Assessment of a large watershed in Brazil using Emergy Evaluation and Geographical Information System (original) (raw)
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Nowadays, most of agricultural production uses conventional management that depends on chemical industry's products, fossil fuels and minerals. Besides that, specifically in Sao Paulo State, Brazil, sugarcane crops is expanding its area on others crops and natural vegetation. To avoid that the dependence of non-renewable resources by agricultural systems be larger than the biological capacity to supply them and, that the land use dynamics do not result in a monoculture, it is urgent to elaborate efficient public policies that aim sustainable development; but for that purpose, there is a need of diagnosis and scenarios studies. In this sense, Emergy Accounting has been used as powerful tool. The main objective of this work is to assess the emergy indices dynamics of Mogi-Guaçu and Pardo watershed, Brazil, considering the natural vegetation and agricultural land use. The simulation procedure covers a time period from 1988 to 2033, and a scenario approach was used from 2002 to 2033. The Land Use Cover Change (LUCC), submodel of the Multi-scale Integrated Model of Ecosystem Services (MIMES) was elaborated, calibrated, validated and ran in the Simile software.
Emergy Evaluation of Semi-Arid Watersheds Under Different Management Strategies
21st Century Watershed Technology: Improving Water Quality and Environment Conference Proceedings, May 27-June 1, 2012, Bari, Italy, 2012
Due to the environmental impacts generated by economic activities and faced with the challenge of producing food for an increasing population, the sustainability of production methods should be analyzed to determine those with the highest relative yield and the least degradation of the environment. Seeking alternatives for sustainable use of the caatinga biome, this research tested two types of management strategies in watersheds of the semi-arid region in Iguatu, Ceará, Brazil, and compared them to a preserved area of caatinga. To evaluate the performance of the systems, an emergetic methodology, suggested by H. T. Odum, was used. The thinned area showed the best emergy results, with a transformity of 12,975 seJ J-1 , while the preserved area and that planted with grass presented transformities of 14,477 and 22,062 seJ J-1 , respectively. Through the activity of thinning, where the energy produced was 45% higher, the transformity was lower than that of the unchanged caatinga, showing that the investment in labor for thinning was offset by an increase in energy production. The high transformity of the untouched caatinga indicates that better use could be made of the available resources. This system could be used for beekeeping, ecological tourism, or any other activity that, as with thinning, would not alter the system beyond its capacity for tolerance but that would allow a more efficient use of the natural resources.
Emergy Evaluation of an Extensive Cattle Ranching System in Pantanal Watershed, Brazil
Emergy allows the sustainability of agricultural and livestock systems to be evaluated. This methodology was applied to analyze livestock systems on traditional farms located in the Pantanal Watershed in Brazil. The goals were to evaluate the sustainability of the system and to show the importance of the presence of native fauna and cattle in maintaining the region’s ecological quality. The results showed that the traditional livestock management in the Pantanal is composed of a high percentage of renewable resources, approximately 98% of the total emergy used. Cattle have the important function of controlling the fires in the region and thus cattle production preserves the local fauna and flora, which produce 7687 kg of biomass/ha/year. The value of this biomass was estimated by the emergy methodology to have a yearly value of US$ 367.80 per hectare of preserved landscape. Even though a large amount of renewable resources are used, thereby preserving the environment, the cost for m...
