集约用地理论模式探析

研究目的:从空间维、时间维和功能维三个理论维度出发,构建集约用地理论模式体系。研究方法:采用归纳演绎法、文献资料法和综合分析法,设计集约用地模式体系的结构框架及阐明模式的特征表现。研究结果:集约用地理论模式体系以子模式和多种组合模式为结构框架,其中,子模式有13种,两两理论组合模式有16种。研究结论:该理论模式体系可指导国民经济行业集约用地规划,为各地因地制宜地开展集约用地研究提供参考。     

矢量CA支持下的耕地补偿空间决策模型研究

研究目的:为实现耕地总量动态平衡,保障耕地资源的持续供给,本文探讨引入矢量CA支持下的耕地补偿空间决策模型用于耕地补偿决策的可行性。研究方法:GIS空间分析技术、实证分析法。研究结果:针对矢量数据处理的便捷与快速性质,提出基于矢量数据格式的元胞自动机支持下的耕地补偿决策模型,着重讨论了二维矢量元胞自动机的邻居模型和转换规则,指出元胞状态转换规则主要依赖于与邻居元胞的大小、距离、相邻边长度和相邻边分维指数、邻居影响力效果指数,在此基础上,研究了耕地补偿决策中的邻居影响力即转换规则。文章以海南省琼海市九曲江乡为例,计算不同参数控制下的多种耕地补偿决策方案,证明了该模型用于耕地补偿决策的可行性。     

Farmers’ Willingness to Participate in Payment‐for‐Environmental‐Services Programmes

Understanding farmers’ willingness to participate in agricultural payment‐for‐environmental‐services (PES) programmes is an essential precondition for designing effective and efficient programmes. Willingness to participate is typically examined via stated preference surveys using the standard hurdle model for whether and how much to participate. Among respondents who decline to participate, such analyses cannot distinguish between respondents who declined due to the payment level and those who were not interested at all. This paper applies a double hurdle model to incorporate a prior condition for whether a respondent is even willing to consider participating in the PES market. The model uses a unique stated preference survey permitting separation of the consideration and enrolment decisions of 1,700 farmers in Michigan, USA. The first hurdle probit model suggests that farmers’ willingness to consider PES chiefly depends on farm and farmer characteristics, while the second hurdle tobit model shows that decisions on whether and how much to enrol depend more on the payment offer and marginal benefit–cost criteria. This study provides fresh insights on facilitating farmer participation in PES programmes using tiered strategies that differ in costs of programme payment and administration.     

低碳理念下的南京市土地集约利用评价

研究目的：从发展低碳经济和转变城市土地利用方式出发,建立低碳理念下的城市土地集约利用评价模型。研究方法：系统分析法,ANP方法,障碍度模型和实证研究法。研究结果：1998—2009年南京市城市土地集约利用水平呈总体上升态势,土地产出效益和土地投入水平在发挥着主要作用,但土地产出效益和土地低碳水平的障碍度最大。研究结论：本评价体系较客观地反映了低碳理念下城市土地集约利用发展水平和趋势。     

A contribution to the assessment of scenic quality of landscapes based on preferences expressed by the public

The purpose of this paper is to validate a model for predicting the public's preference for a landscape using simple statistical techniques. The model assigns numerical values to 42 landscape variables grouped into physical, aesthetic and psychological attributes. The landscape value is obtained using an additive value function. The results of the model on certain landscapes are compared with the preference expressed by the public in a survey of 183 people.The homogeneity of the survey responses was checked in each photograph. It was determined that means and standard deviations of the scores represent the true preference.A strong positive association was observed between preference and certain landscape attributes such as expression, soil use or colour. A marked negative association was detected with respect to landscape alterations.A linear regression was carried out to analyse the predictive capacity of the model. The independent variable was the global score assigned by the model to each photograph and the dependant variable was the mean of the scores assigned by the survey respondents. The high level of correlation obtained indicates that the model is a good predictor of the public's preferences in relation to the set of photographs shown in the survey.To complete the analysis of the model as a preference predictor, a multiple linear regression was carried out between the mean score obtained in the survey and the model elements. Attributes and variables that have the greatest influence on pubic preference were detected.     

