共查询到20条相似文献，搜索用时 31 毫秒
1.
This article examines the relationship between vulnerability and adaptive capacities of urban dwellers to slope failure threats. The Klang Valley Region in Peninsular Malaysia was selected as the study area based on the increasing frequency and impact of slope failures in the last decade. The study identified, examined, and mapped 10 slope failure locations, and the vulnerability characteristics of urban dwellers staying in areas that are prone to and threatened by slope failures were described. The identified vulnerability indicators are related to factors such as (1) socio-economic status, (2) population, (3) external characteristics, (4) physical structure of dwellings, and (5) adaptation measures. Finally, the perceptions of the residents who are at risk of slope failure hazards and their inherent coping mechanisms were analyzed. A model describing the relationships among slope failure threats, vulnerability of urban dwellers, and their adaptive capacities was formulated. 相似文献
2.
Comparative analysis of heavy metal concentration in secondary treated wastewater irrigated soils cultivated by different crops 总被引：4，自引：4，他引：0
O. Dikinya Ph.D. O. Areola Ph.D. 《International Journal of Environmental Science and Technology》2010,7(2):337-346
The use of treated urban wastewater for irrigation is a relatively recent innovation in Botswana and knowledge is still limited on its impact on soil heavy metal levels. The aim of this study is to analyze and compare heavy metal concentration in secondary wastewater irrigated soils being cultivated to different crops: olive, maize, spinach and tomato in the Glen Valley near Gaborone City, Botswana. The studied crop plots have been cultivated continuously under treated wastewater irrigation for at least 3 years. Most crop farms have sandy loam, loamy sand soils. Based on food and agriculture organization, heavy metal threshold values for crop production have been studied. Results showed that the wastewater irrigated soils in the Glen Valley have higher cadmium, nickel and copper than desirable levels, while the levels of mercury, lead and zinc are lower than the maximum threshold values recommended for crop production. The control sites show that the soils are naturally high in some of these heavy metals (e.g copper, zinc, nickel) and that crop cultivation under wastewater irrigation has actually lowered the heavy metal content. Comparing between the crops, mercury and cadmium levels are highest in soils under maize and decline linearly from maize to spinach to olive to tomato and control site. By contrast, concentrations of the other metals are at their lowest in maize and then increase from maize to spinach to olive to tomato and to control site. 相似文献
3.
Clifford Amoako 《GeoJournal》2018,83(5):949-965
In the last five decades, many informal communities in Accra, Ghana have suffered from annual flood hazards. Residents of these communities appear to have successfully resisted evictions by city authorities; survived flood hazards and poor environmental health conditions. These flood affected households continue to survive with increasing housing and population densities in the face of these annual floods. Are they becoming resilient? Have residents built adaptive capacities through learning experiences from previous flood occurrences and evictions attempts? What has produced and continued to shape their responses to flooding? What can be learned from this supposed grassroots resilience to inform flood management in urban Africa? Using case studies of three informal communities of Glefe, Agbogbloshie and Old Fadama, this paper explores the gradual and evolving adaptive capacities and social resilience to flood hazards among poor urban dwellers. The paper reveals the depth of understanding and embodied nature of flood experiences among affected slum dwellers and how these are gradually being transformed into adaptive capacities and shaping their responses. In the absence of efficient state flood interventions, there are emerging and enduring flood responses and adaptation practices shaped by residents’ social networks, political alliances and sense of place. These responses translates into continuous re-structuring of housing units, construction of communal drains, creation of local evacuation teams and safe havens. Urban policy contributions that can be learned from these emerging grassroots capacities for flood vulnerability management have been proposed. 相似文献
4.
Rajendra Bhausaheb Zolekar 《Arabian Journal of Geosciences》2018,11(24):780
Land elements like slope, soil depth, land use/land cover, water holding capacity, soil texture, soil erosion, elevation, potential of hydrogen, etc. determine the suitability for agriculture. Land suitability analysis is a one of the methods of assessment of detecting inherent capacities, potential and suitability levels of the lands for agriculture, and was utilized with the same land elements in this study. A multi-criterion decision making approach using IRS P6 LISS-IV satellite dataset within a GIS environment was used to identify suitable areas for agriculture in the Darna catchment. Experts’ opinions, literature review, and correlation technique were used to decide influencing criteria, assign scores to sub-criteria, and judgment formation in pairwise comparison matrix. All thematic layers of criteria were integrated with each other in GIS using the weighted overlay technique and generated agriculture suitability map into four classes according to FAO. About 23% of the area is under agriculture in the study region. This area can extend up to 69% under agriculture converting fallow land, scrub land, and sparse forest according to soil qualities with suitability levels, i.e., highly suitable (19%), moderately suitable (16%), and marginally suitable (34%). About 31% (19,219 ha) of reviewed area are classified in the class permanently “not suitable” for agriculture. Moderately and marginally suitable land requires the irrigation facility for efficient agriculture. This study emphasizes that about 46% area has potential as agriculture land and it will help improve the financial condition of the farmers. 相似文献
5.
