岷江上游地区环境问题及其驱动力

近年来,岷江上游干旱河谷区土地环境和农产品污染问题日趋严重,耕地数量减少、质量下降,土地沙化形势严峻,阻碍区域和下游经济可持续发展。在分析该区脆弱山地生态基础上,探讨了土地环境的现状和演变。研究发现:土地环境的恶化是系统内在特性和外在干扰体综合作用的结果,内在的脆弱特性决定了土地系统对干扰的抗性差,退化后难以恢复,而强烈的人为干扰则加剧了系统的退化速度和进程。生态修复和重建应系统规划,综合治理,建立强有力的区际生态补偿机制,建设干旱河谷区高产优质农林业。

Land eco-environment problems and its driving forces in the upper reaches of the Minjiang River

The upper reaches of Minjiang River lies in the upper reaches of Yangtze River,northwest of Sichuan Province,and serves as one of the important ecological barriers for the Yangtze River and the major water supply area to Chengdu plain.However,a series of land ecologically maladjusted problems have emerged because of the massive lop and unreasonable utilization of land in recent decades.Land degradation is not only a great environmental problem at present,but also a great economical and social problem.It is one of the important forms of global eco-environmental deterioration,which prevents the sustainable economic development of the upper reach of Minjiang River.For the protection of land environment has not fully been taken into account since 1950s,the land environment and the contamination of agricultural products are causing wide concerns recently.The result shows that the natural and artificial factors,such as geology instability,physiognomy and surface geometry vulnerability,diversity of climatic type,illogical use of land resources,and the excessive grazing are the main driving forces for land eco-environmental problems in the study area.The intrinsic characteristic leads to the lower ability against influences,and intense artificial factors speed up the degradation process further.It is suggested that the eco-environment and local economical development will be improved better through the follow countermeasures such as exploiting and utilizing the pasture scientifically,increasing the vegetation's overlay rate and the degree of land use,renovating the droughty watercourse,rebuilding the habitations and transferring the extra rural labor forces.