Integrated assessment of cropping patterns under different policy scenarios in Quzhou County,North China Plain

Agricultural land use is affected by government policies and leads to different consequences of regional sustainability. In this work, changes in cropping patterns including acreage, cropping locations and management-related environmental impacts were simulated under various policy scenarios for Quzhou County, China. This county is in China's major agricultural region, the North China Plain. Four dominant crop systems were categorized (winter wheat/summer maize, winter wheat/summer maize/spring maize, cotton, and vegetables) and analyzed, following two alternative policy scenarios that either prioritized government funding to subsidize crop production (“subsidy” scenario) or promoted advanced irrigation techniques (“technique” scenario). Input–output coefficients for all four crop systems were determined, mainly irrigation demand, yield, and price of produce, but other factors like a limited area of arable land and scarce regional water resources were also considered. For the simulation, a LINDO Inc. system was linked with the CLUE (Conversion of Land Use and its Effects) model. Temporal changes of crop systems were simulated with the LINDO system, whereas spatial dynamics of cropping patterns were simulated with the CLUE model, based on land suitability maps. The results show that crop patterns changed variably with time under the two scenarios, and water availability was the primary constraint on sustainability of land use. Under the subsidy scenario, winter wheat/summer maize/spring maize became dominant across the entire county, replacing other crop systems. In contrast, the vegetable system gradually occupied farmland surrounding the township under the technique scenario. The different policies produced opposite consequences for regional sustainability. Although a “subsidy” policy contributed to farmers’ income, it did not encourage water conservation for sustainable crop production, leading to land abandonment because of water shortage. In contrast, the “technique” policy partially cut direct financial benefits to farmers, but promoted water conservation and made a substantial contribution to agricultural sustainability.     

基于SPOT/VGT数据的中国北方耕地物候提取研究

耕地物候的空间格局综合反映了作物种植在环境因子及人类活动双重作用下的空间差异性,因此耕地物候识别成为农业遥感应用的热点之一。研究利用SPOT的植被指数产品开展我国北方耕地作物种植制度空间分布的遥感识别并分析耕地种植制度空间分布特征。首先使用非对称高斯函数拟合法对时间序列植被指数进行重构,然后采用多项式和谐波函数拟合数据来确定耕地的生长季个数,最后通过比例阈值法提取耕地的生长季开始期和结束期。在上述过程中结合先验知识引入波峰阈值并通过对NDVI时间序列数据进行"掐头去尾"处理来保证耕地种植制度识别以及物候信息获取的准确性。基于SPOT/VGT数据对我国北方15省的耕地种植制度进行了识别,并在此基础上分别提取了不同生长季的耕地物候信息并分析了其空间格局特征。结果表明,适当引入先验知识有利于正确识别耕地种植制度和准确获取耕地物候信息,2005年我国北方耕地的种植制度以一年一熟为主,一年二熟制主要分布在北纬40°以南的平原地区。其中第一生长季的空间格局差异比第二生长季更加明显,同时生长季结束期分布的时间范围比开始期更为集中。总之我国北方耕地物候的空间格局与种植制度密切相关,受到自然资源和人类活动的共同影响。     

Geographical downscaling of outputs provided by an economic farm model calibrated at the regional level

There is a strong need for accurate and spatially referenced information regarding policy making and model linkage. This need has been expressed by land users, and policy and decision makers in order to estimate both spatially and locally the impacts of European policy (like the Common Agricultural Policy) and/or global changes on farm-groups. These entities are defined according to variables such as altitude, economic size and type of farming (referring to land uses). European farm-groups are provided through the Farm Accountancy Data Network (FADN) as statistical information delivered at regional level. The aim of the study is to map locally farm-group probabilities within each region. The mapping of the farm-groups is done in two steps: (1) by mapping locally the co-variables associated to the farm-groups, i.e. altitude and land uses; (2) by using regional FADN data as a priori knowledge for transforming land uses and altitude information into farm-groups location probabilities within each region. The downscaling process focuses on the land use mapping since land use data are originally point information located every 18 km. Interpolation of land use data is done at 100 m by using co-variables like land cover, altitude, climate and soil data which are continuous layers usually provided at fine resolution. Once the farm-groups are mapped, European Policy and global changes scenarios are run through an agro-economic model for assessing environmental impacts locally.     

