CN 11-5366/S     ISSN 1673-1530
“风景园林,不只是一本期刊。”

The Big Picture: Landscape Dynamics in the Pearl River Delta

  • 摘要: 聚焦珠江三角洲地区的景观动态演变,重点介绍影响该区域在未来变化中的一些关键问题和驱动因素。三角洲的景观形成以自然动态和过程演替为特征,而土壤沉积是形成其景观格局的关键性因素。人类的活动极大程度地改变了珠江三角洲的景观格局。数百年前,大规模的原生林被急剧砍伐,致使其遭受了严重的水土流失和泥沙沉积,直至20 世纪末实施“植树造林”计划,毁林导致生态恶化的情形才有所缓解。在低洼的冲积平原,农业和水产养殖业则在很大程度上依赖于对堤防系统和地下水位的管理。珠江三角洲具有得天独厚的基塘农业系统,但伴随着高强度的城市化进程,其蚕桑生产逐渐萎缩,而高度集约化的现代水产养殖正在这些区域蔓延。近几十年来,珠三角都市群已拥有1.2 亿居民。伴随着人口膨胀,采砂和疏浚常被用来满足日益增长的基建需求,水坝和水库的建设也大量减少了珠江所携带的泥沙沉积,这些因素都致使珠三角的沉积物呈负平衡的状态。与此同时,湿地资源也面临着巨大的考验,诸多问题如土壤侵蚀与采砂工程,进一步加大对滨海和河口湿地的负面影响。上述这些互相牵制且高度复杂的环境问题,亟须通过多尺度、跨学科协作的方法进行研究并寻求解决方法,进而为实现更加可持续的环境管理提供科学的依据。

     

    Abstract: This paper focuses on landscape dynamics in the Pearl River Delta region and highlights some of the key issues and drivers influencing future change. Delta landscapes are characterised by natural dynamics and processes. Sedimentation is the key factor in delta landscapes. The Pearl River Delta landscape today is highly influenced by human activities. Primary forests were harvested centuries ago. Large-scale deforestation caused massive erosion leading to sedimentation and growth of the delta. Only since the late 20th century rehabilitation and afforestation programmes helped preventing erosion. Agriculture and aquaculture in the low-lying alluvial plain largely depends on dike systems and management of water tables. Traditional and unique dike-pond systems found in parts of the delta providing a variety of fish as well as agricultural products including fruit, vegetables, sugar cane and mulberry trees for silk production are on a steady decline. Instead, highly intensive aquaculture is spreading on a big scale in the Pearl River Delta. Massive population increase in recent decades has turned the Pearl River Delta into a megacity of an estimated 120 million inhabitants. This corresponds directly to a rocketing demand in construction material for infrastructure and housing projects. The demand is largely satisfied through sand mining and dredging in the delta region. In addition, the construction of dams and reservoirs reduces sediment supply resulting in an overall dramatic negative balance in sedimentation in the delta region. While wetlands in the Pearl River delta are under pressure e.g. through urbanisation, the reduced sediment load in the rivers combined with the sand extraction in turn amplifies the negative impact in particular on coastal and estuary wetlands. This high level of complexity of interconnected issues requires multi-scale, crossdisciplinary and collaborative approaches leading to a more sustainable environmental management.

     

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