农业土地利用对岩溶地下水影响研究综述

地球表层系统最突出的景观标志是土地利用/土地覆被。人类通过土地利用改变天然土地覆被从而对脆弱敏感的岩溶水文系统产生了重大的影响。文章着重从农业土地利用出发综述了当前农业土地利用对岩溶水影响的研究。农业土地利用对岩溶地下水的影响主要围绕着水质和水量两个核心从以下几个方面展开:天然植被的清除,农业灌溉和排水,农业集约化所带来的化肥杀虫剂等的使用以及污染物质在岩溶含水层中的运移和影响。在此基础上作者从研究内容,理论方法和建立模型等方面都提出了自己的想法和建议。      

Human-environment interactions in agricultural land use in a South China's wetland region: A study on the Zhujiang Delta in the Holocene

The formation and evolution of agricultural land uses in the Zhujiang Delta of South China are examined in the light of the dynamics of people and the environment and their interplay. The origin and propagation of agriculture are found to have a close relationship with the climate and sea level changes in the Holocene era. The development of rice cultivation, horticulture, and dike-pond system exemplifies human-environment interactions in a specified geographical and social context, which are manifested by the impact of environmental changes and population growth on agricultural innovations. The technologies of dike building and land reclamation, which represent local farmers effort to build a new and harmonious relationship with the changed environment, were critical to the agricultural success and sustainability. Imprudent use of a new agricultural technology could damage the environment, as evidenced by a frequent flooding that followed inappropriate dike building and premature reclamation. Diverse agricultural land uses are as a result of the adaptation of agricultural technology innovations to the environmental conditions.     

Parameter estimation for a karst aquifer with unknown thickness using the genetic algorithm method

The combination of ecological fragility and agricultural activity in the loess hilly–gully regions of western China has received broad environmental concerns. In this region, rainfall and soil moisture can fatally influence crop production under dry land farming. In this study, field experiments were conducted, from March 2001 to September 2005, to demonstrate the variation of soil moisture and fertilizer contents at different depths in slope and terraced lands, and to evaluate the ecological impacts and economic benefits in the terraced land of Loess Plateau. The results of both field test and Grey model (GM) calculation show that the terraced land, as compared to the sloping land, in the agricultural area of the Loess Plateau tends to store and retain much water, promoting more favorable interactions between water and fertilizer. During the months from March to June of the year with less rainfall, the water supply for crop growth is mainly derived from the deep storage of soil moisture accumulated from July to September of the previous year. The field experiments indicate that the crop yield of the 3-year-old terraced lands was 27% higher than that of the sloping lands with slopes greater than 10°, and that the crop yield can increase by 27.07 to 52.78% in the following cultivation years. In particular, potato was found to be more drought-resistant than winter wheat, thus it is more suitable for the arid and semi-arid Loess Plateau regions.     

基于主成分和模糊C-均值聚类算法的农业水资源高效利用综合分区

基于农业生态系统环境要素、水的资源属性、水资源的高效利用内涵、生产力水平、土地利用方式、种植结构及种植模式等因子,选取构建农业水资源高效利用综合分区的指标体系(16个定量指标、4个定性指标),采用主成分分析和模糊C-均值聚类算法为区划方法,对川中丘陵区进行量化分区。研究结果将川中丘陵区16个地级市和一个县级市(简阳)分为农业水资源较低利用区、农业水资源低效利用区、农业水资源中等利用区、农业水资源高效利用区和农业水资源较高效利用区5个区,这对南方季节性干旱区水资源利用规划有较强的借鉴作用。     

Pervasive wetland flooding in the glacial drift prairie of North Dakota (USA)