Agriculture and climate change in global scenarios: why don't the models agree

Agriculture is unique among economic sectors in the nature of impacts from climate change. The production activity that transforms inputs into agricultural outputs involves direct use of weather inputs (temperature, solar radiation available to the plant, and precipitation). Previous studies of the impacts of climate change on agriculture have reported substantial differences in outcomes such as prices, production, and trade arising from differences in model inputs and model specification. This article presents climate change results and underlying determinants from a model comparison exercise with 10 of the leading global economic models that include significant representation of agriculture. By harmonizing key drivers that include climate change effects, differences in model outcomes were reduced. The particular choice of climate change drivers for this comparison activity results in large and negative productivity effects. All models respond with higher prices. Producer behavior differs by model with some emphasizing area response and others yield response. Demand response is least important. The differences reflect both differences in model specification and perspectives on the future. The results from this study highlight the need to more fully compare the deep model parameters, to generate a call for a combination of econometric and validation studies to narrow the degree of uncertainty and variability in these parameters and to move to Monte Carlo type simulations to better map the contours of economic uncertainty.     

基于ARIMA模型的我国油菜单产预测分析

[目的]探索我国油菜单产潜力极限、2020年前单产潜力、提高单产潜力的空间及耕地利用布局。[方法]在我国油菜单产光合潜力和"农业生态区划"(AEZ)潜力基础上,基于1961~2010年我国油菜单产统计值,分析"时间序列"数据平稳性,逐步建立ARMA(1,2)模型、ARMA(1,1)模型、AR(1)模型、MA(2)模型和MA(1)模型,根据赤池信息准则(AIC)选择ARMA(1,1)模型建立ARIMA(自回归单整移动平均)模型,拟合2011~2015年我国油菜单产并将其与统计值比较,判断拟合效果并(调整)预测2016~2020年我国油菜单产,将预测值与单产潜力极限对比,得出提高空间。[结果]我国油菜单产最大潜力为3 700kg/hm2,而2017年、2018年、2019年和2020年单产将分别为2 291、2 353、2 471和2 483kg/hm2,分别是最大潜力的61.92%、63.59%、66.78%和67.11%。[结论]文章的结果意味着提高我国未来油菜单产潜力尚有较大空间,应改良中低产耕地与保持高产耕地生产力并重。研究结果旨在为我国油菜生产提供决策参考信息。     

南美白对虾两种养殖模式下的经济效益比较分析

论文比较分析了南美白对虾高位池精养和土池生态养殖两种养殖模式的经济效益。结果表明：高位池精养模式的产量、产值、净利润在绝对值上分别比土池微生态养殖模式高306．44斤／亩、8860．29元／亩、2553．27元／亩,前者经济效益较高;两种养殖模式成本利润率分别为31．39％和26．02％,高位池精养模式提高经济效益主要依靠的是高成本投入,需提高成本利用效率。论文还对影响南美白对虾经济效益的原因进行分析,其中基础设施、总成本和人力成本、产品规格、养殖周期、技术支持和管理水平是造成经济效益差异的主要原因,从而进一步提出提高南美白对虾养殖经济效益的措施。     

不同项目治理模式对示范区农户带动的影响——以农业标准化示范区项目为例

[目的]农业试点示范项目的实施在我国由来已久,其治理模式和制度体系正面临转型,发挥市场主体的能动性,辐射带动更多小农户参与标准化生产,尤为重要。[方法]以农业标准化示范项目为例,探讨示范项目治理模式的转型及对示范区农户的带动机理,并基于301个示范区的调研数据,实证分析不同项目治理模式对示范区农户带动的影响。[结果]我国农业标准化示范项目正在经历从政府主导模式向市场主导模式的转变;市场主导的治理模式在带动农户直接参与标准化生产方面,要优于政府主导的治理模式;具体而言,市场主导模式中,“公司+中介组织+农户+基地+标准”模式,要优于“公司+农户+基地+标准”模式。此外,该研究进一步发现,农业标准化宣传、产业化程度、技术准入门槛、集约化程度、农业机械化水平等因素同样会影响示范区农户带动。[结论]因此,应更好地发挥市场作用,撬动更多社会资本,鼓励新型经营主体参与、承担示范项目,并提升中介组织的协调和推广能力,从而积极形成市场导向的多元治理格局。     

基于投影寻踪模型的林业产业生态系统和谐性研究

以林业产业生态系统为着眼点,运用投影寻踪模型对黑龙江省林业产业生态系统和谐性进行了研究。结果显示:林业产业主体系统和谐度显著小于模型设定的阈值,这表明林业产业生态主体系统在研究时间范围处于微观不和谐状态,分别是一年、四年、两年、三年和一年处于严重失调、中度失调、基本和谐、中度和谐、良好和谐的状态。依据判别模型得出:黑龙江省林业产业生态系统不和谐,从而提出了林业产业规模调整和结构优化的建议。     

