準噶爾盆地亞區

準噶爾盆地亞區

位於阿爾泰山與天山之間,略呈三角形,東北及西北以中蘇、中蒙國界為限,北接阿爾泰山山地草原針葉林區,東南與阿拉善高原溫帶荒漠區為鄰.具溫帶荒漠區特色,盆地西部有兩個較低的山口(額爾齊斯河谷及阿拉山口)為半封閉大型山間盆地.由於北冰洋氣團及西風急流可從山口直接吹入,故降水量稍豐,約10—300毫米.冬季降雪較多可形成穩定雪蓋.四周山高,盆地內海拔低,冬季寒冷,夏氣溫較高(瑪納斯河一帶可種棉)。地質上準噶爾盆地是褶皺系.盆地中的古生代地層為巨厚的中、新生代沉積物所覆蓋.中生代地層是砂岩為主的陸相沉積,向南逐漸增厚,北部厚約700米,南部增至三四千米,最厚達1萬米.新生代地層也向南增厚,北部不到450米,南部拗陷中心厚達500米.新構造運動明顯,南部下降,但因天山強烈上升,山前產生強烈褶皺,形成年輕的構造隆起;北部上升,額爾齊斯河谷是斷陷谷地,布倫托海是斷陷湖盆.地勢較低,內部高差較大.地勢由東北向西南傾斜,額爾齊斯河和烏倫古河中游海拔70—100米,布倫托海(福海)湖面海拔468米,中部偏西的瑪納斯湖257米,西南部的艾比湖189米,是本區的最低點.以北塔山為界,溫帶荒漠可分為準噶爾盆地和諾明戈壁兩個亞區,此外,準噶爾區西部山地西北的額敏谷地,水分條件較好,氣候—生物條件屬於溫帶荒漠草原地帶亦作為本區的一個亞區.

