1. Gansu

Gansu Province is located in the west of China, in the middle and upper reaches of the Yellow River, bordering Shaanxi in the east, Sichuan in the south, Qinghai and Xinjiang in the west, Inner Mongolia and Ningxia in the north and Mongolia in the north.

It is located between 3211'-42 57' north latitude and 9213'-108 46' east longitude, winding from east to west 1600 kilometers, with a total area of 455,900 square meters.

Gansu is located at the intersection of Loess Plateau, Qinghai-Tibet Plateau and Inner Mongolia Plateau. The terrain is complex, the mountains are vertical and horizontal, and the altitude is very different. There are mountains, basins, plains, deserts and Gobi, which are mountainous plateau landforms.

The terrain is inclined from southwest to northeast, long and narrow, with a length of 1659 km from east to west and a width of 530 km from north to south, which can be roughly divided into six distinctive regions. Most of them are above 1000 meters above sea level, surrounded by mountains. There are Liupan Mountain and Longshou Mountain in the north; Minshan, Qinling and Ziwuling in the east; Altun Mountain, west of Qilian Mountain; Nanrang Qingniling.

Gansu is a mountainous province. The main mountain ranges are Qilian Mountain, Wushaoling Mountain and Liupanshan Mountain, followed by Altun Mountain, Mazong Mountain, Heli Mountain, Longshou Mountain, Xiqiao Mountain and Ziwuling Mountain. Most mountain ranges are northwest-southeast. Most of the forest resources in the province are concentrated in these mountainous areas, and most rivers also form their own diversion sources from these mountainous areas.

2. Climate characteristics

There are various climate types in Gansu, which are divided into subtropical monsoon climate, temperate monsoon climate, temperate continental (arid) climate and plateau alpine climate from south to north. The annual average temperature is 0- 15℃, and the climate in most areas is dry, with arid and semi-arid areas accounting for 75% of the total area.

The main meteorological disasters are drought, rainstorm and flood, hail, strong wind, sandstorm and frost. The annual precipitation in all parts of the province is 36.6-734.9 mm, decreasing from southeast to northwest. The precipitation in the west of Wushaoling is obviously reduced, and the precipitation in Longnan Mountain area and the east of Qilian Mountain is more. Affected by the monsoon, precipitation is mostly concentrated in June-August, accounting for 50-70% of the annual precipitation.

The frost-free period in the province varies greatly from place to place. Longnan Valley is generally about 280 days, and Gannan Plateau is the shortest, only 140 days. The altitude in most places is between 1500m and 3000m, and the annual rainfall is about 300mm (40-800mm).