This article describes a unique flood hazard, produced by the dramatic expansion of wetlands in Nelson County, located within the North American Prairie Pothole Region of North Dakota, USA. There has been an unprecedented increase in the number, average size, and permanence of prairie wetlands, and a significant increase in the size of a closed lake (Stump Lake) due to a decade-long wet spell that began in 1993 following a prolonged drying trend. Base-line land cover information from the 1992 USGS National Land Cover Characterization dataset, and a Landsat TM scene acquired 9 July 2001 are used to assess the growth of the closed lake and wetland pond surface areas, and to analyze the type and area of various land cover classes inundated between 1992 and 2001. The open water profile in Nelson County changed from one marked by relatively comparable coverage of closed lake and wetland pond areas in 1992, to one in which wetland open water accounted for the vast majority of total open water in 2001. The bulk of the wetland pond area expansion occurred by displacing existing wetland vegetation and agricultural cropland. Producers responded to the flood hazard by filing Federal Crop Insurance Corporation (FCIC) claims and enrolling cropland in the Conservation Reserve Program (CRP), a federal land retirement program. Land taken out of agricultural production has had an enormous impact upon the agricultural sector that forms the economic base of the rural economy. In 2001 the land taken out of production due to CRP enrollment and preventive planting claims represented nearly 42% of Nelson County’s 205.2 K ha base agricultural land. The patterns obtained from this detailed study of Nelson County are likely to be the representative of the more publicized flood disaster occurring within the Devils Lake Basin of North Dakota.     

基于Cobb-Douglas生产函数的新疆各地区典型作物生产水足迹驱动因素研究

水资源紧缺是限制我国西北干旱区农业发展的主要瓶颈,正确评估地区农业用水效率及其影响机制,可为提高农业用水效率提供理论依据。以新疆为研究区,基于1988-2015年的长系列数据,分别计算出历年北疆、南疆、东疆典型作物（小麦、棉花）生产水足迹,并采用Cobb-Douglas生产函数定量分析气象因素（年降雨量、年日照时数、年均温度、年均风速、年均湿度）和技术因素（农机总动力、有效灌溉率、化肥施用折纯量）对作物生产水足迹的影响贡献率。结果表明： 1988年至2015年,东疆小麦、棉花生产水足迹显著高于北疆和南疆,在气候变化和技术进步的综合影响下,各地区典型作物生产水足迹逐年降低,其中技术进步对新疆典型作物单产水足迹影响显著高于气候因素,是驱动新疆各地区典型作物生产水足迹变化的主要控制因素。地区尺度上,北疆、南疆、东疆气候变化和农业技术发展均呈现显著的地区差异,总体来看,北疆气候条件最适宜作物生长,东疆气候最为恶劣,北疆、南疆农业技术发展速率整体上高于东疆。     

废弃采石场岩质边坡绿化技术及废弃地开发利用探讨

随着我国经济实力的增强和土地资源的利用,人们对废弃采石场岩质边坡绿化及其废弃土地开发整理越来越重视。在本土飘台法、鱼鳞穴法、燕巢法、阶梯台阶法及钢筋混凝土框格悬梁等绿化技术应用的基础上,作者引进了客土喷播法、液压喷播法、三维网喷混植生法、喷混植生法等国外边坡防护绿化新方法,并重视废弃地的开发利用,不仅挖掘出废弃地的土地资源和旅游资源等潜力,而且产生巨大的社会、经济和生态环境效益。文章从废弃采石场环境治理需要解决的岩质边坡绿化及废弃地利用两方面,探讨了绿化技术的适宜性及废弃地开发利用的最佳方式。     