僅限於準噶爾盆地.土地面積約18萬平方公里,其中戈壁約72萬平方公里,沙漠約6萬平方公里.B分為兩個平原區:(1)北部平原,北起阿爾泰山南麓,南至古爾班通古特沙漠北緣,特點是新生代地層薄,戈壁廣布,風蝕作用顯著,形成大片風蝕窪地;(2)南部平原南起天山北麓,北至古爾班通古特沙漠北緣,實際上還可分為兩個帶,北帶主要是沙漠,南帶主要是戈壁,兩者之間則為土質平地和綠洲.位於盆地中心的古爾班通古特沙漠是中國第二大沙漠,固定、半固定沙丘占絕對優勢,流沙僅占3%左右,植被以超旱生的半灌木和小半灌木為主,梭梭、白梭梭等超旱生無葉小喬木也占有顯著地位.植被覆蓋度在固定沙丘為40—50%,半固定沙丘約20%.丘間低地的牧草生長良好,但由於夏季缺飲用水,主要作為冬牧場.氣候主要受溫帶天氣系統和北冰洋冷空氣的影響.日照時數北部約300小時,南部約280—2850小時,作物生長(4—9月)的日照時數,北部約1900小時,南部約1800小時.冬季時,常為冷高壓所盤踞,是中國寒潮的主要通道之一.1月平均氣溫北部低於-17℃,南部為-10℃,但夏季氣溫高於同緯度許多地方,7月平均氣溫為20°—25℃,地勢低洼部位達28℃.≥10℃期間活動積溫南部和盆地中心為350°—390℃,北部為250°—290℃.無霜期除極北部為10—135天外,一般在160天左右,烏蘇至克拉瑪依達180天.年均日較差12°—14℃,最大日較差25℃,是新疆瓜果含糖量高、品質優良的重要原因之一.主要氣象災害是凍害與大風.每年≥8級的大風日數,北部平均33—77天,南部25天,西部風口區70天以上,阿拉山口則達165天.由於降水量較多,植被覆蓋度較大,沙漠已絕大部分固定或半固定,所以沙丘移動現象較少見.降水量西部多於東部,邊緣多於中心,高處多於低處,迎風坡多於背風坡.冬季有穩定積雪,冬春兩委降水量合計占全年30—45%.盆地北部穩定積雪期115—130天,厚25—30厘米;南部積雪期110—130天,厚度不到10厘米.除額爾齊斯河外,均為內流河,盆地內部僅春季融雪期能形成少量徑流.按出山口的流量計算,盆地的河流年徑流總量共200億立方米,其中約有一半由額爾齊斯河流出國境.額爾齊斯河的支流都源自阿爾泰山南坡,成梳狀排列.主要支流有哈巴河、布爾津河、克蘭河等,能匯集的年徑流量108億立方米(其中布爾津河46億立方米,哈巴河24億立方米),現在流出國境的約100億立方米,通過北水南調工程,估計可以南調50—60億立方米.在自然狀態下,準噶爾盆地的內陸河分為4個排水區:(1)布倫托海水系;匯烏倫古河水量,出山口平均年徑流量113億立方米,最近10年入湖水量最多年為6億立方米,最B少年僅015億立方米;1970年後從額爾齊期河引進部分水B量,緩和了布倫托海的水位下降.(2)艾比湖水系:匯烏蘇、清河兩縣天山北坡河流及博爾塔拉谷地河流,總徑流量約26億立方米,近年湖水逐漸乾涸.(3)瑪納斯湖水系:匯沙灣、瑪納斯兩縣天山北坡河流,在自然狀態下也能接納準噶爾西部山地東坡河流,總徑流量26億立方米,瑪納斯河約占一半.準噶爾西部山地東坡10幾條小河早已不能入湖,湖已漸乾涸.(4)天山北坡獨立水系:呼圖壁至木壘間的河流,年徑流量共254億立方米.各河均消失於灌區中.最大為呼圖壁B河,年徑流量為5億立方米,曾流入瑪納斯湖.地下水主要來自河流出山口後河床,渠道及田間滲漏,年補給量約20億立方米(流出國境的不計在內);另外,來自降水及春季融雪補給的約5億立方米.盆地北部廣泛分布的土壤是棕鈣土(旱成土),約占總面積90%.南部主要是荒漠土,也是主要耕作土壤,大多分布在海拔350—500米的平原上,引水灌溉比較方便,缺點是肥力不高,並存在鹽漬化特徵.在沖積扇緣部位,主要是草甸沼澤土和草甸鹽土;由此至沙漠之間,則以鹽化和鹼化的荒漠土為主,農業利用價值不高.根據過去調查資料,盆地內可供開墾的宜農荒地約610萬畝.瑪納斯河流域自古是牧場,1762年(清乾隆27年)開始少量屯墾,解放前夕,居民不過5萬,耕地不過50萬畝,墾殖率不到3%,1950年組建生產建設兵團屯墾戍邊.到1977年,石河子墾區總面積24萬平方公里,包括沙灣、瑪B納斯、石河子三個縣(市),24個國營農場,3個林場和21個人民公社,居民增多到80多萬,耕地擴大到456萬畝,是重要糧食產地,也是緯度最北的棉區和甜菜產地之一,尚有宜農荒地200多萬畝,可開發利用.Is limited to the Junggar Basin. Land area of about 18 million square kilometers, of which about 72 Gobi million square kilometers, the desert is about 60,000 square kilometers. B is divided into two plain areas: (1) north plains, north from the southern foot of Altai, south gurban tungge tesha Mobei edge is characterized by Cenozoic thin, Gobi widely distributed, wind erosion significantly, the formation of large wind depressions; (2) from the southern plains of southern northern foot of Tianshan Mountains to the north gurban Tongut Desert the northernmargin, in fact can also be divided into two belt, northern zone is mainly desert, south zone is mainly desert, between the plains and oasis compared to thesoil. in the basin center gurban Tongut Desert isChina's first two large desert,fixed, semi-fixed sand dunes dominant, quicksand only 3% of the vegetation in the semi-super-xerophytic shrubs and small semi-shrubs mainly Haloxylon, Haloxylon persicum and other super-xerophytic tree also has a non-Ye prominence. vegetation coverage of 40-50% in the fixed dunes, semi-fixed sand dunes about 20%.IColowland grass grew well, but because of lack of drinking water in summer, mainly as winter pasture. temperate climate mainly affected by weather systems and the Arctic Ocean the impact of cold air. sunshine time is about 300 hours north of the south at about 280-2850 hours, crop growth (April-September) of sunshine hours in the north at about 1900 hours, the Southern is about 1800 hours. winter, often as a cold high-pressure The entrenched, is one of the main cold .1 less than the monthly average temperature in northern -17 ℃, the southern -10 ℃, but the summer temperatures higher than in many parts of the same latitude, inJulythe average temperature of 20 ° -25 ℃, low-lying parts of up to 28 ℃. ≥ 10 ℃ accumulated temperature during the activities of the Center for South and basin 350 ° -390 ℃, the north 250 ° -290 ℃. frost-free period of 10-135 days, except the north pole, it is generally 160 days, Usu to Karamay up to 180 days. annual average diurnal 12 ° -14 ℃, the largest diurnal 25 ℃, high-sugar content fruits in Xinjiang, one of the important reasons of good quality. the main meteorological disaster is frost and wind. annual ≥ 8-level strong wind days in the north an average of 33-77 days, 25 days in southern and western outlet area for more than 70 days, Alashankou is up to 165 days. because of more precipitation, vegetation coverage, a larger majority of the desert