Multivariate Analysis of Motorcycle Accidents and the Effects of Exclusive Motorcycle Lanes in Malaysia

This paper presents a multivariate analysis on the impact of the exclusive motorcycle lane on motorcycle accidents along the Federal Highway Route 2, Malaysia. A number of statistical models have been developed to explain the relationship of motorcycle accidents and explanatory variables relevant to motorcycle safety. The best model showed that motorcycle accidents are directly proportional to the cubic power of traffic flow and reduced by approximately 39% with the motorcycle lane. A clear benefit of this lane is observed when the traffic flow exceeds 15,000 vehicles per day per lane for motorcycle proportion of between 20% and 30%. Besides supporting the notion for motorcycle segregation, this finding provides an initial guideline on the warrants for an exclusive motorcycle lane for highly motorcycled countries in Asia.     

Improving the TMDL Process Using Watershed Risk Assessment Principles

Ecological risk assessment (ERA) evaluates potential causal relationships between multiple sources and stressors and impacts on valued ecosystem components. ERAs applied at the watershed scale have many similarities to the place-based analyses that are undertaken to develop Total Maximum Daily Loads (TMDLs), in which linkages are established between stressors, sources, and water quality standards, including support of designated uses. TMDLs focus on achieving water quality standards associated with attainment of designated uses. In attempting to attain the water quality standard, many TMDLs focus on the stressor of concern rather than the ecological endpoint or indicators of the designated use that the standard is meant to protect. A watershed ecological risk assessment (WERA), at least in theory, examines effects of most likely stressors, as well as their probable sources in the watershed, to prioritize management options that will most likely result in meeting environmental goals or uses. Useful WERA principles that can be applied to TMDL development include: development and use of comprehensive conceptual models in the Problem Identification step of TMDLs; use of a transparent process for selecting Numeric Targets for TMDLs based on assessment endpoints derived from the management goal or designated use under consideration; analysis of co-occurring stressors likely to cause beneficial use impairment based on the conceptual model; use of explicit uncertainty analyses in the Linkage Analysis step of TMDL development; and frequent stakeholder interactions throughout the process. WERA principles are currently most applicable to those TMDLs in which there is no numeric standard and, therefore, indicators and targets need to be developed, such as many nutrient or sediment TMDLs. WERA methods can also be useful in determining TMDL targets in situations where simply targeting the water quality standard may re-attain the numeric criterion but not the broader designated use. Better incorporation of problem formulation principles from WERA into the TMDL development process would be helpful in improving the scientific rigor of TMDLs.     

Effects of Changing Environments of Mangrove Creeks on Fish Communities at Trat Bay, Thailand

Effects of changing environments of riverside mangroves, coastal land uses, and water quality on fish communities were studied in Bangphra and Thaprik creeks, Trat Bay, Thailand. Regression analysis revealed that fish species richness in the wet season had a negative relationship with water transparency, nitrate, and phosphate and a positive relationship with zooplankton. In the dry season, species richness had a negative relationship with nitrate and phosphate and a positive relationship with salinity, pH, and zooplankton. Abundances and species richness of fish declined over distance from downstream to upstream in both creeks. Riparian mangroves and water quality also declined with distance upstream in both creeks. Results from one-way analysis of variance and Tukey’s HSD test revealed that the highest zooplankton volume with the lowest amounts of nitrate and phosphate were observed at the downstream station in both creeks in each season. Low zooplankton volume with high amounts of nitrate and phosphate were found at the midstream and upstream stations of the creeks. The midstream and upstream stations of Bangphra Creek had low to moderate abundance of mangroves along the riversides, whereas shrimp farms were mainly found along the riversides at the midstream and upstream stations of Thaprik Creek. Correlation analysis results of land-use types and the significant habitat factors were discussed. This study found that mangrove degradation, shrimp farming, and residential and agricultural areas altered water quality and the health of fish habitats, causing the decreases in fish abundance and species richness.     

Estimating relative demand for wildlife: Conservation activity indicators

An alternative method of estimating relative demand among nonconsumptive uses of wildlife and among wildlife species is proposed. A demand intensity score (DIS), derived from the relative extent of an individual's involvement in outdoor recreation and conservation activities, is used as a weighting device to adjust the importance of preference rankings for wildlife uses and wildlife species relative to other members of a survey population. These adjusted preference rankings were considered to reflect relative demand levels (RDLs) for wildlife uses and for species by the survey population. This technique may be useful where it is not possible or desirable to estimate demand using traditional economic means. In one of the findings from a survey of municipal conservation commission members in Massachusetts, presented as an illustration of this methodology, poisonous snakes were ranked third in preference among five groups of reptiles. The relative demand level for poisonous snakes, however, was last among the five groups.     

WATER YIELD IMPROVEMENT BY VEGETATION MANAGEMENT1

ABSTRACT: Vegetation management aimed at increasing the amount of usable water yield from precipitation falling on upstream watersheds may be one alternative for supplementing water supplies. Indications are that water yields can be increased within a multiple-use framework, which can benefit or at least be compatible with other natural resource objectives. Through changes in vegetation on a watershed, it is possible to reduce evaporation losses only slightly but significantly increase streamflow runoff. In an assessment of potentials for water yield improvement in Arizona, experimental studies on various vegetation zones are reviewed. Because of either limited acreage or limited rainfall, the alpine, grassland, aspen, and desert shrub vegetation zones are not realistic management areas for Arizona. Furthermore, manipulation of pinyon-juniper woodlands does not appear promising at this time. Conversion of chaparral to grasses and forbs does appear to be a possible treatment for water yield improvement, as well as various silvicultural treatments of mixed conifer and ponderosa pine forests. Streamflow increases are given for experiments in chaparral, mixed conifer, and ponderosa pine vegetation zones. However, complete information on possible constraints for these zones is not currently available. Specific assessment of water yield management options for riparian vegetation is difficult to make, due to incomplete knowledge of water yield changes and other constraints for this vegetation zone. Prior to the final adoption of management practices, results of experimental work must be coupled with economic and social considerations.     