Economic contribution of French serradella (Ornithopus sativus Brot.) pasture to integrated weed management in Western Australian mixed‐farming systems: an application of compressed annealing*

Sowing phases of French serradella (Ornithopus sativus Brot.) pasture between extended cropping sequences in the Western Australian wheatbelt can sustain grain production through restoring soil fertility and reducing selective herbicide use. The objective of this article is to investigate the profitability of rotations involving this pasture under a variety of weed management scenarios to obtain greater insight into its value for mixed farming systems in this region. A stochastic search procedure, compressed annealing, is used to identify profitable sets of weed management strategies in a simulation model representing a large number of potential combinations of chemical and non‐chemical forms of weed control. In contrast to a continuous‐cropping sequence, the inclusion of a serradella phase in a rotation is profitable at high weed densities and with increasing levels of herbicide resistance. A single year of pasture in the rotation is optimal if resistance to Group A selective herbicides is present at the beginning of the planning horizon, but a three‐year phase is required if resistance to multiple herbicide groups is observed. Sowing a serradella pasture twice over a two‐year phase is also shown to be economically attractive given benefits of successive high weed kills.     

Reorienting paradoxical land use policies towards coherence: A self-adaptive ensemble learning geo-simulation of tea expansion under different scenarios in subtropical China

The expansion of cash crops has raised contradicting interests between two bureaucratic bodies (the economy-oriented one that advocates cash crop production and the conservation-oriented one that focuses on natural resources protection) in many places around the world. Recent past has saw growing efforts on the theoretical linkages between cash crop production and conservation, but the solutions to the cash cropping −related land use conflicts remain as violent controversy. Using a geo-simulation approach, this paper models the tea expansion under different policy scenarios and evaluates the effectiveness of these policies in Anji County (China), as a contribution to the scientific basis for formulating sustainable cash cropping practices and alternative land use policies. In particular, a new self-adaptive cellular automaton model based on ensemble learning (EL-CA) is developed and three policy scenarios (economy-over-conservation (EOC), conversion-over-economy (COE), and economy-balance-conservation (EBC)) are set to predict the tea expansion patterns in 2025. Results show that the EL-CA model significantly outperforms the traditional CA models based on empirical statistics. We find that the tea expansion under the EOC scenario is much more intensive than that under the COE and EBC scenarios. The most outstanding ecological consequence of tea expansion is the occupation of forests. Employing an equivalent coefficient approach, we further quantify the trade-offs between economic incomes (from tea expansion) and ecological loss (due to ecosystem service value (ESV) declines) under the three policy scenarios. In the EOC scenario, the loss in ESV far exceeds the benefit of tea expansion. Net change of ESV is higher than that of economic return under the COE. The economic benefit is approximately equal to the ecological loss in the EBC scenario. The EBC should be a socially preferred scenario, since it leads to sustainable tea expansion and minimal ecological impacts. Though the EBC scenario is a desirable choice, how to enforce these policies is an important consideration. Given the complexity in the Chinese policy context, we finally propose several possible measures to promote the coherence of paradoxical policies involving the allocation of land for cash crop cultivation.     

An interdisciplinary approach to regional land use analysis using GIS, with applications to the Atlantic Zone of Costa Rica

Policy makers and other stakeholders concerned with regional rural development increasingly face the need for instruments that can improve transparency in the policy debate and that enhance understanding of opportunities for and limitations to development. To this end, a methodology called SOLUS (Sustainable Options for Land Use) was developed by an interdisciplinary team of scientists over a 10-year period in the Atlantic Zone of Costa Rica. The main tools of SOLUS include a linear programming (LP) model, two expert systems that define technical coefficients for a large number of production activities, and a geographic information system (GIS). A five-step procedure was developed for GIS to spatially reference biophysical and economic parameters, to create input for the expert systems and the LP model, to store and spatially reference model output data, and to create maps of both model input and output data. SOLUS can be used to evaluate the potential effects of alternative policies and incentive structures on the performance of the agricultural sector. A number of practical applications demonstrate SOLUS's capability to quantify trade-offs between economic objectives (income, employment) and environmental sustainability (soil nutrient balances, pesticide use, greenhouse gas emissions). GIS-created maps visualize the spatial aspects of such trade-offs and indicate hotspots where local goals may conflict with regional goals.     

