Farmers’ coping response to the low flows in the lower Yellow River: A case study of temporal dimensions of vulnerability

Water scarcity in northern China has been a topic of concern in China for many years, but the increased frequency and duration of “no-flow” events in the Yellow River in the 1990s created a flurry of recent activity in the academic and policy arenas. These low-flow events severely disrupted the supply of irrigation water for agriculture in the lower reaches of the Yellow River and posed a substantial threat to farmers’ livelihoods. Within a broader effort to assess farmers’ vulnerability to water shortages, this qualitative research focuses on the coping mechanisms and adaptive strategies adopted by farming households in three villages in Shandong Province (Ma, Ding, and Xing). With increasing water stress and other stresses from land degradation and lack of market access, farmers’ coping mechanisms have evolved, expanding from one-time adjustments to long-term adaptations, and switching focus from securing reliable water sources to improving irrigation efficiency and diversifying both on-farm and off-farm production. The three villages have different vulnerability profiles and adopted different patterns of adaptive processes that reveal the key roles played by community leaders and the early innovators. The research presented here contributes a temporal and dynamic dimension to the study of vulnerability which is largely missing from the current literature, and provides practical insights about how to improve farmers’ adaptive capacities in the face of water shortages in northern China.     

A GIS-based DRASTIC model for assessing shallow groundwater vulnerability in the Zhangye Basin,northwestern China

Groundwater vulnerability is a cornerstone in evaluating the risk of groundwater contamination and developing management options to preserve the quality of groundwater. Based on the professional model (DRASTIC model) and geographical information system (GIS) techniques, this paper carries out the shallow groundwater vulnerability assessment in the Zhangye Basin. The DRASTIC model uses seven environmental parameters (depth to water, net recharge, aquifer media, soil media, topography, impact of vadose zone, and hydraulic conductivity) to characterize the hydrogeological setting and evaluate aquifer vulnerability. According to the results of the shallow groundwater vulnerability assessment, the Zhangye Basin can be divided into three zones: low groundwater vulnerability risk zone (risk index <120); middle groundwater vulnerability risk zone (risk indexes 120–140) and high risk zone (risk index >140). Under the natural conditions, the middle and high groundwater vulnerability risk zones of the Zhangye Basin are mainly located in the groundwater recharge zones and the important cities. The high, middle and low groundwater vulnerability risk zones of the Zhangye Basin cover around 17, 21 and 62% of study area, respectively.     

Aquifer vulnerability assessment using GIS and fuzzy system: a case study in Tehran–Karaj aquifer,Iran

Aquifer vulnerability assessment techniques have been developed to predict which areas are more likely than others to become contaminated as a result of activities at or near the land surface. This research focuses on the evaluation of groundwater vulnerability to pollution in an urban area. Among several assessment methods, DRASTIC has been selected for this study. ArcGIS has been used to overlay and calculate different layers and obtain the vulnerability map. In order to show the importance of fuzzy algorithms in classification, both Boolean and fuzzy algorithms were used and compared. The fuzzy algorithm could recognize the areas with low and negligible vulnerability potentials whereas the Boolean model classified them as moderate. Two sensitivity tests, the map removal sensitivity analyses and single-parameter sensitivity analysis, were performed to show the importance of each parameter in the index calculation.     

Geochemical studies of northern taiga (gypsum) karst ecosystems and their high vulnerability to natural and anthropogenic hazards

In the taiga gypsum karst ecosystems, gypsum soils formed on the hard gypsum substrates predominate in the soil cover. In these soils, the mineral horizons consist of 95–99% gypsum (CaSO₄·2H₂O) and the litter is the main horizon for nutrient accumulation. For this reason, the ecosystems are vulnerable to fire and erosion by walkers, from which they only recover slowly. Gypsum mining for industrial uses is also leading to the destruction of this unique ecosystem.     

