Visualising public transport accessibility to inform urban planning policy in Hubli-Dharwad,India

Rapid urbanisation in India is a key contributor to the overstressed public infrastructure. The urban public transport system is one of the important infrastructure systems. An effective public transportation network helps the city improve its accessibility, lower carbon footprint, and enhances economic growth and societal equity. India is a relatively poor country with limited public resources. Therefore, investing in an effective urban public transport system needs a tailored approach. Such an approach would entail using public transport to guide urban development. In this context, the first step would be to measure the accessibility levels of the existing public transport network and then use the accessibility mapping outputs to better inform the urban planning process. This study explores the Public Transport Accessibility Level (PTAL) tool that measures the accessibility of the public transport system and provides a spatial visualisation using Geographic Information System. PTAL is implemented taking Hubli-Dharwad as a case study for the base year (2020) superimposed with population and employment density, and future year (2031). The outcome of the research facilitates the city planning process by guiding transportation and land-use zoning integrations, direct public transport investments, demarcation of transit-oriented development zones, parking policies, and identifying locations of affordable and low-cost housing.

     

A conceptual model to integrate the regional context in landscape policy,management and contribution to rural development: Literature review and European case study evidence

Agri-environmental policies and planning influence agricultural landscape management, and thus the capacity to deliver landscape services and to contribute to rural viability. Numerous models and frameworks have been developed to improve comprehension of the mechanisms and interrelationships between policies, landscape and socio-economic values and benefits. As social-ecological systems, landscapes are closely depending from the socio-institutional and territorial context of the specific rural locality. The paper proposes an enhanced framework for assessing these mechanisms by acknowledging the critical role of the regional macro-environment. A literature review and the revisiting of evidence from eight European case studies are applied to establish a comprehensive understanding and exemplification of the links between the policies, landscape, ecosystem services and value flows. Results highlight the need for integrative, inter- and transdisciplinary research approaches. Efficient landscape policies require enhanced regional embeddedness and targeting, acknowledgement of user demands and the capability of regional community and governance structures for policy implementation and natural capital valorisation.     

Severe weather affecting European transport systems: the identification,classification and frequencies of events

Severe weather can have serious repercussions in the transport sector as a whole by increasing the number of accidents, injuries and other damage, as well as leading to highly increased travel times. This study, a component of the EU FP7 Project EWENT, delineates a Europe-wide climatology of adverse and extreme weather events that can be expected to affect the transport network. We first define and classify the relevant severe weather events by investigating the effects of hazardous conditions on different transportation modes and the infrastructure. Consideration is given to individual phenomena such as snowfall, heavy precipitation, heat waves, cold spells, wind gusts; a combined phenomenon, the blizzard, is also considered. The frequency of severe weather events, together with the changes in their spatial extension and intensity, is analyzed based on the E-OBS dataset (1971–2000) and the ERA-Interim reanalysis dataset (1989–2010). Northern Europe and the Alpine region are the areas most impacted by winter extremes, such as snowfall, cold spells and winter storms, the frequency of heavy snowfall. The frequency of hot days is highest in Southern Europe. Severe winds and blizzards are the most common over the Atlantic and along its shores. Although heavy rainfall may affect the whole continent on an annual basis, extreme precipitation events are relative sparse, affecting particularly the Alps and the Atlantic coastline. A European regionalization covering similar impacts on the transport network is performed.     

Foreign Joint Ventures in the People's Republic of China, 1979 to 1985

The motivation of alluring foreign investment is an important landmark of post Mao's economic policies, and has made a great contribution to China's current economic growth. One of the major types of foreign investments in the People's Republic of China has been Foreign Joint Ventures (FJVs). Analysis of FJVs helps us understand the impacts of China's economic reforms. This paper thoroughly scrutinizes the statistics of Foreign Joint Ventures during the period of 1979 to 1985. It concludes that the spatial distribution of foreign joint venture investment indicates three locational considerations: (i) the locational advantages of the eastern coastal region where over 90% of joint venture investment has occurred; (ii) the presence of a well-established industrial and commercial infrastructure, as China's largest industrial and commercial centers have also been the largest receivers of foreign investment; and (iii) historical Sino-foreign economic and cultural relations before 1949, as post 1979 foreign investments have often been concentrated in the foreign countries' former spheres of influence. It has also been found that differences exist in the type and location of investment among the major Western investors.     

