Dynamic modeling of chemical fate and transport in multimedia environments at watershed scale-I: theoretical considerations and model implementation

A geo-referenced environmental fate model was developed for analyzing unsteady-state dispersion and distribution of chemicals in multimedia environmental systems. Chemical transport processes were formulated in seven environmental compartments of air, canopy, surface soil, root-zone soil, vadose-zone soil, surface water, and sediment. The model assumed that the compartments were completely mixed and chemical equilibrium was established instantaneously between the sub-compartments within each compartment. A fugacity approach was utilized to formulate the mechanisms of diffusion, advection, physical interfacial transport, and transformation reactions. The governing equations of chemical mass balances in the environmental compartments were solved simultaneously to reflect the interactions between the compartments. A geographic information system (GIS) database and geospatial analysis were integrated into the chemical transport simulation to provide spatially explicit estimations of model parameters at watershed scale. Temporal variations of the environmental properties and source emissions were also considered in the parameter estimations. The outputs of the model included time-dependent chemical concentrations in each compartment and its sub-compartments, and inter-media mass fluxes between adjacent compartments at daily time steps.     

ALAWAT: A spatially allocated watershed model for approximating stream,sediment, and pollutant flows in Hawaii,USA

The Ala Wai Canal Watershed Model (ALAWAT) is a planning-level watershed model for approximating direct runoff, streamflow, sediment loads, and loads for up to five pollutants. ALAWAT uses raster GIS data layers including land use, SCS soil hydrologic groups, annual rainfall, and subwatershed delineations as direct model parameter inputs and can use daily total rainfall from up to ten rain gauges and streamflow from up to ten stream gauges. ALAWAT uses a daily time step and can simulate flows for up to ten-year periods and for up to 50 subwatersheds. Pollutant loads are approximated using a user-defined combination of rating curve relationships, mean event concentrations, and loading/washoff parameters for specific subwatersheds, land uses, and times of year. Using ALAWAT, annual average streamflow and baseflow relationships and urban suspended sediment loads were approximated for the Ala Wai Canal watershed (about 10,400 acres) on the island of Oahu, Hawaii. Annual average urban suspended sediments were approximated using two methods: mean event concentrations and pollutant loading and washoff. Parameters for the pollutant loading and washoff method were then modified to simulate the effect of various street sweeping intervals on sediment loads.     

A hierarchical approach to fisheries planning and modeling in the Columbia River Basin

The Columbia River Basin is the scene of a massive effort to restore populations of Pacific salmon (Oncorhynchus spp.) and steelhead (O. mykiss). Efficient restoration is confounded by a high level of complexity, competing sociopolitical goals and values, and uncertainty about key system properties. Simulation models and other tools of systems analysis are important to development of a comprehensive, regionally acceptable strategy. Hierarchy theory provides a useful paradigm for organized complexity within the Columbia Basin and the basis for a trilevel hierarchical structure for organizing and integrating models. Life-stage models compose the most basic simulation units at the lowest level in the proposed hierarchical modeling structure. Each life-stage model simulates a distinct period in the life cycle of anadromous salmonids. Population models at the intermediate level simulate the complete life cycles of salmon and steelhead populations. At the highest level in the hierarchy, interpopulation models simulate extensive, long-term processes that affect multiple species and stocks. A hierarchical system of models is preferable to a single model or to a group of models lacking formal structure. A principal advantage is that models have the correct spatial and temporal resolution for analyzing questions at different scales. A hierarchical structure also facilitates the flow of information among models, and aids in understanding the impacts of uncertainty. Constructing a hierarchy of models should involve both bottom-up and top-down perspectives that maintain logical consistency among models, while allowing unique model structures appropriate for each level in the hierarchy.     

