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岷江上游干旱河谷区,山高坡陡、河谷幽深,相对高差3000多米、平均坡度30度以上。长期以米,由于受各种自然因素影响,加上人为活动造成森林的乱砍滥伐、过度放牧和垦荒,森林覆盖率由解放初期的30%下降到八十年代中期的18.5%左右。该区岩体破碎,土层瘠薄,气候干燥,年降水量不足500mm且分布不均,蒸发量为降水量的三倍以上,植被稀疏低矮,部分地区已形成荒漠、半荒漠现象,使十分脆弱的干旱河谷生态环境更为恶化。为恢复和重建该区生态,干旱河谷造林走节水抗旱之路,显得尤为必要和重要。
Arid valley area in the upper reaches of the Minjiang River, steep mountain slopes, deep valleys, the relative height difference of more than 3000 meters, the average gradient of 30 degrees. For a long time, due to various natural factors and deforestation, deforestation and reclamation caused by human activities, the forest coverage rate dropped from 30% in the early liberation period to 18.5% in the mid-1980s. The rock mass is fragmented, the soil layer is infertile, the climate is dry, the annual precipitation is less than 500mm and the distribution is unequal, the evaporation is more than three times of the precipitation, the vegetation is sparsely dipped and deserts and semi-deserts are formed in some areas, The fragile dry valley has worsened the ecological environment. In order to restore and rebuild the ecology of this area, it is especially necessary and important to take the road of water saving and drought relief in the arid valley.