10 research outputs found
Avaliação da aptidão agrÃcola das terras como subsÃdio ao assentamento de famÃlias rurais, utilizando sistemas de informações geográficas
Demand-driven land evaluation; with case studies in Santa Catarina-Brazil
The main objective of this thesis is to improve use and usefulness of information for rural land use decisions based on an operational demand-driven approach for land evaluation with case studies in Santa Catarina State, Brazil. To achieve this objective, the following research questions were formulated: (1) Are the existing land evaluation reports useful to rural decision makers?; (2) What interpreted information is necessary for rural decision-making?; (3) What are the implications of the planning environment for land evaluation?; (4) What primary information are necessary and feasible to collect or generate?; (5) What models and research methods can be used and which adaptations are necessary considering local conditions?; and (6) How do decision makers evaluate methods, tools and the new information? Is it worth to invest time and resources to further improve information?This thesis is a collection of papers, all dealing with case studies inSanta Catarina,Braziland related to demand-driven land evaluation, published or submitted to international peer-reviewed journals. The case studies presented in chapters 4, 5 and 6 were selected according to the main demands of users as identified in the previous chapters.Chapter 2describes and quantifies the use and usefulness of soil surveys and land evaluation reports to land use planners, observe the relation between latent demand and actual supply and suggest improvements on current methods. It is the basis for the thesis, indicating the main directions to be followed. The soil resource inventory and associated land evaluation had some utility, but were not in general used for their intended purpose, namely farm planning. This was mainly because they did not contain crucial information necessary to such planning in the actual context in which the farmer had to take decisions. The primary deficiencies were identified as: (1) no estimate of environmental degradation risk, (2) no financial analysis, (3) no social analysis of decision-makers' attitudes and preferences, (4) no risk assessment for weather, yields, profits and market, and (5) insufficiently-specific land use alternatives. These deficiencies could have been avoided with a demand-driven approach, evaluating and reporting according to the true needs and opportunities of the decision-makers.Chapter 3explains the farmers' decision environment in Santa Catarina state,Brazil, which is typical of many market-oriented but low-income economies, with respect to the actors, political, legal and social frameworks, interactions and dynamics, how these affect decision makers and implications for land evaluation. It shows that different groups of farmers have different needs for information and should be approached in different manner. Some farmers would welcome any information on improving their current farming systems, whilst others are also interested in innovative crops or agricultural processes. Yet another group might need motivation more than information. It suggests that if the land evaluation process is begun with a careful analysis of the decision environment of rural land users (farmers) and follows a demand-driven approach, the results will likely be more realistic and therefore more useful to both policy/planning institutions and direct land users. This should lead to more demand and a "virtuous cycle" where planning, land evaluation and clients' needs and possibilities are increasingly inter-linked.Chapter 4describes the applicability of a data-intensive watershed erosion and water quality model (AGNPS) in a relatively data-poor environment, reporting on the steps necessary to apply the model in a GIS setting, including data preparation, cell size selection, sensitivity analysis, model calibration and application to different management scenarios at small watershed scale in an area of intensive swine production. We calibrated the model by making a best guess for model parameters and performed a pragmatic sensitivity analysis using optimistic and pessimistic settings of these. It was not possible to calibrate over the entire rainfall range, which was thus divided into three (<25 mm, 25-60mm, >60 mm). Predicted sediment concentrations were consistently six to ten times higher than actual, probably because of sediment trapping by vegetated channel banks. Predicted N and P concentrations in stream water, adjusted by this empirical sediment concentration factor, ranged from just below to well above regulatory norms. The study shows that expert knowledge of the area, in addition to experience reported in literature, was able to compensate for poor calibration data. It was possible to apply the model for relative ranking of scenarios (actual, recommended, and excessive manure applications; point source pollution from pig farming) in comparative studies. Finally, we suggest that this methodology could also be useful as a starting point for calibration in a data rich environment.Chapter 5shows that visualization of scenarios with community participation was useful to increase participants' understanding of the water pollution problem, improve their perceptions, stimulate the search for solutions and generate new demands. This was the case even taking into account that rural decision makers are not well educated and not used to visualizing scenarios. In this, Santa Catarina is similar to many areas of the world. This study also addresses decision makers' opinions about the provided information.Chapter 6evaluates the potential of a participatory approach for integrating risk analysis into decision making for rural land use and decision makers' view of the supplied information. It particularly focuses on two of the main risk-oriented information demands in the region: (1) yield predictions for maize on different planting dates and (2) economic information for different land use options. It also investigates decision makers attitudes towards risk, and the degree to which these could be changed by objective information, in Santa Catarina State, Brazil, typical of transitional economies, where neither direct (farmers) nor indirect (extensionists) decision makers had been exposed to concepts of risk. Different groups had markedly different levels of knowledge, analytic capacity, economic conditions, perspectives and needs, and therefore should be approached differently and with group-specific information. Farmers were mostly moderately or extremely risk averse. However, at the end they declared themselves willing to take risks if they have adequate information. Despite their lack of previous exposure to these concepts, participants were able to understand the presented information. It finally suggests that a participatory approach, by gathering, presenting and periodically discussing demanded information with decision makers is certainly a practice to be further explored to effectively integrate risk assessment into rural decision making.Chapter 7:Demand driven land evaluation has been suggested by several authors as an attempt to make the information more relevant and useful to rural decision makers for land use planning. This research showed that this approach is possible in practice and should be further explored, but its effectiveness needs time to be definitely confirmed
