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1.
In Brazil, incorporating the environmental dimension to the planning process is a challenging process. Planning has historically been carried without considering environmental protection concerns. The country's large development projects have engendered a discussion on the feasibility of these works given the conflicts with environmental policies. The strategic environmental assessment (SEA) is a tool that has the potential to integrate the sectoral, territorial and environmental perspectives to promote sustainable development, as shown by international experience. Its use has not yet been regulated in Brazil, only been voluntary initiatives, both public and private, have been implemented. This paper presents the structure and results of the SEA of the plans to expand silviculture of eucalyptus and biofuels in the Extreme South Region of Bahia state, in the Brazilian Northeast, in a context of sectoral planning dissociated from government guidelines for land use policy and environmental protection. It portrays a practical case of methodological proposal for the use of socio-environmental criteria to establish limits for land occupation by monocultures, for each of the municipalities of the study region, according to their specific climate, soil, relief and environmental preservation characteristics. Various alternatives were identified to ensure areas with greater productivity for small family farming and areas with potential for preservation. SEA helped to a better understanding of the effects of the expansion of the planting areas in each alternative, which was essential to help all stakeholders visualize the consequences of their strategies. Consequently, as results the SEA outlined a series of guidelines and restrictions for the various levels of government and the production sector. For instance, SEA suggested for Federal, State and Municipality governments that areas with better soil and climate conditions could be reserved for public policies to incentive the diversification of the uses of the territory, such as food production. SEA also suggests the adoption of incentive programs to establish multiple-use forests. The SEA recommended that the state government integrate its program for strengthening family agriculture with land-use planning criteria, based on cooperative systems The methodology employed has evidences to be replicable in other regions of Brazil and in developing countries.  相似文献   

2.
We propose a simple heuristic that uses open-access models and government data on agricultural activities to estimate total carbon emissions from agriculture, the gross carbon benefit and the opportunity cost per tonne CO2-e from revegetating to environmental plantings or plantation forestry. We test this across ten areas of mixed land-use that represent diverse Australian agricultural systems along a rainfall transect. The local value of agricultural production was obtained from government statistics and used to estimate the current economic opportunity cost of converting cleared agricultural land to mixed environmental plantings for carbon sequestration. Gross carbon benefit from revegetation was closely related to current agricultural use, as was financial opportunity cost. These were not related simply to site productivity potential or rainfall. The proportion of land cleared for agriculture that would need to be re-vegetated to achieve a localised zero-carbon land-use scenario was calculated by the ratio of current agricultural emissions to gross carbon benefit from revegetation; this ranged from 13% to 66% for groups of agricultural industries across Australian rainfall transects. While the heuristic does not capture the detail of models built specifically for local research questions it does provide a different lens on the questions policy makers and land managers may ask about the costs and benefits of revegetating agricultural land, and provides open-access methods to guide them.  相似文献   

3.
This study evaluated the potential effectiveness of future carbon reserve scenarios, where U.S. forest landowners would hypothetically be paid to sequester carbon on their timberland and forego timber harvests for 100 years. Scenarios featured direct payments to landowners of $0 (baseline), $5, $10, or $15 per metric ton of additional forest carbon sequestered on the set aside lands, with maximum annual expenditures of $3 billion. Results indicated that from 1513 to 6837 Tg (Teragrams) of additional carbon (as carbon dioxide equivalent, CO2e) would be sequestered on U.S. timberlands relative to the baseline case over the next 50 years (30–137 Tg CO2e annually). These projected amounts of sequestered carbon on timberlands take into account projected increases in timber removal and forest carbon losses on other timberlands (carbon leakage effects). Net effectiveness of carbon reserve scenarios in terms of overall net gain in timberland carbon stocks from 2010 to 2060 ranged from 0.29 tCO2e net carbon increase for a payment of $5/tCO2e to the landowner (71% leakage), to 0.15 tCO2e net carbon increase for a payment of $15/tCO2e to the landowner (85% leakage). A policy or program to buy carbon credits from landowners would need to discount additions to the carbon reserve by the estimated amount of leakage. In the scenarios evaluated, the timber set-asides reduced timberland area available for harvest up to 35% and available timber inventory up to 55%, relative to the baseline scenario over the next 50 years, resulting in projected changes in timber prices, harvest levels, and forest product revenues for the forest products sector.  相似文献   

