Universal rules for fragmentation of land by humans

The morphology of parcel patterns created by humans both in urban and rural areas is investigated. The parcel size distribution function, f(a), provides a criterion, that enables unambiguous classification of each piece of land as city core, suburbs, or rural area. The morphology of the rural area corresponds to a scale-free structure and follows a power-law distribution f(a) ~ a ⁻ⁿ of the parcel areas with the exponent n ≈ 1. In suburbs, the area distribution follows the log-normal distribution. In the city core, f(a) has an unimodal shape with an algebraically decaying tail, n = 2. Our study is based on data originating mainly from North America, the Hawaiian Islands, and Australia. For the regions analyzed, the characteristics of the parcel size distribution are universal and robust with respect to geographical, historical, and economical conditions accompanying development of a given area. The urbanization process can be described in terms of the changes of the morphology of the patterns of land fragmentation. In this formulation, the rural morphology, which can be thought as natural one because it exhibits a scale-free distribution of parcel sizes, is transformed into the artificial morphology developed in the city centers. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

吉林湾沟国家森林公园旅游资源与质量评析

介绍了湾沟森林公园独特的旅游资源及区位条件,对公园的区域环境质量和风景资源质量进行了评定,进而阐明了该森林公园风景资源价值、环境质量价值和旅游开发价值均较高,具有一定的区域代表性。     

吉林省土地利用综合分区及调控政策研究

首先，根据自然环境条件把吉林省划分为东、中、西三大土地利用区，在此基础上，采用聚类分析法根据社会、经济指标把3个区细分为6类土地利用区。其次，针对各分区土地利用特点及存在的问题提出了调控措施。最后，探讨了协调区域间土地利用的相关对策。     

基于MapGis的基本农田信息提取方法研究

基本农田上图工作是全国第二次土地调查工作的重要组成部分。以MapGis为平台，以基本农田上图方法中的判读转绘法为基础，重点介绍基本农田信息提取的3种实现方法，分别是删除图斑法、提取边界线法、提取图斑法，以保证数据的完整性及准确性。     

托克逊县土地利用动态变化研究

在GIS技术支持下，利用研究区1996年与2009年的2期遥感影像数据，采用土地利用动态度模型、土地利用程度综合指数模型和土地利用转移矩阵对托克逊县近13a土地利用动态特征进行定量分析，总结出托克逊县近13a土地利用变化的特点及原因，提出托克逊县合理用地的对策。     

Improving cover and management factor (C-factor) estimation using remote sensing approaches for tropical regions

The Revised Universal Soil Loss Equation (RUSLE)'s cover and management factor (C-factor) is one of the most difficult factors to obtain, mainly because long-term monitoring soil erosion plots under natural rainfall are needed. Therefore, remote sensing approaches have been used as an alternative for obtaining this factor. However, there is a lack of studies comparing values of this factor computed from remote sensing approaches with measured data. In this study, we compare two widely used remote sensing approaches (C_rA and C_VK) to estimate the C-factor based on the Normalized Difference Vegetation Index (NDVI) with the literature (C_LIT) and field experimental data. We also investigated the influence of C-factor methods on the prediction of soil loss and sediment yield (SY) using measured data in the Guariroba basin, Central-West Brazil. We obtained mean C-factor values of 0.032, 0.023 and 0.137 for C_LIT, C_rA and C_VK, respectively. We found an average annual soil loss of 2.20 t ha⁻¹ yr⁻¹, 2.02 t ha⁻¹ yr⁻¹ and 10.07 t ha⁻¹ yr⁻¹ and SY values of 6875 t yr⁻¹, 6468 t yr⁻¹ and 33,435 t yr¹, for C_LIT, C_rA and C_VK, respectively. Our results indicated a significant improvement in soil loss and SY estimations by using the C_rA approach developed for tropical regions, with a bias of 13% to the measured SY (5709 t yr⁻¹). We conclude that the C_rA method present the most suitable alternative to compute soil loss and SY in tropical regions. Furthermore, this approach allows large-scale evaluation and temporal monitoring, therefore enhancing multi spatial and temporal assessment of soil erosion processes.     

退耕还林对经济社会影响评价的研究

退耕还林推行10年以来,学术界、政界对项目的经济社会影响评价的讨论及争论越来越激烈。本文基于对整个领域研究进展了解,分别从数据、方法及结论等方面对Yao（2010）、Liu（2010）以及Uchita（2009）3篇文献进行简要述评。指出非农就业、农户增收不能单纯通过退耕还林本身实现,而要从思路和技术上跳出仅仅围绕退耕户或者退耕地来讨论项目经济社会影响的局限,并指出了未来可能的研究方向及政策建议。     

连云港云台山楸树资源现状与保护策略

采用标准地与典型抽样调查相结合的方法,对连云港云台山地区的楸树资源进行了全面调查.结果表明：楸树在连云港云台山地区主要分布于云台山的后云台、中云台和前云台地区,总体分布呈从后云到中云、前云逐渐减少的分布现状.在该区域,楸树多呈现散生分布,多为混交林,分布具有不连续性.连云港云台山楸树的数量从20世纪80年代的18707株减少到目前的8914株,减少了52％.针对连云港云台山楸树资源锐减的现状提出了加强楸树资源保护的有效对策.     

昆明北市林区华山松商品林林木资产评估研究

集体林权制度改革日益深化，森林资源资产的处置、转让和抵押贷款等经济行为频繁发生，为了探索森林资源评估理论与实务，选取昆明北市林区华山松为研究对象，结合资产评估理论，对华山松商品林林木资产进行评估。     

基于SuperMapIS.NET的地价动态监测系统及其WEB服务平台开发

从分析现有地价监测系统中存在的问题出发,提出基于SuperMapIS.NET进行地价动态监测系统及其WEB服务平台的设计与开发的原则、系统的功能设计、数据处理流程设计、数据组织结构设计,利用建立的地价监测系统对徐州市2011年第3季度的地价进行动态监测与基准地价更新工作,结果表明该系统可靠、稳定、适应性较强。