Where are Germany’s gains from Kyoto? Estimating the effects of global warming on agriculture

Motivated by the high abatement costs of the Kyoto Protocol for Germany, this paper is estimating the economic impact of global warming on agriculture in that country. The hedonic approach is used as theoretical background. Stating that land prices are – among others – determined by climatic factors, this approach can consequently be used to value global warming. To avoid a priori restrictions stemming from functional forms, the land price function is modeled as quadratic Box–Cox function that nests a wide range of specifications. In a second step, the estimated results are used to forecast the impact of climate change. The results indicate that German farmers will be winners of climate change in the short run, with maximum gains occurring at a temperature increase of +0.6°C against current levels. In the long run, there may be losses from global warming. However, the net present value from climate change is under the most probable scenarios positive.     

多途径解决我国钾盐资源紧缺的对策探讨

探讨了钾盐矿产的应用,钾盐矿产在世界及我国的分布状况,提出了解决我国钾盐矿产资源紧缺问题的途径。     

Structure,diversity and stability of two oligochaete communities according to sedimentary inputs in Lake Geneva (Switzerland)

Two oligochaete communities were sampled monthly during one year in two 35 m deep locations of Lake Geneva (Switzerland). Organic sedimentation was lower and less variable in station 1 than in station 2 (157 versus 214 g C m⁻²yr⁻¹). The oligochaete community in station 1 was more diverse and more stable (persistent over time) than in station 2, as long as the organic sedimentation was low. Diversity and stability decreased in station 1 when the organic sedimentation increased, and during anOscillatoria bloom. The less diverse community in station 2 was more resistent to these changes. Diversity was associated with environmental stability, but resistance to perturbation was greater in the simpler community which is adapted to changing environmental conditions. The value of oligochaete communities as an indicator of the level of eutrophication was reassessed according to our present data. Changes in the structure of oligochaete communities were related to changes in sedimentation processes.     

Locational components of urban and regional public policy in postwar Vietnam: The case of Ho Chi Minh city (Saigon)

Ho Chi Minh city is a primate city in which wartime dislocations have resulted in severely overcrowded conditions as well as a shrunken economic base. The new government has opted for a policy based on the rapid decanting of a large proportion of the urban population by encouraging internal migration to New Economic Zones in the hinterlands. This policy is based on a hierarchial administrative structure with agricultural productivity as its prime goal. A Green Belt policy has been articulated that uses the New Economic Zones as building blocks. The Green Belts constrain urban growth as well as provide foodstuff for the remaining urban residents. The ultimate objective of the overall policy is a balanced urban and regional environment that is in tune with Vietnam's agricultural economy.     

Macrofaune des fonds de cailloux du Léman

In Lake Geneva (Switzerland), the macrofauna of the stony lake bottom was studied in seven stations from 1969 to 1971. The modifications in animal communities since the beginning of the century can be attributed partly to the increasing eutrophication of the lake and partly to the introduction of new species. The stations are classified according to the structure of their animal communities, which enables us to deduce the degree of eutrophication of each station. The analysis of factors which influence the animals' microdistribution on lakebottom stones reveals many complicated interactions. As a result of this complexity, further research projects were concentrated on leeches (Hirudinea) which colonize artificial substrates in imitation of the underface of stones.Helobdella stagnalis, Erpobdella octoculata andGlossiphonia complanata form the major part of collected fauna. Density fluctuations, population structures (age groups) and quantitative relations between these three species as well as their vertical and horizontal distribution patterns were examined in great detail.      

