基于GIS的皖南山区茶叶种植适宜性评价

以石台县为例,运用ArcGIS地理信息系统以及县域耕地资源管理信息系统,利用石台县测土配方施肥项目的采样调查分析结果,该研究通过确定评价单元,建立了具有区域特色的评价指标体系,并采用耕地自然要素评价综合指数法对石台县茶叶种植适宜性进行定量评价分析。     

基于GIS和GPS的南方红壤侵蚀区土地资源评价

绿色GDP概念,来自生态经济学的最新研究成果,是指将经济增长所导致的灾害、环境污染和资源浪费(统称生态环境损失)等,从GDP中扣除,在我国,常规的GDP统计,是不扣除生态环境损失值的。这与国际上通行的规则是不相一致的。按照联合国1995年提出的可持续发展指标的要求,判定一个国家或地区的发展,不单单看其经济增长指标,而要用经济增长值减去生态环境损失值,所得的值为发展值。如果经济增长大于生态环境损失,是为发展;反之,便是负发展。例如:在我国,伐树所得1元的     

水土保持生态效应评价专家系统研发

水土保持生态效应评价已成为当前水土保持研究的热点.水土保持生态效应评价的目的是通过对水土保持各类单项或综合治理措施生态效应的评价,为政府部门决策提供依据.目前,亟需研发专门的水土保持生态效应评价专家系统对这一领域积累的大量的专家知识进行快速、智能评价.本文在收集整理大量领域专家知识的基础上,采用产生式规则构建了水土保持生态效应评价知识库,并利用可视化开发程序语言VC++将专家系统技术与地理信息系统技术相互集成,研制开发了一个界面友好、操作简单的水土保持生态效应评价专家系统,旨在为水土保持生态效应评价提供高效、智能的决策工具.     

Land use and soil conservation strategies for potentially highly erodible soils of central-eastern Nigeria

In areas susceptible to erosion, there is the need for a comprehensive soil conservation programme so as to be able to prevent catastrophic soil erosion problems. The absence of such a programme in central eastern Nigeria, that has a total land area of 20 000 km², necessitated the drawing up of a soil conservation strategy for the area. The aim was to provide information for better land-use planning and proper environmental and soil management. To achieve this, topographic, soil and landform maps of the area at the scale of 1:50 000 were used to delineate into slope land units, viz: 0–4 per cent, <4 per cent, drainage basins and headwaters. These slope units and estimated soil erosion hazard units using the revised universal soil loss equation (RUSLE) were employed to form a general purpose land classification based on the USDA land capability classification and FAO framework on land evaluation.The soil loss tolerance of the area falls between 1·16 and 1·30 Mg ha⁻¹ yr⁻¹, while the erosion hazard units are considered generally suitable for the various land utilization types, with a number of limitations the main ones being erosion and waterlogging. The soil conservation measures proposed involved the application of bioenvironmental processes in the area and appropriate watershed management. The techniques proposed are those based on low input technology, affordable by rural farmers. It is concluded that these soil conservation measures will be adequate for sustainable agricultural production in the area. Copyright © 1999 John Wiley & Sons, Ltd.     

基于GIS的重庆低丘缓坡土地产业转移适宜度评价

为了高效合理开发利用低丘缓坡土地资源、科学构建低丘缓坡土地产业转移适宜度评价指标体系提供理论依据和方法借鉴,该文以GIS技术和实证研究为手段,采用文献研究、问卷调查和实证研究等方法,建立了包括3个评价目标共计13个指标的评价指标体系,构建了以置信区间为基准的指标数据统计分析和处理方法,采用了动态权重的方式对评价指标权重予以修正,利用加权平均模型对适宜度进行了测算评价。研究结果可靠、信度较高、方法可行,在一定程度上丰富了低丘缓坡土地资源适宜性评价的理论和方法,对合理开发利用和管理低丘缓坡土地资源提供了方法借鉴和实践支撑。     

基于RS和GIS技术的县域土地流转应用研究

以安徽省肥西县为例,耕地是土地的精华,是农业生产不可替代的重要生产资料,是保持社会和国民经济可持续发展的重要资源。只有确定了比较合理的价格,出让土地才能获得合法收益,农户转让土地才能得到合法补偿,各种形式的土地流转才能顺利进行。建立土地流转制度,核心问题就是要建立科学的土地价格评估系统,因此使用RS和GIS技术进行的地力评价工作为土地流转提供一个科学的依据。     