基于镉污染风险的湖南省龙山县百合种植区安全区划

湖南省龙山县作为我国重要的百合生产基地县之一,其土壤却存在一定程度的镉(Cd)污染风险。同时,百合作为一种食药同源的植物,其食用和药用的质量安全标准不一致。因此,在龙山县提出百合种植区安全区划具有重要意义。笔者等在龙山县耕地采集326件表层土壤样品和70件百合样品(配套根系土样),在分析土壤及百合中Cd的含量和土壤中氧化物、有机质、pH等指标的基础上,探讨Cd生物有效性的影响因素,并据此建立百合Cd生物富集系数预测模型,结合土地质量地球化学调查数据预测耕地的百合Cd含量,给出百合种植区安全区划及建议。结果表明,研究区土壤存在Cd污染风险,百合具有质量安全问题。研究区Cd的生物有效性受到土壤CaO、S、P、K₂O含量和土壤pH的共同影响。与多元线性回归模型相比,随机森林模型能够更好地预测百合Cd生物富集系数。百合种植区安全区划显示,研究区食用百合优先种植区、药用百合优先种植区、药用百合次级种植区、结构调整种植区面积占比分别为1.49%、92.71%、2.88%、2.92%,建议大力开发药用百合农产品。该研究成果将Cd污染风险耕地的安全利用与食药同源农产品的质量安全有...     

完善新时期水资源管理指标的方法

气候变化和人类活动极大地改变了流域水循环和水资源分布, 以供需管理为核心的水资源管理方法难以缓解缺水的局面。中国提出了新时期水资源相关管理政策, 然而受数据、对象和方法的限制, 新政策采用的管理指标和内涵目标间存在差异, 在缺水地区还必须增加耗水总量控制的约束指标, 实施取水与耗水的双向管控。本文通过综述国内外最新进展和案例, 提出新时期水资源管理指标的完善方法: 建立以蒸散监测为核心的现代耗水要素监测体系;健全以耗水上限为核心的水资源刚性约束方法, 通过综合考虑环境流量用水和生态服务耗水的需求, 核定流域人类活动水资源可消耗量的上限, 实现水资源的刚性约束;实施耗水约束机制, 通过约束农业规模、合理规划生态恢复治理的规模和方式, 实现水资源发展的“四水四定”既定原则。期望通过数据、方法和措施的创新能够切实保障新时期水资源治理模式的有效实施。     

基于镉污染风险的湖南省龙山县百合种植区安全区划

湖南省龙山县作为我国重要的百合生产基地县之一,其土壤却存在一定程度的镉（Cd）污染风险。同时,百合作为一种食药同源的植物,其食用和药用的质量安全标准不一致。因此,在龙山县提出百合种植区安全区划具有重要意义。笔者等在龙山县耕地采集326件表层土壤样品和70件百合样品（配套根系土样）,在分析土壤及百合中Cd的含量和土壤中氧化物、有机质、pH等指标的基础上,探讨Cd生物有效性的影响因素,并据此建立百合Cd生物富集系数预测模型,结合土地质量地球化学调查数据预测耕地的百合Cd含量,给出百合种植区安全区划及建议。结果表明,研究区土壤存在Cd污染风险,百合具有质量安全问题。研究区Cd的生物有效性受到土壤CaO、S、P、K2O含量和土壤pH的共同影响。与多元线性回归模型相比,随机森林模型能够更好地预测百合Cd生物富集系数。百合种植区安全区划显示,研究区食用百合优先种植区、药用百合优先种植区、药用百合次级种植区、结构调整种植区面积占比分别为1. 49%、92. 71%、2. 88%、2. 92%,建议大力开发药用百合农产品。该研究成果将Cd污染风险耕地的安全利用与食药同源农产品的质量安全有效衔接,完善了受污染耕地安全利用的工作方法,为推动龙山县百合产业发展提供了科学依据。     

土地环境质量综合评价模型的建立--以山东半岛蓝色经济区为例

依据多目标区域地球化学调查资料,对土地环境质量综合评价方法进行探讨,建立评价模型。提出土地环境质量综合评价是土壤内部指标分等、外部指标定级,整合全部评价因素的新观点。采用相关系数、半方差函数进行指标筛选,层次分析法确定参评指标权重,通过隶属度函数模型将土壤不同含量单位的指标纳入同一评价体系形成内部因素,叠加区域地下水、农作物质量等外部因素,建立土地质量综合评价模型。根据模型对山东半岛蓝色经济区土地环境质量进行综合评价,结果表明：山东半岛土地可分为优质、优良、良好、中、差5等20级,其中可作绿色（111和121级）及无公害（211和221级）食品生产基地的土地占62．60％;需农业种植结构调整的512和522级土地面积267．54 km2,多位于矿区（金矿、石墨矿、铜铁矿）周边或紧邻城镇地带。土地环境质量综合评价方法及模型的建立对山东其他地区基本农田保护和土地质量等级划分具有一定借鉴意义。     