Variations in water clarity and chlorophylla in Tampa Bay, Florida, in response to annual rainfall, 1985–2004

In the Tampa Bay region of Florida, extreme levels of annual and seasonal rainfall are often associated with tropical cyclones and strong El Niño episodes. We used stepwise multiple regression models to describe associations between annual and seasonal rainfall levels and annual, bay-segment mean water clarity (as Secchi depth [m]), chlorophylla (μg I^?1), color (pcu), and turbidity (ntu) over a 20-yr period (1985–2004) during which estimated nutrient loadings have been dominated by non-point sources. For most bay segments, variations in annual mean water clarity were associated with variations in chlorophylla concentrations, which were associated in turn with annual or seasonal rainfall. In two bay segments these associations with annual rainfall were superimposed on significant long-term declining trends in chlorophylla. Color was significantly associated with annual rainfall in all bay segments, and in one segment variations in color were the best predictors of variations in water clarity. Turbidity showed a declining trend over time in all bay segments and no association with annual rainfall, and was significantly associated with variations in water clarity in only one bay segment. While chlorophylla, color, and turbidity a affected water clarity to varying degrees, the effects of extreme rainfall events (El Niño events in 1998 and 2003, and multiple tropical cyclone events in 2004) on water clarity were relatively short-lived, persisting for periods of months rather than years. During the 20-yr period addressed in these analyses, declining temporal trends in chlorophylla and turbidity, produced in part by a long-term watershed management program that has focused on curtailing annual loadings of nitrogen and other pollutants, may have helped to prevent the bay as a whole from responding more adversely to the high rainfall periods that occurred in 1998 and 2003–2004.     

Soil erosion, policy and people's perceptions in a rural community in KwaZulu-Natal, South Africa

In South Africa the science and practice of soil conservation have been dominated by a technical approach which does not take into account the perceptions, knowledge and needs of people living in rural areas. Attempts to incorporate land users into soil conservation programmes have not had much influence on conservation policies. In order to compare the scientifically-based physical appraisals of an area with the community's perceptions of soil erosion on their land, a project was established in a rural area of KwaZulu/Natal. This paper briefly reviews soil conservation policy in former homeland areas. It then considers the historical development of the community of Cornfields and their responses to changing government policies. The research indicates that rural dwellers have valuable knowledge concerning soil conservation, but that the neglest of such communities by agricultural and conservation authorities has led to the unsustainable use of the land. The area is severely eroded and soils in the area are amongst the most highly erodible in the province. Therefore levels of degradation would be high even without dense human occupation. This evidence is clearly important in future conservation planning and recommendations are made regarding a policy for the management of soil resources in rural areas.     

Distribution,behavior, and transport of inorganic and methylmercury in a high gradient stream

