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1.
Environment, Development and Sustainability - Torrents are ephemeral streams which usually carry heavy bedload and flash flows. The frequent changes in its course caused by meandering and migration...  相似文献   

2.
Since China’s economic reform in 1978, the cities of China have experienced rapid expansion and urbanization, thereby profoundly transforming the spatial pattern of urban land use in the karst regions, particularly in the urban mountainous area within city, and urbanization has had and continues to have a negative impact on urban mountain area in cities of China. With the rapid development of urbanization and civilization in these regions, environmental degradation has been increasingly serious, especially in the urban karst mountain area, thereby resulting in the destruction and breakage of urban hills that induce serious natural hazard, i.e., flood hazard.  相似文献   

3.
The current research was carried out to find the most effective environmental factors in plant species occurrence and providing their predictive habitat models. For this purpose, study was conducted in Poshtkouh rangelands of Yazd province in the central of Iran. For modeling, vegetation data in addition to site condition information including topography, climate, geology and soil were prepared. CCA and Logistic regression (LR) techniques were implemented for plant species predictive modeling. To plants predictive mapping, it is necessary to prepare the maps of all affective factors of models. To mapping soil characteristics, geoestatistical method including variogram analysis and Kriging interpolation were used. Based on obtained predictive models for each species (through LR method) and for whole species (through CCA method) related predictive maps were prepared in GIS. The accuracy of predictive maps were tested with actual vegetation maps. Vegetation modeling results with CCA indicates that predictive map of vegetation corresponds with actual map (with high accuracy). Predictive maps of Cornulaca monachantha, Ephedra strobilacea-Zygophyllum eurypterum, Seidlitzia rosmarinus, and Tamarix ramosissima, which have narrow amplitude, has high accordance with actual vegetation map prepared for the study area. Among species of study area, predictive model of Artemisia sieberi, due to its ability to grow in most parts of Poshtkouh rangelands with relatively different habitat conditions, is not possible. Comparing CCA and LR methods showed that each technique has its advantages and drawbacks. In general, LR will provide better specific-model, but CCA will provide a broader overview of multiple species.  相似文献   

4.
A model for the prediction of oil slick movement and spreading, using Cellular Automata, is presented in this paper. The model is general and can predict the behaviour of oil slicks in regions with complicated boundaries. The effects of winds, surface currents, and oil evaporation have been taken into account. An algorithm for the simulation of oil slick movement and spreading, based on this model, has also been developed and has been used to simulate hypothetical oil slicks in hypothetical geographical regions. The results of the simulation are in qualitative agreement with real oil slick movement and spreading.  相似文献   

5.
The results of censuses taken in 1995 to 2011 along two key routes in the areas of the Sulakskaya and Turalinskaya Lagoons, Dagestan (the western coast of the Middle Caspian Sea), are summarized. The state of the populations of regularly migrating birds and causes of long-term fluctuations in their abundance have been assessed by the method of long-term series of observations on trajectories of active migration along stationary routes. The results show that the abundance of 46 out of the 116 background taxa has decreased, while that of 70 taxa has increased or remained unchanged. The key regulatory factors include hydroclimatic conditions, anthropogenic impact, food supply, synurbanization, and weather. The results provide a basis for developing a unified strategy for the conservation of the birds of Eurasia.  相似文献   

6.
In the wake of the flood that affected Brisbane, Australia, in January 2011, public attention turned to the causes of the event and lessons for minimizing the impacts of future floods. The news media was an important vehicle for understanding and internalizing the 2011 Brisbane flood. Examining how the flood was framed in the media is, therefore, useful to understand broad public perception of floods. We undertook a systematic newspaper analysis during a one-year period to explore media framings of the flood, focused on learning as an aspect of resilience in relation to two themes: (1) perceived links between the flood and climate change and (2) perceived roles of government in managing the flood. We show that media coverage of the flood reinforces aspects of resilience by acknowledging community spirit, self-reliance and the importance of sharing experiences for learning; articulating the risk of extreme events in a changing climate; and highlighting regional management trade-offs. Much of the discourse is likely to inhibit resilience, however, by casting the flood in terms of blame and political opportunity and paying inadequate attention to longer-term aspects of regional resilience. The limited learning observed to date may highlight a need for other mechanisms and actors to lead learning processes. As policy related to the 2011 Brisbane flood, and extreme events more generally, is influenced by the public discourse, it is important to understand the nuances of communication around these events and the media’s role in reinforcing or changing perceptions.  相似文献   