Use of 234U and 238U isotopes to identify fertilizer-derived uranium in the Florida Everglades

Surface water and peat in the northern Everglades have very low natural concentrations of U and are therefore sensitive to the addition of small amounts of U from anthropogenic sources such as fertilizer. Peat samples collected along a nutrient gradient in the northern Everglades have unusually high concentrations of U (>1 μg/g, dry basis) and also have a distinctive ²³⁴U/²³⁸U activity ratio (AR). AR values for U-enriched peat fall in the narrow range of AR values for commercial phosphate fertilizer (1.00±0.05). In contrast, AR values for low-U peat from background sites exceed 1.05. The spatial distribution of anomalous U concentration, and of fertilizer-like AR values in peat, parallel a previously documented pattern of P enrichment. These results strongly suggest that some of the U in nutrient-impacted peatlands is fertilizer-derived. Agricultural drainage water sampled in the northern Everglades has high concentrations of dissolved U (0.3–2.4 μg/l) compared to surface water from background sites (<0.1 μg/l). Measured AR values in drainage water (0.949–0.990) are also permissive of a fertilizer origin for the U and are different from AR values in surface water or peat at background sites (AR>1.05). Synoptic sampling of surface water along drainage canals indicate that Lake Okeechobee, and some drainage from agricultural fields, are sources of dissolved U, whereas wetlands farther downstream act as sinks for U. Historically cultivated agricultural soil has only a marginally elevated (+0.2 μg/g) average concentration of U compared to nearby uncultivated soil and incorporates only 20% of the U from an aqueous solution that was slurried with the soil. In contrast, a similar experiment with fresh Everglades peat indicated uptake of 90% of the added U. These experiments support the proposed removal of U from agricultural fields and concentration of U in downstream peatlands. The methodology of this study can be used to describe the behavior of fertilizer-derived U in other low-U environments.     

作物水分利用效率内涵及研究进展

详细分析了作物水分利用效率的内涵,回顾了国内外的研究历程及进展;在阐述其概念系统的基础上,结合作者的实验,明确了不同水平上的作物水分利用效率的计算模式,为作物水分利用效率的深入研究,实现农业高效用水及农业的持续发展提供理论依据。     

贵州省近40年耕地功能转型评价及演变差异分析

梳理1978年之后贵州省农业政策及农业农户概况,构建耕地功能评价指标体系,并运用熵权法计算指标权重与其功能值,对耕地多功能进行分类和评价,对比全省及各个州市耕地在不同社会经济条件下所承载的功能,分析差异及原因,研究表明:（1）贵州省耕地功能呈下降趋势,功能转型从2006年前后开始,各州市存在一定差异,经济发展较快的地区在2004年前后已提前转型,经济发展较慢的地区在2012年前后转型;（2）耕地功能存在空间分布差异,主要与地区耕地压力和经济发达程度组合状况有关,低耕低压力高GDP（如遵义、六盘水）耕地功能值最高,高耕低压力高GDP（如贵阳市）则次之,高压力低GDP（如安顺等地区）再次之,低压力低GDP（如黔南等地）最低;（3）耕地数量减少,耕地化学品负荷加剧,建议注重耕地生态保护,减少以过度化学品的投入换取粮食产出等不合理做法;从当地实际出发选择适合的农业发展方式,协调粮经作物、种养业发展的关系,推动农业结构优化升级。      