A screening model for fate and transport of biodegradable polyesters in soil

A numerical model for predicting the fate and transport of biodegradable polyester residues in soil, following successive applications of mulch film, was developed and applied. The polymer, applied on surface soil, was assumed to be converted into by-products (monomers), according to a first order kinetics with constant K(1deg). The monomers released were assumed to sorb on soil organic matter (according to a first-order kinetics with constant K(s)), to be leached with the seepage water, through vertical advection and hydrodynamic dispersion, and biodegraded (according to a first-order kinetics with constant K(b)). Results suggested that, to assess a possible build-up of mulch film (as a polymer) on the surface soil, the degradation constant K(1deg) relating the polymer conversion to by-products should be known, whereas the biodegradation constant K(b) indicates there is no danger of groundwater pollution. Likewise, on the basis of by-product concentration in deep soil, soil pollution should not occur.     

Comparison of models of simazine transport and fate in the subsurface environment in a citrus farm

Contamination of groundwater by agrochemicals is now widely recognized as an extremely important environmental problem. Modern agricultural practices involve the combined use of irrigation with the application of large amounts of agrochemicals to maximize crop yield. Due to flood irrigation and natural runoff, agricultural activities might generate soil, surface water and groundwater contamination problems and leaching of pesticides. Modeling of the transport and fate of pesticides, such as simazine, may help understand the long-term potential risk to the subsurface environment. This paper illustrates a comparative study via the use of three different pesticide transport simulation models and the applicability of those models in determining the groundwater vulnerability to pesticides contamination in a citrus orchard located at the Lower Rio Grande Valley (LRGV). The three models used in the study are the pesticide root zone model-3 (PRZM-3), the pesticide analytical model (PESTAN) and integrated pesticide transport modeling (IPTM). The concentration values obtained from all three models are in agreement, and they show a decreasing trend from the surface through the vadose zone. The problem is how to use this information and, specifically, how to combine the testimony of a number of experts into a single useful judgment. With the aid of the fuzzy multiattribute decision making method, PRZM-3 is deemed as the most promising one for such precision farming applications.     

The Application of the Ecological Footprint: A case of passenger transport in Merseyside

The release of carbon dioxide from the burning of fossil fuels is believed to be responsible for climate change. In the UK, road transport emits 22% of the total output of carbon dioxide. This study applies the ecological footprint to Merseyside to ascertain the global environmental impact of passenger transport (expressed in hectares). Results show that car travel has a footprint of 704 000 hectares, which is 87% of the total footprint. It is demonstrated in scenarios that Policy initiatives involving the Local Transport Plan will cause the footprint to increase. It is also shown that individual behaviour could be influenced when highlighting the impacts of different modes of transport along the same route. By using the ecological footprint in educational programmes, the effect can be shown of carbon emissions and land appropriation on the 'school run'; these issues could be promoted alongside others such as health, safety, congestion, global equity and fairness.     

Metal and oxalate contamination in a suburban watershed in the greater Toronto area: the benefits of combining acid leach and selective extraction procedures

Environmentally available concentrations of Fe, Mn, Zn, Cu, Pb, Cr and Ni in soils and sediments from a small suburban catchment, obtained using an acid leach procedure, are compared to the Ontario Ministry of the Environment lowest effect level (LEL) and severe effect levels (SEL) and to Provincial sediment quality guidelines (PSQG's). These data are then compared to the bioavailability, potential bioavailability and non-bioavailability of the same metals, plus oxalate concentration, identified using a selective extraction procedure. This combination of techniques enhanced analytical interpretation with respect to metal mobility and potential metal contamination. Selective extraction highlighted the presence of oxalate as a potential contaminant, especially in poorly drained valley floor deposits (33,633 mg kg(-1) and 26,284 mg kg(-1)) and lakeshore sediments (27,095 mg kg(-1) and 13,729 mg kg(-1)). These levels are considerably in excess of those previously documented in a similar study from Rio de Janeiro, where contamination of urban sediment by sewage is a recognised environmental problem, and could possibly be used both as an indicator of similar contamination and the identification of those areas that warrant further investigation.     