4.
以晋江市为研究区,依据2005年,2010年和2015年3期土地利用数据,从生态系统服务功能角度,运用Costanza的方法,结合谢高地修正的我国生态服务价值当量因子表,分析了晋江市土地利用变化与生态服务价值的响应关系。结果表明:2005-2015年,晋江市的城镇用地显著扩张,而耕地和林地却急剧减少,土地利用的生态系统服务价值总体呈逐年下降趋势。通过分析晋江市土地利用变化对生态服务价值的影响可以为科学合理利用土地,保障人口、资源、环境的可持续发展提供决策支持。敏感性分析表明,生态服务价值对生态服务价值系数的变化是缺乏弹性的,因此结果是可信的。在编制土地利用规划时应将生态服务价值考虑其中,尤其是应注重保护湿地、水域、林地等生态服务价值系数高的土地利用类型,以期实现晋江市的可持续发展。  相似文献   

5.
随着地理信息系统的发展,其成果广泛应用于土地利用监管、生态环境监测以及农业等各个方面。依据达州市2013年和2020年土地利用情况的矢量数据,通过土地利用动态度和主成分分析的方法,对达州市土地利用变化状况及其驱动因素进行分析。结果显示:达州市未利用土地占比大,建设用地持续增长;而驱动因素主要有社会经济发展、人口增长和政策。  相似文献   

6.
Changes in land use and land tenure can influence both physical fragmentation and ownership fragmentation of landscapes, with implications for biodiversity. In this study, we evaluated changes in land use and land tenure in the Tijuana River Watershed, a region of high biodiversity and endemism, following the implementation of a new Agrarian Law which allowed for privatization and sales of communal land (ejidos) beginning in 1992. In order to understand changes in land use and cover, we constructed maps from aerial photographs and Aster images and measured changes between 1994 and 2005. In order to understand changes in land tenure, we collected data from Mexican government sources on ejido land size, ownership, and sales, and we conducted 55 structured interviews with ejidatarios in the watershed. Our results demonstrate that land-use/cover change between 1994 and 2005 was dominated by an increase in urban area and grasslands, and a decrease in coastal sage scrub, chaparral, and, to a lesser degree, agriculture. In particular, the conversion of coastal sage scrub has left a far more fragmented landscape than existed in 1994. In addition, most of the ejidos in the watershed, as well as individuals interviewed, had participated in some stage of the land certification and titling process allowed by the new Agrarian Law, resulting in substantial changes in land tenure. However, land tenure security appeared to play a larger role than a desire to sell land and, contrary to studies from other regions, full title to the land was obtained in a range of urban and rural settings, rather than primarily on land closest to urban zones. Our results suggest that past predictions regarding future urban growth and fragmentation of native vegetation in the region have proven accurate and highlights regions of change that merit further study.  相似文献   

