环境水力学研究中的预报模型的研究现状

主要介绍目前世界上环境水力学研究中,湍流模式下,预报模型的发展、现状及种类。并简单分析了模型的原理以及模型的适用性与非适用性,来说明实际工程中对瑞流模式研究的重要性和可行性。     

Green Costs,Red Ink: Determinants of Municipal Defensive Expenditures inOntario

Book reviews are in these Articles.

Understanding Peasant Agriculture: An Integrated Land-Use Model for the Punjab Joseph H. Astroth, Jr. Chicago: University of Chicago, Committee on Geographical Studies, 1990. (Geography Research Paper No. 223). ix and 173 pp., maps, photos, figs., apps., biblio., and index; $12.00 paper (ISBN 0-89065-127-2).

National Integration in Indonesia: Patterns and Policies Christine Drake. Honolulu: University of Hawaii Press, 1989. xvi and 354 pp., maps, diags., tables, index, and biblio. $35.00 cloth ISBN 0-8248- 1229-8).

Urban Economic Theory: Land Use and City Size. Masahisa Fujita. New York: Cambridge University Press, 1989. x and 366 pp., diag., graphs, biblio. notes, append, biblio., index. $65.00 cloth (ISBN 0-521-34662-2).

The Sugar Cane Industry: An Historical Geography from Its Origins to 1914. J. H. Galloway. Cambridge, MA: Cambridge University Press, 1989. xiii and 266 pp., maps, tables, diags., index, and biblio. $44.50 cloth (ISBN 0-521-24853-1).

Government Policy and Industrial Change. David Gibbs, ED. New York: Routledge, 1989. xvi and 317 pp., 15 figs., 53 tables, index, and biblio. $59.95 cloth (ISBN 0-415-01032-2).

English Agriculture: An Historical Perspective. David Grigg. New York: Basil Blackwell, 1989. vii and 256 pp. $60.00 cloth (ISBN 0-631-16033-7).

London 2001. Peter Hall. London: Unwin Hyman, 1989. xii and 226 pp., maps, diags., index, and biblio. $34.95 cloth (ISBN 0-04-4451 61 -X).

The Land that Became Israel: Studies in Historical Geography. Ruth Kark, ED. Translated from the Hebrew by Michael Gordon. Jerusalem: The Magnes Press, The Hebrew University and New Haven and London: Yale University Press, 1990. x and 332 pp., maps, diags., plates. $27.50 cloth (ISBN 0-300- 04718-5).

Die Farmer-Genossenschaften in den USA – Eine agrargeographie Untersuchung. Werner Klohn. Vechta, Federal Republic of Germany: Vechtaer Druckerei, 1990. Vechtaer Arbeiten zur Geographie und Regionalwissenschaft, Band 9. 285 pp., maps, photos, diags., and biblio. 39.80 DM paper (ISBN 3-88441-083-0).

Agricultural Development in Japan: The Land Improvement District in Concept and Practice. Gil Latz. Chicago, IL University of Chicago Press, 1989. vii and 135 pp., maps, diags., index, and biblio. $12.00 paper (ISBN 0-89065-129-9).

Land Use Planning Made Plain. Hok Lin Leung. Kingston, Ontario: Ronald P. Frye &; Company, 1989. xv and 237 pp., maps, diags., tables, append., index, and refs. $19.95 paper (ISBN 0-919741-98-3).

Computers in Geography. David J. Maguire. New York: Halsted Press, 1989. xv and 248 pp., maps, photos, diags., index, and biblio. $31.95 paper (ISBN 0-470-21 194-6).

Maps with the News: The Development of American Journalistic Cartography. Mark Monmonier. Chicago: The University of Chicago Press, 1989. xii and 331 pp., maps, illus., index, and biblio. $24.95 cloth (ISBN 0-226-53411-1).

Geographic Information Systems and Cartographic Modeling. C. Dana Tomlin. Englewood Cliffs, NJ: Prentice Hall, 1990. xviii and 249 pp., maps, diags., review questions, selected readings, appendix, index, $44.20 cloth (ISBN 0-13-350927-3).     