Climate sciences foresee a future where extreme weather events could happen with increased frequency and strength, which would in turn increase risks of floods (i.e. the main source of losses in the world). The Mediterranean basin is considered a hot spot in terms of climate vulnerability and risk. The expected impacts of those events are exacerbated by land-use change and, in particular, by urban growth which increases soil sealing and, hence, water runoff. The ultimate consequence would be an increase of fatalities and injuries, but also of economic losses in urban areas, commercial and productive sites, infrastructures and agriculture. Flood damages have different magnitudes depending on the economic value of the exposed assets and on level of physical contact with the hazard. This work aims at proposing a methodology, easily customizable by experts’ elicitation, able to quantify and map the social component of vulnerability through the integration of earth observation (EO) and census data with the aim of allowing for a multi-temporal spatial assessment. Firstly, data on employment, properties and education are used for assessing the adaptive capacity of the society to increase resilience to adverse events, whereas, secondly, coping capacity, i.e. the capacities to deal with events during their manifestation, is mapped by aggregating demographic and socio-economic data, urban growth analysis and memory on past events. Thirdly, the physical dimension of exposed assets (susceptibility) is assessed by combining building properties acquired by census data and land-surface characteristics derived from EO data. Finally, the three components (i.e. adaptive and coping capacity and susceptibility) are aggregated for calculating the dynamic flood vulnerability index (FVI). The approach has been applied to Northeast Italy, a region frequently hit by floods, which has experienced a significant urban and economic development in the past decades, thus making the dynamic study of FVI particularly relevant. The analysis has been carried out from 1991 to 2016 at a 5-year steps, showing how the integration of different data sources allows to produce a dynamic assessment of vulnerability, which can be very relevant for planning in support of climate change adaptation and disaster risk reduction.
相似文献6.
7.
按照土壤 植物 大气连续体(SPAC)理论,灌溉决策的指标可分为三类:土壤水分、作物水分生理状况和气象因素。对这三方面的研究现状与进展作了详细的阐述。在土壤水分监测技术方面,时域反射仪(TDR)技术、微波技术、近红外辐射等的应用,使监测更加准确和便利;用于灌溉决策的作物水分生理信息监测包括:细胞液浓度、叶/水势、茎果微变化、生理电阻电容、声发射等,从目前国际上研究情况来看,叶冠层温度和茎流变化是指示作物水分状况较好的指标;在估算大气蒸发力方面,以参考作物蒸散量为指标,估计作物参考蒸散量的方法以联合国粮农组织(FAO)最新推荐的Penman-Monteith方法较为精细。并对目前灌溉决策指标的综合运用情况进行了总结。讨论了作为精准农业重要组成部分的"精量控制灌溉"今后的发展方向,建议以通过对作物、土壤、气象复合系统的分析和判断,指导灌溉的适时和适量。 相似文献
8.
以受山洪灾害影响突出的云南文山城区为研究区,从承灾体属性特征和社会承灾能力二个方面探讨了城市山洪灾害易损性分析的方法;利用高分辨率遥感卫星影像为数据源完成城市土地覆盖类型解译,在此基础上应用GIS定量分析城市山洪灾害易损性。对承灾体属性特征定量分析结果表明,文山城区50年一遇山洪淹没范围内的承灾体中城市房屋建筑的易损性最大。对易损性要素中的社会承灾能力分析认为,由于文山城区段防洪河道行洪能力低,蓄滞洪能力弱。山洪灾害的易损性仍然较高,山洪对文山城威胁形势严峻。 相似文献
9.
