Boundaries. – On the basis of the agreements of the Yalta Conference between the United States, Great Britain and the Soviet Union, communicated on February 13, 1945, and to which Poland later joined, Poland ceded all the eastern part of its territory to the Soviet Union. territory, east of the so-called Curzon line, for a total area of 181,000 sq km; in exchange, on the basis of the agreements of the Potsdam conference (also held by the heads of the three aforementioned powers), communicated on 2 August 1945, Poland was assigned: the southern part of East Prussia; the territory of the free city of Gdansk; all the former Germanic territories to the east of the Oder and its tributary Neisse Occidentale (in pol. Nisa); overall, an area of 104,000 sq. km.
These conspicuous territorial variations; the appalling loss of life suffered during the war and the German occupation by the movements, voluntary or forced, which occurred in its population; the enormous destruction suffered by its inhabited centers, by the industrial equipment and by the communication routes: all this has profoundly changed the geographic physiognomy of Poland.
It should be noted, first of all, that its territory has undergone a considerable shift towards the west: in fact, while before the Second World War its extreme longitudes (all eastern) were 15 ° 47 ‘and 28 ° 22’, the current ones are: 14 ° 5 ‘(Polish-German border on the Oder west of Cedynia, German Zehden) and 24 ° 19’ (Polish-Russian border on the Bug north of Sokal).
According to Localcollegeexplorer, the territory has also undergone a shortening in the sense of latitudes, since the extreme northern point is now at 54 ° 50 ′ (Cape Rozewie, on the coast of Pomerania), and the southern one at 49 ° 0 ′ (Polish-Russian border- at the Užok pass), while previously the extreme points were at 55 ° 51 ‘and 47 ° 44’.
Ancient Poland was roughly in the shape of a triangle, with almost equal sides; the shape of the present territory is close to that of a square. The perimeter of the borders of the republic has a development of 3566 km. (in 1938, 5534 km.), of which 497 data from maritime coasts (in 1938, 140 km.) and 3069 from land borders. Of these, 456 km. they are with Germany (12.8% of the total land and sea border), 1292 km. with Czechoslovakia (36.2%) and 1321 km. with the USSR (37%). The surface, of 311,730 sq km, is less than 76,660 sq km. to that of pre-war Poland.
Ancient Poland was a typical example of a state with almost no “natural” borders. Also in this regard the situation has improved, above all due to the fact that the western border is now mostly given by a large river, such as the Oder, and by its important tributary Nisa Occidental; that the eastern one follows the Bug for a good distance and that the maritime border now represents 14% of the state perimeter, compared to 2.5% in 1938.
It should be remembered that between Poland and Czechoslovakia the territory of Cieszyn (Teschen) is in dispute, in which the Ostrawa-Karwina coal basin is located, of which Poland claims a greater strip than the one assigned to it in 1918 and that it had succeeded in obtaining in 1938, at the time of the Germanic occupation of the Sudeten country. Negotiations are underway to resolve this issue.
Relief. – The new Poland is formed: 1) by a fairly considerable stretch of the Baltic coast, between the mouths of the Oder, with the is0la of Wolin (Wollin) and the extreme eastern part of Uznam (Usedom), and the Zalew Wiślany (Frisches Haff), with the coasts mainly compact, low and fringed, in Pomerania, by dune cords and a series of lakes a few meters deep, which were already lagoons, then closed by sandy shores (the coastal plain widens considerably in correspondence with the Vistula delta plate and south of the Zalew Wiślany, in the East Prussian plain, of which the south-western part belongs to Poland); 2) from the so-called Baltic Ridge, formed by the morainic hills of Pomerania and Masuria, separated by the Vistula corridor, from 100 to 300 m high. and sprinkled with numerous lakes; 3) from the wide central strip of the plains of Posnania, Cuiavia, Masovia and Podlasia, clayey or sandy, or consisting of bottom moraines, in some parts uniformly flat, in others wavy, or surmounted by moraine hills or alignments of continental dunes, but characterized above all by the wide valleys carved by the ablation waters of the Quaternary glacier; 4) from the Silesian basin, traversed by the upper Oder, closed to the SW. from the Sudetenland and that the modest hills of Trzebnica (Katzengebirge) separate from the plains of Posnania and Cuiavia; 5) from the north-eastern side of the Sudetenland, more steep than the Czech side, with heights on the border reaching 1603 m; 6) from the reliefs of Little Poland, of modest height (Łysogóry, 612 m.); 7) from the Lublinese surveys, also they are very modest and continue towards the SE. with the Roztocze on which the watershed between the Baltic and the Black Sea passes; 8) from the Sandomierz basin, enclosed between the reliefs of Little Poland and Lublin, the Roztocze and the Carpazî and crossed by the upper Vistula and the upper San; 9) from a section (Western Beskids) of the outer area of the Carpazî, consisting of sandstones and clayey schists, with a strip of crystalline nuclei, the Tatras, where in Polish territory they reach 2499 m.
Weather conditions. – As a consequence of the shift towards the west of its borders, the continentality of the climate of Poland has decreased, losing the regions where in January the lowest average temperatures were recorded, always below 4 ° below zero (Wilno, −5 °, 0 ; Pińsk, −5 °, 4; Tarnopol, −5 °, 9), and in July temperatures not lower than those of the rest of Poland, indeed, at times, higher (Pińsk, 19 °, 0 compared to 18 °, 8 of Poznań and 18 °, 9 of Warsaw). The territories acquired in the west, where Atlantic influences are most felt, have a milder climate than the rest of Poland (Szczecin, −1 °, 2 in January and 18 °, 1 in July; Wroclaw, respectively −1 °, 6 and 18 °, 7).
A continental waters. – From the hydrographic point of view, the territory of the new Poland includes almost all (89.9%) of the Vistula basin and almost all (89.9%) of the Oder. In the course of the Vistula, pre-war Poland did not have the mouths, which were part of the territory of the free city of Danzig; moreover, it had free use of the riverways and the port of this city. Now the edges of the Bug, San and Poprad basins, tributaries of the Vistula, remain outside the new boundaries.
The following are excluded from the Oder basin: the highest part of the main river basin, south of the Porta Morava; the highest part of the western Nisa basin; a narrow strip along the left bank, both of the Nisa and of the lower Oder. Poland also includes a considerable strip of the Pregola (Pregel) basin, and the small basins of the Pomeranian rivers that flow down to the Baltic from the moraine: the Rega, the Prośnica (Persante), the Wieprz (Wipper), the Słupia (Stolpe) and the Łeba (Leba).
While about a quarter of the territory of pre-war Poland was tributary to the Black Sea (through the Prypeć, the Dnestr and the Prut), all, it can be said (99.9%), the territory of the new Poland sends its waters to the Baltic, with lowland rivers at a nival regime, largely navigable and connected to each other by navigable canals.
It is in Masuria that the largest lakes of Poland are now found: that of Śniardwy (L. Spirding: 122 sq. Km., 25 m. Of max. Depth) and that of Mamry (L. Mauer: 104 sq. Km., 38 m.).