Ecological Modelling, 2015
By tracking the different flows of emergy (the total amount of solar energy that was directly or indirectly required in a production process) it is possible to account for all environmental work previously involved in generating a resource, product or service. This donor-side perspective for environmental assessment has the advantage over usual economic and energy analysis in the ability to value renewable and nonrenewable environmental resource inputs both from the economy (purchased resources) and from nature (free resources) and compute their values on a common basis. On this basis, this paper presents the use of emergy synthesis on three cropping systems of the Pampa Region (Argentina) with the aim of evaluating the long-term trends (1984-2010) in emergy use and the effect of the adoption of new technologies in the study area. The cropping systems evaluated were wheat/soybean double cropping (W/S); maize (M), and spring soybean (S). Results form the emergy synthesis showed that the cropping systems studied were not only more productive but also more efficient over time. The range of the observed values for the emergy yield ratio (EYR) were 1.77-5.59, proving that the three cropping systems are considerably supported by renewable and locally available resources. The environmental load ratio (ELR) that represents the ratio between non-renewable and renewable resource inputs ranged between 0.3 and 1.43, a significant lower range compared to other extensive cropping systems. However, when inspecting the temporal dynamics of the emergy indicators, M and W/S showed a statistically significant optimum behavior, with the most favorable values just before the use of a more intensive cropping management represented by the use of genetically modified cultivars, the no-tillage adoption and the more frequent use of fertilizers at higher doses. By the time of these adoptions, both the EYR and ELR showed a breakpoint in their temporal dynamic, exhibiting a negative slope during the last years of the time series. Although the observed ranges of the emergy indicators can place these production systems among the most efficient and with the lower environmental impact, the negative trend in the emergy indicators shown in recent years constitutes a risky scenario in terms long-term sustainability.
Emergy efficiency of land-use systems in the brazilian semi-arid region
Revista Ibero-Americana de Ciências Ambientais, 2020
Emergy analysis is used to evaluate agricultural management systems in order to diagnose their efficiency in using economic and natural resources. In this study, emergy analysis was used to evaluate an agroforestry production model and compare it to the traditional production model used in the semi-arid region of the northeast of Brazil. The agroforestry model comprises three subsystems: agrosilvopastoral (ASP), silvopastoral (SP) and preserved caatinga (CAT). For the traditional model, three subsystems were evaluated: an area under cultivation (AC); an area lying fallow for six years (F6); and an area fallow for nine years (F9). For each model and its respective subsystems, all input and output energy flows were identified. These flows were later quantified and transformed into emergy using their respective transformity values. The emergy performance of the systems and subsystems was evaluated by the indices: transformity (Tr), emergy investment ratio (EIR), emergy yield ratio (EYR...
Journal of Environmental Management, 2003
Emergy (with an 'm') synthesis was used to assess the balance between nature and humanity and the equity among forest outcomes of a US Forest Service ecosystem management demonstration project on the Wine Spring Creek watershed, a high-elevation (1600 m), temperate forest located in the southern Appalachian mountains of North Carolina, USA. EM embraces a holistic perspective, accounting for the multiple temporal and spatial scales of forest processes and public interactions, to balance the ecological, economic, and social demands placed on land resources. Emergy synthesis is a modeling tool that allows the structure and function of forest ecosystems to be quantified in common units (solar emergy-joules, sej) for easy and meaningful comparison, determining 'system-value' for forcing factors, components, and processes based on the amount of resources required to develop and sustain them, whether they are money, material, energy, or information. The Environmental Loading Ratio (ELR), the units of solar emergy imported into the watershed via human control per unit of indigenous, natural solar emergy, was determined to be 0.42, indicating that the load on the natural environment was not ecologically damaging and that excess ecological capacity existed for increasing non-ecological activities (e.g. timbering, recreation) to achieve an ELR of 1.0 (perfect ecological-economic balance). Three forest outcomes selected to represent the three categories of desired sustainability (ecological, economic, and social) were evaluated in terms of their solar emergy flow to measure outcome equity. Direct economic contribution was an order of magnitude less (224 X 10" solar emergy-joules (sej) ha-') than the ecological and social contributions, which were provided at annual rates of 3083 and 2102 X 1012 sej ha-', respectively. Emergy synthesis was demonstrated to holistically integrate arid quantify the interconnections of a coupled natul-e-hu~nan system allowing the goals of ecological balance and outcome equity to be measured quantitatively.
