SPATIALLY DISTRIBUTED MODELING OF STREAM FLOW DURING STORM EVENTS1

ABSTRACT: The purpose of this paper is to present a new approach for the spatially distributed modeling of water flow during storm events. Distributed modeling of flow during storm events is an important basis for any environmental modeling, including turbidity or sediment transport. During the initial phase of a rainstorm, surface runoff is the main contributor of flow. To provide the spatial components for distributed hydrological modeling a Geographic Information System (GIS) was used to map and visualize contributing areas around a stream channel. Stream segments were defined using the hydrologic response unit (HRU) concept. Lateral flows were derived from GIS output for each segment of the stream and at each time interval of the rain storm and were routed using the kinematic routing equation. This approach is new in hydrological modeling and can be used to enhance many existing simulations. The model is also unique in the fine time scale (i.e., intervals are on the order of minutes). Model results showed good correlation with measured discharge values; however, further studies of contributing area behavior, its relationship with soil types and slope categories, and the influence of watershed size are needed to improve model performance. This model will be used in the future as the basis to model turbidity in streams.     

Bridging the gaps for global sustainable development: A quantitative analysis

Global human progress occurs in a complex web of interactions between society, technology and the environment as driven by governance and infrastructure management capacity among nations. In our globalizing world, this complex web of interactions over the last 200 years has resulted in the chronic widening of economic and political gaps between the haves and the have-nots with consequential global cultural and ecosystem challenges. At the bottom of these challenges is the issue of resource limitations on our finite planet with increasing population. The problem is further compounded by pleasure-driven and poverty-driven ecological depletion and pollution by the haves and the have-nots respectively. These challenges are explored in this paper as global sustainable development (SD) quantitatively; in order to assess the gaps that need to be bridged.Although there has been significant rhetoric on SD with very many qualitative definitions offered, very few quantitative definitions of SD exist. The few that do exist tend to measure SD in terms of social, energy, economic and environmental dimensions. In our research, we used several human survival, development, and progress variables to create an aggregate SD parameter that describes the capacity of nations in three dimensions: social sustainability, environmental sustainability and technological sustainability. Using our proposed quantitative definition of SD and data from relatively reputable secondary sources, 132 nations were ranked and compared.Our comparisons indicate a global hierarchy of needs among nations similar to Maslow's at the individual level. As in Maslow's hierarchy of needs, nations that are struggling to survive are less concerned with environmental sustainability than advanced and stable nations. Nations such as the United States, Canada, Finland, Norway and others have higher SD capacity, and thus, are higher on their hierarchy of needs than nations such as Nigeria, Vietnam, Mexico and other developing nations. To bridge such gaps, we suggest that global public policy for local to global governance and infrastructure management may be necessary. Such global public policy requires holistic development strategies in contrast to the very simplistic north–south, developed–developing nations dichotomies.     

Genetic and Demographic Threats to the Black Rhinoceros Population in the Ngorongoro Crater

A resident population of 13 black rhinoceros ( Diceros bicornis ) persist in Ngorongoro Crater, Tanzania. The effective population size ( N _e ) may be as few as 5 animals. Projected growth for this population suggests that the effective population size will remain small for the near future, threatening this Iocal population with extinction due to the stochastic factors associated with small population size. A summary of historic and recent demographic data for this population reveals a population crash during the period of heavy poaching that affected this species throughout its range. Although poaching of this species has been brought under control the population remains small. These data and models of projected population growth argue for consideration of more-intensive management within the framework of the small population paradigm. This case is an example of applied conservation resulting from this paradigm used in conjunction with rather than competing with the declining population paradigm. We identify additional monitoring, particularly of density-dependent behaviors, that will be necessary for designing a successful management program. Finally, the use of molecular markers for developing an accurate pedigree for this population is suggested in order to maintain a genetically healthy population. These strategies have broad applicability to black rhinoceros conservation throughout Africa.     