7.
Globally, there is growing demand for increased agricultural outputs. At the same time, the agricultural industry is expected to meet increasingly stringent environmental targets. Thus, there is an urgent pressure on the soil resource to deliver multiple functions simultaneously. The Functional Land Management framework (Schulte et al., 2014) is a conceptual tool designed to support policy making to manage soil functions to meet these multiple demands. This paper provides a first example of a practical application of the Functional Land Management concept relevant to policy stakeholders. In this study we examine the trade-offs, between the soil functions ‘primary productivity’ and ‘carbon cycling and storage’, in response to the intervention of land drainage systems applied to ‘imperfectly’ and ‘poorly’ draining managed grasslands in Ireland. These trade-offs are explored as a function of the nominal price of ‘Certified Emission Reductions’ or ‘carbon credits’. Also, these trade-offs are characterised spatially using ArcGIS to account for spatial variability in the supply of soil functions.To manage soil functions, it is essential to understand how individual soil functions are prioritised by those that are responsible for the supply of soil functions – generally farmers and foresters, and those who frame demand for soil functions – policy makers. Here, in relation to these two soil functions, a gap exists in relation to this prioritisation between these two stakeholder groups. Currently, the prioritisation and incentivisation of these competing soil functions is primarily a function of CO2 price. At current CO2 prices, the agronomic benefits outweigh the monetised environmental costs. The value of CO2 loss would only exceed productivity gains at either higher CO2 prices or at a reduced discount period rate. Finally, this study shows large geographic variation in the environmental cost: agronomic benefit ratio. Therein, the Functional Land Management framework can support the development of policies that are more tailored to contrasting biophysical environments and are therefore more effective than ‘blanket approaches’ allowing more specific and effective prioritisation of contrasting soil functions.  相似文献   

8.
The Brazilian Cerrado, a biodiverse savanna ecoregion covering 1.8 million km2 south and east of the Amazon rainforest, is in rapid decline because of the expansion of modern agriculture. Previous studies of Cerrado land-use and land-cover (LULC) change imply spatial homogeneity, report widely varying rates of land conversion, use ambiguous LULC categories, and generally do not attempt to validate results. This study addresses this gap in the literature by analyzing moderate-resolution, multi-spectral satellite remote sensing data from 1986 to 2002 in two regions with identical underlying drivers. Unsupervised classification by the ISODATA algorithm indicates that Cerrado was converted to agro-pastoral land covers in 31% (3646 km2) of the study region in western Bahia and 24% (3011 km2) of the eastern Mato Grosso study region, while nearly 40% (4688 km2 and 5217 km2, respectively) of each study region remained unchanged. Although aggregate land change is similar, large and contiguous fragments persist in western Bahia, while smaller fragments remain in eastern Mato Grosso. These findings are considered in the current context of Cerrado land-use policy, which is dominated by the conservation set-aside and command-control policy models. The spatial characteristics of Cerrado remnants create considerable obstacles to implement the models; an alternative approach, informed by countryside biogeography, may encourage collaboration between state officials and farmer-landowners toward conservation land-use policies.  相似文献   

9.
目前土地利用和管理的政策重点为:调结构、调过剩产能、完善城乡统筹中土地制度,严格保护耕地.针对资源供应的刚性影响逐步扩大,全社会的发展理念发生着深刻的变化,为提高资源利用效率、走节约集约道路提供了良好的外部环境.应该供需双向调节,加速结构调整、统筹城乡发展,促进城市转型,加快宜居城市建设、实施建立差别化供地政策、强化耕地建设性保护专项工作.对2011年来讲,促进经济发展方式转变,节约集约用地是关键,严格保护耕地是硬任务,应推动土地利用方式根本转变.促进经济发展方式转变和经济社会又好又快发展.  相似文献   

10.
基于CA-Markov模型的大连市旅顺区土地利用变化及预测研究   总被引:1,自引:0,他引:1  
实时监测土地利用及其变化(LUCC)的状况对于经济增长、社会进步、环境保护以及生态文明建设具有重要的意义。本文基于IDRISI软件中的CA-Markov模型,分析了大连市旅顺区1994年-2014年的土地利用变化,同时预测了2024年的土地利用状况。结果表明:旅顺自1994年来,建筑用地面积逐年增加,并主要集中在中南部和西部沿海地区,与此同时,耕地面积也逐年增加,但由原来的西部逐渐演退至北部区域的丘陵地带,林地面积逐步萎缩,面积大幅下降,其主要被开垦为耕地或建筑用地,在本区域中南、西南部,林地大多直接转变为建筑用地或先转变为耕地再转变为建筑用地,而北部则主要转变成了耕地和相对较小的居民点,水域(湖泊、河流)的面积逐年减少,湖泊、水库面积萎缩,随着城镇化的加快和人口数量的不断增加;由于不断地城市用地开发和林地的砍伐以及耕地的弃用等综合因素导致,未利用地减少。总体上,旅顺的土地利用变化由于经济建设的力度不断加大,人工自然景观用地越来越多,生态安全压力不断增大,未来十年间,旅顺土地利用将持续20年来的趋势,但变化速度放缓。  相似文献   