ValorE: An integrated and GIS-based decision support system for livestock manure management in the Lombardy region (northern Italy)

Intensive agriculture and livestock breeding represent critical factors in the Lombardy region since the nitrate vulnerable zones are 62% of utilised agricultural plain area. The aim of reducing the environmental risk caused by agriculture activities (e.g. nitrogen losses into groundwater and atmosphere) can be only achieved through a critical and scientific analysis of livestock manure management in a whole-farm perspective. Keeping in mind this objective, the decision support system (DSS) ValorE was developed. It can be described as a tool able to evaluate from the environmental, technical, agronomic and economic points of view the main components of manure management (production, storage, treatment and land application) for a variety of livestock types (i.e., cattle, swine, poultry, sheep, goats and horses), under different scenarios adopted at farm and territorial scale. ValorE consists of three main components: data management subsystem, model management subsystem and two versions of user-interface, both for farm and territorial scale. Most of the inputs to the DSS comes from external databases, while a software tool developed in the .NET environment and implemented using object oriented programming (C# language), provides the logic to manage the scenario simulation of agronomic and environmental farm-scale models. Users and stakeholders can carry out comparative analysis, starting from the knowledge of the current perspective, in terms of manure management system at farm or territorial scale by interrogating the available databases. Moreover, they can generate different alternative scenarios thanks to different options for the manure handling and cropping system simulation. Then they can finally evaluate and compare different scenarios through multidisciplinary and synthetic indicators but also visualise spatial effects exploiting the coupled webGIS. ValorE is therefore an attempt to offer a comprehensive tool for improving both farm strategy and decision making process, which is particularly important in a very intensive agricultural area, with one of the highest livestock density in the world, as Lombardy.     

Cost of best management practices to combat agricultural runoff and comparison with the local populations’ willingness to pay: Case of the Austreberthe watershed (Normandy,France)

Land Use and Cover Changes (LUCCs) significantly increase the frequency of mudflows in the silty areas of north-western Europe and particularly in the NUTS 3 Seine-Maritime region (France). Predicting the effects of a range of possible LUCCs helps local authorities choose policies that can help to mitigate the risks to which local populations are exposed. In this article we build scenarios for changes in farming systems, with a 2015 horizon and with 2007 as the initial situation. These scenarios are assessed through combined biophysical and economic approaches. Two scenarios for the disappearance of dairy farming are chosen. One scenario has no public-action program (StopMilk), while the other one has a program based on the funding of best management practices (StopMilk-E). These scenarios are assessed at the small watershed scale (7 km²) in terms of both changes in farming systems and effects on runoff (use of the STREAM model). Finally, the economic evaluation of additional costs of StopMilk-E is extrapolated at the level of the Austreberthe watershed syndicate (214 km²), using the French Land Parcel Identification System (LPIS) with a spatially referenced database of cropping plans. StopMilk leads to a significant increase in runoff whereas the local public-action program proposed under StopMilk-E reduces runoff to below the 2007 level. The Austreberthe watershed residents’ willingness to pay for a 15-year program is around €395,000/year, which is not sufficient to balance the cost of the modified farming practices (€640,000/year over the first 3 years). Funding of the practices would require either subsidies from a higher level (Europe), borrowing by the community, and/or a more selective approach in the type and the location of farming practices to be funded. The method used for calculating costs at the watershed syndicate level shows the huge potential of new databases like LPIS (available in France since 2006) for the assessment of environmental issues.     