Applicability of a distributed watershed pollution model in a data - poor environment in Santa Catarina state, Brazil
A participatory approach for integrating risk assessment into rural decision - making : a case study in Santa Catarina, Brazil
Incomplete information is one of the main constraints for decision-making, which are then by definition risky. In this study, formal risk concepts were introduced in decision-makers¿ meetings according to local demands and following a participatory approach, as a first step towards integrating risk assessment into rural decision-making in Santa Catarina, Brazil. Semi-structured interviews and meetings were conducted with extensionists and farmers. The following information was presented and discussed: (1) the time series and frequency distribution of maize yield predictions, simulated by the GAPS computer program for 16 feasible planting dates, representing climatic risks, both within and between years; and (2) a simple economic analysis (gross margin) and income probabilities for seven land-use options over a recent five-year period, followed by an interactive exercise where probabilities of achieving user-supplied target gross margins were calculated according to participants¿ actual information, using the computer program @RISK. This paper also investigates decision-makers¿ attitudes towards risk, and how these were influenced by objective information. Although results from a study such as this are not definitive, considering that the effects of the information on actual decision-making require some time to become evident, it was already possible to conclude that the risk-orientated information presented according to local demands and following a participatory approach had a positive impact on decision-makers¿ understanding and perceptions. This approach should be further explored to effectively integrate risk assessment into rural decision-makin
The use of land evaluation information by land use planners and decision-makers: a case study in Santa Catarina, Brazil
Using spatial information to improve collective understanding of shared environmental problems at watershed level
The decrease in stream water quality due to intensive agriculture is an environmental problem of concern in various parts of the world. This problem may not be appropriately addressed due to insufficient knowledge of its causes, in particular, the locations of the primary pollution sources and the relative magnitude of the problem under different management scenarios. In some situations, this information may be known but not adequately communicated to, or perceived by, the stakeholders who should decide on corrective action. A participatory approach, which includes the negotiation between suppliers and users of information and visualisation of scenarios, could be a powerful tool to overcome these inadequacies. This paper describes the provision of spatial information and the results of spatially explicit pollution modelling exercise to stakeholders in a participatory workshop, and evaluates the extent to which this information influenced decision-making. Workshops were organised with farmers and extensionists in the west region of Santa Catarina State, Brazil. Spatial information (synoptic satellite image, orthophoto mosaic, location of pig producers) and results from a spatially explicit dynamic pollution model (AgNPS) for previously prepared scenarios were presented. Questionnaires were administered at four different times during the workshops to test participants¿ reactions to, and opinions of, the information provided. Participants were able to understand and react to the spatial information despite their lack of previous exposure to such materials. Both visualisation and discussion caused major shifts in perception of the problem and suggestions for solutions. Participatory visualisation of scenarios enhanced perception and increased understanding of the water pollution problem caused by intensive pig farming and stimulated the collective search for solution
The Use of land evaluation information by land use planners and decision-makers; a case study in Santa Catarina, Brazil
Land evaluation is the prediction of land performance over time under specific uses, to guide strategic land use decisions. Modern land evaluation has a 30 year history, yet the results have often been disappointing. Land users and planners have been reported to ignore land evaluations, perhaps reflecting poor quality, low relevance, or poor communication. To test the success of a large land evaluation exercise undertaken as part of micro-catchment project in Santa Catarina State, southern Brazil, we queried agricultural extensionists, considered as the primary land evaluation clients. We used a questionnaire with both structured and open questions, to determine their experiences with, and attitudes to, the current land evaluation method. The soil resource inventory and associated land evaluation had some usefulness, but were not in general used for their intended purpose, namely farm planning. This was mainly because they did not contain crucial information necessary to such planning in the actual context of the farmer taking decisions. The primary deficiencies were identified as: (1) no estimate of environmental degradation risk; (2) no financial analysis; (3) no social analysis of decision-makers' attitudes and preferences; (4) no risk assessment for weather, yields, profits and market; and (5) insufficiently-specific alternative land uses. These deficiencies could have been avoided with a demand-driven approach, evaluating and reporting according to the true needs and opportunities of the decision-makers