has been fixed or semi-fixed, so the rare phenomenon of sand dune movement. precipitation in the west than the east, the edge than center, height is more than the lower, windward slope than the leeward slope. a steady snow in winter, winter and spring precipitation in two committees together, accounted for 30-45%. Basin, north of the stability period of 115-130 days of snow,thick25-30 cm; the south the snow 110-130 days, the thickness of less than 10 cm. In addition to the Irtysh, the are flow river, the basin is only a view to the formation of a small amount of spring snowmelt runoff. by a pass of the volume, the river basin, the total annual runoff of 200 billion cubic meters, of which about half of the outflow from the Irtysh territory. Elgin Cis River tributaries from the southern slope of Altai, into a comb-like arrangement. major tributaries are Habahe, Burqin River, Crane River, can bring together the annual runoff of 10.8 billion cubic meters (of which 4.6 billion cubic meters Burqin River m, Habahe 2.4 billion cubic meters), now out of the border about 100 billion cubic meters of water through the North-South transfer projects with an estimated 50-60 billion cubic meters can be transfer to the south. in a natural state, the Junggar Basin, inland river sub - 4 Drainage District: (1) Buluntuohai water; Health ulungur water, out of Yamaguchi average annual runoff of 11.3 billion cubic meters, the last 10 years into the lake for many years for the most amount of 600 million cubic meters, most juveniles is only B 01.5 billion cubic meters; in 1970 from Elgin Qi period after the introduction of part of the river water, B the amount of water level decline eased Buluntuohai. (2) Ebinur water: Department of Usu,Qinghe River and the northern slope of Tianshan Counties Bortala river valley, with a total runoff about 26 billion cubic meters, the lake gradually dried up in recent years. (3)Manas Lake Department: Department of Sandy Bay, the northern slope of Tianshan counties Manas river, in a natural state can also be to accept the western Junggar mountains Dongpo rivers, the total runoff of 2.6 billion cubic meters, accounting for about half of the Manas River. Junggar east slope of 10 a few western mountain stream into the lake has long been prohibited, lake gradually dried up. (4) northern slope of Tianshan Independent River: The river between Hutubi to Mori, the annual runoff of 254 billion cubic meters. the river have disappeared in the irrigation area. maximum Hutubi B River, the annual runoff of 500 million cubic meters, he flows Mana l.. groundwater mainly from the river bed after a pass, channel and field leakage, the annual supply of about 2 billion cubic meters (excluding out of territory); In addition, supply from rainfall and snowmelt in the spring of about 500 million cubic meters m. widely distributed in the northern basin, the soil is brown calcium soil (dry soil formation), accounting for 90% of the total area. the South is mainly desert territory, is also the major farming soil, most of 350-500 meters above sea level located in the plains, the water diversion for irrigation more convenient drawback is that fertility is not high, and there is a salinity characteristics. in the alluvial fan edge parts, mainly meadow marsh soil and meadow saline soil; this to the desert between, places the desert soil salinization and alkalization the main agricultural use value is not high. based on past survey data, the basin can be reclaimed about 610 million mu of wasteland suitable for agriculture. Manas River Valley are ancient pastures, 1762 (27 years of the QingEmperorQianlong) started a small settlement in the liberation of on the eve of the residents, but 50000, however, 50 million mu of cultivated land, and planting rate of less than 3% in 1950 toform aproduction and construction corps Zhunkenshubian. By 1977, Shihezi Reclamation total area of 24 square kilometers, including Sandy Bay, Ma BNas, Shihezi three counties (cities), 24 state farms, 3 forest and 21 communes, residents increased to 80 million, expanded to 456 million mu of cultivated land is an important grain producing area, is also the most northern latitude of cotton andOneof beetorigin, there are more than 200 million mu of wasteland suitable for agriculture can be developed and utilized.

相關詞條

熱門詞條

聯絡我們