Hazardous industrial sites have always represented a threat for the community often provoking major accidents overcoming the
boundaries of the plants and affecting the surrounding urban areas. If the industrial sites are located in natural hazard-prone
areas, technological accidents may be triggered by natural events, generating so-called na-tech events which may modify and
increase the impact and the overall damage in the areas around them. Nevertheless, natural and technological hazards are still
treated as two separate issues, and up to now the methods for na-tech risk assessment have been developed mainly for specific
natural hazards, generally restricted to some plant typologies and to the area of the plant itself. Based on a review of the
current na-tech literature, this article illustrates a risk assessment method as a supporting tool for land use planning strategies
aimed at reducing na-tech risk in urban areas. More specifically, a multi attribute decision-making method, combined with
fuzzy techniques, has been developed. The method allows planners to take into account, according to different territorial
units, all the individual na-tech risk factors, measured through both quantitative and qualitative parameters, while providing
them with a na-tech risk index, useful to rank the territorial units and to single out the priority intervention areas. The
method is designed to process information generally available about hazardous plants (safety reports), natural hazards (hazard
maps) and features of urban systems mainly influencing their exposure and vulnerability to na-tech events (common statistical
territorial data). Furthermore, the method implemented into a GIS framework should easily provide planners with comparable
maps to figure out the hazard factors and the main territorial features influencing the exposure and vulnerability of urban
systems to na-tech events. The method has been tested on a middle-sized Municipality in the Campania Region, identified as
2nd class seismic zone, according to the Ordinance 3274/2003, in which a LPG storage plant, classified as a plant with major
accident potential by the Seveso II Directive (art. 9), is located just within the city core. 相似文献
10.
Climate change alters global food systems, especially agriculture and fisheries—significant aspects of the livelihoods and food security of populations. The 2014 IPCC Fifth Assessment Report identified Southeast Asia as the most vulnerable coastal region in the world, and highlighted the potential distribution of impacts and risks of climate change in the region. While climate hazards may differ across geographical regions, the impact of climate extremes on food production will affect marginal farmers, fishers and poor urban consumers disproportionately, as they have limited capacities to adapt to and recover from extreme weather events. Governments and other stakeholders need to respond to climate extremes and incorporate adaptation into national development plans. Unfortunately, there is still limited peer-review publication on the subject matter. This paper presents some findings from research on observed and projected loss and damage inflicted by climate extremes on agricultural crops in Southeast Asia. 相似文献
11.
Alternative water management options to reduce vulnerability for climate change in the Netherlands 总被引：1，自引：0，他引：1
Urbanization, land subsidence and sea level rise will increase vulnerability of the urbanized low-lying areas in the western
part of the Netherlands. In this article possibilities are explored to reduce vulnerability of these areas by implementing
alternative water management options. Two main water management fields are distinguished, water supply and flood control.
A four-component vulnerability framework is presented that includes threshold capacity, coping capacity, recovery capacity,
and adaptive capacity. By using the vulnerability framework it is shown that current water supply and flood control strategies
in the Netherlands focus on increasing threshold capacity by constructing higher and stronger dikes, improved water storage
and delivery infrastructure. A complete vulnerability decreasing strategy requires measures that include all four capacities.
Flood damage reduction, backup water supply systems and emergency plans are measures that can contribute to increasing coping
capacity. Recovery capacity can be increased by multi-source water supply, insurance, or establishing disaster funds. Adaptive
capacity can be developed by starting experiments with new modes of water supply and urbanization. Including all four components
of the vulnerability framework enables better understanding of water and climate related vulnerability of urban areas and
enables developing more complete water management strategies to reduce vulnerability. 相似文献
12.
天津城市发展中的若干环境地质问题 总被引：11，自引：0，他引：11
随着天津城市经济建设活动的加快和海岸带的开发利用，城市环境地质问题日益突出。地下水开采等因素引起的地面沉降量超过1000mm的面积达4080．48km^2，并形成多个沉降中心。地面沉降损失地面高程，带来河流泄洪能力减小、雨后城市积水、海岸带抵御风暴潮能力降低、城市地下管网破坏等一系列危害。污水灌溉和工业排污、石油开发等因素引起了土壤与地下水的污染，直接危害着人们的健康。农业开发、城市建设等因素加速了湿地萎缩，恶化了湿地的生态环境。浅层地下成水开采强度低、地面沉降降低地面高程，土壤盐渍化继续加重。这些环境地质问题都将制约着天津市的社会经济发展。引进与开发改善生态环境技术，防治与缓解城市地质灾害和生态环境恶化，必须作为一项长期的工作纳入城市规划和管理体系之中，以确保城市可持续发展策略的实施。 相似文献
13.