Concentrations of Hg remain elevated in physical and biological media of the South River (Virginia, USA), despite the cessation of the industrial use of Hg in its watershed nearly six decades ago, and physical characteristics that would not seem to favor Hg(II)-methylation. A 3-a study of inorganic Hg (IHg) and methylmercury (MeHg) was conducted in physical media (soil, sediment, surface water, porewater and soil/sediment extracts) to identify non-point sources, transport mechanisms, and potential controls on Hg(II)-methylation. Data collected from surface water and sediment indicate that the majority of the non-point sources of IHg to the South River are within the first 14 km downstream from the historic point source. Partitioning data indicate that particle bound IHg is introduced in this reach, releasing dissolved and colloidal bound IHg, which is transported downstream. Extraction experiments revealed that floodplain soils released a higher fraction of their IHg content in aqueous extractions than fine-grained sediment (FGS). Based on ultrafiltration [<5000 nominal molecular weight cutoff (NMWC)] the majority of soil IHg released was colloidal in nature, providing evidence for the continued evolution of IHg for Hg(II)-methylation from soil. Strong seasonal patterns in MeHg concentrations were observed in surface water and sediment. The highest concentrations of MeHg in surface water were observed at moderate temperatures, suggesting that other factors limit net Hg(II)-methylation. Seasonal changes in sediment organic content and the fraction of 1 N KOH-extractable THg were also observed and may be important factors in controlling net Hg(II)-methylation rates. Sulfate concentrations in surface water are low and the evidence suggests that Fe reduction may be an important Hg(II)-methylation process. The highest sediment MeHg concentrations were observed in habitats with large amounts of FGS, which are more prevalent in the upper half of the study area due to the lower hydrologic gradient and agricultural impacts. Past and present land use practices and other geomorphologic controls contribute to the erosion of banks and accumulation of fine-grained sediment in this section of the river, acting as sources of IHg.     

Pollutant transport in a shallow unconfined aquifer in Perry,Ohio

The groundwater system in northern Perry Township in Lake County, Ohio, is a shallow, unconfined aquifer consisting of periglacial lake beach deposits and less permeable lacustrine plain deposits. Groundwater flow is generally toward Lake Erie from south to north and is controlled by the top of the Ashtabula Till, but strong, local variations are caused by northward flowing streams During the study period, water levels in most wells exhibited a seasonal fluctuation of less than 0 3 m from their mean values. The areal distributions of chloride and nitrate concentrations indicate that road salt runoff easily infiltrates the aquifer and that nitrate may be sourced from fertilizer application. Ground-water flow and solute transport models indicate that in excess of 27 years are required to obtain chemical steady-state under hydrologic steady-state conditions. The simulations also demonstrate that nitrate loading must occur in more than one cultivated field in order to obtain the observed wide-spread nitrate distribution.     

Nutrient transport in a riverine-influenced,tidal freshwater bayou in Louisiana

Transport of ammonium (NH₄ ⁺), nitrate + nitrite (NO₃ ^?), total Kjeldahl nitrogen (TKN), soluble reactive phosphate (SRP), and total suspended solids (TSS) was measured in a freshwater tidal bayou located in a marsh system near the mouth of the Atchafalaya River in Louisiana. Sampling was conducted six times over one year and was timed to assess effects of seasonal variation in river flow and mean sea level of the Gulf of Mexico on material fluxes. Net fluxes of all materials were large and ebb directed in all seasons except fall, when net transport was 2 to 3 orders-of-magnitude smaller than in any other season. These results demonstrate that riverine forcing was the primary influence on materials transport in all seasons except fall when tidal forcing was most important. The range of net fluxes (g s^?1) for each nutrient was as follows (a negative sign indicates a net export toward the Gulf): NO₃ ^?, ?0.006 to ?6.69; TKN, 0.09 to ?10.41; NH₄ ⁺, ?0.02 to ?1.36; SRP, ?0.001 to ?0.53; TSS, ?2 to ?81. Analysis of nutrient concentrations indicated the marsh/aquatic system removed NO₃ ^?, SRP, and TSS from the water column from late spring through early fall and released NH₄ ⁺ and TKN in summer. The results of this study show that net materials export per unit cross section channel area increased as riverine influence increased.     