7.
Based on a feasibility study, we have recently proposed a multivariate regression model for the impact of air pollution on the mortality of a long-term exposed population. This article proceeds by providing some experimental results, since this model has been fitted to data on a cross sectional basis for 41 census tracts in the Munich metropolitan area. The results obtained so far could be supportive to more detailed epidemiological studies of air pollution which have been conducted in many industrial countries; unfortunately, only relatively few have been conducted in West Germany.  相似文献   

8.
Records of prehistoric tropical cyclones occur in the form of ridges of coral rubble, sand, shell, sand and shell, and pumice; erosional terraces in raised gravel beaches; barrier washover deposits; and, sediments deposited in the shallow offshore marine environment. Other less well-documented records occur as variations in isotopic ratios within speleothems and possibly tree rings, and changes in pollen records resulting from introduction of new species after forest disturbance due to cyclonic winds. As yet, such records have not been identified beyond 5500 years of age. Recent palaeotempestological studies in the United States and northern Australia have highlighted that the frequency and magnitude of these natural hazards do not remain constant over time, and there are periods when cyclogenesis is enhanced, and others of relative quiescence. Recognition of such regime changes, or non-stationarity in the long-term record, is important for risk assessments of this hazard. Until now however, few if any risk assessments have incorporated data from the long-term record of tropical cyclones, and instead have relied on generally short instrumented historical records. The longer-term records suggest that such an approach may miscalculate the 1% Annual Exceedance Probability risk to coastal communities from future tropical cyclones.  相似文献   

9.
Tehran metropolitan region (TMR) has experienced rapid urbanization in the last few decades. This accelerating urbanization trend mainly arising from high natural population growth and rural–urban migration along with rapid socioeconomic changes formed unplanned and uncontrolled urban expansion in peri-urban areas and resulted in degrading environmental quality and considerable changes in the urban landscapes of the TMR. Thus, the main objective of this research is to model spatial pattern of urban growth in eastern corridor of TMR using GIS-based SLEUTH model and the prediction of future developments of the region from 2014 to 2060. The SLEUTH is one of the most powerful models for urban growth modeling. This model analyzes the spatial pattern of urban growth based on historical data obtained from satellite images of 1987, 2003, 2011, and 2014. The results indicate that the most important factors affecting the urban growth are slope resistance and road gravity. The slope resistance is the highest coefficients value, which illustrates the limiting influence of the slopes on general trend of urban growth in eastern corridor of the TMR. The road gravity stands in second place where it displaces orientation of linear form of outlying pattern alongside the transportation network; it represents that the main pattern of urban growth in peri-urban areas of the region have a linear nature and edge expansion due to slope resistance and road-influenced growth, while spread, diffusion, and breed coefficients display low probability of new spreading center and spontaneous growth in the study area. In addition, the prediction of urban growth for 2020–2060 revealed that urban expansion which was 41,500 ha in 2014 will increase to 179,400 ha in 2060 with noticeable growth rate of 145.6 %. Comparing study area and other researches indicate that the urban growth happens in high rate in eastern corridor. One of the main reasons of this growth goes back to the formation of the second homes for residents of Tehran metropolitan city.  相似文献   

10.
Some high-activity hot particles (HP) were found in the flood plain of the Yenisei River, near the Krasnoyarsk Mining-and-Chemical Combine (MCC), and their radionuclide compositions were determined. The ratios of plutonium and caesium isotopes in the particles are indicative of their reactor origin. The 137Cs activity of the particles amounts to 29,200 kBq/particle, which is higher than the corresponding activities of the fuel particles that formed as a result of the accident at the Chernobyl NPP. All the particles have been divided into two major groups according to the 137Cs/34Cs ratio: in the first group, the 137Cs/134Cs ratio is more than or equal to 3000, and in the second the 137Cs/134Cs ratio is less than or equal to 1000. The particles of the first and the second groups were preliminarily estimated to be formed 30 and 20 years ago, which suggests that there must have been at least two accidents at the MCC reactors, with part of the fuel released into the Yenisei River.  相似文献   