耕地中重金属含量超标直接影响农作物和灌溉水的质量,而且严重影响人体健康.通过调查内蒙古包头工业区周边灌溉水、化肥、农作物及根系土中砷和镉含量及形态特征,研究其转化和富集规律,结果表明,区内土壤和灌溉水呈偏碱性,灌溉水和化肥中砷、镉含量符合国家标准;玉米、向日葵、甘蓝、葱的根系土和可食部分砷含量均未超标,砷主要以残渣态形式存在;4种农作物根系土中镉有不同程度超标现象,向日葵籽粒镉含量超标50%,其余作物可食部分镉含量均未超标.通过分析发现,向日葵籽粒镉超标的原因是与镉赋存形态主要为碳酸盐态和腐殖酸态及向日葵籽粒对镉的富集高于其他植物有关. 相似文献
14.
镉是一种毒性很大、在自然界中分布广泛的重金属元素。利用辽河流域生态地球化学调查中取得的土壤、大气干湿沉降、灌溉水及农药化肥等样品,对沈阳细河地区土壤中镉污染源进行了甄别及追踪。结果表明: 沈阳细河地区土壤中镉元素污染是由人为源引起,且镉元素污染源主要为污水灌溉、大气降尘及磷肥三种途径。 相似文献
15.
《Geoforum》2016
This paper examines, first, the conditions under which irrigating farmers are being alienated from their water through a state-led process of dispossession, and then, second, details the dialectical process of farmers’ resistance to these efforts. The paper advances recent scholarship on water grabbing and ‘accumulation by dispossession’ by drawing on a case from northwestern India to explore the connections between non-agrarian economic growth, irrigated agriculture and farmer livelihoods. Specifically, it examines an urban water infrastructure development project that aims to provide water to Jaipur, the Indian state of Rajasthan’s capital city, through the appropriation of an existing rural dam/reservoir complex built for irrigation and redirecting it to domestic, commercial and industrial uses. Drawing on an examination of policy documents and interviews with farmers and state planners, this paper argues that these transfers must be understood as a supply-side solution to support economic growth, where the lack of stable water supplies is a barrier to capital accumulation. The paper contributes to critical scholarship by showing that the processes underpinning water’s reallocation are specific acts of ongoing ‘dispossession’ through extra-economic means under advanced neoliberal capitalism, which alienates water away from peasant producers towards new centers of capital accumulation, dialectically creating peasant resistance to these efforts. 相似文献
16.
Thomas Wilson Carol Stewart Jim Cole David Johnston Shane Cronin 《Environmental Earth Sciences》2010,61(4):675-688
Agriculture is critically dependent on continuity of water quality and quantity. It is well-established that even small quantities
of volcanic ash can disrupt municipal water supplies, with known impacts to quality including: acidification, increases in
turbidity and ionic concentrations. In addition, delivery systems may be blocked or damaged by hard and abrasive suspended
ash and related ash-cleanup operations place extra stress on water reserves. The aim of this study was to characterise the
key areas of vulnerability of farm water supplies to volcanic ashfall, and to identify management recommendations to reduce
these. From literature review and case studies of farms impacted by the 1991 Pinatubo (Philippines) and 1991 Hudson (Chile)
eruptions, key issues were: sedimentation of irrigation ditches and drinking water ponds, turbidity induced abrasion of sprinkler
nozzles and water pumps, and damage to electric pumps (by ash on air-intakes). Building on this, we characterised the water-use
regimes and water supply system vulnerability of eight case-study farms from across the North Island, New Zealand. From this,
we propose an index system to evaluate the vulnerability of farm water supply systems. The key contributors to the vulnerability
index include: water source, storage capacity, reliance on electricity, independence/interconnectedness of system elements,
volume of water use and other load factors. These allow identification of key strategies for mitigating water supply vulnerability
during prevention, preparation, response and recovery phases of a volcanic eruption. 相似文献
17.
A. Cachada S. M. Rodrigues C. Mieiro E. Ferreira da Silva E. Pereira A. C. Duarte 《Environmental Geology》2009,57(1):91-98
This study aims at assessing the extent of total mercury (Hg) contamination in urban and agricultural soils under long-term
influence of a chlor-alkali plant, located at about 1 km away from a town centre. Moreover, it aims at identifying the main
factors controlling Hg contents’ distribution and associated potential hazards to environment and human health. The median
value of total Hg for soil surface layer (0–10 cm) was 0.20 mg/kg (data ranging from 0.050 to 4.5 mg/kg) and for subsurface
layer (10–20 cm) 0.18 mg/kg (data ranging from 0.046 to 3.0 mg/kg). The agricultural area showed higher Hg concentrations
(ranging from 0.86 to 4.5 mg/kg) than urban area (ranging from 0.05 to 0.61 mg/kg), with some results exceeding target values
set by the Dutch guidelines. Mercury concentrations observed in the studied area are more likely to be associated with the
influence of the chlor-alkali plant and with the use of historically contaminated sludges and water from a nearby lagoon in
agriculture, than to the impacts of urban development. The statistical correlations between Hg concentrations and soil properties
suggest that anthropogenic metal sources should influence the spatial distribution more than the geological properties. Although
the Hg emissions were drastically reduced 10 years ago, the area under influence of the chlor-alkali plant is still facing
potential health and environmental threats arising from soil contamination. 相似文献
18.