Seven-frequency VLBI Observations of the GHz-Peaked-Spectrum Source OQ 208

We present quasi-simultaneous VLBI images of the GHz-Peaked-Spectrum radio source OQ 208 obtained with the Very Long Baseline Array at 1.4,1.7,2.3,5.0,8.4,15.4GHz and the European VLBI Network at 6.7 GHz.The low frequency(1.4,1.7 and 2.3GHz)ob- servations reveal a weak and extended steep-spectrum component at about 30mas away at position angle-110°,which may be a remnant emission.The radio structure of OQ 208 con- sists of two mini-lobes at 5.0,6.7,8.4 and 15.4 GHz.Our spectral analysis further confirms that the southwest lobe undergoes free-free absorption and finds that the free-free absorption is stronger in the inner region.By fitting the 8.4 GHz images from 1994 to 2005,we obtain a separation speed of 0.031±0.006 mas yr~(-1)between the two mini-lobes.This indicates a jet proper motion of 0.105±0.020 c and a kinematic age of 219±42 yr for the radio source.     

Climatic control on river discharge simulations,Zackenberg River drainage basin,northeast Greenland

A spatially distributed, physically based, hydrologic modeling system (MIKE SHE) was applied to quantify intra‐ and inter‐annual discharge from the snow and glacierized Zackenberg River drainage basin (512 km²; 20% glacier cover) in northeast Greenland. Evolution of snow accumulation, distribution by wind‐blown snow, blowing‐snow sublimation, and snow and ice surface melt were simulated by a spatially distributed, physically based, snow‐evolution modelling system (SnowModel) and used as input to MIKE SHE. Discharge simulations were performed for three periods 1997–2001 (calibration period), 2001–2005 (validation period), and 2071–2100 (scenario period). The combination of SnowModel and MIKE SHE shows promising results; the timing and magnitude of simulated discharge were generally in accordance with observations (R² = 0·58); however, discrepancies between simulated and observed discharge hydrographs do occur (maximum daily difference up to 44·6 m³ s^?1 and up to 9% difference between observed and simulated cumulative discharge). The model does not perform well when a sudden outburst of glacial dammed water occurs, like the 2005 extreme flood event. The modelling study showed that soil processes related to yearly change in active layer depth and glacial processes (such as changes in yearly glacier area, seasonal changes in the internal glacier drainage system, and the sudden release of glacial bulk water storage) need to be determined, for example, from field studies and incorporated in the models before basin runoff can be quantified more precisely. The SnowModel and MIKE SHE model only include first‐order effects of climate change. For the period 2071–2100, future IPCC A2 and B2 climate scenarios based on the HIRHAM regional climate model and HadCM3 atmosphere–ocean general circulation model simulations indicated a mean annual Zackenberg runoff about 1·5 orders of magnitude greater (around 650 mmWE year^?1) than from today 1997–2005 (around 430 mmWE year^?1), mainly based on changes in negative glacier net mass balance. Copyright © 2007 John Wiley & Sons, Ltd.     

A Late‐glacial chironomid record from Hawes Water,northwest England

This paper presents the results of a high‐resolution Late‐glacial chironomid stratigraphy from Hawes Water, a small carbonate lake in northern Lancashire. The samples were from a core taken from the terrestrialised margin of the present lake, which represents an intermediate depth between the true littoral and the profundal. The chironomid assemblage showed a high degree of sensitivity to both broad‐scale and short‐term temperature changes. Comparison with an existing proxy temperature record (δ¹⁸O) for the site confirmed the presence of four temperature inversions within the Late‐glacial Interstadial. A mean July air temperature inference model, derived from acid, soft‐water lakes in Norway and Svalbard, was applied to the data. Despite the absence of carbonate lakes within the Norwegian training set, there was a close similarity between trends in estimated July air temperature and the δ¹⁸O trace, with a particularly strong correspondence in the periods of clay deposition. This suggests that this model is highly robust. The inferred maximum Interstadial temperature was 13.4°C, dropping initially to 7.5°C in the Loch Lomond Stadial. Temperatures reach a maximum of nearly 10°C in this period, cool for a short period before rising rapidly to 13.2°C at the start of the Holocene. These temperatures are similar to but slightly higher than those estimated for Whitrig Bog, southeast Scotland, and lower than those inferred from coleopteran‐based models for sites in South Wales. Copyright © 2004 John Wiley & Sons, Ltd.