Sediment production and transport in a proglacial stream: Hilda Glacier, Alberta, Canada

Hilda Glacier, a small cirque glacier in the Canadian Rocky Mountains, yields two principal types of sediment: ablation till, deficient in fine material and produced by rockfalls and avalanches falling on to the glacier surface, and basal lodgement till, rich in fines and formed mainly by subglacial erosion. Recent recession from its Neoglacial maximum has exposed large areas of basal till with thin veneers of ablation till which, when combined with present subglacial and supraglacial debris, provide abundant material for erosion and transport by the mcltwatcr stream. Sediment transport measurements over two summers (1977–1978) showed that bed load and suspended load occur in approximately equal proportions and that dissolved loads are minor. Local source variations, especially bank slumps, are a major cause of scatter in sediment rating curves. Suspended-sediment concentrations are greater early in the melt season due to availability of loose sediment produced by freezing and thawing. Other contributors to scatter in suspended-sediment rating curves include rain showers and diurnal hysteretic effects. Although the distinction between bed load and suspended load is never sharp, available data suggest that the sand/ gravel grain-size boundary (-1ø) approximates the suspendcd-load/bed-load division for characteristic Hilda flows transporting gravel. This approximation, combined with till grain-size analyses, suspended-sediment measurements, and spatial distributions of till types, leads to the following computations of fluvial sediment sources: for suspended load - 6% supraglacial, 47% subglacial, 47% channel banks; for bed load - 46% supraglacial, 27% each subglacial and channel banks. Supraglacial debris provides only about one-fourth of all fluvial sediment, but nearly half of the bed load.     

Partnership approach to disaster management in Bangladesh: a critical policy assessment

The geographic location of Bangladesh at the confluence of the three mighty river systems of the world renders her one of the most vulnerable places to natural disasters. Human-induced climate change exacerbates the problem. This study shows that the Government of Bangladesh has already established a multi-layered institutional mechanism for disaster management, with formal recognition of the role of various stakeholders. Historically, NGOs and other informal support mechanisms in the country also have made significant contributions during and after disaster recovery. Despite the presence of some strengths, such as long experience in disaster response and recovery, the people’s resilience, and donor support, the current management strategies suffer from a host of policy and institutional weaknesses. Most prominent is the absence of a functioning partnership among the stakeholders within these formal set-ups. What is lacking is the development and embodiment of a culture of collective decision-making in planning, in resource sharing, and in implementing disaster management policies and programs in an integrated and transparent way. The paper suggests a partnership framework to implement prevention, preparedness, response, and recovery phases of disaster management.     

Modeling hydrothermal, suspended solids transport and residence time in a deep reservoir

This article presents the modeling of hydrothermal characteristics and suspended solids in a long and large-volume reservoir with a highly fluctuating water level. A laterally averaged two-dimensional hydrothermal and water quality model was configured for the Shihmen Reservoir in northern Taiwan. The model was validated with measured data of water surface elevation, water temperature, and concentration of suspended solids in 2006. The results show that the numerical model was able to reproduce the measured data. The validated model was then used to investigate the effects of water withdrawal schemes at different depths and to estimate the residence time in the reservoir. When water is withdrawn from a great depth, the relatively warm water from the upper layers can replace that in the deep layers, thereby facilitating heat transfer from the surface to the deeper layer. Bottom-water withdrawal results in a lower concentration of suspended solids compared with withdrawal from depths of 20 and 40 m. The simulated results show that the residence time is approximately 154 days in the Shihmen Reservoir.     

Changes in seasonal water transport in a Louisiana estuary,Fourleague Bay,Louisiana

Water transport in Fourleague Bay is strongly influenced by the discharge of the Atchafalaya River and prevailing wind conditions. In three 50-h intensive surveys, we measured transport through the major inlets of the bay during the three major river discharge/weather regimes of the year: strong frontal passage, high river flow, and calm, low river flow. Wind stress caused significant changes in both transport and water levels. North winds, dominant during winter frontal passages, caused a net export of water. During the high river flow survey, southeasterly winds created an opposing hydraulic pressure gradient in the Gulf of Mexico, diverting river flow into Fourleague Bay. This resulted in an increase in water elevation and the inundation of adjacent marshes. We believe that this high-discharge, southerly wind condition is the major mechanism leading to sheet flow and sedimentation on the marsh. Calm, low-discharge conditions, typical of late summer, produced classic tidally-dominated circulation.     