Shaping the landscape: Agricultural policies and local biodiversity schemes

This paper analyses the potential effect of local agro-environmental policies in promoting multifunctionality in a rural landscape, with a two-scale modelling framework: a regional scale for food demand and a local scale for the forces driving land use. The framework has been designed in four steps. First, the relative influence of the driving factors on the current land use pattern has been analysed. Two scenarios are designed that vary the external demand for the total land use, and alter more or less quickly the specific location factors that drive the landscape pattern. The first scenario considers trends in the external and internal driving forces. The second relies both on totally decoupled farm subsidies and unregulated housing growth. In both scenarios a local agro-environmental policy is introduced and we compare its consequences with the previous scenario's landscape pattern. The third step consists of a modelling exercise that analyses the likely outcome of each scenario on the development of land use patterns on a local scale. Last, these landscape patterns have been translated into ecological indexes that assess the effect of the policy options on the multifunctionality of the local landscape.     

省级开发区土地集约利用评价改进研究

为了解决现行评价工作中的不足,对影响安徽省级开发区土地集约利用的因素进行系统性分析,构造全面的评价指标体系和分析视角,使开发区管理机构全面、真实的掌握土地集约利用状况,促进土地节约集约利用.通过收集资料、调查研究,以客观评价为主、主客观评价相结合,系统性分析了影响省级开发区土地集约利用因素,以“开发区管委会”和“入区企业”两类主体,分别构建土地集约利用评价指标体系,实现既考虑到各个省级开发区的实际情况又能很好地为开发区的横向比较和整个省域内开发区的统筹和规划,以及相关政策的制定提供参考作用,使成果的利用更具针对性.     

土地利用效率影响因素分析——基于湖北的调查

在水土流失严重、非农建设用地不断扩张以及可供开发利用的土地后备资源匮乏的大背景下,农业生产用地的有效使用成为当务之急。本文以复种指数、土地生产率、资金投入产出率和劳动力投入产出率等作为测度土地利用效率的指标,着重分析了土地细碎化和农户兼业等因素的影响。依据湖北省农村的随机抽样数据,实证分析得到的结论表明,土地细碎化对土地利用效率产生影响,在统计意义上不明显;农户兼业对复种指数的作用为正,对资金投入产出率的作用为负,对土地生产率和劳动力投入产出率的作用不显著;传统循环农业模式有利于提高土地利用效率。为此,本文提出必须毫不犹豫地坚持土地家庭承包经营方式不动摇;进一步加大"三农"投入力度;加快工业化和城镇化步伐,推动农村剩余劳动力尽快转移;大力扶持循环农业发展模式。     

Forests to fields. Restoring tropical lands to agriculture

In discussing land use in tropical forest regions, there is an emphasis on the following topics: the need for the expansion of cropping areas, the precedent for use of the tropical forest for cropping based on past use patterns, the pressure from conservationists against cropping, debunking the mythology that forests are "natural" and refuting the claims that forest clearance is not reversible, the archeological evidence of past forest use for agricultural purposes, abandonment of tropical land to forest, and rotation of forest and field. The assumption is that the way to stop food importation is to increase crop production in the tropics. Crop production can be increased through 1) land intensification or clearing new land, 2) output per unit of land increases, or 3) reallocation to agriculture land previously cleared and overgrown with tropical forest. "Temporary" reuse of land, which reverted back to tropical forest, is recommended. This reuse would ease population pressure, and benefit bioconservation, while populations stabilize and further progress is made in international plant breeding. The land would eventually be returned to a forest state. Conservation of tropical forest areas should be accomplished, after an assessment has been made of its former uses. Primary forests need to identified and conversion to farming ceased. Research needs to be directed to understanding the process of past forest regeneration, and to devising cropping systems with longterm viability. The green revolution is unsuitable for traditional cropping systems, is contrary to demands of international funding agencies for sustainability, and is not affordable by most poor farmers. Only .48 million sq. km of closed forest loss was in tropical rainforests; 6.53 million sq. km was lost from temperate forests cleared for intensive small-scale peasant farming. The use of tropical forest land for farming has some benefits; crops in the wetter tropics are perennial, which would "reduce seasonal soil tillage, increase nutrient cycling, and remove a lower proportion of biomass." Water availability would not be a problem. Low soil nutrient levels could be increased with cutting and burning or fertilizer. The key is proper and careful management, particularly under intensive cropping systems such as rice production or extensive long fallow shifting cultivation.     