淮河流域伏牛山区水土保持生态自然修复适宜性评价与分区

伏牛山区水土流失危害严重,实施水土保持生态修复是加快区域水土流失防治步伐的有效措施。针对大区域生态修复工程建设亟待解决的适宜性区划问题,采用主导因子分级组合及其专题图叠加分析法,对伏牛山区生态自然修复的适宜性进行评价与分区。1)提出地貌类型、土地覆被类型和地面坡度3个主导因子作为生态自然修复适宜性评价与分区指标,并对其进行分级(分类)和分区;2)按照实施封禁保育(促进生态自然修复)措施的适宜程度,提出"适宜"、"暂不适宜"和"不适宜"3个生态自然修复适宜性等级,并确定其区域分布格局;3)将伏牛山区的生态自然修复适宜性划分为2个大区(一级区)、4个亚区(二级区)和15个类型区(三级区)。研究结果可为伏牛山区水土保持生态自然修复工程的规划布局提供技术支撑。     

西南山地丘陵区农村居民点用地适宜性评价与分区优化

农村居民点是中国农村人口的主要聚居形式。以西南山区丘陵区的重庆市丰都县兴义镇为例,运用ArcGIS空间分析、数理统计、SPSS聚类分析等多种研究方法,构建了农村居民点用地布局影响评价体系。在评价结果基础上对兴义镇农村居民点用地进行分区优化。(1)通过单因素量化分析和综合评价法分析可知,兴义镇农村居民点用地布局综合适宜度0~45.52,其中高度适宜性区域面积占兴义镇土地总面积的25.16%,中度适宜区面积占29.49%,低度适宜区面积占29.09%,不适宜区面积占16.26%。(2)利用聚类分析法划分出了4个类型区域:即适度挖潜区、重点发展区、限制扩建区和优先整治区,各区农村居民点面积分别为:113.30,188.59,104.01和41.72 hm²。(3)针对各类型区的具体特征,提出了相应的优化方案。     

遥感和GIS在土地适宜性评价研究中的应用——以呼和浩特武川县为例

在遥感和GIS技术支持下将武川县的土壤类型数据与地形坡度数据、土壤侵蚀数据、降水量和温度数据叠加分析后,进行土地适宜性评价,针对农林牧业用地,利用土地资源特性进行诊断,衡量其对农林牧业适宜与否及适宜程度,并将其结果划分出等级,为土地利用规划以及确定退耕还林还草地的空间地域分布提供依据.     

Development of a land suitability model for saffron (Crocus sativus L.) cultivation in Khost Province of Afghanistan using GIS and AHP techniques

In this study, we have attempted to develop a land suitability model for saffron, an agronomic crop, which is economically viable, environmentally bearable and socially equitable at Khost Province of Afghanistan. The objective was to determine different land suitability classes for saffron cultivation using Analytical Hierarchy Process (AHP) and Geographic Information System (GIS). A decision tree was developed encompassing the physical, economic and social criteria. We used the secondary data (meteorological, remote sensing) from available sources and also substantial primary data generated from soil survey, interviews and experts’ opinion. A total of 30 physical and socio-economic factors were included in the analysis. The final land suitability result showed that out of the total land area of Khost Province, 1.5, 4.5, 8.6 and 85.4% areas were highly suitable, moderately suitable, marginally suitable and not suitable, respectively. This modelling approach can be applied to determine the suitability of land for other crops covering a wider geographical region of Afghanistan.     

黄土高原水土保持功能的重要性评价与分区

根据黄土高原生态环境特点和水土流失现状,选择水源涵养、土壤保持、蓄水保水、防风固沙、防灾减灾以及农田防护等水土保持功能进行评价.在此基础上进行黄土高原水土保持功能重要性综合评价,评价结果表明:黄土高原地区水土保持功能均处于中等重要以上;其中极重要地区比例最大,占全区面积的80.03％;中等重要地区较少,占全区面积的19.97％.最后根据6个单因子功能重要性评价结果,利用ArcGIS中的空间分析叠加功能,确定黄土高原水土保持功能区划的基本界线,将黄土高原划分为9个水土保持功能区,并提出黄土高原各区的生态保护方向,促使自然生态系统更有效地支持社会和经济的发展,为改善黄土高原生态环境质量奠定基础.     

