湖南鼎城区农业旱灾恢复力评价

为探索水田农业区农业旱灾恢复力变化的内外驱动力、影响恢复力提升的制约因素,基于灾害系统理论,以水田农业典型区湖南鼎城为研究区,对其乡镇农业旱灾恢复力的时间变化和空间分布进行评价分析。结果表明,两类评价结果具有较高的吻合度,优质水田面积扩大、作物种植结构改变和农民收入增加是农业旱灾恢复力提升的重要因素。     

从风险到优势——孤儿的抗逆力研究

从社会工作优势视角出发,运用抗逆力理论,研究探讨了孤儿在经历创伤、面临风险时存在哪些外部保护因素和内在优势因素。通过对8个孤儿的质性研究发现：孤儿面临贫困、养护结构脆弱、社会歧视、缺乏稳定感和归属感等风险因素,并且这些风险具有多重性、高危性、长期性等特征。但是,外部支持因素和个体内在优势帮助他们提升其抗逆力,外部支持因素主要包括亲属网络、模拟的亲缘关系、友缘关系、学校和社区、社会福利系统;内在优势则包括自立人格、家庭责任和感恩情感、兴趣和特长,以及积极思维。     

黄土高原农户生计恢复力及其生计建设路径——以陕北佳县为例

以陕北佳县为例,从自组织能力、缓冲能力和学习能力三个维度构建评价指标体系,利用贡献度模型识别生计恢复力主要贡献因子,并对提升农户生计恢复力的生计建设路径进行探究.结果 表明:1)农户生计恢复力水平整体不高,其中自组织能力最强,缓冲能力次之,学习能力最弱;2)除自组织能力外,各地貌分区间农户生计恢复力以及学习能力、缓冲能...     

齿形带料沿自身宽度平面上弯曲变形的回弹值

小型发电机定子铁心卷叠加工中带料的回弹数值，是该工艺专用设备设计中的重要参数之一．本文从材料纯弯曲中的弹塑性变形与卸载回弹的计算入手，结合试验结果，归纳推导出的回弹值计算公式，可以实际应用．     

盐碱、干旱胁迫下甜高粱能源性状及抗逆机理研究进展

生物质能源作物的快速发展是缓解当前能源资源短缺和环保压力的一条重要途径。甜高粱茎秆产量和含糖量较高,能够生产燃料乙醇,是当前替代油气资源的重要能源作物,此外,甜高粱具抗旱、耐盐碱的特性,又使其成为干旱、盐碱地区的目标能源植物。为推动我国在盐碱、干旱地区的能源产业发展,通过对国内外干旱、盐碱生境下甜高粱能源性状变化和抗逆性研究进行综述表明:目前关于甜高粱在盐碱、干旱方面的研究尚处于起步阶段,胁迫条件下各品系不同生育期能源性状研究不够全面;甜高粱抗逆机理如渗透调节物质、分子及生理机制研究亟待深入;各地气候、土壤差异引起土壤的盐碱、干旱规律不同,同时土壤盐碱、干旱现象往往交互而生,实地开展甜高粱能源性状转化及分子、生理生态适应性的研究对于我国在盐碱、干旱地区甜高粱的顺利栽培、成熟管理措施的制定以及生物质能源的发展将具有推动作用。     

回弹——取芯法测定混凝土强度的相

不破坏结构而能对已建成的混凝土结构或正在施工的混凝土工程质量进行定量的评价，这是无损测试技术要实现的根本目的。通过回弹测强建立回弹值与芯样实测抗压强度之间的关系方程，并由这种关系方程来推定整个工程混凝土的抗压强度，进而达到评价混凝土内部质量的目的，避其钻芯法造成结构或构件的局部破坏，以便更全面地反映厚实混凝土的质量情况。     

青海省果洛州草地畜牧业雪灾的恢复力

雪灾是造成我国高寒地区畜牧经济损失的重要原因,灾害恢复力理论对增强畜牧业防灾减灾能力具有重要作用。为甄别草地畜牧业灾后恢复薄弱环节,更好地开展防灾减灾工作。本文以脆弱性与恢复力相互关系为理论基础,结合雪灾特点和草地畜牧业系统属性,构建灾害恢复力综合模型和指标体系,分析1990—2015年青海省果洛州草地畜牧业雪灾恢复力时空变化特征及影响因素。结果表明:(1)纵向上,1990—2015年果洛州草地畜牧业恢复力呈波动上升态势,根据变化速度可分为快速上升(1990—2003年)和缓慢上升两个阶段(2004—2015年),系统承灾能力显著增强,阈值范围扩大;(2)空间上,玛沁县恢复力最强,玛多县恢复力最弱,高值区呈现由西北向东南转移趋势,恢复力空间差异有所减小;(3)雪灾是影响草地畜牧业恢复力的核心要素,防灾建设能力对恢复力有重要影响,减灾行为对恢复力的调控作用不容忽视。     