Forthcoming events

Tropical cyclones (hurricanes and typhoons) produce high winds that can generate waves capable of damaging coral reefs. As cyclones frequently pass through northeast Australia's Great Barrier Reef (GBR), it is important to understand how the spatial distribution of reef damage changes over time. However, direct measurements of wave damage, or even wave heights or wind speeds, are rare within the GBR. An important factor in estimating whether cyclone damage was possible is the magnitude and duration of high‐energy wind and waves. Thus, before the spatio‐temporal dynamics of past cyclone damage can be modelled, it is necessary to reconstruct the spread, intensity, and duration of high‐energy conditions during individual cyclones. This was done every hour along the track taken by each of 85 cyclones that passed near the GBR from 1969 to 2003, by implementing a cyclone wind hindcasting model directly within a raster GIS using cyclone data available from the Australian Bureau of Meteorology. Three measures of cyclone energy (maximum wind speed—MAX, duration of gales—GALES, and continuous duration of gales—CGALES) were derived from these data. For three cyclones, where field data documenting actual reef damage from cyclone‐generated waves were available, the predictive ability of each measure was assessed statistically. All three performed better in predicting reef damage at sites surveyed along the high‐energy reef front than those surveyed along the more protected reef back. MAX performed best for cyclone Joy (r ² = 0.5), while CGALES performed best for cyclones Ivor (r ² = 0.23) and Justin (r ² = 0.48). Using thresholds for MAX and GALES obtained via comparison with field data of damage, it was possible to produce a preliminary prediction of the risk of wave damage across the GBR from each of the 85 cyclones. The results suggest that while up to two‐thirds of the GBR was at risk from some damage for 30–50% of the time series (～18 out of 35 years), only scattered areas of the region were at risk more frequently than that.     

Geochemistry of the High Dam Lake sediments,south Egypt： implications for environmental significance

The goal of the present work is to perform a geochemical assessment of High Dam Lake bottom sediments for determining the fate, dispersion and levels of trace elements causing environmental pollution, and provided an access to their probable sources. The sediment samples were analyzed using ICP-MS for 20 elements; Ag, Ba, Cr, Cu, Ga, Hf, Mn, Pb, Rb, Sc, Se, Sn, Sr, Ta Th Ti, T1, U, V and Zr, and their obtained data were treated using statistical, graphical and mapping techniques. The results showed the data set of all analyzed elements affected by outliers and extreme values that caused deviation away from normality. Kruskal-Wallis test revealed that median of some trace element levels in Lake sediments, was not significantly different and other elements rejected the Null hypothesis. Most analyzed elements had high values of median and mean in sediments of Lake Nubia rather than Lake Nasser and their normalization gave the same results of calculated environment factors. Subsequently, Lake Nubia sediments possessed high combined EF levels ofTh, Sc, Sn, Ag, Zr, Hf, Ta, Sr, U, Ti, V, Cr, and Mn, causing significant contamination, which was great potentially related to industrial, agricultural, urbanization and mining activities. Whereas, combined EF of Se, Cu, Ga, Pb, Ba, Rb, and Tl, which are highly elevated in southern Lake Nasser sediments owing to their source are great possibly derived from Lake Nubia and geogenic activities. With decreasing distance towards the High Dam body, the contaminant elements were diminished due to reduction in the environmental factors and Sudanese pollution sources leading to the northern Lake Nasser considered to be less contaminated. Overall, the present study is an environmental alert for contaminated sediments that carried contaminants and considered the secondary source of pollution impact on ecosystem, and subsequently, their environmental risk on Human health.     