元谋干热河谷区旱坡地生态农业模式的水土保持效益研究

对元谋干热河谷区4种旱坡地生态农业模式的水土保持效益进行了系统的研究。结果表明：与对照模式“罗望子＋裸地”相比，建立的4种模式均体现了良好的水土保持效果，其中．“罗望子＋木豆＋柱花草”模式截持降雨。增加地表盖度．改善土壤物理性状，提高蓄水保水能力，防治水土流失效果最佳，其余3种模式均有明显的生态效益。根据需要．若重新对套入模式的主栽灌草层作物进行科学合理的搭配，重建后的优化复合生态农业模式，无论是生态效益，还是经济和社会效益都将得到充分的体现。     

我国水土流失综合防治的政策变迁与评价

我国水土流失防治政策经历了从单向性到综合性渐趋完善的变迁过程。在水土流失防治的历史沿革中,治理目标、治理主体、治理区域发生了阶段性变化,采用相应的政策执行手段,形成了水土流失综合防治政策体系。以分析我国防治水土流失的重大政策变迁为基础,运用制度经济学、环境经济学、专家调查等方法,对我国防治水土流失的政策实施进行综合评价。通过水土流失防治政策的最终实施效果与预期政策目标对比分析,对水土流失综合防治的任务确定、要素配置、组织方法、运行效率进行判断。同时,总结了水土流失综合防治政策实施的主要经验及存在的问题,并提出了完善水土流失综合防治政策的途径。     

Participatory soil and water conservation planning using an erosion mapping tool in the central highlands of Kenya

Despite several approaches that aimed at mobilising East African farmers to embrace soil and water conservation (SWC) activities, farmers hardly responded since they were seldom involved in the planning of SWC activities. Two tools that employ farmers' participation were developed and applied at Gikuuri catchment in Kenya. The first tool involved farmers to map soil erosion using their own indicators and determine the soil erosion status at catchment scale. This formed the basis upon which they undertook to plan for SWC measures at catchment scale. Farmers also predicted crop yield losses based on the soil erosion status. Farmers widely approved the soil erosion status map since their own indicators and perceptions were used. The second tool provided cash flow trends for a variety of SWC activities and farmer situations. Farmers can use land with a high, moderate or low erosion status and often have rather different socio‐economic settings. The net benefits over 5 yr for bench terraces, fanya juu terraces and grass strips were illustrated to assist farmers in making informed decisions on SWC adoption. The two tools increased awareness on the need for collective actions among farmers and showed fields that cause run‐on on downslope fields. The improved awareness of erosion problems and the related financial consequences increased farmers' willingness to share the investment costs for cut‐off drains. Copyright © 2007 John Wiley & Sons, Ltd.     

基于生态生产生活视角的北方农牧交错区土地宜耕性评价

北方农牧交错区是中国生态脆弱地区,土地荒漠化问题突出,土地利用是导致土地荒漠化的主要原因。生态文明建设背景下,研究该区域土地宜耕性对促进该地区生态环境保护和土地资源科学利用具有重要意义。该文以位于北方农牧交错区的科尔沁左翼后旗为例,基于生态、生产、生活的视角,构建评价指标体系对土地宜耕性进行评价,表明,现状耕地中不适宜耕作的耕地面积为15 996.87 hm~2,占耕地总面积的5.339%,因生态、生产、生活因素使得耕地不适宜耕作的面积分别为7 519.23、9 337.23、6 039.99 hm~2。建议在退耕还林工程中优先对该部分耕地进行退耕。适宜耕作的草地面积为197 195.94 hm~2,占草地总面积的32.18%,即有三分之一左右的草地可以开发利用为耕地。但是,从土壤适宜性和地形条件两方面对适宜耕作的草地进行分析,揭示出适宜耕作的优质草地面积比例很小。为避免土地开发利用导致农牧交错区生态环境的破坏和荒漠化的扩张,建议在跨省域耕地占补平衡中应当优先开发利用质量较高的耕地后备资源,且需始终坚持国家统筹。     

Mapping Slight and Moderate Saline Soils in Irrigated Agricultural Land Using Advanced Land Imager Sensor (EO-1) Data and Semi-Empirical Models