Sulfate transport in a Coastal Plain confining unit, New Jersey, USA

 A transient 1-D, two-pathway non-equilibrium deterministic advective dispersion model was used to examine the distribution of chloride (43–100 mg/L) and sulfate (57–894 mg/L) concentrations in the 35-m-thick section of the Lower confining unit, Atlantic Coastal Plain, New Jersey, USA. The model was used to constrain hypotheses about how pore-water chemistry changed over time. Explanations of the solute concentrations were explored by inverse and direct methods given a few known constraints, including concentrations of pore-water constituents from 12 core samples, reported simulated flow rates, and estimated hydrogeologic properties. The hypothesis that is best supported by the model results is that the distribution of chloride and sulfate concentrations in the confining unit reflect the history of the aquifer system since it was filled with seawater at the last eustatic high, about 84×10³yr BP. The model simulates fresh-water flushing of the seawater-permeated silts at a steady upward pore-water flow velocity of 8.8×10^–6 m/d, with a dispersion coefficient of 9.2×10^–7 m²/d, a dimensionless partition expression for chloride, β_Cl=0.981, and a dimensionless exchange coefficient, ω_Cl=0.31×10^–2. Sulfate concentrations were simulated over the flow path using flow and dispersion values calculated for chloride transport plus a retardation term. Parameters for sulfate transport include retardation coefficient=4.51, β_SO4=0.994, and ω_SO4=0.31×10^–2. Sensitivity analysis indicates that the model is most sensitive to flow velocity, and that fresh-water flushing of the confining unit is best simulated by having seawater concentration levels at the inflow boundary of the confining unit exponentially decrease with a concentration half-life rate of 825 yr. Received, January 1997 / Revised, April 1998, October 1998, January 1999 / Accepted, January 1999     

Submarine hydrocarbons in Southeast Asia resources,environment, and policy

This paper reviews some issues related to the existence, ownership, and development of SE Asia's offshore oil and gas resources. First, the resource potential in submarine areas of the region and the rate at which this potential will be developed is discussed. Some environmental concerns that arise from the development of these resources are then reviewed. The international dimension of those environment-related problems is pointed out. Application of benefit/cost analysis in addressing these complex issues is then discussed, in the context of economic development.     

From centre to periphery: Changing spatial structures in Rural South India, 985–1985

The paper is an attempt on polarized development. over the last millennium, focussing on a small agrarian region in the Tamil country of South India. From the perspective of Friedmann's General Theory, the paper traces the development of this region through five successive stages of integration, each of which encompassed the study area into a wider and more complex spatial system. Elementary innovations are identified that, at each of these stages, generated specific types of authority-dependency relationships which, in turn, integrated the respective innovative cores and their dependent peripheries into single spatial systems. The paper shows how the institutional and spatial structures of rural South India have been successively transformed in this process, to serve the needs of the various core regions. It also demonstrates how, since colonial times, new types of authority-dependency relationships have emerged that, by organizing the dependency of the peripheries through systems of market and supply, have resulted in development of the core regions, on the one hand, and underdevelopment of the peripheries, on the other.     

Groundwater inflow and associated transport of phosphorus to a hypereutrophic lake

Hydrogeochemical data from lake, sediment pore, and well waters were used to quantify groundwater seepage and the associated transport of phosphorus to Lake Persimmon, Florida, USA. The data show that lake chloride concentrations vary as a function of lake elevations that are controlled by groundwater inflow. A whole-lake average seepage rate, estimated using a simple one dimensional advection-diffusion model fitted to the lake chloride profile, currently averages 2.3 ± 0.3 cm yr^-1 and is in reasonable agreement with the rate of advective flow obtained from the pore water chloride profile. The ratios of nutrient regeneration versus sulfate consumption indicate that the phosphorus enrichment in deeper portions of sediment pore water is most likely a result of groundwater phosphorus transport through sediment. Thus, the net inputs of groundwater phosphorus to the lake, calculated using the deep pore water phosphorus concentration, are about 7.4 ± 4.3 mg P m^-2 yr^-1 and comparable with recent in situ estimates from seepage meters. This study provides a simple hydrogeochemical method for estimating hydrologic and phosphorus inputs via groundwater to the lake, thereby supporting current efforts for lake management.     