Urban agriculture and land use in cities: An approach with the multi-functionality and sustainability concepts in the case of Antananarivo (Madagascar)

Urban planners are increasingly interested in agriculture around cities and have to decide whether to maintain or not areas of agricultural land use within and close to growing cities. There is therefore a need for researchers to design tools to guide public decision-making on land use. Various approaches, originating from different disciplines, may be adopted in this respect. We designed an interdisciplinary research program in order to test two related concepts: the “sustainability” and the “multi-functionality” of agriculture. We show that these concepts provide a useful framework for obtaining appropriate knowledge about urban agriculture, which urban planners could apply in real situations. In close collaboration with urban planners, we applied an interdisciplinary research methodology, based on common farm surveys and territorial approaches, to the Antananarivo area (Madagascar). The main functions analyzed were the food production and environmental roles of urban agriculture. Two aspects of sustainability were assessed: the farm sustainability and the territorial sustainability, with expert scores. This approach identified a wide diversity of farming systems that performed differently, depending on their intra- or suburban location. The food supply function appeared to be important not only for fresh produce but also for rice consumption. The function of protection against flooding is now important and this importance will increase with climate change. A diagnosis of sustainability was made and discussed with urban planners: several farming systems and zones were identified in which agriculture was considered important as a means of maintaining or developing the food supply, employment and incomes, and even landscape or environmental quality. We also identified other areas in which poor production conditions and/or the negative effects of urbanization on agriculture jeopardized its sustainability. This methodology appeared to be useful for determining the most appropriate role of urban agriculture in the land-use planning of this city. Our study raises new questions on the subject and should lead to more focused research programmes. We discuss several points of interest and the limitations and possible extension of this method.     

农村集体经营性建设用地价格影响因素的实证分析*——基于江西省余江县179份交易案例

[目的]确定农村集体商服用地、工业用地价格的影响因素,为科学评估农村集体经营性建设用地地价、构建城乡统一建设用地市场提供参考。[方法]利用全国农村土地使用制度改革试点之一的江西省余江县179个交易案例,运用特征价格模型分析农村集体商服用地、工业用地价格的影响因素及各类因素的贡献率。[结果](1)农村集体商服用地价格的主要影响因素依次为乡镇财政收入、人均纯收入、到客运站距离、到国道的距离、教育设施;农村集体工业用地价格的主要影响因素依次为人均纯收入、人均农村居民点面积、到客运站的距离、到国道的距离。(2)社会经济因素、区位交通因素和公共设施因素对集体商服用地价格的贡献度分别为69. 0%、20. 4%和10. 6%;社会经济因素和区位交通因素对集体工业用地价格的贡献度分别为52. 8%和47. 2%。[结论]总体上与国有城镇建设用地价格存在共性规律,但存在部分因素与国有建设用地价格规律存在差异,农村集体经营性建设用地估价不宜完全套用城镇建设用地的思路。     

Maize production and environmental costs: Resource evaluation and strategic land use planning for food security in northern Ghana by means of coupled emergy and data envelopment analysis