An Analysis of Public Agricultural Research in the Canadian Prairie Provinces

This study has developed a four-equation model of agricultural research in Canada using some aspects of special interest theory, institutional theory and economic variables. The demand, supply and allocation equations were developed with special reference to the Canadian agricultural research sector and the more restrictive prairie agricultural research sector. The conceptual model developed is designed to explain the allocation of public expenditures on commodity specific applied research. The reduced-form equation of the model was estimated for 6 commodity classes (2 crops, 4 livestock groups) to test the applicability of the model over the commodity groups.
The evaluation of the reduced-form equation model and the implications that derive from it give an interesting view of the Canadian research sector. Some variables did perform as a priori expected with relative consistency and certain equations performed very well. These results lead to some implications for the Canadian agricultural research sector.
The general performance of the reduced-form equation and its ability to explain the total variation of expenditures on commodity specific agricultural research gives limited support to the model developed. Nevertheless the results tend to indicate that agricultural research is responsive to economic and institutional variables.     

基于图模型反问题的上下游水污染冲突事件的第三方调解策略研究

针对上下游水污染冲突,基于冲突分析图模型反问题理论构建了第三方调解模型,在充分考虑冲突双方偏好底线的前提下,获取双方做出最小让步后的冲突化解策略。基于反问题理论构建了一个0-1多目标规划第三方调解模型,并进行模型求解设计。最后,将模型应用于跨流域上下游水污染冲突事件,进一步验证了该模型求解调解方案及调整偏好的有效性。研究表明,所提方法能找到使上下游地区做出最小偏好让步的最优状态,有效辅助第三方制定调解策略,从而化解水污染冲突,为相关水资源冲突调解提供借鉴。     

肇东市可持续发展示范区循环经济发展模式研究

循环经济是实现可持续发展的新经济模式;以肇东市可持续发展示范区为基础,建立适合当地的循环经济发展模式,并对新循环经济模式与传统经济模式进行对比分析。     

基于无人机影像的冬小麦深度学习分类

[目的]传统分类方法存在人为主观选择特征、模型无法在大范围泛化的问题,文章利用非监督特征学习的深度学习方法进行冬小麦识别,以解决传统分类方法无法在大范围进行自动化作物识别的不足。[方法]该文集成残差网络(Residual Nets,ResNets)和金字塔场景解析网络(Pyramid Scene Parsing Network,PspNets)构建Res.PspNet,进行冬小麦深度学习自动化分类。在山东全省获取80个村的无人机航拍影像,利用米级遥感影像和对应的标记样本作为"海量标记样本"训练土地覆盖识别模型,以此为基础模型迁移训练冬小麦分类模型,自动提取出冬小麦分布。[结果]实验结果表明,以训练出的土地覆盖数据作为基础模型训练冬小麦模型,收敛速度快,具有很好的泛化性,在不同农业景观调查村中均得到比较准确的结果。从整体验证区域来看,冬小麦总体精度达到了90%以上,区域冬小麦总面积精度达到99%。平原区冬小麦识别精度更高,总体精度达到了90%以上,区域面积精度达到99%,表明模型对冬小麦种植地块规整、生长状态均质的区域,识别精度较高,而山区由于地块破碎、冬小麦长势差异较大,空间卷积会弱化小麦特征且出现"同物异谱"现象,这影响了在该区域内冬小麦的识别精度。[结论]Res.PspNet卷积神经网络能够有效地学习出无人机影像的特征,实现了基于航片影像进行非监督自动化冬小麦"端—端"分类,这也将一定程度上降低冬小麦提取的工作量。     

黄河三角洲未利用地适宜性评价的资源开发模式 ——以山东省东营市为例

摘要：研究目的：探讨黄河三角洲地区未利用地资源的开发模式,为区域土地利用优化和土地整治提供依据。研究方法：GIS 技术,加权指数和法和极限条件法。研究结果：（1） 未利用地面积2676.25 km2,占研究区域面积的33.94% ;从未利用地的构成来看,盐碱地、沼泽地、滩涂所占比例接近90%,决定了该区域未利用地开发难度大,极易造成土地退化和生态环境恶化。（2） 未利用地适宜性等级与离海洋远近和地势高低呈现正相关。研究结论：提出了生态农业开发利用、农林牧综合开发利用、林牧草综合开发利用、林牧生态用地保护、牧草生态用地保护、入海口生态保护和滨海水产养殖开发利用7种未利用地开发模式,以提高区域土地利用效率和生态环境建设。     

The impact of agricultural conservation easement on nearby house prices: Incorporating spatial autocorrelation and spatial heterogeneity