德昌旱地粮菜四熟种植模式的效益和能量分析

德昌县旱地粮菜四熟模式是一年生产一季玉米和三季蔬菜。该模式可充分利用安宁河中下游丰富的温光资源,一年内亩产粮食627.5kg,蔬菜总计11935kg,经济收入2430.4元。其光能利用率达3.864%,能量产投比2.15,是适合城郊区旱地种植的一种较好模式。进一步增施磷钾肥是本模式获得更多农产品、提高资源利用率、维持和培肥土壤的重要措施。     

Social, economic, and ecological impacts of the "Grain for Green" project in China: a preliminary case in Zhangye, Northwest China

This paper provides applications of the integrated assessment (IA) approach in a case study in the Heihe River Basin of Northwest China. Some socio-economic and ecological impact results of forestry land use scenarios are presented in the paper. While seven types of land use scenarios for carbon sequestration purposes were considered for the IA applications, this paper mainly presents impacts of land use scenarios within the Grain for Green (GFG) category [see Yin et al., this volume]. China's national Grain for Green Project was implemented in order to protect and improve ecosystems, while allowing an evolution of agricultural management practices compatible with raising peasants' incomes. Zhangye Prefecture, located in the Heihe River Basin of an arid area in Northwest China, was chosen as the investigation site of the IA case study. Based on fundamental orientation theory, the social sustainability impacts of GFG land use options were assessed. Between 2002 and 2004, the GFG project brought US$23.56 million yuan in net income to the prefecture's peasants. Project implementation resulted in a 1.71 Gg increase in net primary productivity (NPP), as well as a 44.36 Gg rise in net ecosystem productivity (NEP). This suggested that, in Zhangye Prefecture, the Grain for Green Project could enhance the sustainability and stability of the local society, increase peasants' net income, as well as protect and remediate local ecosystems.     

A methodology of characterizing status and trend of land changes in oases: a case study of Sangong River watershed, Xinjiang, China

Land change is often studied with Markov models to develop a probability transition matrix. The existing methods dependent on such matrixes cannot effectively characterize some important aspects associated with land change such as status, direction, trend and regional variations. This study presents mathematical models to quantify these elements, defining unbalanced, quasi-balanced and balanced status, one- and two-way transitions and the rising or falling trends. Using these models and remote-sensing imageries, the landscape was studied for a case area, the oasis of Sangong River in Xinjiang, Northwest China where typical arid conditions prevail. Land expansion and contraction among various land types and for the entire oasis were analyzed for the periods of 1978-1987, 1978-1998 and 1987-1998. The changes were closely related to a strong economic growth after the land-reform campaign and adoption of the market economy in China in the 1980s to early 1990s, a process not strictly Markovian that requires stationarity and randomness. Information on land-change status and trend is important for a better understanding of the underlying driving processes but also for land-use planning and decision-making.     

黄山市新安江流域水环境质量评价与管理措施

新安江是我国江南跨省级行政区的一条重要河流，其水质和水量对下游浙江省的生态安全和资源支持具有重要作用。针对安徽省黄山市境内新安江流域内存在的主要水环境问题，采用尼梅罗水质指数和超标加权法对新安江流域水环境质量进行了评价和分析。结果表明，新安江流域水环境质量整体较好，达到Ⅱ、Ⅲ类标准，大部分河段均能满足地表水环境功能要求；下游河段水质略差，但符合地表水Ⅲ类标准。在此基础上，提出了新安江流域水环境管理措施。     

Nutrient Sources and Transport in the Missouri River Basin,with Emphasis on the Effects of Irrigation and Reservoirs1

