Macroinvertebrate community response to inter‐annual and regional river flow regime dynamics

Spatio‐temporal variability in river flow is a fundamental control on instream habitat structure and riverine ecosystem biodiversity and integrity. However, long‐term riverine ecological time‐series to test hypotheses about hydrology–ecology interactions in a broader temporal context are rare, and studies spanning multiple rivers are often limited in their temporal coverage to less than five years. To address this research gap, a unique spatio‐temporal hydroecological analysis was conducted of long‐term instream ecological responses (1990–2000) to river flow regime variability at 83 sites across England and Wales. The results demonstrate clear hydroecological associations at the national scale (all data). In addition, significant differences in ecological response are recorded between three ‘regions’ identified (RM1–3*) associated with characteristics of the flow regime. The effect of two major supra‐seasonal droughts (1990–1992 and 1996–1997) on inter‐annual (IA) variability of the LIFE scores is evident with both events showing a gradual decline before and recovery of LIFE scores after the low flow period. The instream community response to high magnitude flow regimes (1994 and 1995) is also apparent, although these associations are less striking. The results demonstrate classification of rivers into flow regime regions offers a way to help unravel complex hydroecological associations. The approach adopted herein could easily be adapted for other geographical locations, where datasets are available. Such work is imperative to understand flow regime–ecology interactions in a longer term, wider spatial context and so assess future hydroecological responses to climate change and anthropogenic modification of riverine ecosystems. Copyright © 2008 John Wiley & Sons, Ltd.     

Effect of roof solar reflectance on the building heat gain in a hot climate

The effect of the roof solar reflectance on the thermal performance of a building is often ignored. However, there are significant differences in heat gain from light and dark-coloured roof surfaces. In this paper an equation for the average daily downward heat flow of a sunlit roof is derived. Using building simulation, it is first shown that the thermal mass of the roof does not significantly affect the overall daily heat gain (although it causes a time lag and reduction in peak heat flow). As a consequence the daily heat gain from the roof may be estimated by integrating the equation for the steady-state downward heat transfer over the day. For north Australia the derived equation suggests that a light-coloured roof has about 30% lower total (air temperature difference and solar-driven) heat gain than a dark-coloured one. The effect of aging (change in solar reflectance with time) is considered in the calculations and a relationship between the solar absorptance of new and aged material is suggested. A classification of roof colours with respect to their solar absorptance (dark, medium, light and reflective) is proposed to enable a quick and simple assessment of the effect of roof colour on the heat gain and R-value.     

气候变化和人类活动对于滹沱河区水资源变化的影响

滹沱河区1980--2000年系列与1956--1979年系列的平均水资源相比，以每年2．59％的速度减少。其中，由于气候变化使径流量以每年1．01％的速度减少；由于人类活动使径流量以每年1．58％的速度减少。在气候变化的影响中，年降水量的减少5．8％成为径流减少的主要因素，气温平均每年升高0．05％，使得蒸发量增加，也对径流量减少有一定影响。     

江西省永修县土地生产潜力初探

对永修县土地生产潜力的估算方法进行了阐述，并估算了永修县土地的光合生产潜力、光温生产潜力、气候生产潜力、土地生产潜力及社会生产潜力。和现实生产力进行了比较和分析，提出了一些提高土地生产力的主要途径。     

Outdoor measurements and temperature comparisons of seven monitoring stations: Preliminary studies in Curitiba,Brazil

Urbanization brings several changes to the natural environment. First, vegetation is supressed and natural scenery is modified, in order to accommodate manmade buildings and streets. Consequences bring a direct effect on fauna and flora and, due to a modified environment, with heat fluxes having a different pattern from that of the original site, on climatic features, such as on air temperature and humidity, radiative and convective heat exchanges. Thus, one of the factors that can contribute directly to the creation of urban climate is land use. The present study investigates how land use influences local temperatures in Curitiba, Brazil (25°31′S, 917 m elevation). For that purpose, seven different locations of the city were analyzed during a 1-month period by monitoring air temperature and humidity. Also, land use patterns around each location were quantified, according to five different categories established for that purpose: water area, built area, free area, paved area and green area. The monitoring of climatic data occurred in winter (June/July) of 2002. Comparisons were made regarding averages of the minimum, average and maximum temperatures for each location, qualitatively and quantitatively. As a final step of this study, formulas were developed expressing the local temperatures as a function of air temperatures, solar radiation and the wind speed of the meteorological station, which was used as reference station.     

