle, the depth of the embayment in the centre being 5 miles. The main direction for the southern part faces about north-west, and of the northern part west-north-west. The winds which have most effect on the coast are those from the south-west, changing round to north-west.

The set of the flood tide is from south to north, the range decreasing from 5 feet at the Hook of Holland to 4 feet at the Texel.

The coast-line is bordered seaward by a sand beach extending from 100 to 120 yards to low water, lying at a slope of about 1 in 70; and on the land side by sand-dunes, which vary from 1 to 3 miles in width, and from 40 to 50 in height. These decrease in size towards the Texel.

With the exception of the detrital matter brought down in suspension by the river Mass, there is no source from which a

"Tidschrift Van bet Koningklijk, Instituut Van Ingenieurs" (1883).

2 "Uitkomst Van het Onderzoek of de Schelpvisscherij Langs de Noordzeekust Nadeelig Kan Zijn Voor Het Weerstandsvermogen Van Het Strand en het Behoud Der Duinen als Zeewering" (1896).

supply of material to feed the beach can be obtained. The cliffs which border the French coast, from which the shingle and sand on the beach there is derived, terminate at Sangatte. The drift of the shingle and sand from the erosion of these cliffs extends, as already described, only for a limited distance, and dies out a little beyond Calais and Dunkirk.

The Dutch coast, between the periods to which the present investigations extend, has been subjected to two disturbing elements, in addition to one abnormally heavy gale in December, 1894; the opening out of the new waterway to Rotterdam through the Hook of Holland; and the construction of the harbour at Ymuiden for the entrance to the Amsterdam Canal. The long jetties and piers extending across the beach, led to a considerable transposition of material at those parts of the shore; but the effect was local, and extended only over a short distance.

As a general result, the measurements show that during the last half-century, on the Dutch coast, the sea has been encroaching on the land. The low-water line has crept landward, and the beach has become more steep. There has also been a wasting away of the foot of the sand-dunes.

For the first part of the period over which the observations extend (1843-56), there appears to have been a retreat of the low-water line from the shore, and consequent increase in width of the beach, in the northern portion of the coast for the first 44 miles, and this continued up to 1866 to a less extent. After this the low-water line began to advance landwards until 1877, when the northern beach began again to grow wider, but the decrease continued along the southern half. On an average there has been a loss of beach along the whole coast between 1846 and 1894, the total average loss for the forty-six years being 52 yards for North Holland and 36 yards for South Holland. The greatest change has taken place between the Helder and Petten, a distance of 12 miles, the low-water line having advanced landward an average of 53 yards. Near Callangstoog, where the effect of the great gale of 1894 was most felt, the low-water line is from 66 to 90 yards more inland than in 1846, and the foot of the dunes has been driven back more than 100 yards.

Near Zandvoort there has been a gain of 33 to 40 yards. Near Scheveningen the low-water line has approached nearer the shore, over a length of about 4 miles for about 66 yards, and the