11.
广义立体土地资源资产价值研究   总被引:1,自引:0,他引:1  
研究目的:通过对土地概念演进分析,指出土地资源资产不仅有广义和狭义之分,而且有平面与立体之别,其土地资源资产价值必然表现出广义立体价值形态。研究方法基于对土地资源资产概念在理论与实践中认识的深化,应用资源经济学和生态经济学方法,对广义立体土地资源资产价值进行理论分析。研究结论广义立体土地资源资产价值的提出和应用有利于合理增加供给,抑制过度需求,调节供需矛盾:有利于提高土地资源资产利用的效率和集约度;有利于农地的保护:有利于将资源资产纳入国民经济核算体系,有利于对土地资源资产实施系统管理。  相似文献   

12.
The environmental, cultural and economic consequences of land use change, including abandonment of agricultural use, have been recognized for a long time. It has often been assumed that the transformations of the agricultural systems in developed countries (and particularly in Europe) took place, for the main part, in the immediate years after the Second World War. In this paper we present a review of different statistical and cartographic sources available for a peripheral region in Europe (Galicia, Spain) characterized by small-scale farming and a very fragmented property system, that suggests otherwise: modernization of agriculture apparently took place without major changes in agricultural area until the country gained access to the European Economic Community, and the effect of Common Agricultural Policy reforms during the decade of 1990 is suggested as a major driver for the net decrease of agricultural area in the region between 1956 and 2004. On the other hand, this paper emphasizes the spatial complexity of agricultural abandonment with a case study, showing a large degree of variability at municipal scale and thus the need of future EU-level projects to work at least at municipal (Local Administrative Units 2, LAU 2) level. Finally, a multinomial logistic model for observed changes is included that shows how biophysical limitations were the main drivers behind abandonment of agriculture at parcel scale, while structural qualities related to property structure were strongly associated to the incorporation of former shrublands to agricultural use. Besides, Farm Structure Surveys were revealed as an unreliable source for the assessment of changes in total agricultural area in the studied region.  相似文献   

13.
Land evaluation, an integral part of land use planning, has been established as one of the preferred methods to support sustainable land use management. In essence, land evaluation aims to compare and match each potential land use with the properties of individual parcels of land, also called land units. A land unit is an area that is, according to predetermined properties, different from the surrounding land and can be assumed to have homogeneous land properties (e.g. climate, soils, cover). Land components (also called landform elements, terrain units or land surface segments) are often used as land units, mainly because their boundaries frequently coincide with transitions in environmental conditions. Although land components have traditionally been delineated by studying topographical maps, interpreting aerial photographs and making field measurements, such manual mapping techniques are very time-consuming and subjective. Land component maps can be generated more objectively and faster by using computer algorithms. This paper compares the maps produced by three algorithms, namely the automated land component mapper (ALCoM), the iterative self-organizing data analysis technique algorithm (ISODATA) and multi-resolution image segmentation (MRS), to determine which technique produces the most homogenous and morphologically representative land components for an area in the Western Cape province of South Africa. The results revealed that the three methods produced significantly different land component maps. While ISODATA's units were relatively homogenous, their boundaries rarely followed morphological discontinuities. ALCoM performed better in delineating land components along terrain discontinuities, but produced relatively heterogeneous land components. Overall, MRS performed consistently well and was significantly more sensitive to morphological discontinuities than the other two methods tested. Land use managers should, however, use MRS with care as more research is needed to determine what effect its different input parameters have on land unit boundaries.  相似文献   

