珠穆朗玛峰地区新构造运动与环境地质灾害

NEOTECTONISM AND ENVIRONMENTAL GEOHAZARDS, MT ZHUMULANGMA AREA

研究区新构造运动强烈,环境地质灾害频繁,差异上升运动明显.除第四纪色龙盆地、定日盆地表现为相对下降外,其余均表现为上升,反映在环境地质灾害上,山洪、泥石流在雨季经常毁坏盆地内的公路。冰川后退形成的多达4级冰积埠阶地,佩枯错水面从67.9万年(P.B.)到12.6万年(P.B.)下降速率为0.021mm/a,从12.0万年(P.B.)到1.8万年(P.B.)下降速率为0.067mm/a,有加速下降的趋势,附近草地沙化严重,说明藏南面临十分严重的干旱形势,这可能与二氧化碳的过度排放、臭氧层变薄和温室效应等有关。雨季,第四纪盆地易发生洪流、泥石流等自然灾害;在珠穆朗玛峰和希夏邦马峰则容易产生雪崩。旅游、登山要避开7、8月份。

In the study area, there are intense neotectonism, frequent environmental geohazards. With the exception of relatively descending Quaternary Selong and Dingri basins, this area displays ascending. It mirrors the features of environmental geohazards: flooding, landslideing and mud-rock flowing, which often destroy the highways: the glacial retreat formed the 4 grade terraces north Nylam town; the descending velocity of water level of Peikucu is 0.021 mm/y from 67.9×10ky(P.B.)to 12.6 ×10ky(P.B.), 0.067 mm/y from 12.0 ×10ky(P.B.)to 1.8 ×10ky(P.B.); the velocities possess the ascending tendency. The grassland, adjacent to the region, is seriously desertificated. It shows the situation of the arid or dry weather and soil maybe becomes grim South Tibet. The terrain is perhaps related to greenhouse effect. In the rainy seasons, flood, landslides, and mud-rock flow easily happen in the Quaternary basins. There are avalanches in Mt Zhumulangma and Mt Xixiabangma, and people don't tour and climb in this area on July or August.