Emergy analysis was used to analyze three agricultural systems to compare and contrast resource use, productivity, environmental impact, and overall sustainability. Emergy analysis was appropriate for this task because of its ability to transform different types of inputs to a common form (solar energy equivalents) to allow meaningful comparisons across the three systems. The systems analyzed were conventional corn (Zea mays L.) production in Kansas, USA, blackberry (Rubus rubus Watson) production in Ohio, USA, and a Lacandon polycultural rotation system in Chiapas, Mexico. Despite these different systems and diverse inputs, emergy allowed the quantification and comparison of flows for each system on a common basis. This allowed system-level conclusions and demonstrated the utility of emergy analysis when evaluating agricultural systems. The greatest inputs of emergy across the three systems were for fertilization and irrigation of the corn system. These two inputs accounted for 95% of the purchased emergy input to the corn system. The indigenous system was most reliant on renewable resources, and therefore, had the lowest level of environmental loading. The sustainability index for the three systems ranged from 0.06 for the corn system, to 0.65 for the blackberry system, to 115.98 for the indigenous system. The respective energy and emergy yield for each system were 2.6E9 J ha À1 year À1 and 3.57E15 sej ha À1 year À1 for the indigenous system, 3.71E10 J ha À1 year À1 and 8.59E15 sej ha À1 year À1 for the blackberry system, and 1.40E11 J ha À1 year À1 and 1.30E16 sej ha À1 year À1 for the corn system. While the indigenous system has the highest level of sustainability, its energy yield was 14 times less than the blackberry system, and 53 times less than the corn system. The results confirm the need for food production systems with large yields that are more dependent on renewable energies. #
Emergy Net Primary Production (ENPP) as basis for calculation of Ecological Footprint
Ecological Indicators, 2010
reference number: 0001 -54) Society needs urgently good tools to understand the biosphere mechanisms, get conscious of Earth's biophysical limits and make appraisals of environmental performance of human dominated systems. In this context, the Ecological Footprint (EF) appears as one of the most important tools. But, according to calculations based on emergy analysis, the indicators of EF could underestimate the problem of human carrying support. EF does not consider the work of untouched nature in productivity and ecosystems services. To improve this, we propos: (a) to include the ecosystems non considered in EF: tundra, deserts and zones covered by ice; (b) to consider the value of NPP (in emergy units: seJ/m 2 /yr) as the base for calculation of Equivalent Factors (EQF); because several publications argue that NPP is particularly relevant in sustainability analyses, because human beings appropriate NPP to fuel production and consumption activities and because these activities, in turn, will affect NPP in the future; (c) to include in EF, as carbon emissions (in ton C/m 3 of water), the consumption of fossil energy used in collection, treatment and distribution of water for domestic use. Introducing these changes to conventional EF and taking as reference the Peruvian economy (during 2004) the Biocapacity was 14.6 gha/capita and the Footprint 6.6 gha/capita. It means that Peru can support 2.2 times its population if present life style is maintained, in opposition to the 4 times ratio obtained with conventional EF. The results obtained with improved approach show a worse situation of than that revealed by conventional EF.
Ecological Modelling, 2008
In this work, emergy analysis was used in association with the Geographical Information System (GIS) in order to improve the evaluation of family-managed farms that adopt either the ecological or the chemical production models. Three small farms, located in Amparo County, in São Paulo state, Brazil, were studied. One of them, Duas Cachoeiras farm, uses agroecological concepts for its agricultural production. The two others (Santa Helena farm and Três Lagos farm) use the conventional chemical model. In an attempt to improve the precision of the data used in emergy analysis, the Universal Soil Loss Equation (USLE) was incorporated to the GIS tool to calculate the topsoil loss in the farms. The GIS tool also allowed the calculation of the amount of rain water that infiltrates the ground and can recharge the aquifer. This percolated water is a system output and was incorporated in the emergy accounting. Another modification in comparison to previous emergy analyses was that the renewability factor of each input was considered in the emergy accounting. Results showed that the agroecological farm is more sustainable and can be used as a model for small farms in their transition to ecological agriculture. The GIS-emergy tools were used to compare the environmental performance of the four main productive areas of Duas Cachoeiras farm (annual cultures, orchard, forest, and pasture). These results demonstrate the emergy performance of each kind of land use and may be used in watershed planning. is a problem of the production and consumption model. So the problem is not technological but political. The chemical agriculture establishes a vicious cycle: chemicals destroy the topsoil quality (structure, organic matter content, pH, micro-biota, rain drop protection); therefore, the ground absorbs less water and becomes nutrient-deficient and vulnerable to erosion. The soil loses ecological functions and decreases in quantity and quality. 0304-3800/$ -see front matter