Around the world, especially in semi-arid regions, millions of hectares of irrigated agricultural land are abandoned each year because of the adverse effects of irrigation, mainly secondary salinity and sodicity. Accurate information about the extent, magnitude, and spatial distribution of salinity and sodicity will help create the sustainable development of agricultural resources. In Morocco, south of the Mediterranean region, the growth of the vegetation and potential yield are limited by the joint influence of high temperatures and water deficit. Consequently, the overuse of surface and ground water, coupled with agricultural intensification, generates secondary soil salinity. Knowing when, where, and how salinity may occur is very important to the sustainable development of any irrigated production system. Remedial actions require reliable information to help set priorities and to choose the type of action that is most appropriate in each situation. Ground-based electromagnetic measurements of soil electrical conductivity (EC) are generally accepted as the most effective method for quantification of soil salinity. Unfortunately, these methods are expensive, time consuming, and need considerable human resources for land surveying. Moreover, the dynamic nature of soil salinity in space and time makes it more difficult to use conventional methods for comparisons over large areas. A major challenge of remote sensing, as a potential alternative technique, is to detect different levels of soil salinity. The main aim of this research is to assess the potential of the Advanced Land Imager (ALI) sensor on board the Earth Observing-1 (EO-1) satellite, with its rich infrared bands, for the discrimination and mapping of slight and moderate soil salinity in the Tadla’s irrigated agricultural perimeter in Morocco. To achieve this goal, semi-empirical predictive models developed in a previous study using second order regression analysis between the EC of salt-affected soils and different spectral salinity indices were applied to the ALI image. This was atmospherically corrected and the radiometric sensor drift was calibrated. Visual comparisons and statistical validation of these models using ground truth were undertaken in order to identify the best semi-empirical model for slight and moderate salinity mapping. The obtained results show that the model based on the Normalized Difference Salinity Index (NDSI) does not give any results. The model based on the Salinity Index-1 (SI-1) and the SI-Advanced Space-borne Thermal Emission and Reflection Radiometer (SI-ASTER) confuses vegetation with high soil salinity, although the model does bring out areas of lower salinity. Both R² of 0.67 for the SI-1 and 0.65 for the SI-ASTER further reinforce that these models cause too much confusion to be used with accuracy for salt-affected soil detection. The semi-empirical model based on Soil Salinity and Sodicity Index-1 (SSSI-1) performs better than the two last models. However, there is a relative confusion between the classes in the slight and moderate salinity and in areas that are shown by the validation map; the higher class of salinity does not appear to contain higher levels of salinity. The statistical validation of this model reinforces what is seen on the derived map with only an R² = 0.68. The model based on the SSSI-2 clearly provides the best results in comparison to the ground truth. Its derived map gives the closest overall visual approximation of the EC map, with a whole range of values. With a statistical validation of R² = 0.97 to the ground truth, it is by far the best performance of any of the other models, and the different classes are statistically well separated, which further reinforces the accuracy of the visual analysis.     

基于最小数据集与LESA体系的县域耕地质量评价

建立科学合理的县域耕地质量评价体系对快速准确摸清耕地质量家底和建立耕地保护分区具有重要指导意义。该研究基于主成分分析法建立最小数据集精选指标,构建土地评价与立地条件分析（land evaluation and site assessment,LESA）体系,开展耕地质量综合评价,分析耕地质量区域分布特征及差异性特征并划定耕地保护分区。结果表明：1）自然质量指标最小数据集由砂粒、有机质、全钾、有效磷、pH值、综合污染指数、耕层质地、容重、阳离子交换量组成,立地环境指标最小数据集包括排水条件、连片度、生态兼容性、河流距离、路网密度、灌溉能力、农田林网化率、耕地利用类型。2）采用LESA评价模型计算耕地自然质量指数及立地环境指数,确定LESA体系为FLESA=0.5FLE+0.5FSA（FSA、FLE、FLESA分别为耕地立地环境条件、自然质量条件和综合分值）,采样点综合评分为51.517～81.838。综合比选各插值误差检验结果后采用普通克里金法进行耕地质量结果空间插值,评价单元耕地质量综合评分为52.148～79.624。3）铁岭县耕地资源可划分为5个等级区：1级区划分为永久基本农田核心保护区,占比20.52%;2级区划分为耕地自然地力条件重点治理区,占比36.79%;3级区和4级区耕地土壤和立地条件均存在多样性的限制因素,可划分为耕地综合整治区,占比36.33%;5级区划分为耕地生态自然保育区,占比6.36%。4）经计算基于最小数据集与LESA相结合的评价结果有效系数为0.615,相对偏差系数为0.009,说明该体系耕地质量评价结果准确,可信度较高。该研究成果简化了县域耕地质量评价指标体系,量化了自然质量与立地条件协同关系,为开展耕地质量提升和保护利用提供了理论和方法依据。     