Mixed land‐use patterns and the development of spatial structure of Nigerian cities

Differences exist in the spatial structure of cities in both the developed and developing world owing to the contradistinctive nature of their urban growth processes. The structure of Nigerian cities is characterised by the preponderance of mixed land uses resulting primarily due to the organic nature of city growth and more fundamentally, owing to the dynamics of informal urban economic activities. This paper examines mixed land‐use patterns in selected Nigerian cities and appraises their relevance in the general city growth process. By suggesting principles and speculative spatial patterns expressing desirable use combinations, an attempt is made to rationalise the utility of the concept such that its environmental impact is understood and given planning resolution.     

NEW HAMPSHIRE WATER LAW: AN INTERPRETIVE OVERVIEW1

ABSTRACT: New Hampshire's riparian water law, first modified judicially, has been more drastically changed by recent legislative and administrative action. As it stands, however, the judicially enforced doctrine of reasonable use appears to be utterly inadequate to handle increasing water demands. The protection of the public interest has imposed substantial limitations on the use of riparian water rights, all under the guise of the exercise of the police power, i.e., the protection of the public health, safety, and welfare. The efficient use of the state's water resources has been further crippled by the widespread and indiscriminate exercise of eminent domain. As a result, the state is now considering the imposition of a permit system that has the potential to streamline the allocation of water. Such a system should take into consideration the public interest factors that have recently frustrated the exercise of riparian rights and the effective use of the state's water resources.     

Jute bioblanket as a soil rehabilitation strategy in Sorocaba,Brazil: Soil chemistry and SWOT approaches

Soil erosion and the invasion of exotic plant species are major constraints to achieve sustainable development around the world. Currently, we find few products devoted concomitantly to combatting soil erosion as well as the establishment of unwanted exotic plants. In this paper, we introduce a new product, called herein a bioblanket, that protects the soil and impedes the establishment of exotic plant species. This product is of simple design, and to manufacture it, we use two biodegradable materials: jute tissue and grass wastes. We designed this product to combat soil erosion and the germination and establishment of new, unwanted, invasive plant species. In this paper, we describe our evaluation of how successful this product was in terms of improving the chemical attributes of soil. We also identified the product's potentialities and weaknesses by means of strengths, weaknesses, opportunities, and threats (SWOT) analysis. The bioblanket ameliorated the chemical attributes of the soil, as evidenced especially by the neutralization of acidity (8.5%) and aluminum toxicity (33%), and by an increment in nutrients concentration. We argue that after adequate treatment and management, the residues of plants that are normally considered unwanted materials can be transformed into a raw material to control the propagation of unwanted plant species, and concomitantly control soil erosion while improving the chemical conditions of the soil. The improvement of the soil chemical attributes was one of the main positive effects reported through the SWOT analysis. In addition, the SWOT analysis revealed some features that need improvement in future generations of the product, but we argue that these features do not impede the benefits for the use of the product in its present form.     

Loss coefficient of nitrogenous non-point source pollution under various precipitation conditions

In this study, calibrations of non-point source (NPS) pollution models are performed based on Black River basin historical real-time runoff data, sedimentation record data, and NPS sources survey information. The concept of NPS loss coefficient for the watershed or the loss coefficients (LC) for simplicity is brought up by examining NPS build-up and migration processes along riverbanks in natural river systems. The historical data is used for determining the nitrogenous NPS loss coefficient for five land use types including farmland, urban land, grassland, shrub land, and forest under different precipitation conditions. The comparison of outputs from Soil and Water Assessment Tool (SWAT) model and coefficient export method showed that both methods could obtain reasonable LC. The high Pearson correlation coefficient (0.94722) between those two sets of calculation results justified the consistency of those two models. Another result in the study is that different combinations of precipitation condition and land use types could significantly affect the calculated loss coefficient. As for the adsorptive nitrogen, the order of impact on LC for different land use types can be sorted as: farm land > urban land > grassland > shrub land > forest while the order was farmland > grass land > shrub land > forest s>urban land for soluble nitrogen. __________ Translated from Acta Scientiae Circumstantiae, 2006, 26(3): 392–397 [译自: 环境科学学报]     

岷江流域不同土地利用方式下紫色土有机碳储量特征

以岷江中下游流域紫色土为研究对象,按流域分上中下游区段3个抽样层采样,研究不同土地利用方式下紫色土有机碳储量特征,为紫色土退化评估及地力维护提供参考.结果显示,紫色土有机碳总量以林地(14.151g/kg)显著高于果园地(9.458g/kg)、菜园地(8.542g/kg)、草坡地(7.875g/kg),以玉米地(6.226g/kg)最低.水溶性有机碳含量呈现林地>果园地>菜园地>草坡地>玉米地趋势.同时,流域上、中、下游紫色土有机碳总量总体上差异显著,且以上游区段紫色土有机碳总量最高.流域中下游紫色土有机碳总量变化较大,其中,林地以下游高于中游,果园及草坡地以中游高于下游.菜园地、玉米地在3个区段上差异未达显著水平.岷江流域紫色土有机碳储量总体特征表现上游最高,中下游变化复杂,下游略高于中游区域.图1表4参10