Model-based analysis of urban settlement process in eco-sensitive area of developing country: a study with special reference to hills of an Indian city

Rapid and unplanned expansion of a city into its eco-sensitive areas like hills, wetlands, and forests is becoming a major concern, particularly in developing countries. Understanding the process and causes of such unplanned urban expansion is of paramount importance for framing sustainable urban development policies. This paper presents a modelling concept that relates urban settlement in such eco-sensitive areas with potential socio-economic, demographic and geographical factors. The model is applied to an Indian city Guwahati, which is experiencing serious environmental degradation due to unplanned urban settlement in its eco-sensitive hilly areas. While topographical and settlement data were derived using satellite data in GIS platform, all other necessary data were collected from relevant government organizations. On validation of the multi-linear regression model, the coefficient of determination and the root mean square error are obtained as 0.938 and 1.7, respectively. Model results show that geographical parameters are less influencing as compared to the other socio-economic and demographic factors. Sensitivity analysis of urban settlements in hills of Guwahati city carried out with respect to the considered factors reveals that land value and free space availability in the surrounding area of a hill are the most sensitive parameters. This indicates that city development plans should give more importance to outward spatial expansion in plain areas with regulated land value and zoning scheme to minimize unauthorized settlement in eco-sensitive hilly areas of Guwahati city.     

ZnO nanophotocatalysts coupled with ceramic membrane method for treatment of Rhodamine-B dye waste water

In the present investigation, hybrid treatment process has been developed for the treatment of synthetic dye wastewater. Photocatalysis and ceramic nanoporous membrane are mainly used for process integration to minimize the fouling and increase the flux. Commercial ZnO powder has been used as a nano-photocatalyst for the degradation of rhodamine-B dye in the hybrid system. Commercial ceramic nanoporous tubular membranes have been used for the rejection of dye and suspended catalysts. Photocatalysis process alone has shown the 33% of decolorization, whereas ceramic nanofiltration has shown the 50% of decolorization. Integration of photocatalysis and ceramic nanofiltration were shown 96% of dye decolorization over 90 min of operation.     

Understanding the paradox of rising consumption of alternative medicine in Kenya

Kenya has been expanding provision of healthcare services, taking health facilities closer to the people. While this would be expected to reduce dependence on complementary/alternative medicine, the consumption has continued to rise. This raises the question of whether alternative medicine is replacing conventional medicine or the two are jointly used to deal with diseases. Thus, this study sought to establish the relationship of the two remedies in household choice of healthcare and explored the determinants of such choices. The study used bivariate probit analysis on cross-sectional data. The study found that consumption of conventional medicine and alternative medicine was indeed interdependent. The two were, on average, substitutes although some groups still consumed them jointly. Gender, education and age of the household head, price of conventional medicine, distance to conventional medicine facilities and social networks were found to influence the decisions. Male household heads, price of conventional medicine and distance to conventional medical facilities had a positive relationship with the probability of using alternative remedies. Education and age of household head, and social capital were associated with lower likelihood of choosing alternative remedies. The results of this study have important ramifications for medical researchers, health policy makers and health insurance providers. For medical researchers, joint use of alternative and conventional medicines makes it important to understand the interactions between the two so as to avoid adverse reactions that may endanger the lives of patients. For the health policy makers, because patients have different preferences for healthcare services, it is useful to provide alternative medicine and conventional medicine in a joint and integrated health system for patients’ freedom of choice, and for safety and efficacy of treatment. Health insurance providers, on their part, need to explore the possibilities and modalities for bringing users of alternative medicine, and joint users of alternative and conventional medicines under their cover.     

The impact of global change on economic values of water for Public Irrigation Schemes at the São Francisco River Basin in Brazil

Economic values of water for the main Public Irrigation Schemes in the sub-middle region of the São Francisco River Basin, in northeastern Brazil, are determined in this study using an integration of a global agro-economic land and water use (MAgPIE) with a local economic model (Positive Mathematical Programming). As in the latter, the water values depend on the crops grown, and as Brazilian agriculture is strongly influenced by the global market, we used a regionalized version of the global model adapted to the region in order to simulate the crop land use, which is in turn determined by changes in global demand, trade barriers, and climate. The allocation of sugarcane and fruit crops projected with climate change by the global model, showed an impact on the average yields and on the water costs in the main schemes resulting in changes in the water values locally. The economic values for all schemes in the baseline year were higher than the water prices established for agricultural use in the basin. In the future, these water values will be higher in all the schemes. The highest water values currently and in the future were identified in municipalities with a significant proportion of area growing irrigated sugarcane. Being aware of current water values of each user in a baseline year and in a projected future under global climate and socioeconomic changes, decision makers should improve water allocation policies at local scale, in order to avoid conflicts and unsustainable development in the future.     