Recovering the urban forest: The role of trees,tree culture,and place attachment before and after Hurricane Harvey

Trees can be powerful symbols that contribute to the production and consumption of places. Disaster events, such as hurricanes, alter the physical landscape, causing tree damage and loss. In places with strong tree cultures, the reforestation of damaged landscapes becomes an implicit element of recovery plans; however, less is known about the implications of tree loss to community recovery. In 2017, Hurricane Harvey made landfall near the coastal communities of Rockport and Fulton, Texas. Rockport-Fulton, known for its beach tourism, is home to a remnant live oak (Quercus virginiana) forest shaped by coastal onshore winds. Many of Rockport-Fulton’s windswept oaks were damaged or lost along with native and non-native palm trees. Rockport-Fulton’s history is imbued with stories situated around its oak forest. Drawing from multiple sources and participant observations from repeated site visits, we analyzed references to Rockport-Fulton’s trees in news media, organizational communications, and public exhibits before and after Harvey to understand the area’s tree culture and its associated discourses. We also interviewed tourists, business owners, and community members nine months after Harvey to understand their perceptions of recovery efforts. Our findings show that tree narratives pre- and post-Harvey amplify social-ecological systems definitions of resilience and that tree loss was a dominant theme in the recovery process for all participants. Yet we also found that tourists discussed the damage to palm trees, whereas community members focused on the loss of live oaks. Despite these preferences, trees available through replanting efforts contained few live oak and palm species; furthermore, recovery plans did not amplify trees in recovery strategies. Overall, our findings highlight the importance of replanting trees during the disaster recovery process in a way that not only enhances local biodiversity but also reaffirms place characteristics to meet community members’ and visitors’ expectations.     

Probing soil physical and biological resilience data from a broad sampling of arable farms in Scotland

Physical and biological soil stabilities (i.e. resistance and resilience) were measured on a range of arable farms across eastern Scotland under a range of management practices, with the objective of using a geographically restricted set of soils under similar land use to detect any underlying associations between soil stability, management factors and soil properties. Data were analysed using a combination of a stepwise fixed effects model selection within a linear mixed‐model framework (LMM) and neural network analysis using a Kohonen self‐organising map (KSOM). In general, physical and biological measures of stability were associated with both physical and biological soil properties, particularly bulk density, water retention characteristics, soil carbon and bacterial community structure. A strength of KSOM is its ability to fit more flexible models than the linear relationships of LMM. However, a weakness is that it does not have the ability of LMM to model the sampling design, which is likely to lead to overstating statistical significance. Consequently, KSOM identified more significant associations between soil properties and stability than LMM, while the latter identified significant associations at the between‐farm level. The high‐level land management decisions of farm type (conventional, organic, integrated), crop type or underlying soil type were not associated with stability at this regional scale, thus indicating that the effects of different management practices between farms were overridden by the soil properties on each farm. Management decisions on improving soil stability therefore need to be taken at the individual field scale.     

The 10 Australian ecosystems most vulnerable to tipping points

We identify the 10 major terrestrial and marine ecosystems in Australia most vulnerable to tipping points, in which modest environmental changes can cause disproportionately large changes in ecosystem properties. To accomplish this we independently surveyed the coauthors of this paper to produce a list of candidate ecosystems, and then refined this list during a 2-day workshop. The list includes (1) elevationally restricted mountain ecosystems, (2) tropical savannas, (3) coastal floodplains and wetlands, (4) coral reefs, (5) drier rainforests, (6) wetlands and floodplains in the Murray-Darling Basin, (7) the Mediterranean ecosystems of southwestern Australia, (8) offshore islands, (9) temperate eucalypt forests, and (10) salt marshes and mangroves. Some of these ecosystems are vulnerable to widespread phase-changes that could fundamentally alter ecosystem properties such as habitat structure, species composition, fire regimes, or carbon storage. Others appear susceptible to major changes across only part of their geographic range, whereas yet others are susceptible to a large-scale decline of key biotic components, such as small mammals or stream-dwelling amphibians. For each ecosystem we consider the intrinsic features and external drivers that render it susceptible to tipping points, and identify subtypes of the ecosystem that we deem to be especially vulnerable.