Development and Comparison of Multiple Regression Models to Predict Bankfull Channel Dimensions for Use in Hydrologic Models

Channel dimensions are important input variables for many hydrologic models. As measurements of channel geometry are not available in most watersheds, they are often predicted using bankfull hydraulic geometry relationships. This study aims at improving existing equations that relate bankfull width, depth, and cross‐sectional area to drainage area (DA) without limiting their use to well‐gauged watersheds. We included seven additional variables in the equations that can be derived from data that are generally required by hydrologic models anyway and conducted several multiple regression analyses to identify the ideal combination of additional variables for nationwide and regional models for each Physiographic Division of the United States (U.S.). Results indicate that including the additional variables in the regression equations generally improves predictions considerably. The selection of relevant variables varies by Physiographic Division, but average annual precipitation (PCP) and temperature (TMP) were generally found to improve the models the most. Therefore, we recommend using regression equations with three independent variables (DA, PCP, and TMP) to predict bankfull channel dimensions for hydrologic models. Furthermore, we recommend using the regional equations for watersheds within regions from which data were used for model development, whereas in all other parts of the U.S. and the rest of the world, the nationwide equations should be given preference.     

Hydrologic Model Framework for Water Resources Planning in the Santa Cruz River,Southern Arizona1

Abstract: The authors develop a model framework that includes a set of hydrologic modules as a water resources management and planning tool for the upper Santa Cruz River near the Mexican border, Southern Arizona. The modules consist of: (1) stochastic generation of hourly precipitation scenarios that maintain the characteristics and variability of a 45‐year hourly precipitation record from a nearby rain gauge; (2) conceptual transformation of generated precipitation into daily streamflow using varied infiltration rates and estimates of the basin antecedent moisture conditions; and (3) surface‐water to ground‐water interaction for four downstream microbasins that accounts for alluvial ground‐water recharge, and ET and pumping losses. To maintain the large inter‐annual variability of streamflow as prevails in Southern Arizona, the model framework is constructed to produce three types of seasonal winter and summer categories of streamflow (i.e., wet, medium, or dry). Long‐term (i.e., 100 years) realizations (ensembles) are generated by the above described model framework that reflects two different regimes of inter annual variability. The first regime is that of the historic streamflow gauge record. The second regime is that of the tree ring reconstructed precipitation, which was derived for the study location. Generated flow ensembles for these two regimes are used to evaluate the risk that the regional four ground‐water microbasins decline below a preset storage threshold under different operational water utilization scenarios.     

城郊地区土地利用总体规划的结构设计

本文运用系统工程中的分解与协调原理，借助成都市龙泉驿区土地利用总体规划，对城郊土地利用总体规划进行结构设计，较好地达到了城郊地区土地利用总体规划的定量、定位与定时的统一，宏观控制与微观操作的统一．     

A Decision Support Framework for Environmental Planning in Developing Countries

This paper presents a decision support framework for environmental planning in developing countries. The interest in protecting the natural environment from pollution gained increased importance in the 1990s with a push by world communities for sustainable development. Developing countries as well as the industrialized nations are expected to cut down on pollution and control the use of non-renewable natural resources. Although the concept of sustainable development sounds plausible, it is difficult to implement in many countries due to their conflicting goals. The world-wide targets on emissions, use of fossil fuels, reduction in water and atmospheric pollution require the participation of every nation. These goals are not easily achievable by some of the poorer developing countries partly because of their economic dependence on natural resources and partly because of their inability to afford more modern and efficient technologies. Thus, environmental planning goals are often in conflict with the development,social and economic needs of a country. In this paper, we develop a decision support framework that utilizes multicriteria and optimization models to address environmental planning problems. This framework is based on identifying the priorities of conflicting goals by working through and reducing the conflicts. A strategic planning framework is introduced into the decision support system since national planning is a strategic issue and these goals can only be achieved by adopting a systemic view.     