14.
In the coming decades, an increasing competition for global land and water resources can be expected, due to rising demand for food and bio‐energy production, biodiversity conservation, and changing production conditions due to climate change. The potential of technological change in agriculture to adapt to these trends is subject to considerable uncertainty. In order to simulate these combined effects in a spatially explicit way, we present a model of agricultural production and its impact on the environment (MAgPIE). MAgPIE is a mathematical programming model covering the most important agricultural crop and livestock production types in 10 economic regions worldwide at a spatial resolution of three by three degrees, i.e., approximately 300 by 300 km at the equator. It takes regional economic conditions as well as spatially explicit data on potential crop yields and land and water constraints into account and derives specific land‐use patterns for each grid cell. Shadow prices for binding constraints can be used to valuate resources for which in many places no markets exist, especially irrigation water. In this article, we describe the model structure and validation. We apply the model to possible future scenarios up to 2055 and derive required rates of technological change (i.e., yield increase) in agricultural production in order to meet future food demand.  相似文献   

15.
The rate and location of cropland expansion onto cattle pastures in Brazil could affect global food security, climate change, and economic growth. We combined mapping, statistical modeling, and qualitative methods to investigate patterns and processes of pasture to crop conversion (P2C) in Mato Grosso State (MT), Brazil, a globally important center of agricultural production. P2C land constituted 49% of cropland expansion from 2000 to 2013. For a random sample of ̃250 m pixels in MT, we estimated a regression model skilled at predicting P2C land in the rest of the state as a function of cattle ranching suitability, cropping suitability, and P2C conversion costs. Surprisingly, just 1/7 of pasture agronomically suitable for cultivation had undergone P2C. Hedonic regressions revealed that agronomic characteristics of land were associated with less than 20% of the variation in cropland suitability. Instead, the majority of the variation stemmed from a combination of proximity to agricultural infrastructure, characteristics of neighboring lands, and time fixed effects. The weak relationship between agronomic characteristics of land and P2C location suggests a less certain future for P2C than projections made with agronomic models. Consequentially, complications may arise for greenhouse gas mitigation policies in Brazil predicated on widespread expansion of cropland on pasture vs. natural areas. Our follow-up qualitative research shows that because P2C has often involved land rentals or sales, poorly functioning land institutions may have constrained P2C. Locally poor land quality, omitted from agronomic P2C predictions, can either catalyze or constrain P2C by limiting returns to ranching, farming, or both. Interventions to control rates and locations of P2C should take these insights into account.  相似文献   

16.
In order to reduce the soil erosion rate on the Chinese Loess Plateau, the Chinese government launched in 1999 the “Grain for Green” program (GfG). The objective of this program was to increase the forest cover on steep slopes in the landscape by planting trees and sowing grasses on former cropland. The program was a massive investment by the Chinese government. By the end of 2005 the GfG-program was implemented in an area of 87,000 km2 in which about 400–600 million trees were planted. At present it is not known to what extent this program was successful. This paper examines the effects of the GfG-program on the mean annual vegetation cover in the Shaanxi province. A decadal time series of SPOT VEGETATION imagery from 1998 till 2005 were used to calculate NDVI-values in four counties with different rainfall regimes. By means of a regression between preceding rainfall and NDVI-values the effects of rainfall variability were filtered out. A trend analysis of the corrected NDVI time series pointed out that the GfG-program resulted in a significant increase of the vegetation cover on farmland in the northern part of Shaanxi province. In the southern part of the province, which has a more humid climate and large areas of irrigation farmland no significant increase of the vegetation cover on farmland could be detected.  相似文献   