This paper applies an integrated methodology which is constituted of the following: (i) the Emergy-Data Envelopment Analysis (EM-DEA), (ii) environmental Cost-Benefit Analysis (CBA), (iii) Value Chain Analysis (VCA), and (iv) Sustainability Balanced Scorecard (SBSC) approaches, -to support multicriteria decision analysis (MCDA) for strategic agricultural land use planning, which could contribute to improve food security in northern Ghana. Five scenarios of land use and resource management practices for maize production were modelled. The business-as-usual scenario was based on primary data, which were collected using semi-structured questionnaires administered to 56 small-scale maize farmers through personal interviews. The dominant land use was characterised by an external input ≤12 kg/ha/yr inorganic fertilizer with/without the addition of manure in rainfed maize systems. The project scenarios were based on APSIM simulations of maize yield response to 0, 20, 50 and 100 kg/ha/yr urea dosages, with/without supplemental irrigation. The scenarios were dubbed as follows: (1) no/low input systems were denoted by Extensive0, Extensive12, and Intercrop20, and (2) moderate/high input systems were denoted by Intensive50, and Intensive100. The EM-DEA approach was used to assess the resource use efficiency (RUE) and sustainability in maize production systems, Ghana. The measured RUE and sustainability were used as a proxy for further analyses by applying the environmental CBA and VCA approaches to calculate: (a) the environmental costs of producing maize, i.e. resource use measured as total emergy (U), and (b) benefits from the yielded maize, i.e. (b i) food provision from grain measured in kcal/yr, and (b ii) potential electricity (bioenergy) which could be generated from residue measured in MWh/yr. The information which was derived from the applications of the EM-DEA, CBA and VCA approaches was aggregated by applying the SBSC approach to do a sustainability appraisal of the scenarios. The results show that, when labour and services are included in the assessment of RUE and sustainability, Intercrop20 and Intensive50 achieved greater marginal yield, better RUE, sustainability and appraisal score. The same scenarios caused lesser impacts in terms of expansion of area cultivated compared to Extensive0 and Extensive12. Meanwhile the impacts of Intercrop20 and Intensive50 in terms of ecotoxicity, emissions, and demand for resources (energy, materials, labour and services) were lesser compared to Intensive100. The implications of the various scenarios are discussed. The environmental performance of the scenarios are compared to maize production systems in other developing regions in order to put this study within a broader context. We conclude that, the EM-DEA approach is useful for assessing RUE and sustainability of agricultural production systems at farm and regional scales, as well as in connecting the management planning level and regional development considerations.     

Farmers,Biodiversity and Plant Protection: Developing a Learning Environment for Sustainable Tree Cropping Systems

More diverse, perennial cropping systems often have better natural mechanisms for keeping pests at bay. But while scientists emphasise the broad benefits of conservation in terms of effective ecosystem functioning, farmers are more interested in biodiversity for the provision of food or of services such as shade or windbreaks. Because of their limited knowledge of the role of biodiversity in plant protection, farmers sometimes unconsciously disturb natural regulatory mechanisms. Some citrus farmers in Vietnam introduced sapodilla as an intercrop to diversify their source of income, and because this fruit tree requires little care. However, this apparently worthwhile attempt to combine two valuable crops has misfired. The ecological conditions that traditionally sustained natural pest control in citrus have been disturbed, thus trapping farmers in the pesticide treadmill. The weaver ant Oecophylla smaragdina stopped protecting citrus from stinkbugs and leaf-feeding caterpillars after facing competition from the black ant Dolichoderus thoracicus, which favours sapodilla trees as a nesting habitat. To avoid similar scenarios in the future, methods for linking scientific research on ecosystem functions with farmers' own knowledge, experience and priorities are presented. Examples are given of ways in which farmers in perennial cropping systems learn, and how scientists can facilitate this learning process.     

Quantifying land-use change impacts on the dynamic evolution of flood vulnerability

Recently, dramatic flood disasters have occurred incrementally in several regions of the world. Land-use change as one of the main affecting factors becomes a key component in flood risk management. This study strives to deal with quantifying how changes in land use to affect the dynamic evolution of flood vulnerability. The floodplains of Wuhan, which are located in the Yangtze River Basin, have been selected as an example. In this paper, we use GIS to gather different historical geometric data as sources of land-use information. By proposing the Simpsons-dominance index and location index to analyze the characteristics of land-use changes, and building a quantitative model to measure flood vulnerability, a series of flood vulnerability maps demonstrate differential flood vulnerability of floodplains of Wuhan in three inundation scenarios and four historical periods. Finally, the non-parametric correlation is used to reveal the interactive effect of land use and flood vulnerability. Based on this study, comprehensive flood disaster management strategies for land-use planning are proposed for government decision-makers to reduce the flood vulnerability of Wuhan in future.     