11.
The results of a radiometric survey of the Techa river flood plain near the village of Muslumovo in the Chelyabinsk region of Russia are presented. The observed territory extended 16.6 km along the riverbed, with a total area of 2.5 km2. The collimated scintillation detector technique was applied to in situ field measurements of 137Cs deposition on the soil. Maps of 137Cs deposition and soil penetration depth were developed on the basis of approximately 5000 measurements. The total 137Cs deposition within the surveyed territory has been estimated at 6.6 TBq. The means of the total 137Cs soil depositions at half-kilometer sites on the flood plain and its distribution along the river have also been calculated. A maximum 137Cs contamination above 7.5 MBq/m2 is associated with a bank height up to 1 m above the usual water level. The data identify zones of intensive radionuclide sedimentation and transit zones.  相似文献   

12.
This paper discusses the application of genetic algorithms to the construction of rule-based models. Water quality time series will be explored to extract predictive rules for algal blooms in freshwater lakes. The hypertrophic Japanese Lake Kasumigaura is used to demonstrate the technique.  相似文献   

13.
Within the FP7 EU project NanoValid a consortium of six partners jointly investigated the hazard of silver nanoparticles (AgNPs) paying special attention to methodical aspects that are important for providing high-quality ecotoxicity data. Laboratories were supplied with the same original stock dispersion of AgNPs. All partners applied a harmonised procedure for storage and preparation of toxicity test suspensions. Altogether ten different toxicity assays with a range of environmentally relevant test species from different trophic levels were conducted in parallel to AgNP characterisation in the respective test media. The paper presents a comprehensive dataset of toxicity values and AgNP characteristics like hydrodynamic sizes of AgNP agglomerates and the share (%) of Ag+-species (the concentration of Ag+-species in relation to the total measured concentration of Ag). The studied AgNP preparation (20.4 ± 6.8 nm primary size, mean total Ag concentration 41.14 mg/L, 46–68% of soluble Ag+-species in stock, 123.8 ± 12.2 nm mean z-average value in dH2O) showed extreme toxicity to crustaceans Daphnia magna, algae Pseudokirchneriella subcapitata and zebrafish Danio rerio embryos (EC50 < 0.01 mg total Ag/L), was very toxic in the in vitro assay with rainbow trout Oncorhynchus mykiss gut cells (EC50: 0.01–1 mg total Ag/L); toxic to bacteria Vibrio fischeri, protozoa Tetrahymena thermophila (EC50: 1–10 mg total Ag/L) and harmful to marine crustaceans Artemia franciscana (EC50: 10–100 mg total Ag/L). Along with AgNPs, also the toxicity of AgNO3 was analyzed. The toxicity data revealed the same hazard ranking for AgNPs and AgNO3 (i.e. the EC50 values were in the same order of magnitude) proving the importance of soluble Ag+-species analysis for predicting the hazard of AgNPs. The study clearly points to the need for harmonised procedures for the characterisation of NMs. Harmonised procedures should consider: (i) measuring the AgNP properties like hydrodynamic size and metal ions species in each toxicity test medium at a range of concentrations, and (ii) including soluble metal salt control both in toxicity testing as well as in Ag+-species measurements. The present study is among the first nanomaterial interlaboratory comparison studies with the aim to improve the hazard identification testing protocols.  相似文献   

14.
We estimated the cost of flood damage using numerical simulations based on digital map data and the flood control economy investigation manual submitted by the Ministry of Land, Infrastructure, Transportation, and Tourism in Japan. The simulation was carried out using a flood model incorporating representative precipitation data for all of Japan. The economic predictions, which estimate flood damage caused by extreme rainfall for the return periods of 5, 10, 30 50, and 100 years, are as follows: (1) the cost of flood damage increases nearly linearly with increases in extreme precipitation; (2) assuming that flood protection is completed for a 50-year return period of extreme rainfall, the benefit of flood protection for a 100-year return period of rainfall is estimated to be 210 billion USD; (3) the average annual expected damage cost for flooding is predicted to be approximately 10 billion USD per year, based on the probability of precipitation for a return period of 100 years and assuming that flood control infrastructures will be completed within the 50-year return period and will be able to protect from flooding with a 50-year return period; (4) urban and rural areas are predicted to suffer high and low costs of damage, respectively. These findings will help to derive measures to enhance flood protection resulting from climate change.  相似文献   

15.
The effect of atmospheric discharge from the Pechenganikel' Integrated Plant, the main source of sulfur dioxide in northern Europe, on changes in acidity and cation exchange properties of forest litters formed on podzol soils was estimated in forest ecosystems at the northern limit of their range. As the plant is approached, the contents of exchangeable potassium and acidity proved to decrease, whereas the contents of nickel and copper increased by two orders of magnitude and reached one-quarter of the total cation exchange capacity. The multivariate analysis of spatial interrelations revealed the natural structure of litter properties, including those concerning exchangeable bases, pollutants, and parameters of acidity.  相似文献   

