黃土高原森林草原乾草原區，東起呂梁山西至青藏高原邊緣山地，北起鄂爾多斯南緣長城一線南至秦嶺北麓，大致在北緯34°—39°，東經104°—112°間，略呈矩形.占居山西、陝西、寧夏、甘肅等省（自治區）的大部或一部，為世界上最典型的黃土堆積區。
基本介紹
- 中文名：黃土高原森林草原乾草原區
- 緯度：北緯34°—39°
- 經度：東經104°—112°
- 占地面積：約30萬平方公里
- 經過省市：山西、陝西、寧夏、甘肅等省
地區簡介,英文解說,
地區簡介
廣義的黃土高原包括山西高原，總面積約30萬平方公里；狹義的黃土高原僅包括陝甘黃土高原及隴西高原.陝甘黃土高原位於呂梁山與六盤山之間，黃土連續分布、厚度大（平均20—60米），頂面高度為海拔10—1300米.黃土地層出露完整，具獨特的黃土地貌（塬、梁、峁、墹），溝谷發育，並由潛蝕作用形成獨特的黃土碟、陷穴、黃土橋及黃土柱等黃土微地貌.六盤山以西為隴西高原，海拔20米，黃土厚度增大，成為波狀起伏的嶺谷.全年降水量為350—650毫米間，90%以上降於日均溫10℃以上時期，利於農耕，但夏多暴雨且強度大，易形成嚴重的侵蝕下切和水土流失.黃河的許多支流流經其間，使黃河含沙量達37公斤立方米，最大可達100公斤立方米以CC上.如1961年8月1日陝北綏德韭園溝大雨歷時31小時，B降雨577毫米.其中短歷時暴雨10分鐘，強度達33毫米B分，估算侵蝕泥沙可達26200噸平方公里，占全年侵蝕量C的764%.這一數字相當於每平方米流失土壤262公斤.大B於10℃積溫為320°—360℃間，且晴多雨少、雲量少，氣候條件亦和利農耕.乾燥度從最東部晉陝交界處的15至西部B隴西高原達40。從東向西植被由落葉闊葉林經森林草原至B乾草原，在黃土峁梁頂部陽坡為雜草草原和灌叢；陰坡及侵蝕溝頭、峁梁下部基岩陡壁上有森林，以側柏為主，亦有山楊林；中北部和西南部已墾地區陡壁及荒坡上有典型草原植被；海拔150—200的山嶺上有次生幼齡林（梢林）。六盤山以西海拔200米以上的山嶺上有少數殘存森林，包括松、柏及楊、樺、椴等.全區可分為陝北隴東丘陵溝壑亞區、陝北隴東切割塬亞區、渭河谷地亞區、隴中切割丘陵亞區、隴西高原北部切割丘陵亞區，共5個亞區.
英文解說
Luliangshan the east edge of Qinghai-Tibet Plateau mountain west, the southernmarginof theGreatWall north of Ordos northern foot of Qinling south line, roughly at latitude 34 ° -39 °, longitude 104 ° -112 °, the slightly rectangular. Occupies Shanxi, Shaanxi, Ningxia,Gansu and other provinces (autonomous regions) in most or one for the world's most typical loess accumulation zone. a broad sense, including the Loess Plateau in Shanxi plateau, with a total area of about 300,000 square kilometers; the narrow sense includes only the Shaanxi Loess Plateau Gan Longxi Loess Plateau and the plateau. Shaanxi-Gansu Loess Plateau is located in Luliangshan and Liupanshan between the continuous distribution of loess, the thickness large (an average of 20-60 meters), top height of 10-1300 m above sea level. loess strata exposed in the full , with the unique loess topography (plateau, beam, hilly, Jian), gully development, potential loss by the formation of the unique role of the loess dish, stuck points, bridges and loess loess loess micro-column and other landforms. Liupanshan plateau to the west of longxi , elevation 20 meters, loess thickness increases, becoming wavy undulating ridge valley. annual precipitation is 350-650 mm, the 90% drop in the average daily temperature above 10 ℃ period conducive to farming, but more rain and the intensity of the summer large, easy toform aserious erosion andsoilerosion under the cut. many of the tributaries of theYellowRiver flows through the meantime, so that the Yellow River sediment up to 37 kilograms cubic meters, up to 100 kg m3 to CC. If it is August 1, 1961 Shaanxi North Suide Jiuyuangou heavy rain lasted for 31 hours, B rainfall 577 millimeters. which lasted a short 10-minute rain intensity up to 33 millimeters B points to estimate the erosion of sediment of up to 26.2 thousand tons square kilometers, accounting for annual erosion C, 764% . This figure is equivalent to 262 kilograms per square meter of soil erosion. Big B at 10 ℃ accumulated temperature of 320 ° -360 ℃, the wet and less sunny, cloud less, climatic conditions and interests of farming also. aridity from the most eastern part of Shanxi Shaan at the junction 15 to the west plateau B Longxi 40. From east to west by deciduous broad-leaved forest vegetation by forest-steppe to the B steppe, in the loess hilly beam at the top of the weeds in grassland and shrub sunny; north slope and erosion ditch head, hilly steep rock on the lower beam forests, with P. orientalis the main, there are Populus; north-central and southwestern areas have been reclaimed, and steep slopes have typical grassland vegetation; elevation of 150-200 of the mountains there are young secondary forest (tip forest). Liupanshan west of the mountains over 200 meters above sea level there are a few remnants of forests, including pine, cypress, and Yang, birch, linden and so on. The region can be divided into northern Shaanxi, Gansu hilly sub-region, northern Shaanxi, Gansu cutting plateau sub-region, Wei River Valley sub-region, Gansu hilly sub-region in the cutting, cutting Longxi hilly sub-region in northern plateau, a total of five sub-regions.
