Chengdu is situated in the middle of Sichuan Province, the West Sichuan Plain.Covering an area of 12390 sq km, it is 192 KM long from east to west and 166 KM wide from south to north. Up to the year 2000, the city zone of Chengdu is 208 sq km. Chengdu is adjacent to Deyang City in the northwest, Ziyang District in the southeast, Meishan District in the south, Ya'an District in southwest and Aba Tibetan and Qiang Autonomous Prefecture in the northwest. Chengdu belongs to inland zone. It is 1,600 km away from the East China Sea and 1,090 km from the South China Sea. Topographic Features The geology of Chengdu has a long history and the stratigraphic exposure is relatively complete. The hypsography of Chengdu slants gradually from northwest to southeast. Characterized by hills and gullies is the western peripheral area of Sichuan Basin, which is 1,000 -3,000 above the sea level. The highest part is Shuanghe (Twin rivers) located in Dayi county with an altitude of 5,364 meters and a relative altitude of 1000 meters. At the bottom of Sichuan basin is the eastern part of Chengdu, forming the heartland of Chengdu plain. It is mainly composed of alluvion plains, mesas and part of low hills, where there the land is profound and fertile. The lowest part of the basin is only 387 meters, which located in Yutai, Jintang County. Due to the great difference of 4,977 meters on altitude between the east and the west of Chengdu, the moisture and heat distribution varies quite remarkably. As a result, in the mountainous areas of the west areas, the temperatures of air, water and land are much lower than that of the eastern plain. Moreover, even in the same mountain, the vertical distributions of different climatic zones occur. As a result, large varieties of vegetations grow in profusion, which provides favorable conditions for the development of agriculture and tourism for Chengdu. Climate: Located in the bordering areas of the Sichuan northwest highland and Sichuan basin, Chengdu has its own climatic features. First, the eastern part of the city is different from western part in climatic zone, due to the abrupt change of the height from the east to the west. In Chengdu, generally speaking, the west is cool while the east is warm at the same time. Even in the same mountain, the foot of hill is several degrees higher in temperature than that on the top of the hill. This dramatic change in temperature is favorable for the agricultural development. Second, the winter in Chengdu is short, with a long frost-free period of over 337 days each year. The annual average temperature is around 16.4 degree. Even in the cold January, the average temperature is some 5.degrees. It rarely snows. Compared with other areas of the Changjiang River, it is 2-3 degrees higher. Third, there is not much precipitation in winter and spring while it is affluent in summer and autumn with the total precipitation volume of 1,124 centimeters. And this figure is comparatively stable, the ratio of the year with most rainfall and the year with least precipitation being 2:1. Fourth, the climatic elements of light, water and heat almost occur in the same season, which is a very favorable combination to the growth and propagation of the vegetation. Fifth, the wind speed is low. On the plain and in the mountainous areas, the normal speed of wind is around 1 to 1.5 meters per minute. The total sunshine hours average 1,042 to 1412 each year.