An investigation of the potential for natural ventilation and building orientation to achieve thermal comfort in warm and humid climates

The aim of this study was to analyze the most important factor, the climatic conditions with respect to thermal comfort in buildings. The impact of building location and climate and orientation on thermal comfort were investigated.With the help of dynamic computer simulations the different hourly weather data were analyzed. First of all the climate determines the amount of solar radiation and mean outside temperature that a building is exposed to. The climate also influences the amount of energy that is used for heating and cooling but also the amount of energy that is used for lighting. There is solar excess which determines the amount of solar energy that is unwanted in the building. With growing amounts of glass and a glazing system that allows large solar heat gains,the impact of orientation is substantial. A detailed analysis was conducted to evaluate the potentials for improving thermal comfort. Detailed results are given in sample graphics and tables in the study. In a tropical climate the improvement in comfort by NV range between 9% and 41% (Kuala Lumpur in April). For a subtropical climate the improvements vary between 3% and 14%. In a temperate climate the improvements vary between 8% and 56%. The results showed that NV has a good potential in tropical and temperate climates but not in subtropical climates. Especially in Hong Kong it seems to be very difficult to apply NV. The results showed that in particular in the hottest period (summer) the potential for comfort improvements is rather small. The design of climate responsive building envelopes should take this into consideration.     

Effect of potential atmospheric warming on temperature-based indices describing Australian winegrape growing conditions

Background and Aims:  This paper describes the changes in temperature-based indices used to classify viticultural climates in Australia for three warming scenarios produced by the Commonwealth Scientific and Industrial Research Organisation: Mk3.0 global climate model for the years 2030, 2050 and 2070.
Methods and Results:  Temperature indices that describe grapevine growing season temperature (GST), ripening period temperature, accumulated biologically effective degree days and growing season length were calculated to produce maps of Australia for each warming scenario. Summary statistics of each index's median and range are presented for each Australian wine region under each warming scenario. The greatest change in GST (above the 1971–2000 mean) was modelled to occur for the Perth Hills region, increasing by 1.0°C by 2030, 1.9°C by 2050 and 2.7°C by 2070. The least change in GST was modelled to occur for the Kangaroo Island region, increasing by 0.5°C by 2030, 0.9°C by 2050 and 1.3°C by 2070.
Conclusion:  Of the 61 recognised wine regions, a median GST of over 21°C (an indicator of the limit of quality wine grape production conditions) was found for three regions for the period 1971–2000, for eight regions for the 2030 scenario, 12 regions for the 2050 scenario and 21 regions for the 2070 scenario.
Significance of the Study:  Without appropriate adaptations, some established viticultural regions of Australia may become less suitable for quality winegrape production, whereas regions that were once considered unsuitable for quality winegrape production may become more suitable.     

Simulation and validation of radiative transfers in urbanised areas

The energy balance at the soil-atmosphere interface is the fundamental equation to simulate the microclimate of urban areas. It implies the equilibrium of several energetic terms, such as: radiation (in the solar and infrared wavelengths), conduction (soil heat flux), convection (sensible heat flux) and evapotranspiration (latent heat flux). This article deals with the 3D-numeric simulation of heat transfers in an urban canyon and the validation of the appropriate algorithms and results. The simulation procedure and parameterisation of the surface elements are briefly described. All the heat transfer algorithms are taken from the existing literature. Among the mechanisms, the terrestrial infrared radiation is the most difficult term to be simulated, because realistic surface temperatures must be obtained. For this reason, at each time step, a special iterative treatment is applied to solve the energy balance equation until complete stabilisation of the surface temperatures. As a result, the simulation model is able to give all the components of the energy balance equation for every mesh. The aim of the paper is to demonstrate the validity of this approach by comparing the simulation results with the experimentation. The reliability of the simulated radiative fluxes is judged against a data set specially acquired during a dedicated experimental campaign that took place in an urban canyon of a French city (Strasbourg) during summer 2002.