A Hydrologic Data Screening Procedure for Exploring Monotonic Trends and Shifts in Rainfall and Runoff Patterns

A thorough understanding of past and present hydrologic responses to changes in precipitation patterns is crucial for predicting future conditions. The main objectives of this study were to determine temporal changes in rainfall‐runoff relationship and to identify significant trends and abrupt shifts in rainfall and runoff time series. Ninety‐year rainfall and runoff time series datasets from the Gasconade and Meramec watersheds in east‐central Missouri were used to develop data screening procedure to assess changes in the rainfall and runoff temporal patterns. A statistically significant change in mean and variance was detected in 1980 in the rainfall and runoff time series within both watersheds. In addition, both the rainfall and runoff time series indicated the presence of nonstationary attributes such as statistically significant monotonic trends and/or change in mean and variance, which should be taken into consideration when using the time series to predict future scenarios. The annual peak runoff and the annual low flow in the Meramec watershed showed significant temporal changes compared to that in the Gasconade watershed. Water loss in both watersheds was found to be significantly increasing which is potentially due to the increase in groundwater pumping for water supply purposes.     

Urbanization and the Environment in Southern Africa: Towards a Managed Framework for the Sustainability of Cities

In sub-Saharan Africa, Southern Africa is the most urbanized region. This dynamic is rapidly transforming the nature of Southern African human settlements which, in turn, has a chain reaction of consequences from negative environmental impact to the need to develop policy for the sustainability of the region's cities. This paper examines the relationship between urbanization trends and environmental change in Southern Africa, and then advocates and discusses priority areas of a managed policy framework for a more constructive approach to responding to the challenge of the sustainability of cities in the region. The paper concentrates on those countries that are members of the Southern African Development Community (SADC).     

A Decision-Aid Framework to Provide Guidance for the Enhanced Use of Best Available Techniques in Industry

Best Available Techniques (BATs) contribute significantly to the reduction of industrial environmental burdens with respect to air pollution, wastewater, and solid wastes. In Europe, the application of BATs is prescribed by Directive 96/61/EC, which, however, leaves the selection of specific BATs to plant operators. In making their choices, installations have to consider not only the environmental benefits of BATs, but also all relevant cost components. In assessing the economic attractiveness of potential BATs and their combinations, as well as incentives and disincentives to be instituted, the cost of environmental externalities, usually not reflected in market prices, should be taken into account. In this paper, a decision-aid framework combining an assessment of environmental externalities and the utilization of multicriteria methods and, more specifically, Multiobjective Mathematical Programming, capable of addressing all these issues in a comprehensive and coherent manner, is presented. This is illustrated by its application for the region of Attica in Greece, where over 50% of the industrial basis and Athens, with its 4 million inhabitants, are located. The implementation of the framework and its associated tools to 800 installations led to the identification of the specific BATs, alone or in combination, that provide the most cost-effective reductions of four air pollutants (PM10, SO₂, NO_x, VOC) and CO₂. The results also clearly demonstrate the increased pollution reductions that would result from the adoption of BATs made economically attractive by the inclusion of externalities. Estimates of investments and net present values with and without incentives/disincentives are also provided.     

Operational Atmospheric Modeling System CARIS for Effective Emergency Response Associated with Hazardous Chemical Releases in Korea

The Chemical Accidents Response Information System (CARIS) was developed at the Center for Chemical Safety Management in South Korea in order to track and predict the dispersion of hazardous chemicals in the case of an accident or terrorist attack involving chemical companies. The main objective of CARIS is to facilitate an efficient emergency response to hazardous chemical accidents by rapidly providing key information in the decision-making process. In particular, the atmospheric modeling system implemented in CARIS, which is composed of a real-time numerical weather forecasting model and an air pollution dispersion model, can be used as a tool to forecast concentrations and to provide a wide range of assessments associated with various hazardous chemicals in real time.This article introduces the components of CARIS and describes its operational modeling system. Some examples of the operational modeling system and its use for emergency preparedness are presented and discussed. Finally, this article evaluates the current numerical weather prediction model for Korea.Published online     

Toward a Conceptual Framework for Blending Social and Biophysical Attributes in Conservation Planning: A Case-Study of Privately-Conserved Lands

