Geography of Yanchang county

Yanchang County, located in the northeast of Shaanxi Province, east of Yan 'an area, downstream of Yanhe River, with latitude of 3614' ~ 36 46' and longitude of109 33' ~10 30'. It borders the Yellow River in the east, Daning and Yonghe counties in Shanxi Province in the west, Yichuan in the south, Duolei in the west, Yan 'an in the west and Yanchuan in the north.

The mileage from the county seat to other places is: 72km from Yan 'an City in the west, 0/00km from Yichuan County/Kloc-0 in the south and 72km from Yanchuan County in the north; It is 440 kilometers south from the provincial capital Xi via Yan 'an and 404 kilometers through Yichuan. The northeast is bounded by Xi 'an Road, which is away from the capital Beijing 1652km, Weinan Road 1492km and Taiyuan Road 92 1km. Yanchang County has a continental monsoon semi-arid climate with four distinct seasons: cold, warm, dry and wet, with short summer and long winter.

Winter: under the control of the powerful Siberian cold air mass, the climate is cold, dry and snowy. June 10 to April 10 every year, with an average of 177 days. The average temperature is -3.6℃.

Spring: The polar continental air mass weakens, the tropical heating mass moves northward, the temperature rises, and the precipitation increases. Due to the activity of cold air mass, the daily temperature difference is large, which is prone to cold wave, frost and strong wind. There are many strong winds, sandstorms (yellow winds) and floating dust, and there are often spring droughts. Every April 1 1 to June 10, about 6 1 day. Average temperature 10 ~ 22℃.

Summer: Affected by subtropical high, the temperature is high, there is much precipitation, there are many thunderstorms and sometimes hail. Affected by cold air activities and topography, rainfall distribution is uneven, and summer drought often occurs. Every June 1 1 to August 10, about 6 1 day. The average temperature is 23.65438 0℃.

Autumn: Warm and humid air masses alternate with dry and cold air masses, with rainy days and rapid cooling. It's sunny in late autumn and crisp in autumn. Every August 1 1 to1October 15, about 66 days. Average temperature 10 ~ 22℃.

Due to the influence of topography, the climate between the east and the west is very different. The annual average temperature along the eastern part of the Yellow River is 9.5 ~ 1 1.4℃, and the accumulated temperature is ≥0℃ 3662 ~ 4556℃, ≥ 10℃ 3 100 ~ 3900℃, and ≥ 20℃/. The annual average temperature in the sewer area of Shaoshan West is 8.5 ~ 9.5℃, and the accumulated temperatures are ≥0℃ and 3000 ~ 3800℃, ≥ 10℃ and 2800 ~ 3400℃, and ≥20℃ and 16 13.2℃. There is a difference of 15 ~ 20 days in the customary sowing season between the east and the west, and a difference of 20 ~ 30 days in the harvest season.

Humidity in Yanchang County: 5 months of drought (March-June,165438+1October) and 3 months of severe drought (65438+February-February). Semi-arid 1 month (1month) and humid for 3 months (July-September).