Developing grain production policy in terms of multiple cropping systems in China

Multiple cropping is one of the simplest ways to increase grain production, and it has an important role in the food security of China. This paper evaluates the multiple cropping systems of China, and identifies the regional obstacles that limit the use of multiple cropping with the aim to give some implications for developing grain production policy. A time series analysis of remote sensing data coupled with an econometrics model—stochastic frontier analysis (SFA) was used to derive the multiple cropping index (MCI), potential multiple cropping index (PMCI), multiple cropping efficiency (MCE), and potential increment of multiple cropping index (PIMCI) to evaluate the multiple cropping systems. Regional obstacles to the use of multiple cropping were identified by zoning socioeconomic and ecological environmental factors that impact its application. The MCE of China in 2005 was 87.5%, with a gap of 22% between the MCI and the PMCI. The Bohai Rim, the rim of Tianshan Mountain, the Sichuan Basin, and the middle reach of Yangtze River are the main regions that larger PIMCI could be anticipated. The whole country (excluding areas that lacked data) was divided into seven distinct regions in terms of the impact factors and further classified into low-efficiency high-potential regions (LHRs), high-efficiency low-potential regions (HLRs), high-efficiency medium-potential regions (HMRs), and medium-efficiency high-potential regions (MHRs) according to regional multiple cropping performance. Considering about the obstacles and benefits to each region, different strategies should be implemented to different regions for regional grain production increase. Special attention should be paid to the improvement of MCE in north and southwest China with the expectation to increase grain production of China. The results would help implement “The plan to increase grain production capacity by 50 million tons nationwide” launched by the central government of China.     

基于Logistic回归模型的镇域农村居民点变化驱动力分析

农村居民点是农村人地关系的核心,弄清楚引起农村居民点变化的驱动因子的作用强度、贡献程度,是开展农村居民点整理、布局优化、制定相关政策重要依据。借助GIS技术,构建了具有统一数据基础的空间数据库,结合专家知识和研究区的实际情况,选择了5个内部因子、8个外部因子,利用Logistic回归模型,以潼南县崇龛镇为例,从居民点综合变化、增加、减少3个不同的角度开展了居民点变化驱动力分析,结果表明农村居民点变化是内部因子和外部因子共同作用的结果,但内部因子的贡献程度远高于外部因子,说明农村居民点在开展区位择优的过程中,更加关注与自身生产生活息息相关的因子。且引起居民点综合变化、增加、减少的驱动因子并不一致,说明居民点的变化是复杂的,在开展整治规划工作前应该从多角度进行详细分析,才能为政策的制定提供科学的依据。     

基于能值理论的湖南省耕地利用集约度演变研究

研究耕地资源的高效集约利用对社会经济发展具有重要意义。采用能值理论的研究方法,运用湖南统计年鉴相关数据,从农业机械集约度、化肥集约度、农药集约度、农膜集约度和劳动力集约度等5个方面,着重分析了湖南省2003~2012年间耕地利用集约度的时空变化特征。结果表明:总体看,2003~2012年,湖南省耕地利用集约度呈增长趋势,10年间耕地利用集约度共上升了0.252 8,其中生产要素集约度共增加了0.230 2,而复种指数增加了0.018 4。从各要素看,2003~2012年湖南省的农业机械、农药、农膜、化肥集约度都呈增长趋势,研究期间农药集约度增加了0.035×10~(13)sej/hm~2;化肥增加了3.111×10~(13)sej/hm~2;农膜增长了0.01×10~(13)sej/hm~2。而劳动集约度呈下降趋势;复种指数在研究时间段内总体呈上升趋势;耕地利用集约度在生产要素集约度和复种指数的综合作用下不断上升;从区域差异看,长株潭城市群和环洞庭湖区耕地利用集约度较高,因为该区域有比较优越的地理经济区位。而化肥、机械、劳动力投入水平都比较低的山地丘陵地区,工业辅助能集约度要低于劳动集约度,耕地利用集约度低。并结合分析结果和湖南省情提出了相关建议。