Siam (Thailand) Rivers and Morphology

By | December 17, 2021

Exploration. – Marco Polo during his return journey touched the eastern beaches of the Malacca Peninsula (Locac), subjected to Siam: but his news about it is scarce and uncertain. Ludovico de Varthema also gives some information on Siam in his Itinerary when he speaks of the cities of Tenasserim and Malacca, which he had visited. The first Europeans who had relations with the kingdom of Siam were the Portuguese, who sent an embassy to Ayudhya after the conquest of Malacca (1511). Duarte Fernandez, head of the embassy, ​​was received with much benevolence at the Siamese court, and returned to Malacca with rich gifts for his king. A second embassy was sent shortly thereafter under the orders of Antonio de Miranda and Duarte Coelho, who sailed around the Malay Peninsula to Trengganu and from there reached Ayudhya with an arduous and painful journey on land.

Towards the middle of the century XVI Siam was visited by Fernão Mendes Pinto, known above all for being among the first Europeans to enter Japan. At the beginning of the century XVII also the Dutch began their trade with Siam, followed shortly thereafter by the English. But notable progress in the knowledge of that country was made only when French Catholic missionaries (1662) entered from Mergui, through Tenasserim, who were followed by embassies sent by Louis XIV (of the first, which left Brest in 1685, was part of the ‘Abbot De Choisy, who then wrote an interesting Journal du voyage de Siam ; the second, sent a few years later, was directed by S. de La Loubère, who published a valuable report in 1691). For Thailand 2016, please check softwareleverage.org.

Rivers and morphology– Northern Siam to the North. of the 18th parallel is a mountainous region, covered by large forests, formed by a bundle of folded chains consisting of granite, limestone, sandstone and clayey schists and directed from N. to S., which reach at heights above 2500 m. (Doi Intanon, 2577 m.), Chains between which the valleys of the Menam spring branches open (from west to east: Menam Ping or Me Ping, Menam Wang, Menam Yom, Menam Nan). These valleys are sometimes reduced to narrow wild ravines, sometimes they open into large and fertile basins, such as that of Chiengmai, 600-800 m high. Gorges usually correspond to areas where rivers have been forced to cut more resistant rocks. The mountains rise steeply on the valley floor, but often a hilly area with fans and fluvial terraces precedes them. The culminating areas occur where dome-shaped (in granite) or tabular (in sandstone and clayey schist), where harsh and acute (in limestone). Karst phenomena and forms are widespread in the limestone areas.

The mountainous region of northern Siam continues towards the border with Burma with a series of chains (Tenasserim Mountains) also directed from north to south and formed by a nucleus of granite rocks on which metamorphic schists, quartzites and anthracolytic limestones rest . These chains rise up to over 1800m. and on the Siamese side north of the 16th parallel they are cut by the valleys of some tributaries of the Menam, and to the south by those of the Meklong and its tributaries; then they continue in the Malay Peninsula (here they are mainly formed by crystalline schists), of which about 70,000 sq km belong to Siam. The Tenasserim Mountains have deep furrows, used by communication routes, such as the Three Pagodas Pass (Bhra Chedi Sam Ong: 220 m.), Important for communications between central Siam and Moulmein, the Kao Maun Pass (230 m.), for those between Siam and the coast of Tenasserim, and the groove of the Isthmus of Kra. This is 100 km wide. and 76 m high, and it was planned to cut it with a navigable canal; but the project is severely hampered by the British, because its execution would take away much of its importance in Singapore. In the peninsula the flat coastal selvedge is very limited, especially on the Indian Ocean, where the coast, very articulated and accompanied by a swarm of islands, is often high and rocky and seems to have been subjected to recent submersion movements. because its execution would take away much of its importance in Singapore. In the peninsula the flat coastal selvedge is very limited, especially on the Indian Ocean, where the coast, very articulated and accompanied by a swarm of islands, is often high and rocky and seems to have been subjected to recent submersion movements. because its execution would take away much of its importance in Singapore. In the peninsula the flat coastal selvedge is very limited, especially on the Indian Ocean, where the coast, very articulated and accompanied by a swarm of islands, is often high and rocky and seems to have been subjected to recent submersion movements.

Central Siam, the most important section of the country both from a historical and anthropic point of view, as well as from an economic point of view, is formed by a large fertile lowland crossed by the middle and lower Menam and by numerous tributaries, which have covered it with the their floods (fine sands and clays). The southernmost part of the lowland is constituted by the great delta of the Menam, which begins at 200 km. from the mouth of the river. In the plain, which rises slowly towards the north, here and there rise isolated limestone hills. A series of reliefs covered by forests, including the Dang Praya Yen Mountains, separate the Menam lowland from the Korat plateau, which forms eastern Siam and which is divided by Cambodia, to the south, by the chain called Pnom Dang Rek, high on 1000 m. The plateau, formed by limestone and red sandstone tectonically little disturbed, from which crystalline schists and granite emerge here and there, it is 200-300 m high. and covered by lateral and saline soils that are not very fertile; in it open the valleys of Nam Mun and Nam Si (Mekong), which are instead fertile and well populated.

Siam (Thailand) Rivers