Natural and man-made disasters have been increasing and affecting millions of people throughout the world. Floods are the
most common natural disasters affecting more people across the globe than all other natural or technological disasters and
also are the most costly in terms of human hardship and economic loss. In order to explore the total economic loss, components
of economic loss, and factors influencing economic loss during flooding, a retrospective study was carried out in year 2000
in areas that suffered floods in 1998 in Hunan province, China. A total of 10,722 families were investigated using a multistage
sampling method. We found that the total economic loss to the 10,722 families investigated was US$ 8.925 million; translating
into an average economic loss of US$ 832.45 per family and US$ 216.75 per person. Economic loss related to property loss,
income loss, and increased medical cost accounted for 57.38%, 40.00%, and 2.62% of the total economic loss, respectively.
Economic loss was significantly related to a family’s pre-flood income; duration of the flood; severity of flood; and type
of flood. River floods yielded the highest economic loss and drainage problem floods yielded the lowest loss. We recommended
that flood-related preventive measures should focus on the prevention of river floods and shortening the duration of floods
with the view of significantly minimizing economic losses associated with floods. 相似文献
1 Introduction
Rivers provide a unique opportunity to have average information about chemical and physical erosion, about the major geochemical fractionations created by these major geological processes but also about the impact and disturbances of human activities on the Earth Engine. 相似文献
Observations from the Cloud-Aerosol Interaction and Precipitation Enhancement Experiment-Integrated Ground Observation Campaign (CAIPEEX-IGOC) provide a rare opportunity to investigate nocturnal atmospheric surface-layer processes and surface-layer turbulent characteristics associated with the low-level jet (LLJ). Here, an observational case study of the nocturnal boundary layer is presented during the peak monsoon season over Peninsular India using data collected over a single night representative of the synoptic conditions of the Indian summer monsoon. Datasets based on Doppler lidar and eddy-covariance are used for this purpose. The LLJ is found to generate nocturnal turbulence by introducing mechanical shear at higher levels within the boundary layer. Sporadic and intermittent turbulent events observed during this period are closely associated with large eddies at the scale of the height of the jet nose. Flux densities in the stable boundary layer are observed to become non-local under the influence of the LLJ. Different turbulence regimes are identified, along with transitions between turbulent periods and intermittency. Wavelet analysis is used to elucidate the presence of large-scale eddies and associated intermittency during nocturnal periods in the surface layer. Although the LLJ is a regional-scale phenomenon it has far reaching consequences with regard to surface-atmosphere exchange processes. 相似文献
We present a simple model based on already existing and widely used equations for estimating particle mass fluxes on surfaces sheltered by live vegetation. Wind-tunnel measurements of vertical profiles of mass flux in three different dense live plant canopies, and as a function of the spatially averaged skin friction velocity \({u_{\tau }}'\), provide the baseline set of data. For the bare-sand surface, the total mass flux Q shows the typical \(b({u_\tau }' - {u_{\tau t}}')^{3 }\) increase with increasing skin friction velocity \({u_{\tau }}'\), where b is a constant and \({u_{\tau t}}'\) is the threshold at the onset of particle erosion. Similar relations, however, with different values for b and \({u_{\tau t}}'\) compared to the bare-sand surface were found for experiments with 5.25 and 24.5 plants \(\hbox {m}^{-2}\) and can be explained by the spatial variations of \(u_{\tau }\) for the canopy cases. Based on the resulting parameters b and \({u_{\tau t}}'\), which are found to be functions of the roughness density \(\lambda \), we present a final simple relation \(Q(\lambda ,\, {u_{\tau }}')\) used for estimating the total mass flux for surfaces sheltered by live vegetation. 相似文献
