Revegetation Strategies for Bauxite Refinery Residue: A Case Study of Alcan Gove in Northern Territory, Australia

Alumina extraction from bauxite ore with strong alkali produces waste bauxite refinery residue consisting of residue sand and red mud. The amount and composition of refinery residue depend on the purity of the bauxite ore and extraction conditions, and differs between refineries. The refinery residue is usually stored in engineered disposal areas that eventually have to be revegetated. This is challenging because of the alkaline and sodic nature of the residue. At Alcan Gove’s bauxite refinery in Gove, Northern Territory, Australia, research into revegetation of bauxite residue has been conducted since the mid-1970s. In this review, we discuss approaches taken by Alcan Gove to achieve revegetation outcomes (soil capping of refinery residue) on wet-slurry disposal areas. Problems encountered in the past include poor drainage and water logging during the wet season, and salt scalding and capillary rise during the dry season. The amount of available water in the soil capping is the most important determinant of vegetation survival in the seasonally dry climate. Vegetation cover was found to prevent deterioration of the soil cover by minimising capillary rise of alkalinity from the refinery residue. The sodicity and alkalinity of the residue in old impoundments has diminished slightly over the 25 years since it was deposited. However, development of a blocky structure in red mud, presumably due to desiccation, allows root penetration, thereby supplying additional water to salt and alkali-tolerant plant species. This has led to the establishment of an ecosystem that approaches a native woodland.     

Guiding restoration of riparian ecosystems degraded by plant invasions: Insights from a complex social-ecological system in the Global South

Restoring riparian ecosystems in human-dominated landscapes requires attention to complexity, and consideration of diverse drivers, social actors, and contexts. Addressing a Global North bias, this case study uses a mixed-method approach, integrating historical data, remote sensing techniques and stakeholder perceptions to guide restoration of a river in the Western Cape, South Africa. An analysis of aerial photographs of the riparian zone from 1953 to 2016 revealed that although anthropogenic land conversion happened primarily before the 1950s, several land use and land cover classes showed marked increases in area, including: waterbodies (+ 1074%), urban areas (+ 316%), alien weeds (+ 311%) and terrestrial alien trees (+ 79%). These changes have likely been driven by land fragmentation, disturbance, and agricultural intensification. Stakeholder interviews revealed that despite the clear need for restoration, several barriers exist to successful implementation; these stem from inadequate financial resources, inappropriate funding models, institutional challenges, and a lack of techno-scientific knowledge. We give several recommendations to overcome these barriers.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01691-y.     

From drought relief to post-disaster recovery: The case of Botswana

This article discusses the initiative of the Government of Botswana in formulating and introducing a programme to assist recovery in rural areas after the present drought period as an important aspect of the national development effort. It examines the process by which this Post Drought Recovery Programme was arrived at, its limitations, the extent of its appropriateness to longer-term factors which render rural households more vulnerable to drought, and suggests conclusions which may be drawn to inform the design of similar programmes elsewhere.     

采用碳纤维加固火灾后预应力混凝土框架的试验研究

首先简要介绍了预应力混凝土框架火灾试验情况、火灾后采用碳纤维加固试验过程，然后对加固后的混凝土框架进行静力试验．通过对试验结果进行分析．发现加固后的预应力混凝土框架承载力显著提高，延性和整体刚度得到改善，碳纤维能较好地发挥作用。因此碳纤维加固技术是一个值得进一步深入研究的课题。     

对浑河沈阳城区段水体“休养生息”的探讨

结合“休养生息”内含,探讨了浑河沈阳城区段水体“休养生息的”的必要性及意义。通过对现有法律、法规的进一步完善,强化准入制度,把“休养生息的”制度化、法律化;通过采用污水处理厂建设,实施雨污分流及生态恢复等措施,达到浑河沈阳城区段水体“休养生息的”的目的。