17.
This study compiles and analyses national-level data on land use change (LUC) and its causes in Indonesia and Malaysia over the past 30 years. The study also explores the role that palm oil has played in past LUC and that projected growth in palm oil production may play in LUC until 2020 and suggests strategies to minimize negative effects. Data collection for the study revealed that the quality and quantity of data on LUC on a national scale over time are low. Despite these uncertainties, the overview of past LUC indicates that large changes in land use have occurred in Indonesia and Malaysia. In Indonesia, LUC can primarily be characterized by forest cover loss on 40 million ha (Mha) of land, a 30% reduction in forest land. Deforestation in Malaysia has been smaller in both absolute and relative terms, with a forest cover loss of nearly 5 Mha (20% reduction in forest land). Other large changes in Malaysia occurred in permanent cropland (excluding oil palm), which has decreased rapidly since the early 1990s, and in land under oil palm cultivation, which experienced a sharp increase. Projections of additional land demand for palm oil production in 2020 range from 1 to 28 Mha in Indonesia. The demand can be met to a large extent by degraded land if no further deforestation is assumed. In Malaysia, expansion projections range from 0.06 to 5 Mha, but only the lowest projection of oil palm expansion is feasible when only degraded land may be used. The role of palm oil production in future LUC depends on the size of the projected expansion as well as agricultural management factors such as implementation of best management practices, earlier replanting with higher yielding plants, and establishment of new plantations on degraded land. The current use of degraded land needs to be investigated in order to reduce possible indirect LUC, land tenure conflicts, or other social impacts. In addition to minimizing direct and indirect LUC by the palm oil sector, measures that reduce deforestation triggered by other causes must also be implemented. A key element for doing so is better planning and governance of land use, which entails more appropriate demarcation of forest land and protection of land that still has forest cover, improved monitoring of land use, and more research to uncover the complexities and dynamics of the causes and drivers of LUC.  相似文献   

18.
关于土地利用与管理形势观测点建设有关问题的思考   总被引:1,自引:0,他引:1  
土地利用与管理形势观测点建设对于国家土地督察机构有效地开展形势分析工作,提升土地督察工作科学性和工作成效具有重要意义。本文在实际工作的基础上,对土地利用与管理形势观测点建设工作有关问题进行了思考,重点从土地利用与管理形势及其观测点的内涵,观测指标体系构建、观测点布局、观测指标数据获取和验证等方面进行了有益探索,以期能为督察机构开展形势分析工作提供有益参考。  相似文献   

19.
This paper links urbanization strategies to changes in land use and associated impacts on rural communities and agro-ecosystems in a rural area of China. Energy, monetary and human time variables as well as information on environmental pressures, have been combined to compare different typologies of households and the metabolism of different patterns of land use from an integrated perspective. The results show that urbanization strategies, aimed at shifting the current land use and at displacing the local population, while increasing the economic efficiency is also associated with an increase in fossil energy consumption and environmental pressure, as well as a reduction of the multifunctional characteristic of the area under investigation. Based on these findings the paper also offers a critical discussion of the Chinese rural development policy arguing that the multifunctionality of rural areas should be taken into account by Chinese policy-makers and planners as a viable strategy to achieve rural development targets.  相似文献   

20.
With growing awareness of fire hazard as an environmental threat within tropical rainforests, the state of Brazil initiated a set of fire control policies aimed at monitoring and ameliorating fire hazard in the Amazon region. These policies were developed in the aftermath of large-scale fire events and reflect a conservationist discourse that responded to internal as well as international environmental concerns. In doing so, the policies have framed the “fire problem” around those who use fire in their land use practices, in particular small-scale agriculturalists. Yet, land policy in general has repeatedly failed to address the institutional arrangements which compel small-scale farmers to use fire in their agricultural practices and the underlying development processes that have made the landscape more vulnerable to accidental spread of fire. Using regional level data on small-scale farmers, I suggest that the conservation oriented approach of fire policy may not be enough to curtail accidental fire events and instead that the fire issue needs to be positioned within rural development as well.  相似文献   

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