Brown, Juliane B., Lori A. Sprague, and Jean A. Dupree, 2011. Nutrient Sources and Transport in the Missouri River Basin, With Emphasis on the Effects of Irrigation and Reservoirs. Journal of the American Water Resources Association (JAWRA) 47(5):1034‐1060. DOI: 10.1111/j.1752‐1688.2011.00584.x Abstract: SPAtially Referenced Regressions On Watershed attributes (SPARROW) models were used to relate instream nutrient loads to sources and factors influencing the transport of nutrients in the Missouri River Basin. Agricultural inputs from fertilizer and manure were the largest nutrient sources throughout a large part of the basin, although atmospheric and urban inputs were important sources in some areas. Sediment mobilized from stream channels was a source of phosphorus in medium and larger streams. Irrigation on agricultural land was estimated to decrease the nitrogen load reaching the Mississippi River by as much as 17%, likely as a result of increased anoxia and denitrification in the soil zone. Approximately 16% of the nitrogen load and 33% of the phosphorus load that would have otherwise reached the Mississippi River was retained in reservoirs and lakes throughout the basin. Nearly half of the total attenuation occurred in the eight largest water bodies. Unlike the other major tributary basins, nearly the entire instream nutrient load leaving the outlet of the Platte and Kansas River subbasins reached the Mississippi River. Most of the larger reservoirs and lakes in the Platte River subbasin are upstream of the major sources, whereas in the Kansas River subbasin, most of the source inputs are in the southeast part of the subbasin where characteristics of the area and proximity to the Missouri River facilitate delivery of nutrients to the Mississippi River.     

Impact of Changing Climate and Land Cover on Flood Magnitudes in the Delaware River Basin,USA

Changing climate and land cover are expected to impact flood hydrology in the Delaware River Basin over the 21st Century. HEC‐HMS models (U.S. Army Corps of Engineers Hydrologic Engineering Center‐Hydrologic Modeling System) were developed for five case study watersheds selected to represent a range of scale, soil types, climate, and land cover. Model results indicate that climate change alone could affect peak flood discharges by ?6% to +58% a wide range that reflects regional variation in projected rainfall and snowmelt and local watershed conditions. Land cover changes could increase peak flood discharges up to 10% in four of the five watersheds. In those watersheds, the combination of climate and land cover change increase modeled peak flood discharges by up to 66% and runoff volumes by up to 44%. Precipitation projections are a key source of uncertainty, but there is a high likelihood of greater precipitation falling on a more urbanized landscape that produces larger floods. The influence of climate and land cover changes on flood hydrology for the modeled watersheds varies according to future time period, climate scenario, watershed land cover and soil conditions, and flood frequency. The impacts of climate change alone are typically greater than land cover change but there is substantial geographic variation, with urbanization the greater influence on some small, developing watersheds.     

Integrating forage,wildlife, water,and fish projections with timber projections at the regional level: A case study in southern United States

The impact of timber management and land-use change on forage production, turkey and deer abundance, red-cockaded woodpecker colonies, water yield, and trout abundance was projected as part of a policy study focusing on the southern United States. The multiresource modeling framework used in this study linked extant timber management and land-area policy models with newly developed models for forage, wildlife, fish, and water. Resource production was integrated through a commonly defined land base that could be geographically partitioned according to individual resource needs. Resources were responsive to changes in land use, particularly human-related, and timber management, particularly the harvest of older stands, and the conversion to planted pine.     

People,environment and place: the function and significance of human hybrid relationships at an allotment in South East England

Allotments are a valued part of the British cultural landscape, with benefits often associated with exercise and fresh food. However, there are other significant but less tangible values that are often implicit in green-space research, but which require further substantiation. This article sheds light on the role of allotments as places where people engage in meaningful relationships with the natural world. Drawing on in-depth qualitative data, we develop a co-constructionist understanding of the human–nature relationships which exist between plot-holders and the non-human agents they encounter. These non-human elements are implicated in formulating important social values, such as identity, knowledge and community. Furthermore, they are seen to help collapse the natural-social dualism, which is often cited as a root cause of unsustainability, and enrich the lives of plot-holders in diverse and significant ways. Advocacy for their inclusion in urban communities is discussed in relation to the development of socially and environmentally sustainable cities.     

