筑坝在湿地恢复中的作用——以拉萨市拉鲁湿地为例  

Roles of Dam Building in Wetland Restoration:A Case of the Lalu Wetland in Lhasa City

作　　者：摆万奇[1] 土艳丽 李建川 王兆锋[1] 郭光亮 曲扎 张镱锂[1] 

机构地区：[1]中国科学院地理科学与资源研究所,北京100101 [2]西藏自治区高原生物研究所,拉萨850001 [3]拉萨市环境保护局,拉萨850000

出　　处：《资源科学》2010年第9期1666-1671,共6页Resources Science

基　　金：国家科技支撑计划项目(编号:2007BAC06B03);国家重点基础研究发展计划项目(编号:2010CB951704)

摘　　要：对拉鲁湿地筑坝过程及其生态效应的分析表明,湿地筑坝是一项经济有效、具有普遍意义和推广价值的湿地恢复技术,其优越性表现在它的简易性和低成本。筑坝能够迅速扩大湿地水面覆盖,合理配置水资源,为湿地功能全面恢复奠定基础。筑坝后拉鲁湿地水面从偏于西南低洼处,向较高的东北部扩展。在新增水面覆盖内,原有的湿生、中生或旱生植物群落,在2年左右时间内便被酸模叶蓼(Polygonum lapathifolium)、杉叶藻(Hippuris vulgaris)、水葱(Scirpus tabernaemontani)、芦苇(Phragmites communis)等为主的水生植物取代,鸟类尤其是水鸟的种类与数量随之增加。湿地景观明显改善,湿地生态功能得以充分发挥。水面覆盖和水生植物增加后,牲畜的活动空间和可食用牧草数量减少,放牧压力自然缓解,促进了湿地保护。The Lalu wetland of Lhasa City in Tibet,covering an area of 6.2 km2 and having an average elevation of 3645 m,represents the highest and largest urban wetland in the world.Since it has become a national wetland reserve in 2005,a large amount of capital has been invested in restoring its ecological vitality.Dam building,the central part of the ecological restoration project in the Lalu wetland,has experienced two stages.At the first stage,the largest and most influential earth dam with 1210 m long,5 m wide and 1.2 m high used for impoundment was completed in the first half of the year 2007,leading to an increase in water coverage of nearly 5%in dry season and 7%in rainy season,respectively.The authors systematically examined the roles of the dam building in wetland restoration primarily based on examining and comparing ecological changes before and after dam construction.The second stage lasted from the winter of the year 2008 to the spring of the year 2009,in which more earth dams of totally 7547 m long were built.These dams have various sizes ranging in height from 0.9 m to 1.5 m and in width from 3.5 m to 3.7 m accounting for terrains and river flows,connecting each other to jointly partition the east Lalu wetland into diverse units for diversion,irrigation and water storing.The two-stage dam building shown above has made water coverage over the Lalu wetland reach nearly to 90%.Primarily resulting from dam building,great changes have been observed in landscape patterns and ecological functions of the Lalu wetland.Water coverage expanded from low-lying land in the southwest to higher land in the northeast which used to be in desertification.In the increased water area,tropophytes,like Eleocharis soloniensis,Carex rubrobrunnea,Blysmus sinocompressus,Potentilla anserine,Cirsium lanatum,Echinochloa crusgalli,and Cynoglossum zeylanicum have been replaced by hydrophytes,like Polygonum lapathifolium,Hippuris vulgaris,Scirpus tabernaemontani,Phragmites communis within 2 years.In the meanwhile,the numbers and species of

关 键 词：湿地筑坝 湿地恢复 湿地保护 拉鲁湿地 

分 类 号：X37[环境科学与工程—环境工程]