Land use history and botanical changes in the calcareous hillsides of Upper-Normandy (north-western France): new implications for their conservation management

Historical studies were made of the changing land use (260-1995) of 14 calcareous hillsides in Upper-Normandy to investigate botanical changes over the last 200 years. Before the French Revolution in 1789, most of these hillsides were used as vineyards mixed with common sheep walks. After the French Revolution, they were distributed among inhabitants for cultivation (cereals) but they were abandoned in the nineteenth century and grazed again. Our results show that this history is correlated with important changes in the floristic composition of the calcareous hillsides between 1816 and 1995. The species richness of arable weeds and fallow-land species of former cultivated fields or vineyards decrease faster than that of chalk grassland species. The consequences of these long-term dynamics are discussed with regards to the ecological requirements and the rarity status of the species that have disappeared since 1935. We conclude with the need to take account of land use change processes, e.g. the alternation of arable fields and grasslands, to maintain the present species-richness of calcareous hillsides.     

基于RS和GIS的乌江流域(重庆段)湿地景观动态分析

为了探究三峡库区的建立对乌江流域(重庆段)即重庆东南地区湿地环境产生的影响,以landsat-5 TM和landsat 8OLI遥感影像为主要数据源,基于eCognition和ArcGIS平台,采用面向对象分类的方法,建立重庆地区乌江流域1995、2005和2015年湿地景观数据库,利用景观动态变化度、景观破碎度及土地利用转移矩阵等方法,分析重庆地区乌江流域内湿地景观近20年的时空变化特征.结果表明:1)重庆地区乌江流域整体湿地景观面积近20年处于增长趋势,动态变化指数最高为水库,最低为水田;2)湿地景观转移以湿地景观内部转移为主,湿地景观与非湿地景观转移为辅,人工湿地增加比重高于天然湿地;3)研究区内景观破碎度呈现先增加后减少的趋势,说明该区域湿地环境先恶化后得到改善;4)1995、2005和2015年,天然湿地景观分维数均低于1.6,人工湿地均高于1.7,说明人工湿地景观格局比天然湿地复杂.天然湿地的稳定性指数远低于人工湿地,且接近于0,说明自然湿地内部空间结构更加脆弱.通过三峡工程及其他水利工程的建设,导致乌江流域(重庆段)湿地景观格局发生变化,对该地区的湿地环境总体改善起到明显的促进作用.随着三峡工程建设、库区蓄水,以及龙潭水利工程、江口电站等水利设施修建,乌江流域内湿地总体面积增加,人工湿地变化较天然湿地更为明显,但天然湿地相比人工湿地更易受外界干扰,应加强相对应的保护措施.研究为保护该地区湿地景观,建立乌江流域湿地生态系统动态监测体系,以及为武陵山区精准扶贫提供技术支持.     

Assessment of erosion in the Boyer River watershed (Canada) using a GIS oriented sampling strategy and Cs measurements

Starting in the 1980's, the Rainbow Smelt (Osmerus mordax) population of the Boyer River (Canada) gradually declined due to water eutrophication and excessive siltation in the spawning area. Sediments and agricultural nutrients reach hydrosystems through runoff and soil erosion. The objectives of the study were to quantify the soil and sediment loss from agricultural fields and to identify the areas at risk, using ¹³⁷Cs measurements. Using a Geographical Information Systems (GIS), the watershed was subdivided into 6 isosectors presenting specific soil/slope combinations. Representative fields from each isosector were sampled for ¹³⁷Cs. Using GIS, the data for individual fields were extrapolated to isosectors and the whole cultivated area of the watershed. Based on this approach, it was estimated that around 30% of the arable lands of the watershed show erosion rates higher than 6 t ha^− 1 yr^− 1, which is considered as a tolerable level for Canadian soils, and that 45% of the residual area presents an erosion rate close to that limit. The average sediment production at the edge of fields was estimated at 2.8 t ha^− 1 yr^− 1, for an annual production of more than 60 000 t of material. Loamy soils with a slope higher than 2% were estimated to generate the highest sediment rate (6.9 t ha^− 1 yr^− 1) and nearly 40% of the overall sediment production.