Energy consumption and carbon emission for tourism transport in World Heritage Sites: a case of the Wulingyuan area in China

Transport profoundly affects energy use and carbon dioxide emissions in the tourism sector. The Wulingyuan Scenic Area (WSA), a natural heritage destination in China, is chosen for the case study. The energy consumption and carbon emission of 10 types of tourism transportation modes at the destination are measured and analyzed using a bottom‐up approach for the period of 1979 to 2010. Scenarios were created to project the effects of single and multiple factors on energy consumption and carbon emission by tourism transportation during 2011‐2020. The results showed the following: (a) there is a large difference in energy consumption and carbon emission per capita and per kilometer per capita among the 10 vehicle modes; (b) the monthly energy consumption and carbon emission of tourism transportation differed significantly, the month with the highest (October) are respectively 6.8 and 4 times that of the lowest month (January); (c) the highest annual growth rate of energy consumption and carbon emission are respectively as 32.16% and 27.98% during 1979‐2010; and (d) the amount of energy consumption and carbon emission in the multiple factor scenarios are lower than that in the reference and single factor scenarios during 2011‐2020.     

Roles of environmental movement organisations in land-use planning: case studies of the Niagara Escarpment and Oak Ridges Moraine,Ontario, Canada

The paper explores the roles of environmental movement organisations (EMOs) in land-use planning, including domain creation (establishment of new or modified landscape planning boundaries) and regime change (adoption of new or modified legal and planning rules). The research involved two case studies of land-use planning processes: the Niagara Escarpment and Oak Ridges Moraine, Ontario, Canada. The two cases together reveal an evolution of land-use planning towards collaborative processes on mainly private lands in Southern Ontario during the period from 1960 to 2002. The results suggest that EMOs can create new planning domains through agenda setting activities, build landscape value and vision, educate governments and the public, and work to maintain and alter regimes. Collaborative planning has emerged as an important process in which some EMOs are now participating.     

The comparison of a revised Leopold matrix and fuzzy methods in environmental impact assessment,a case study: The construction of Al‐A'amiriya residential complex,Baghdad, Iraq

Environmental impact assessment (EIA) is an efficient method to recognize and alleviate the unfavorable and inevitable impacts of human activity on the environment. The EIA is dependent on expert opinions, which can be influenced by personal experience and knowledge. To evaluate this influence, we carried out EIA of 6,000 residential apartment units of Al‐A'amiriya, Baghdad, Iraq, using a revised Leopold matrix and fuzzy methods. The matrix results reflected the direct opinions of experts. The fuzzy method was developed according to the principles of expert comments. In the matrix method, the environmental impacts of each activity were evaluated by scores between −5 (very bad) to 5 (very good). The inputs to the fuzzy method were intensity and weather stability. The fuzzy estimation of the environmental impact was composed of a group of three values; P1 as the intensity, P2 as the extent, and P3 as the persistence. We gathered the expert opinions and used the Analytical Hierarchical Process to determine the weighting coefficient of each fuzzy anticipation. The matrix method was dependent on the expert opinions. The mean values of the matrix and P‐values in each column and row scores depict the impacts of a project on the environmental aspects and each element of construction on the environment. The comparison of the results indicated an average difference of 30% between the Leopold matrix and fuzzy methods. In regard to the availability and sufficiency of data, the difference was around 10%.     

Drivers of social equity in renewable energy at the municipal level: the case of local Japanese energy policy and preferences

ABSTRACT

Recent research has allowed us to quantify the costs and benefits of adopting renewable energy in specific municipalities, but how do these outcomes vary among communities at the national scale? This study uses survey responses from 47 Japanese municipalities to model these impacts and identifies key technological, social, and demographic factors that shape which communities benefit more from the renewable energy transition. On average, introducing renewable energy improves social equity, any financial burden on electricity prices is born most by wealthier residents, not the poor, and towns are predisposed to benefit from renewables no matter the amount introduced. To improve these impacts, towns can increase the amount of solar they host, or they can adjust the amount of CO2 emissions, PM emissions, tax revenue, jobs gained, or unpopular renewable power plants in their town. However, preferences and demographics matter as well. Age, education, and local preferences in favor of employment and community development all significantly relate to equity potential outcomes. Policymakers should consider adjusting their local energy priorities using these levers if they hope to engineer a renewable energy transition that is both positive and popular for their constituents.