Environmental determinants of leech assemblage patterns in lotic and lenitic habitats

Leeches (Clitellata: Hirudinida) are abundant predators or ecto-parasites inhabiting various freshwater habitats; however many biotic and abiotic drivers of their assemblage patterns have been deduced rather than directly tested. To study species richness and composition changes in leech assemblages, 109 sites of running and stagnant water bodies were sampled in three regions of the Czech Republic in 2007–2010, together with several explanatory variables that are known or expected to be important predictors of leech distribution. In total, 17 species of leeches were recorded, varying between 0–7 and 0–9 species in lotic and lenitic sites, respectively. These differences in species richness of lotic and lenitic sites were highly significant, contrary to the abundances, which varied between 0–283 and 0–295 individuals. The main change in species composition was controlled by water temperature and morphological characteristics (e.g. substrate and cover of macrophytes), mostly reflecting the differences between lotic and lenitic habitats. We found the density of benthos (i.e. prey availability) to be the best predictor of species composition in both lotic and lenitic sites, together with the percentage of canopy cover. However, the other significant predictors (i.e. the substrate and water conductivity found to be significant in lotic sites, and the mean annual temperature and PO₄^3? in lenitic sites), differed between these habitats. Other than mean annual temperature and water temperature, which had different effects on species richness in lotic and lenitic sites, there were no other differences between lotic and lenitic sites in terms of how species richness and abundance responded to all other analyzed predictors. Our results stress the importance of prey availability and canopy for leech distribution patterns. Differences in the significant predictors of leech assemblage patterns between lotic and lenitic sites raise fundamental questions about the underlying mechanisms and ecological constraints to leech distribution in these main types of aquatic systems.     

Heavy metal pollution and assessment in the tidal flat sediments of Haizhou Bay,China

The heavy metal inventory and the ecological risk of the tidal flat sediments in Haizhou Bay were investigated. Results show that the average concentrations of heavy metals in the surface sediments exceeded the environment background values of Jiangsu Province coastal soil, suggesting that the surface sediments were mainly polluted by heavy metals (Cd, Cr, Cu, Mn, Pb and Zn). In addition, the profiles of heavy metals fluxes can reflect the socio-economic development of Lianyungang City, and heavy metals inputs were attributed to anthropogenic activities. Cr, Cu, Pb and Zn were mainly present in the non-bioavailable residual form in surface sediments, whereas Cd and Mn were predominantly in the highly mobile acid soluble and reducible fractions. The ecological risk of the polluted sediments stemmed mainly from Cd and Pb. According to the Sediment quality guidelines (SQGs), however, the adverse biological effects caused by the heavy metals occasionally occurred in tidal flat.     

The Effects of Environmental Conditions on Concentration and Emission of Ammonia in Chicken Farms during Summer Season

This paper presents a field study conducted in northwest Turkey and characterizes the NH₃ concentration and emission measured in summer season from three chicken farms. The influence of environmental conditions on NH₃ concentration and emission was also investigated in this study. Ammonia concentration, temperature, relative humidity and airflow rate were continuously recorded for four sequential days. The environmental conditions were measured using a multifunction temperature and humidity‐meter with a hot wire probe. Portable multiple gas detectors with electro‐chemical sensors were used to measure NH₃ concentration. The NH₃ emission rates for houses were calculated by multiplying simultaneously measured NH₃ concentrations and air flow rates. The average daily mean (ADM) house concentrations of house 1 (H1), house 2 (H2), and house 3 (H3) were measured as 4.43, 3.71, and 6.20 ppm, respectively. NH₃ concentration was inversely proportional to temperature (r = ?0.279), relative humidity (r = ?0.063) and airflow rate (r = ?0.554) for all monitored houses. The ADM house NH₃ emission was 135 g/(h house) for H1, 255 g/(h house) for H2, and 117 g/(h house) for H3. The combined average emission rate in this study (0.26 g/(d bird)) was lower than the emission rate measured in chicken farms in the USA. However, our results were comparable to rates calculated in European studies because house design, ventilation system and bird diet applied in Turkish chicken farms are very similar to those employed in European countries. The NH₃ emissions were significantly correlated to NH₃ concentrations (r = 0.45, p ≤ 0.001) and airflow rates (r = 0.97, p ≤ 0.001). A clear diurnal pattern was obtained for NH₃ concentrations rather than NH₃ emissions at the end of the study.     

