Planning for cooler cities: a plan quality evaluation for Urban Heat Island consideration

ABSTRACT

City strategic plans and enabling policies provide a framework for and inform future development across multiple scales. An exemplar city strategic plan will be one based on evidence, enabled by complementary policy outcomes, and built on the knowledge of the existing landscape. This study evaluated the plan quality of eighteen metropolitan strategic plans for city members in the 100 Resilient Cities initiative. A protocol was developed containing thirty-two indicators to assess plans capacity to act as a strategic planning tool to develop, analyse and implement strategies for the Urban Heat Island (UHI) and climate change mitigation and adaptation. The evaluation indicated that strategies addressing the UHI are rarely included in metropolitan plans. Strategic plans showed a lack of evidence-base to inform the potential actions. Urban warming is often linked to extreme weather events anticipated under climate change, not the UHI as a systemic and increasing phenomenon. We recommend that the pathway to addressing UHI mitigation and adaptation may lie in its nexus to aspects of climate change that concurrently can serve to support liveable and resilient cities.     

POTENTIAL EFFECTS OF CHANGED CLIMATES ON HEAVY RAINFALL FREQUENCIES IN TIlE MIDWEST1

ABSTRACT: An important question posed by potential future shifts in climate relates to possible shifts in heavy rainfall events (intensity and/or frequency) used to design hydraulic structures. Heavy rain events were defined as those producing amounts having average recurrence intervals of two years or longer for a specific storm period at a given location. Estimates of such heavy rainfall shifts in the humid continental climate of the midwest were derived by using spatial and temporal analogs. Comparisons in areas of relatively warm, wet conditions were made with those having measurably cooler, drier average conditions. The spatial-temporal analogs provided comparative differences in precipitation and temperature similar to the magnitude of changes obtained from GCM estimates. Spatial analogs/analyses indicated 10 to 15 percent increases in the frequency distribution of rain events having recurrence intervals of 5 to 50 years. Two periods of notably drier and warmer conditions during the past 90 years revealed 5 to 15 percent decreases in the number of 2- to 10-year heavy rain events. The suppression percentages showed a strong tendency to increase with increasing recurrence interval from 2 to 10 years.     

红壤丘陵区土地利用变化对土壤质量影响

以鄂南红壤丘陵典型区的三个村为代表 ,应用地理信息系统对 1981和 1998年两个时期的土地利用变化和土壤质量进行对比研究 ,分析了土地利用变化对土壤质量的影响。结果表明 :研究区土地利用结构总体上具有农业型特点 ,17a间水田减少了 2 1% ;其余的利用方式则有不同幅度的增加 ,居民地、水域、林地、园地和旱地增加了 4 2 .2 %、99.6 %、8%、5 6 .8%和 8%。土壤质量有从优劣两端向中等靠拢的趋势 ,17a后 、 、 和 等地面积分别减少 18.6 %、12 .2 %、2 9.6 %和 2 5 % ; 等地增幅达 5 1.9%。土地利用方式及管理措施是影响土壤质量演变方向和强度的关键因子 ,园地和林地的土壤质量大多得到明显改善 ,水田的Δ SQI多数呈下降的趋势 ,旱地的土壤质量变化比较复杂 ,与土地利用结构相关。依此 ,本文探讨了定向培育土壤质量的途径     

日本城市化中的耕地变动与经验

日本是一个国土面积狭小、耕地资源稀缺的国家。然而，在人均土地资源极为有限的条件下，日本在较短时间内达到了高度城市化，同时付出了较小的用地代价。在其整个城市化进程中，日本还出现了三个耕地面积增长时期。尽管各时期增长原因不尽相同，但却反映出耕地面积变动与城市化发展的密切关系。事实表明，日本选择了一条节约有限土地资源的城市化发展道路，这些经验对我国城市化发展中的耕地利用与保护有积极的借鉴意义。     

Island-based catchment—The Taiwan example

Rapid economic and industrial development in Taiwan over the past five decades has elevated the islands standing and earned it a place in the group known as the Four Small Dragons of Asia. Such growth, however, has been at the expense of the environment. There are currently nearly 23 million people juggling for space on the small island of 35,873 km². Aggravating the matter further, the central mountain ranges and hills take up 73.6% of the land area with some 156 peaks surpassing 3,000 m. As a result, most people live in coastal plains which amount to only 9,490 km². Pressure to move people inland has led to road construction and deforestation, both of which have contributed to an already high denudation rate of topsoil. As a consequence of this, thirteen rivers in Taiwan are now ranked among the top 20 worldwide in terms of sediment yield. Aside from this, the frequency of both floods and droughts increased prior to 1990, perhaps because of deforestation and global warming. Fortunately, the new conservation-orientated forest management policy of 1991 has alleviated the problem, somewhat, and the occurrence of floods and droughts has since decreased. The problem of water shortage, however, has worsened because of the warming trend in atmospheric temperature. Damming may ameliorate the water shortage problem but may affect the shoreline stability, as well as the ecology and water quality in the estuaries. Furthermore, these detrimental effects may go far beyond the estuaries, and even fisheries on the continental shelves may be affected.     

