Geographical environment of Uda District

Wuda District, located in the central and western Inner Mongolia Autonomous Region, is one of the jurisdictions of Wuhai City. It borders the Yellow River in the east, Shizuishan City in Ningxia in the south and Alashan League in the west, and is located in the center of the "Ning Meng-Shaanxi" economic zone. North latitude 39 20'-39 40', east longitude106 30'-106 50'. Baotou-lanzhou railway and 1 10 national highways pass through the territory, 20 kilometers away from Wuhai airport and 38 kilometers away from expressway port.

Located in the middle latitude, Wuda District belongs to temperate continental climate, with annual average temperature of 9.3℃, daily temperature difference of 10-25℃, annual average precipitation of 260 mm, frost-free period of 160 days and annual sunshine of 3000-3300 hours.

Less precipitation is the main obstacle to agricultural production in Uda area. All kinds of crops are irrigated by the Yellow River. The annual precipitation 168.5mm is mainly concentrated in July and August, accounting for 59% of the annual precipitation, and the annual evaporation is 3496.0mm, which is 2 1 times of the precipitation. The annual average humidity is 43%, the minimum months are April and May, and the humidity is 365,438+0%. The largest month is August, with humidity of 52% and dryness of 4.05, which belongs to extremely arid desert area. The annual average temperature is 9℃, and the highest extreme temperature is 39.6℃, which occurred in1July 22, 997. The lowest extreme temperature is -26.7℃, appearing in 197 1 year 1 year 22. The difference is 66.3c.

The wind speed in Uda area is high, with many windy days and strong evaporation. The annual average wind speed is 4.8 m/s ... The average number of days of gale of Grade 7 and 8 is 32 days, and the average number of days of sandstorm is 22.7 days. The southern wind is dominant in Uda, with a frequency of 20 and an extreme maximum wind speed of 28 m/s. Strong winds and sandstorms often occur at the turn of spring and summer, especially from March to May. Uta has a dry climate. The frequent occurrence and long duration of gale is one of the main obstacles to agricultural production. Rainstorms are rare, severe, frost and other low-temperature weather often affect agricultural and animal husbandry production. Drought is one of the typical disasters of agricultural production in Uda District. There are different degrees of dry weather almost every year, which is an area where agricultural production cannot be developed without irrigation. 1996101From October 22nd to March 28th of the following year, there was not a drop of water in Uda District, and the continuous drought lasted for 157 days. Drought can occur all year round, but it is mainly spring drought, summer drought and continuous drought in spring and summer.

Sandstorm is also the main factor that causes ecological deterioration and affects industrial and agricultural production in Uda District, especially in spring and summer, with the most in March-May. The average number of windy days is 22.7 days, and the instantaneous maximum wind speed is 28 m/s. When the gale comes, sand and stones fly, the sown seeds are scraped off the ground, and the planted vegetable seedlings are uprooted, which will cause flowers and fruits to fall during the flowering and fruiting period.

Udaxi is high in the east and low in the east, with many peaks and bare ground. This precipitation of about 20 mm can form mountain torrents. Flash floods and heavy rains occur simultaneously. Because of the high valley, low slope and large slope, it is easy to produce mountain torrents, and the water is fast, fast and destructive. Once the flash floods broke out, the land and farmland were washed away, causing land destruction and deterioration, and a large amount of sediment was imported into the Yellow River. Mountain torrents also damaged roads, railways and bridges, causing traffic disruption, transportation stoppage and house collapse, causing serious losses to people's lives and property. There is little hail in Uda, and there is occasional hail from April to September when crops grow, which causes losses to vegetables, melons and grapes. The average first frost period over the years is 65438+1October 20th, and the final frost period is 65438+March 4th. Both spring frost and autumn frost can happen, but spring frost is heavier than autumn frost.