Regulating Environmental Factors of Nutrients Release from Wheat Straw Biochar for Sustainable Agriculture

One mechanism by which biochar application enhances soil nutrient availability is through direct nutrients release from biochar. However, factors controlling the release processes are poorly understood. In this study, the effects of pH, biochar to water ratio, temperature, ionic strength, and equilibration time on the release of PO, NO, NH, K⁺, Na⁺, Ca²⁺, and Mg²⁺ from biochar were evaluated in simulated experiments. The release of PO, K⁺, Ca²⁺, and Mg²⁺ was significantly affected by extraction pH, suggesting that their release from biochar was pH dependent or an H⁺‐consuming process. Correlation analysis indicated that PO and Ca²⁺, PO and Mg²⁺, and Ca²⁺ and Mg²⁺ were co‐solubilized with increasing soil acidity. To a lesser extent, the recovery of the nutrients was also affected by the ratio of biochar to water: more nutrients were soluble with more water supply. In contrast, the release of Na was not affected by pH while the concentration increased with decreasing biochar to water ratio. Meanwhile, other factors (temperature, ionic strength, and equilibration time) had less effect on nutrient release from biochar. Under the influence of pH, the patterns of NO and PO release from biochar were different: extractable NO concentration was not affected by the pH but more PO was released in strongly acidic conditions. Our data suggested that P was mainly retained in inorganic forms while N was in organic forms in biochar. We conclude that environmental factors have marked influences on nutrients release from biochar.     

Can we learn from the past? Towards better analogies and historical inference in society-environmental change research

In light of the challenges posed by contemporary environmental changes, interest in past environmental impacts and societies’ responses to them is burgeoning. The main strength of such research lies in its ability to analyze completed society-environment interactions. Scholars have argued that such analyses can improve our understanding of present challenges and offer useful lessons to guide adaptation responses. Yet despite considerable differences between past and present societies, our inherently limited knowledge of the past and our changing understanding of it, much of this research uses historical antecedents uncritically, assuming that past societal impacts and responses are directly analogous to contemporary ones. We argue that this approach is unsound both methodologically and theoretically, thus drawing insights that might offer an erroneous course of action.To illustrate the challenges in drawing historical analogies, we outline several fundamental differences between past and present societies as well as broader limitations of historical research. Based on these points, we argue that scholars who apply historical inference in their work should do so critically, while reflecting on the objectives of learning from the past and the limitations of this process. We suggest a number of ways to improve past-present analogies, such as defining more explicitly what we can learn from the past, clarifying the rationale for using the analogy, and reducing the number of variables compared between past and present.     

100 global bright spots of green growth: Co-occurrence of nighttime light gain and forest gain, 1990–2015

Economic growth commonly occurs at the expense of environmental quality, but there are exceptions. Here we use satellite data to identify places where exceptional economic growth and exceptional environmental improvement co-occurred between 1990 and 2015. We term as “bright spots of green growth” those spatial clusters with the most cells above the 95th percentile within their world region in both economic growth (as proxied by increase in nighttime lights) and one aspect of environmental improvement (forest area). Because the locations of bright spots are sensitive to methodological choices, we applied two different approaches to identifying bright spots. The two approaches differed in their choice of nighttime lights data (DSMP-OLS in Approach A vs. DSMP-VIIRS composite in Approach B); choice of forest area data (forest cover vs. forest land-use); time period (2000–2010 vs. 1990–2015); and clustering technique (visual inspection vs. HDBSCAN algorithm). We identified the top five bright spots in each of ten world regions using each of two approaches, for a total of 100 global bright spots of green growth. We then tested the extent to which the attributes of bright spots were consistent with four non-mutually exclusive theories of green growth. Of the bright spots we identified, around two-thirds (65% using Approach A; 71% using Approach B) had significantly higher-than-regional-average growth in the share of labor employed in services, consistent with sectoral shift and “tertiarization.” Fewer than half (38%; 46%) had significantly higher growth in income, consistent with the “Environmental Kuznets Curve” theory. Some (54%; 29%) had significantly higher growth in timber plantation area, consistent with “eco-industry”-driven rural development. Few (0%; 10%) had significantly higher growth in protected area coverage, consistent with public policy-induced forest conservation. Our findings suggest sectoral shift toward services, rather than rising income per se, may be a promising pathway for other regions seeking to combine economic growth and environmental improvement.