可持续生计分析研究综述

可持续生计分析框架是围绕可持续发展而提出的一种新的研究工具,是一种旨在分析社会和物质环境之间多维复杂关系的框架。通过对可持续生计研究中的国外进展的系统阐述和理论总结,较为清晰和全面地把握了可持续生计分析框架的发展轨迹和重要成果,重点阐明了可持续生计分析框架中的脆弱性背景、生计资本、生计战略和生计输出、结构和过程的转变等组分以及它们之间的相互关系,显示出人们如何利用大量的资本、权利和可能的策略去追求某种生计出路的途径。并在此基础上,讨论了可持续生计分析框架在规划确认和设计、规划新的项目和检查评估现有发展活动中的应用;这些研究在扶贫领域具有较强的参照和指导意义。     

Comparison of aquifer vulnerability assessment techniques. Application to the Néblon river basin (Belgium)

Five different methods for assessing intrinsic aquifer vulnerability were tested in a case study and their results compared. The test area was a slightly karstified district in the Condroz region of Belgium. The basin covers about 65 km² and the karst aquifer provides a water-supply of about 28,000 m³d^-1. The methods tested were: EPIK (Doerfliger et al. 1999), DRASTIC (Aller et al. 1987), 'German method' (von Hoyer and Söfner 1998), GOD (Foster 1987) and ISIS (Civita and De Regibus 1995). The results are compared and critically examined. From the analysis, it seems that reducing the number of parameters is unsatisfactory, due to the variety of geological conditions. The various methods produce very different results at any given site. As only physically-based methods can be checked for their reliability, it is clear that future vulnerability mapping techniques must incorporate such methods.     

Buried Quaternary valleys in western Denmark—occurrence and inferred implications for groundwater resources and vulnerability

Numerous geophysical investigations in the western part of onshore Denmark constitute the basis for a delineation of buried Quaternary valleys. The geophysical methods comprise primarily Transient ElectroMagnetic (TEM) and reflection seismic surveys, and the geophysical data have been combined with lithological data from boreholes. Buried valleys appear both as single valleys and in dense networks. The internal structure of the valleys is typically complex due to repeated erosional and depositional events. Buried valleys are common geological structures in the region and they influence the distribution of Tertiary and Quaternary sediments greatly. A large number of buried valleys in the region contain important aquifers, whose natural protection varies depending on thickness and character of overlying clay layers. Many of these aquifers are deep-seated and well protected, but because of the prevailing heterogeneity of the valley infill and the erosional incisions created by different valley generations, preferential flow paths for downward transport of contaminated water from shallow aquifers may occur.     

平面框架结构抗震易损性的简化分析方法

本文采用静力凝聚技术把平面框架结构简化为一维链状结构，从整体性能上估计结构的抗震易损性，引入状态向量，把结构运动微分方程化为状态方程的形式，地震地面加速度被模拟为均值为零的平稳过滤Ｇａｕｓｓ白噪声过程，在时域内导响应相关函数的解析表达式，通过求解协方差反应矩阵方程直接得到系统的均方响应，考虑变形极限状态，采用首次超越失效准则计算不同ＰＧＡ水平下的结构易损性。最后，用一座位于大庆市的九层框架结构的计     

山西忻州市地震灾害损失预测

介绍了忻州市历史地震震害，给出了忻州市城区的房屋建筑，生命线工程震害预测结果，次生灾害分析预测结果，地震造成的经济损失和人员伤亡的预测方法和结果。     

全球变化对农业的影响及适应对策

政府间气候变化专门委员会是为气候变化框架公约提供科学和技术评价的机构，下设负责气候和温室气体、影响和对策、社会和经济问题三个工作组。它的第一次评价报告完成于１９９０年，修订于１９９２年。为了于１９９５年９月完成它的第二次评价报告，ＩＰＣ组织了世界各国２００多名各领域的科学家（１３名来自中国）分５０多个章节撰写，于１９９５年３月完成了ＩＰＣＣ第二次评价报告的第三稿。本文浓缩介绍了ＩＰＣＣ第二工作组Ｄ