There has been increasing recognition within systematic conservation planning of the need to include social data alongside biophysical assessments. However, in the approaches to identify potential conservation sites, there remains much room for improvement in the treatment of social data. In particular, few rigorous methods to account for the diversity of less-easily quantifiable social attributes that influence the implementation success of conservation sites (such as willingness to conserve) have been developed. We use a case-study analysis of private conservation areas within the Little Karoo, South Africa, as a practical example of the importance of incorporating social data into the process of selecting potential conservation sites to improve their implementation likelihood. We draw on extensive data on the social attributes of our case study obtained from a combination of survey questionnaires and semi-structured interviews. We discuss the need to determine the social attributes that are important for achieving the chosen implementation strategy by offering four tested examples of important social attributes in the Little Karoo: the willingness of landowners to take part in a stewardship arrangement, their willingness to conserve, their capacity to conserve, and the social capital among private conservation area owners. We then discuss the process of using an implementation likelihood ratio (derived from a combined measure of the social attributes) to assist the choice of potential conservation sites. We conclude by summarizing our discussion into a simple conceptual framework for identifying biophysically-valuable sites which possess a high likelihood that the desired implementation strategy will be realized on them.     

The Comparative Accuracy of Two Hydrologic Models in Simulating Warm‐Season Runoff for Two Small,Hillslope Catchments

This article assesses the performance of two hydrologic models in simulating warm‐season runoff for two upland, low‐yield micro‐catchments near Coshocton, Ohio. The two models, namely the Storm Water Management Model (SWMM) and the Gridded Surface‐Subsurface Hydrologic Analysis (GSSHA), were implemented with contrasting levels of complexity, with the former representing the catchments as lumped spatial units and computing evaporation only from standing water, and the latter incorporating fine‐scale variation in topography and soil properties and computing evapotranspiration from soil based on weather data. Our investigation began with uncalibrated model runs for 1990‐2003 except for 1994 using a priori parameter values. Then a set of calibration experiments were performed wherein the sensitivity of model performance to the length of calibration records was examined. Our results pointed to large errors associated with simulations from both models: even the calibrated models were unable to reproduce the seasonal and between‐catchment contrasts in runoff response. Using a priori parameter values, SWMM attained better results than GSSHA. However, with simple calibration, GSSHA outperformed SWMM in several respects. It was also found that extending the record of calibration rendered relatively minor changes to model performance. The practical and scientific implications of the findings are discussed.     

The Value of Validated Vulnerability Data for Conservation Planning in Rapidly Changing Landscapes

Data needed for informed conservation prioritization are generally greater than the data available, and surrogates are often used. Although the need to anticipate threats is recognized, the effectiveness of surrogates for predicting habitat loss (or vulnerability) to land-use change is seldom tested. Here, we compared properties of two different vulnerability surrogates to validated vulnerability—validated prediction of habitat conversion based on a recent assessment of land-use change. We found that neither surrogate was a particularly effective predictor of vulnerability. Importantly, both surrogates performed poorly in places most imminently threatened with habitat conversion. We also show that the majority of areas protected over the last two decades have low vulnerability to the most active threatening process in this biome (habitat conversion). The contrary patterns of vulnerability and protection suggest that use of validated vulnerability would help to clarify protection needs, which might lead to the improvement of conservation decisions. Our study suggests the integration of validated vulnerability into conservation planning tools may be an important requirement for effective conservation planning in rapidly changing landscapes. We apply our results to discuss the practical considerations and potential value of incorporating validated vulnerability into conservation planning tools both generally and in the context of New Zealand’s indigenous grasslands.     

Revealing the Diversity of Natural Hydrologic Regimes in California with Relevance for Environmental Flows Applications

Alterations to flow regimes for water management objectives have degraded river ecosystems worldwide. These alterations are particularly profound in Mediterranean climate regions such as California with strong climatic variability and riverine species highly adapted to the resulting flooding and drought disturbances. However, defining environmental flow targets for Mediterranean rivers is complicated by extreme hydrologic variability and often intensive water management legacies. Improved understanding of the diversity of natural streamflow patterns and their spatial arrangement across Mediterranean regions is needed to support the future development of effective flow targets at appropriate scales for management applications with minimal resource and data requirements. Our study addresses this need through the development of a spatially explicit reach‐scale hydrologic classification for California. Dominant hydrologic regimes and their physio‐climatic controls are revealed, using available unimpaired and naturalized streamflow time‐series and generally publicly available geospatial datasets. This methodology identifies eight natural flow classes representing distinct flow sources, hydrologic characteristics, and catchment controls over rainfall‐runoff response. The study provides a broad‐scale hydrologic framework upon which flow‐ecology relationships could subsequently be established towards reach‐scale environmental flows applications in a complex, highly altered Mediterranean region.     

