论文部分内容阅读
黄土区包括山西、陕西、甘肃、宁夏、内蒙及河南中西部地区,面积约27.5万多平方公里。这一地区自然环境的主要特点是:黄土覆盖深厚,夏季暴雨集中,丘陵纵横交错,冲刷侵蚀剧烈。整个地区黄土覆盖厚度约120—200米,其中与土壤关系密切的新黄土(又称马兰黄土)厚度也达20—70米。全区气候属大陆型季风气候,冬季受蒙古高气压控制,春季以后蒙古高压逐渐衰退,北太平洋副热带高压向北扩张,7月前后达到最盛时期。因而降雨多集中在7、8、9月,且多以暴雨形式降落;这三个月的雨量,约占全年雨量的65—70%,其中最大降雨强度,每分钟可达2.4毫米。
Loess area, including Shanxi, Shaanxi, Gansu, Ningxia, Inner Mongolia and central and western Henan Province, an area of about 275,000 square kilometers. The main features of the natural environment in this area are: deep loess cover, concentrated heavy rain in summer, criss-crossing hills and hills, and intense erosion and erosion. Loess cover the entire area of about 120-200 meters in thickness, of which the soil is closely related to the new loess (also known as Malan loess) thickness of 20-70 meters. The climate of the whole area belongs to the continental monsoon climate. In winter, it is controlled by the high pressure in Mongolia. After spring, the high pressure in Mongolia is gradually declining. The North Pacific subtropical high extends northward and reaches its peak before and after July. Rainfall therefore concentrated in July, August and September, mostly in the form of heavy rain; these three months accounted for about 65-70% of the annual rainfall, with the maximum rainfall intensity of up to 2.4 millimeters per minute.