Quantifying Targets for Rehabilitating Degraded Areas of the Great Lakes

/ One attempt to quantify targets for rehabilitating degraded aquatic ecosystems has been through a United States-Canada program to develop and implement comprehensive remedial action plans (RAPs) to restore beneficial uses in 42 Great Lakes Areas of Concern. The International Joint Commission has facilitated agreement on listing/delisting guidelines for determining when use impairments exist in areas of concern and when uses have been restored, while federal/state/provincial governments and local stakeholders have provided leadership in establishing quantitative targets for restoring uses and in determining how to achieve them. The listing/delisting guidelines have been instrumental in helping reach agreement on problem definition (lack of agreement on problem definition has historically been used as a reason to delay action) and reaching agreement on quantitative targets for restoring uses. Quantitative, ecosystem-based targets are being used to drive the RAP process, help organizations pursue a common mission of restoring uses, and help achieve greater accountability. As a priority, the target-setting process must also recognize the importance of establishing both short- and long-term milestones in order to measure and celebrate incremental progress in restoring uses.KEY WORDS: Use impairments; Restoring uses; Quantitative targets     

Phosphate recovery from greenhouse wastewater

A study was conducted to investigate the suitability of phosphate recovery from greenhouse wastewaters by using precipitation/crystallization process. More than 90% of the phosphate could be removed from the greenhouse wastewater. Various calcium phosphate salts were obtained in the process; hydroxyapatite [Ca5(PO4)3OH] could be the main product from the precipitates. Phosphate removal was affected by the presence of magnesium ion in wastewaters. An increase of magnesium concentrations in wastewaters decreased phosphate removal rates. The chemical contents of precipitates in terms of calcium, magnesium and phosphate were affected by calcium to magnesium molar ratio. Higher calcium contents were obtained at wastewaters with high calcium to magnesium molar ratio. An addition of magnesium did not affect the potassium contents in the precipitates. K-struvite, MgKPO4 x 6H2O, was not the major product in the precipitate, even with addition of a large quantity of magnesium.     

Quantitative assessment of tidal wetlands using remote sensing

Effective management of tidal wetlands requires periodic data on the boundaries, extent, and condition of the wetlands. In many states, wetlands are defined wholly, or in combination with other criteria, by the presence of particular emergent halophytic plants. Many important characteristics of the wetlands ecosystem are related directly to the production of emergent plant material or may be inferred from knowledge of the distribution of emergent plant species. Remote-sensing techniques have been applied to mapping of the distribution of wetland vegetation but not to quantitative evaluation of the condition of that vegetation.Recent research in the tidal wetlands of Delaware and elsewhere has shown that spectral canopy reflectance properties can be quantitatively related to the emergent green biomass ofSpartina alterniflora (salt marsh cord grass) throughout the peak growing season (April through September, in Delaware). Periodic measurements of this parameter could be applied to calculations of net aerial primary productivity for large areas ofS. alterniflora marsh in which conventional harvest techniques may be prohibitively time consuming. The method is species specific and, therefore, requires accurate discrimination ofS. alterniflora from other vegetation types. Observed seasonal changes in species spectral signatures are shown to have potential for improving multispectral categorization of tidal wetland vegetation types.     

Emissions Scenarios Database and Review of Scenarios

This paper reviews and analyzes more than 400 scenarios of global and regional greenhouse gas emissions and their main driving forces - population, economy, energy intensity, and carbon intensity - drawn from an extensive literature survey and summarized in a database. This new and growing database is available online, which makes summary statistics on these scenarios widely available. The scenarios in the database were collected from almost 200 different literature sources and other scenario evaluation activities. The ultimate objective of the database is to include all relevant global and regional emissions scenarios. This paper shows how the database can be utilized for the analysis of greenhouse gas emissions ranges across the scenarios in the literature and for the analysis of their main driving forces. The scenarios in the database display a large range of future greenhouse gas emissions. Part of the range can be attributed to the different methods and models used to formulate the scenarios, which include simple spreadsheet models, macroeconomic models and systems-engineering models. However, most of the range is due to differences in the input assumptions for the scenarios, in particular of the main scenario driving forces. Special emphasis is given to an analysis of medians and ranges of scenario distributions and the distributions of the main scenario driving forces in the database. The analysis shows that the range for projected population increase in the world, across the scenarios in the database, is the smallest of all main driving forces (about a factor of 3 in 2100). The range of economic growth, measured by the gross world product, and the range of primary energy consumption vary by a factor of 10 in 2100. Carbon intensity of energy, an indicator of the degree of technological change, varies by nearly two orders of magnitude in the year 2100. In addition, this paper presents the first attempt to analyze the relationships among the main scenario driving forces. Subsequent papers in this special issue give further analyses of the relationships among the main scenario driving forces and their other relevant characteristics.