A Conceptual Framework for Analysis of Water Resources Management in Asia

Effective and efficient water resources management to meet the increasing demands for food, energy, and domestic and industrial water is an imperative for Asian countries. As a basis for analyzing Asian water resources management problems, a three-element conceptual framework is presented: (1) water resources management as a system, composed of a set of facilities, operating rules, and incentives applied to water resources through an institutional arrangement; (2) water resources management as a process involving several stages beginning with planning and continuing with design, construction, operation and maintenance; and (3) water resources management as a set of linked activities and tasks required to produce the desired outputs. Using this framework to assess performance it is possible to analyze the linkages among water resources problems, water resources management, and water resources organizations and administrative arrangements. Examples are presented of such linkages as applied to problems of erosion and sedimentation, flooding, salinity, water demand-supply imbalances, and water pollution. Brief analytical summaries of eight critical water resources management problems in Asia are presented, along with an illustration of the complexity of water resources organization and administration, using Thailand as the example.     

A Framework for Developing Management Goals for Species at Risk with Examples from Military Installations in the United States

A decision framework for setting management goals for species at risk is presented. Species at risk are those whose potential future rarity is of concern. Listing these species as threatened or endangered could potentially result in significant restrictions to activities in resource management areas in order to maintain those species. The decision framework, designed to foster proactive management, has nine steps: identify species at risk on and near the management area, describe available information and potential information gaps for each species, determine the potential distribution of species and their habitat, select metrics for describing species status, assess the status of local population or metapopulation, conduct threat assessment, set and prioritize management goals, develop species management plans, and develop criteria for ending special species management where possible. This framework will aid resource managers in setting management goals that minimally impact human activities while reducing the likelihood that species at risk will become rare in the near future. The management areas in many of the examples are United States (US) military installations, which are concerned about potential restrictions to military training capacity if species at risk become regulated under the US Endangered Species Act. The benefits of the proactive management set forth in this formal decision framework are that it is impartial, provides a clear procedure, calls for identification of causal relationships that may not be obvious, provides a way to target the most urgent needs, reduces costs, enhances public confidence, and, most importantly, decreases the chance of species becoming more rare.     

A Framework for Landscape Ecological Design of New Patches in the Rural Landscape

This study developed a comprehensive framework to incorporate landscape ecological principles into the landscape planning and design process, with a focus on the design of new patches in the rural landscape. The framework includes two interrelated phases: patch analyst (PA) and patch designer (PD). The patch analyst augments the process of landscape inventory and analysis. It distinguishes nodes (associated with potential habitat patches) from links (associated with corridors and stepping stones between habitats). For natural vegetation patches, characteristics such as size, shape, and spatial arrangement have been used to develop analytical tools that distinguish between nodes and links. The patch designer uses quantitative information and analytical tools to recommend locations, shapes, sizes, and composition of introduced patches. The framework has been applied to the development of a new golf course in the rural Mediterranean landscape of Apulia, Southern Italy. Fifty new patches of Mediterranean maquis (24 patches) and garrigue (26 patches) have been designed and located in the golf course, raising the overall natural vegetation area to 70 ha (60% of total property). The framework has potential for use in a wide variety of landscape planning, design, and management projects.     

A Method for Comparative Analysis of Recovery Potential in Impaired Waters Restoration Planning

Common decision support tools and a growing body of knowledge about ecological recovery can help inform and guide large state and federal restoration programs affecting thousands of impaired waters. Under the federal Clean Water Act (CWA), waters not meeting state Water Quality Standards due to impairment by pollutants are placed on the CWA Section 303(d) list, scheduled for Total Maximum Daily Load (TMDL) development, and ultimately restored. Tens of thousands of 303(d)-listed waters, many with completed TMDLs, represent a restoration workload of many years. State TMDL scheduling and implementation decisions influence the choice of waters and the sequence of restoration. Strategies that compare these waters’ recovery potential could optimize the gain of ecological resources by restoring promising sites earlier. We explored ways for states to use recovery potential in restoration priority setting with landscape analysis methods, geographic data, and impaired waters monitoring data. From the literature and practice we identified measurable, recovery-relevant ecological, stressor, and social context metrics and developed a restorability screening approach adaptable to widely different environments and program goals. In this paper we describe the indicators, the methodology, and three statewide, recovery-based targeting and prioritization projects. We also call for refining the scientific basis for estimating recovery potential.