Tunisia has invested heavily in irrigation schemes to secure water supply. The management of irrigation systems has been denied to local water user associations (WUA). These WUAs are assimilated to a natural monopoly. They sell water to farmers at the unit operational cost (marginal production cost). Such a price does not allow for budgetary balance, which leads to a chronic deficit of these WUA. It also does not reflect the scarcity of the resource, a situation that contributed to irrigated area expansion, an increase in the agricultural water demand, and misallocation of the resource. Low cost recovery results in poor maintenance, infrastructure deterioration, and water distribution inefficiency. The purpose of this paper is two folds: (i) to propose an alternative price scheme which ensures cost recovery and water use efficiency and (ii) to examine the impact of this new price on the farms’ surplus. To achieve this goal, we assumed that irrigation’s water price increase will be necessary. A field survey of 75 farmers in the center of Tunisia was conducted to estimate the irrigation water demand function. We also used the data collected on 36 WUAs in the region to estimate the irrigation water production cost function using the OLS method for both demand and cost functions, and the peak and the non-peak irrigated demand functions (i.e., summer and winter). The methodology consisted of maximizing social surplus to derive optimal prices for both seasons. The main results show that an increase in price in the range of 11 to 15 % in the winter and 50 to 75 % in the summer results in 11 % decrease of the annual quantity consumed and in a 2 % increase in the social surplus. 相似文献
19.
Olalekan John Taiwo 《GeoJournal》2013,78(1):103-115
The issue of food security has received increasing emphasis in developing countries, particularly in the cities. The emphasis on food security has engendered agricultural expansion and encroachment on the coastal and inland wetlands in these nations. To facilitate and sustain the security of food in the developing countries local and international policies have been designed and employed; they have specifically targeted abounding food production towards ensuring human survival in the cities. However, the various ecological and socio-economic benefits derivable from the preservation of wetlands and inland valleys in these urban environments may be lost, with the transformation in the land use and cover. This study is therefore concerned with how wetland degradation and loss can be checked and mitigated, focusing on the developing countries and their cities. In this respect, the farmer’s awareness of the impacts of wetland cultivation and the role of accessibility, socio-economic and biophysical factors influencing the choice of wetland farming are examined. To this end, structured questionnaire on choice of wetland agriculture in the urban and periurban wetland areas of Lagos city was administered to the farmers. Simple frequency analysis is used to explain and interpret the data generated. The data reveals a generally low level of farmers’ awareness of the implication of wetland cultivation; it shows different categories of factors influencing the choice of wetland farming. Provision of irrigation infrastructure and improvement in living standard of the people through poverty eradication can discourage disadvantageous encroachment on wetlands in cities. 相似文献
20.
Seasonal water scarcity in southern China has been an issue of concern for many years. The increased frequency of low precipitation
in the growing season of rice created a flurry of discussions in the academic and policy arenas. These events severely disrupted
the supply of irrigation water for agriculture in paddy field areas and posed a substantial threat to farmers’ livelihoods.
Within a broader context of accessing farmers’ resilience to agricultural drought, this paper focuses on the response mechanisms
and adaptive strategies adopted by farming households in three types of areas (Plain, Hill, Mountain) in Dingcheng, Hunan
Province. With the increasing drought frequency and the pressure from the demand for livelihood improvement, farmers’ response
mechanisms have evolved, expanding from short-term adjustments to long-term adaptations, and switching focus from securing
reliable water sources to improving irrigation efficiency and diversifying both on- and off- farm productions. The three types
of geographic units have different resilience profiles and have developed diverse patterns of adaptive processes that update
the conceptual model of Disaster Resilience of “Loss-Response” of Location. It presents a temporal dimension to the study
of resilience, which is largely missing from the current literature and provides insights into how to enhance farmers’ response
capacities in the face of agricultural drought in southern China. 相似文献