Pathways for sediment transport and retention in a vegetated,mid-channel island: Connecting sediment dynamics to morphology in Meinmahla Island,Ayeyarwady Delta,Myanmar

Vegetated mid-channel islands play an important though poorly understood role in the sediment dynamics and morphology of tide-dominated deltas. Meinmahla Island is a mangrove-forest preserve at the mouth of the Bogale distributary channel, in the Ayeyarwady Delta, Myanmar. In this relatively unaltered mid-channel island, sediment dynamics can be directly connected to morphology. Field measurements from 2017 to 2019 provide insight into the pathways for sediment transport and resulting morphological evolution. Water depth, salinity and turbidity were monitored semi-continuously, and velocity profilers with turbidity and salinity sensors were deployed seasonally in single-entrance (dead-end/blind) and multi-entrance tidal channels of the island. The morphological evolution was evaluated using grain size, ²¹⁰Pb geochronology, remote sensing and channel surveys. The data show that ebb-dominant, single-entrance channels along the island exterior import sediment year-round to the land surface. However, these exterior channels do not deliver enough sediment to maintain the observed ca 0.8 cm/yr accretion rate, and most of the sediment import occurs via interior, multi-entrance channels. Interior channels retain water masses that are physically distinct from the water in the Bogale distributary, and estuarine processes at the tidal-channel mouths import sediment into the island. Sediment is sourced to the island from upriver in the wet season and from the Gulf of Mottoma in the dry season, as the location of the estuary shifts seasonally within the Bogale distributary. The salinity and biogeochemistry of the distributary water are affected by interactions with sediment and groundwater in the island interior. The largest interior channels have remained remarkably stable while the island has aggraded and prograded over decadal timescales. However, the studied multi-entrance channel is responding to a drainage-network change by narrowing and shoaling. Overall, mid-channel islands trap sediment and associated nutrients at the river–ocean interface, and these resilient landscape features evolve in response to changes in drainage-network connectivity.     

Methylene blue transport in a sand-illite mixture and its implications for contaminant transport

Understanding contaminant transport in clay-containing soils is critical for accurate prediction of the travel distances of contaminants and for the design and implementation of corresponding remediation plans. This study examined the breakthrough behavior of methylene blue (MB) through sand-illite mixtures using laboratory soil-column experiments at five inlet concentrations, three flow rates, and five illite contents. Kinetic and equilibrium adsorption tests were performed to evaluate the maximum adsorption capacities of the sand and illite used in the soil-column experiments. In addition, the bed efficiency, MB saturation, and adsorption rate were calculated to quantitatively describe the observed breakthrough curves. The observed breakthrough curves, bed efficiencies, MB saturations, and adsorption rates in this study demonstrated the presence of a threshold illite content of ~10% for the adsorption efficiency of contaminants. This implies the need to evaluate the threshold clay content for accurate predictions of contaminant transport through gap-graded clay-containing soils.

     

Two-phase, partially miscible flow and transport modeling in porous media; application to gas migration in a nuclear waste repository

We derive a compositional compressible two-phase, liquid and gas, flow model for numerical simulations of hydrogen migration in deep geological repository for radioactive waste. This model includes capillary effects and the gas high diffusivity. Moreover, it is written in variables (total hydrogen mass density and liquid pressure) chosen in order to be consistent with gas appearance or disappearance. We discuss the well possedness of this model and give some computational evidences of its adequacy to simulate gas generation in a water-saturated repository.