Environmental changes in Sepetiba Bay,SE Brazil

Sepetiba Bay is an example of an aquatic environment that has been severely impacted by human occupation and industrial activities in its basin. Some 400 industries including metallurgical, petrochemical and pyrometallurgical smelters, which emitted pollutants to air, soil and water, were established in Sepetiba Basin during the past 30 years. Apart from these point sources, changes in land use have also resulted in a large remobilization of pollutant deposition on Sepetiba Bay Basin. Studies have pointed out significant changes in sedimentation rates, concentrations of inorganic pollutants (Zn, Cd, Pb and Hg) and more recently, eutrophication, pointing to this area as an example of an impacted coastal zone. Notwithstanding local sources, Sepetiba Bay also suffers environmental impacts caused by diversion of river waters from adjacent basins, with some 30% of the total Hg flux to Sepetiba Bay and a 10-fold increase in water and sediment fluxes resulting from this. Decreasing environmental quality compromises both the large biodiversity and the potential economic uses of Sepetiba Bay, including fisheries and tourism. Monitoring of heavy metal levels in organisms (algae, mollusks, crustaceans and oysters) often shows concentrations well above the limits allowed following Brazilian legislation for food quality. Historical evolution of these concentrations suggests a worsening of the situation. Failure to monitor the effect of land-based activities, including those from other basins artificially associated with Sepetiba Bay has resulted in poor scenario construction and proper management planning.     

A GIS/Simulation Framework for Assessing Change in Water Yield over Large Spatial Scales

Recent legislation to initiate vegetation management in the Central Sierra hydrologic region of California includes a focus on corresponding changes in water yield. This served as the impetus for developing a combined geographic information system (GIS) and simulation assessment framework. Using the existing vegetation density condition, together with proposed rules for thinning to reduce fire risk, a set of simulation model inputs were generated for examining the impact of the thinning scenario on water yield. The approach allows results to be expressed as the mean and standard deviation of change in water yield for each 1-km² map cell that is thinned. Values for groups of cells are aggregated for typical watershed units using area-weighted averaging. Wet, dry, and average precipitation years were simulated over a large region. Where snow plays an important role in hydrologic processes, the simulated change in water yield was less than 0.5% of expected annual runoff for a typical watershed. Such small changes would be undetectable in the field using conventional stream flow analysis. These results suggest that use of water yield increases to help justify forest-thinning activities or offset their cost will be difficult.     

Sustainable Development in Small Island Developing States

This paper explores the status of sustainable development in small island developing states (SIDS), through the presentation of a case study on the Maldives, which is a typical small island developing state in the Central Indian Ocean. At the outset, a brief history of sustainable development as related to SIDS on the international agenda is outlined, starting from Rio to Barbados to Johannesburg. SIDS are expected to face many challenges and constraints in pursuing sustainable development due to their ecological fragility and economic vulnerability. It is the position of this paper that issues related to environmental vulnerability are of the greatest concern. A healthy environment is the basis of all life-support systems, including that of human well-being and socio-economic development. Priority environmental problems are: climate change and sea-level rise, threats to biodiversity, threats to freshwater resources, degradation of coastal environments, pollution, energy and tourism. Among these, climate change and its associated impacts are expected to pose the greatest threat to the environment and therefore to sustainable development. For small islands dependent on fragile marine ecosystems, in particular on coral reefs, for their livelihoods and living space, adverse effects of climate change such as increased frequency of extreme weather events and sea-level rise will exacerbate the challenges they already face. It is concluded that the paper path from Rio to Barbados to Johannesburg has made significant progress. However, much remains to be done at the practical level, particularly by the developed countries in terms of new and additional efforts at financial and technical assistance, to make sustainable development a reality for SIDS.     

Ecological tax reforms and environmental benefits in Italy and Sweden

The paper calculates the implications of including monetary measurements of environmental emission changes for the welfare impacts of ecological tax reforms in Italy and Sweden. Taxes on emissions of SO₂, NO_x and CO₂ are investigated. Country-specific computable equilibrium models are used for estimating net welfare changes of the introduction of these taxes, the incomes of which are used for reducing distorting labour taxes. The results indicate that the inclusion of environmental benefits reduces the costs of ecological tax reforms considerably for both countries, and may even turn into net welfare gains.     

Decline in Endangered Species as an Indication of Anthropic Pressures: The Case of European Mink Mustela lutreola Western Population

Populations of threatened species, especially predators at the top of the food chain, may be affected by anthropic pressures. The endangered western population of European mink Mustela lutreola has shown a large decline over 50% of its natural range. M. lutreola disappeared from northwestern France between 1984 and 1997, and the decline was associated with an increase in mustelid trapping, changes in watercourse quality, and habitat modifications due to agricultural practices. The pattern of decline showed a fragmentation restricting the minks into very small areas. Trapping was the first known cause of mortality. Although feral American mink Mustela vison may compete with autochthonous carnivores, M. lutreola had disappeared from streams before the introduction of the American species, suggesting that competitive interactions were not responsible. Furthermore, American mink has never been found or has remained rare in 62.4% of the area from which M. lutreola has disappeared. During the past 25 years, permanent grassland surfaces were reduced by 40%, whereas fodder culture increased by 470%, causing considerable habitat changes. Furthermore, 55.7% of water courses were classified as being of bad quality or polluted. Therefore, our data suggests that a conjunction of intensive trapping, alterations in water quality and habitat modification was critical for the European mink's decline. Although there are difficulties in ascribing specific cause to distribution changes in a top predator, this decline can be regarded as an indication for anthropic pressures on natural habitats.