The impact of farmland under agricultural conservation easement (ACE) contract on the values of nearby residential properties is investigated using housing sales data in two Pennsylvania counties. ACE-protected farmland had a positive impact on nearby property values in one study county but a negative impact in the other. The paper also looks at the impact of forest land use, and discovers that preserved forest land had a positive impact on the nearby property values in both counties. House prices showed strong spatial correlation in both counties, and a spatial error components (SEC) model fit the data better than the OLS model, a spatial-lag model (SLM), or a spatial autoregressive error model (SEM). Geographically weighted regression (GWR) showed that the impact of ACE-protected farmland on nearby property values varied within one of the two study counties, with positive impacts in some parts of the county and negative impacts in other parts. The impact of forest cover on property values also varied, with positive impacts within both counties. A new hybrid GWR-SEC model is introduced that incorporates both spatial correlation in prices and spatial heterogeneity in the model parameters. Statistical goodness of fit measures showed that the GWR-SEC model fit better than the GWR model or a hybrid GWR-SEM model.     

Suitability evaluation of urban construction land in Pendik district of Istanbul,Turkey

Urban land suitability analysis is a complex process that requires geo-physical and environmental information and relevant expertise to analyse and interpret the information. This paper focuses on the integration of geographic information systems (GIS) and multi-criteria decision analysis (MCA) for the assessment of potential suitability of urban development in Pendik district located in eastern Istanbul, Turkey. Various factors, including geo-physical attributes, accessibility, built-up area and infrastructure, vegetation, and green and blue amenities, were used for the land-use suitability assessments. Two different approaches (a deterministic and a fuzzy modelling approach) were utilised to evaluate the suitability of land uses for residential, industrial/commercial and recreational developments. Standardisation of values and unification of scales in map layers were done using the traditional deterministic approach in the first model, whereas fuzzy logic was used in the second model for the same purpose. AHP weighted the sub-criteria in the first model, and the fuzzy AHP method was used in the second model. The map layers were overlaid using the weighted linear combination for both cases using the GIS software. The final stage of the suitability assessment process consisted of a sensitivity analysis of the selected factors and their associated weights. The integration of fuzzy logic, fuzzy AHP and GIS is an advanced methodology and can improve suitability evaluations compared with those of alternatives based on traditional approaches. From our findings, we note that suitable lands for urban development are mainly located in the central and southern parts of the case study area. Our results also highlight how the spatial distribution of suitability classes vary with the selected model utilised for suitability assessment. The methodologies described in the paper can be extended to similar contexts, both locally and internationally.     

电子商务背景下农产品F2F电商模式及其发展策略分析

由于信息交流不通畅、农产品价格波动频繁等原因,农产品电子商务在互联网技术发展带动下应运而生,各类农产品电商模式不断出现,其中农产品F2F电商模式就是最为重要的发展模式之一。文章通过归纳总结,从当前几种农产品电商模式特点出发,提出了农产品电商新模式——F2F(Farm to Family)。该文阐述了农产品F2F电商模式的运营模式内涵及当前发展现状,其次,剖析了F2F农产品模式的优劣点,最后根据前文分析,提出了积极构建农产品物流配送系统、积极培养农产品电子商务优秀人才、强化农产品的品质管理加快农产品电商发展的对策措施。     

Hybridizing local and generic information to model cropping system spatial distribution in an agricultural landscape

For quantitative water management, fine analysis of spatial and temporal interactions between cropping systems and water resources helps identify time and site-specific withdrawal situations. However, it is a methodological challenge to provide fine-resolution analyses at the scale of large watersheds used for crises management. In this study, we present a methodology based on multiple methods and mixed sources of information to finely model an agricultural landscape (AL) that represents the spatial distribution of cropping systems. Our approach is based on progressively hybridizing databases and local actors' and experts' knowledge to produce a spatially explicit and dynamic model. The Land Parcel Identification System database, which resulted from the European Common Agricultural Policy, is crucial for our method since it provides the spatial and temporal basis of our model (i.e., geographic delineation of islets and information about crop sequences). Local knowledge is used to identify factors determining spatial distribution of cropping systems and to build a generic model that simulates farmers' crop-management strategies. The model was qualitatively and quantitatively evaluated using a multi-agent simulation platform (MAELIA). We asked local experts on quantitative water management to evaluate the ability of the platform to reproduce intra- and inter-annual dynamics at different levels when using our model of the AL as input. The experts were satisfied with the results; they validated the predicted dynamics of the variables, and some discussed the objectivity of the values. We discuss the method’s contribution to current challenges in modeling large agricultural areas and the associated tradeoffs. The approach is promising for policy makers who wish to develop integrated, locally adapted land-management strategies.