Geographic location, Lang Son provinceLangSon is a frontier mountainous province of Vietnam to the North-East.- This province covers an area of 830521 hectares (or 8305.21 square kilometers) and sharing with China a border line at 253 kilometers in length.- Location: The province is located between 20027’ to 22019’ northern latitude and 106006’ to 107021’ eastern longitude- This province is bounded on the North by CaoBang province: 55km.- It is bounded on the North-East by China: 253km.- It is bounded on the South by BacGiang province: 148km.- It is bounded on the South-East by QuangNinh province: 48km.- It is bounded on the West by BacKan province: 73km.- It is bounded on the South-West by ThaiNguyen province: 60km.
LangSon has got two international border gates including DongDang railway border gate and HuuNghi road border gate, two national border gates such as ChiMa (in LocBinh district) and BinhNghi (in TrangDinh district)..., and it shares seven border markets with China. So LangSon has an important strategic position in the North-East of Vietnam.Langson province has ten districts such as HuuLung, ChiLang, CaoLoc, LocBinh, DinhLap, VanLang, TrangDinh, VanQuan, BinhGia, BacSon; one city: LangSon city; and 226 communes and towns. LangSon city is the social economic political center of the province.TopographyThe popular kind of terrain in LangSon is low mountains and hills. The average altitude in comparison with the sea level is 252m; the lowest point is 20m in the south of HuuLung district and the highest one is 1541m in MauSon mountain. Mountains and hills cover over 80% of the province’s total area.Climate, weatherLangSon’s climate is a typical climate of the Northern Vietnam. There is a clear distinction between seasons. In different seasons, the temperature is also different because of the mountainous terrain’s complexity and the rapid denaturation of cold air in the moving process in the inner tropic has caused significant differences in temperature between areas.Annual average temperature: 17-22o Celsius.- Annual average rainfall is from 1200 to 1600 mm.- Annual average relative humidity is from 80 to 85%.- The average amount of cloud in a year accounts for 7.5/10% of the sky.- Annual average sunny hours are about 1600 hours.The wind direction and the wind speed of LangSon are both affected by the circulation of atmosphere and varied by the terrain. North wind is usual in cold season. There are south and south-easterly winds in hot season. The wind speed is not strong in general. It averages from 0.8 to 2meters per second, but the velocity is differentiated unevenly among regions of the province.The network of rivers and streamsThe density of rivers and streams in LangSon is defined between medium and rather dense. Main rivers that run through the province are:KyCung RiverThis river rises from BacXa mountainous region at an altitude of 1166 meters in DinhLap district. It runs towards the TayGiang River valley of China.The length: 52kmThe area of the valley: 6660km2BaThin RiverThis river rises from the highland in QuangTay-China and pours into the right bank of KyCung River in KhuatXa commune – LocBinh district.The length: 54kmThe area of the valley: 320km2BacGiang RiverThe length of the river: 114km2The area of the valley: 2670km2BacKhe RiverThe length of the river: 54kmThe area of the valley: 801km2Thuong RiverIt is the second biggest river of LangSon originating from NaPaPhuoc Mountain Chain (ChiLang district). It runs in the depression of MaiSao-ChiLang and the locality of BacGiang province.The length of the river: 157kmThe area of the valley: 6640km2Hoa RiverThe length of the river: 47kmThe area of the valley: 385km2Trung RiverThe length of the river: 65kmThe area of the valley: 1270km2
Source: "langson.gov.vn"