In this study, high resolution surface measurements of diverse slope movements are compared to environmental factors such as ground surface temperature (GST) and snow cover, in order to reveal and compare velocity fluctuations caused by changing environmental conditions. The data cover 2 years (2011–2013) of Global Positioning System (GPS) and GST measurements at 18 locations on various slope movement types within an alpine study site in permafrost (Mattertal, Switzerland). Velocities have been estimated based on accurate daily GPS solutions. The mean annual velocities (MAV) observed at all GPS stations varied between 0.006 and 6.3 ma?1. MAV were higher in the period 2013 compared to 2012 at all stations. The acceleration in 2013 was accompanied by a longer duration of the snow cover and zero curtain and slightly lower GST. The amplitude (0–600 %) and the timing of the intra-annual variability were generally similar in both periods. At most stations, an annual cycle in the movement signal was observed, with a phase lag of 1–4 months to GST. Maximum velocity typically occurred in late summer and autumn, and minimum velocity in late winter and beginning of spring. The onset of acceleration always started in spring during the snowmelt period. At two stations located on steep rock glacier tongues, overprinted on the annual cycle, short-term peaks of velocity increase, occurred during the snowmelt period, indicating a strong influence of meltwater. 相似文献
A preliminary assessment of toxic element pollution caused by artisanal and small-scale gold mining in the Bonsa river of Ghana as well as the influence of TOC and SO42? concentration on these traces in the sediment has been determined. With the exception of mercury (Hg), manganese (Mn), and arsenic (As), the concentration of aluminum (Al) in filtered river water exceeded the WHO guideline limit of 0.1 mg L?1 in drinking water. Analyses of toxic element in sediment using Canadian Sediment Quality Criteria, contamination factor, geoaccumulation index, and enrichment factor indicate that river sediment is severely contaminated with Hg confirming the negative impact of the amalgamation technique in gold beneficiation in Ghana. The level of Hg in the surface water exceeded reported values from some rivers in Africa, Asia, and South America. The ranking order of the mean element concentration in both matrices followed the conservative order of traces found in the Earth crust except copper, which was below the detection limit of 0.01 mg kg?1. A Pearson correlation matrix of the toxic element and geology of the river bedrock indicates that the Hg contamination is of anthropogenic origin whilst As, Mn, and Al are the result of natural enrichment. The partitioning of elements in the sediment compartments is independent of TOC and SO42? concentration. Health-risk assessment based on average daily dose, hazard quotient, and cancer risk indicates that Hg is a health risk to the human population. In conclusion, the study has shown that there is a likely anthropic affection of the river and that this situation has worsened since earlier studies. In order to sustain aquatic life and to prevent future human health hazard, an immediate mercury remediation in the river is recommended. 相似文献
Policy documents and academic literature suggest that Clean Development Mechanism (CDM) finance could complement traditional ‘energy access’ (EA) funding in developing countries, including the Least Developed Countries (LDCs). Yet these propositions have not been empirically tested. This study helps fill this gap by examining constraints to CDM project passage through five stages of an idealized project development cycle (PDC) in Tanzania, and their implications for the ability of the CDM to contribute to financing energy access in LDCs. Twenty-five semi-structured interviews and documentary material were analysed using an analytical framework developed for systematic investigation of constraints. Institutional constraints such as the under-performance of Tanzania's Designated National Authority were the most often mentioned obstacles for project development. Yet non-institutional constraints such as limited energy sector mitigation potential, indigenous skill shortages, and low carbon market prices also hinder project development. Institutional constraints buttress, rather than supersede, pre-existing non-institutional constraints, and together they prevent energy projects from completing the PDC and accessing CDM finance. The number and severity of constraints suggest that the situation is unlikely to change rapidly, and that the CDM sustains and exacerbates existing global inequalities. Since traditional energy access funding is insufficient to address these inequalities, new funding and policy mechanisms are required.
Policy relevance
The CDM fails to fill the EA financing gap in Tanzania. This is also true for other LDCs where comparable project development challenges prevail. The CDM therefore appears to sustain uneven development patterns overlooking those most in need. Claims about its potential to enhance EA are misplaced, and the situation is unlikely to change rapidly. CDM and carbon market projects more widely will have limited ability to help financing EA in LDCs, even if the institutional setting within which they are implemented were reformed in the future. Yet traditional energy funding will be inadequate on its own. The debate over extending the CDM post-2017, when the second Kyoto Protocol commitment period expires, should be informed by honest appraisal of its merits and defects. Policy makers should revisit lessons provided by this article and wider research to help ensure that new EA mechanisms are not hampered by constraints and can benefit those most in need. 相似文献