Water management and aquatic ecosystem services of a tropical reservoir (Itaparica,São Francisco,Brazil)

Reservoirs have a wide variety of uses that have led to frequent conflicts over ecological conservation and contamination, especially as land management has intensified. Oligotrophication must be implemented in numerous tropical reservoirs that experience advanced eutrophication to maintain aquatic ecosystem functions. To quantify impacts on ecosystem functions and to develop an adaptive management policy, multiple studies have been conducted on the Itaparica Reservoir, São Francisco River, in the semi-arid north-eastern region of Brazil. Here, we add to that existing body of knowledge through investigating how nutrient accumulation is affected by water exchange between the main river flow and Icó-Mandantes Bay. Operational water-level fluctuations in the reservoir create large desiccated littoral areas that release high amounts of nutrients when they are rewetted. In particular, water-level variation promotes proliferation of Egeria densa, a noxious weed, thus elevating trophic levels of the Itaparica Reservoir and Icó-Mandantes Bay. Analysis with a P efficiency model determined 25 μg P L^?1 to be the critical concentration and further indicated that the critical load in both bodies of water have been exceeded. Moreover, intensive fish aquaculture using net cages has led to further overtaxing of the reservoir. We conclude that an effective ecological reservoir management policy must involve oligotrophication, harvesting of noxious water weeds for use as soil amendment in agriculture or biogas production, “blue” aquaculture, and limiting hydroelectric power production based on current water availability.     

Salinity evolution of the Tigris River

Major modifications regulating the Tigris River, originated in the 1940s and continuing to the present, have resulted in changes in salinity in the system over time and in different portions of the river course. The increase in salinity is due to decreases in stream discharge due to dams, water management structures such as the Lake Tharthar system, irrigation return flow, and soluble minerals in the basin. This research documents the increase and evaluates the causes of the salinity increase of the river from predevelopment to present using published and previously unavailable data. The predevelopment salinity was under 600 ppm, since 1984 has exceeded the 1000 ppm threshold recommended for drinking water downstream of Amara. A minimum instream flow for the river is calculated at Baghdad and Kut at 185 cubic meters per second (cms), approximately 15% of the mean historical flow of the river, but above the lowest minimum flow recorded at 140 cms. Recommended salinity management options discussed include (1) eliminating Lake Tharthar as a water storage facility, (2) managing saline inflows from tributaries, and (3) employing a minimum instream flow for the river.     

Community participation in cultural heritage and environmental policy formulation in Botswana

Cultural heritage does not have direct economic benefits. However, if properly managed it can stimulate social cohesions, improving the environment and have beneficial economic spin offs for the local communities. This paper discusses the role of communities in the formulation of the policies concerning their local environment. It argues that community engagement by policy makers is important in giving legitimacy and ownership of the policies. Furthermore, this paper discusses the potential of cultural heritage in diversifying the economy in Botswana. This paper recommends for the re-assessment of the relationship between the state and local communities which is critical in resuscitating the seemingly ailing community business organizations. In conclusion, it argues for the sustainable management of cultural heritage as a social and economic resource in the next 50 years of Botswana’s independence.     

Challenges for modelling and integrating environmental performances in concept design: the case of an automotive component lightweighting

The objective of this paper is to discuss the main barriers for modelling and integrating the environmental performances in the automotive concept design. Incorporating environmental assessment in the early design phase of a vehicle component is known as an important challenge that car makers need to face in order to develop more sustainable design solutions; in this regard, the Life Cycle Assessment is the most widespread methodology for the environmental assessment and comparison of alternatives. The present work illustrates the combination of such methodology with the traditional design procedure at two different levels of the component design phase, material choice and concept design. In particular, the potential benefits originated by a lightweight solution for the automotive component Throttle Body are evaluated by considering environmental and technical implications at the same level. The case study shows that a multi-disciplinary approach for design effectively allows the integration of the environmental issue in the company’s established procedures. However, interpretation of results is still a challenging aspect due to the inevitable contradicting elements which should not discourage to develop comprehensive sustainability assessment within the early design stage.     

H∞ loop-shaping controller design for a grid-connected single-phase photovoltaic system

This paper presents a H_∞ loop-shaping controller for controlling dc-link voltage by regulating the switching signal of the inverter associated with a grid-connected single-phase photovoltaic system. To facilitate a robust control design, state-space realisation of the system model is made with uncertainties represented by linear fractional transformation. The controller is achieved through H_∞ synthesis followed by obtaining desired loop shapes through the choice of the proper weighting functions. The controller order is reduced by Henkel-norm method for facilitating its practical implementation. Controller performance is evaluated through carrying out simulations on MATLAB/Simulink platform under standard and changing atmospheric conditions, and fault condition.