16.
Frequent erosion along the banks of the river Bhagirathi–Hooghly constitutes one of the most important hazards in West Bengal, India. This frequent nature of erosion is induced by hydraulic control by the construction of Farakka Barrage in 1975 and Indo-Bangladesh water sharing treaty of 1977 and 1996. Water sharing treaties result in fluctuating discharge on 10-day scale in the lean period (January–May). The stream discharge variability affects the bank erosion through its impacts on erodibility factors of banks. It has been observed that in the pre-Farakka period bank erosion was huge only during the monsoon months, and rest of the year, there was little or no bank erosion because in the pre-monsoon and post-monsoon periods, the river Bhagirathi received very little or no discharge from the river Ganga. But in the post-Farakka period, the river Bhagirathi received considerable amount of water in variable quantities from the river Ganga, especially in lean period which has steadied the river bank erosion in the year round. It is to mention that benefits of this planning are to survive the port-industrial economy of South Bengal and provision of fresh water for inhabitants of Kolkata. So beneficiaries of this controlled hydrology must have to pay affluent tax for the victims by this project. In this paper, the nature, mechanism and pattern of bank erosion and its impact on socio-economic vulnerability of the people in the selected erosion-prone areas have been depicted. At the end, a search for social justice for the victims has been articulated from the perspective of Pareto-optimal justice.  相似文献   

17.
This paper is a response to a recent special issue of Regional Environmental Change, “Quantifying vulnerability to drought from different disciplinary perspectives” (vol. 8, number 4, 2008). In this paper, we examine some of the challenges facing efforts to understand vulnerability to drought through quantification as they are manifest in some of the articles in this special issue.
Edward R. CarrEmail:
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18.
Environment, Development and Sustainability - Watersheds in the subtropical Himalayan basins are highly prone to land degradation due to deforestation, landslides, intensive agriculture, population...  相似文献   

19.
It has recently been recommended that a shift from traditional flood prevention to more adaptive strategies is made, focusing on the reduction in and recovery from flood impacts as a means to improve resilience to climate impacts. This shift has had implications for the public–private divide in adaptive flood risk governance. In an urban context, it means that private actors such as developers and residents come into play, necessitating governance arrangements which cross the public–private divide. The division of responsibilities for water safety between the public and private sectors affects the way legitimacy is gained for these arrangements and raises new legitimacy issues. The paper offers an analysis of public and private responsibilities in adaptive flood risk governance arrangements, as well as of the legitimacy of the arrangements in the light of the public–private divide. A comparative case study is presented for three urban regeneration projects in un-embanked areas in Hamburg, Germany, Helsinki, Finland, and Rotterdam, the Netherlands, where adaptive strategies have been applied. The results show that network arrangements with joint public–private responsibilities use direct forms of participation and deliberation, but that these do not necessarily lead to more legitimate arrangements in the eyes of stakeholders as is often suggested in the literature. Both network and more public hierarchical arrangements can be perceived as quite legitimate under certain conditions.  相似文献   

20.
During the coming years, a management and remediation strategy for the Chernobyl cooling pond (CP) will be implemented. Remediation options include a controlled reduction in surface water level of the cooling pond and stabilisation of exposed sediments. In terrestrial soils, fuel particles deposited during the Chernobyl accident have now almost completely disintegrated. However, in the CP sediments the majority of 90Sr activity is still in the form of fuel particles. Due to the low dissolved oxygen concentration and high pH, dissolution of fuel particles in the CP sediments is significantly slower than in soils. After the planned cessation of water pumping from the Pripyat River to the Pond, significant areas of sediments will be drained and exposed to the air. This will significantly enhance the dissolution rate and, correspondingly, the mobility and bioavailability of radionuclides will increase with time. The rate of acidification of exposed bottom sediments was predicted on the basis of acidification of similar soils after liming. Using empirical equations relating the fuel particle dissolution rate to soil and sediment pH allowed prediction of fuel particle dissolution and 90Sr mobilisation for different remediation scenarios. It is shown that in exposed sediments, fuel particles will be almost completely dissolved in 15–25 years, while in parts of the cooling pond which remain flooded, fuel particle dissolution will take about a century.  相似文献   

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