Mapping landslide susceptibility in Travis County, Texas, USA

A geographic information system (GIS) was used to construct a landslide hazard map for Travis County, Texas. The County is experiencing rapid growth, and development has encroached into unstable terrain that is vulnerable to landslides. Four layers of data were superimposed to create the landslide hazard map. Slope was given the most emphasis, followed by geology, vegetation, and proximity to faults. The final map shows areas of low, medium, and high landslide susceptibility. Areas of high susceptibility occupy stream and reservoir banks, rock escarpments, and agricultural land. The landslide hazard map can be a useful geologic criterion for land use planning. Planners can use the map to allocate appropriate land uses to unstable terrain, and to identify existing structures at risk from landslide activity. The methods presented in this paper can be adapted to other counties in the U.S. and elsewhere. Results of this study suggest that geographic information systems can effectively compile and overlay several data layers relevant to landslide hazards.     

Evaluating the effectiveness of local government farmland protection programs

The effectiveness of farmland preservation programs in fast-growth areas cannot be determined solely on the basis of stability in the agricultural land supply within the subject jurisdiction, but must take into consideration extrajuridictional agricultural land loss which can result from stringent local development controls. A better measure of program effectiveness is the coefficient of conversion, which expresses the area of agricultural land converted to urban use per unit of urban growth. The rationale for such a measure and its application in Modesto, California are discussed.     

土地利用变化对水文系统的影响研究

以秦淮河流域为研究区域，利用现代遥感、地理信息系统等多种数字技术，获取流域空间分布的下垫面信息和中间状态信息，细致地刻画了流域内的水文过程，建立了研究区域数字水文模型。利用所建立的数字水文模型，对定义的土地利用变化情景进行了模拟。模拟结果表明，模型可以定性和定量地反映各种土地利用变化对水资源系统尤其是对水量平衡和防洪情势的影响程度。     

Human impacts on soils: Tipping points and knowledge gaps

Soil ecosystem functions are derived from plant, animal and microorganism communities and the non-living environment interacting as a unit. Human activities have affected soil ecosystem functions and in many cases caused soil ecosystem collapse. This review provides a synthesis of current knowledge of human impacts on soil ecosystems, with a special focus on knowledge gaps regarding soil ecosystem shifts and tipping points, using the island of Crete, Greece as an example. Soil ecosystem shifts are abrupt changes that occur at “tipping points” and have long-lasting effects on the landscape and both the biotic and abiotic structure of the soil. These shifts can occur due to climate change, land use change, fertilization, or above-ground biodiversity decline. The environmental pressures in the agricultural land of Crete, place the island very close to tipping points, and make it an “ideal” area for soil ecosystem shifts. Reversing the trend of the shift while using the soil ecosystem services, means that significantly more organic matter needs to be added to the soil compared to the amount added under set-aside conditions. Potential nutrient supply and demand calculations indicate that fertilizer demand in Crete can be satisfied by recycling of bio-residue and livestock excreta produced on the island. Soil fertility improves faster if, in addition to bio-fertilization, farmers use traditional agricultural practices such as crop rotations and legume row plantings within olive trees and orchards. A renewed soil fertility paradigm shift requires a “holistic” management of biotic-soil–water resources in order to provide sufficient and an appropriate type of organic matter to the plant–microorganism system to maximize food production.     

黑河流域节水生态农业与流域水资源集成管理研究领域

概述了中国内陆河流域面临的水问题和日益激化的用水矛盾,强调了内陆河地区支柱产业——绿洲农业应该坚持节水和生态的方向,流域集成管理是持续农业的基础。长期从事该方面研究的黑河流域是个较好借鉴,同时也提供了深入开展相关研究的基础,为此提出了以黑河流域为背景的四大研究流域：水文、生物、经济系统水循环与水资源形成演变,节水农业的生物学研究与抗旱品种繁育,农业节水新材料研发与工程节水技术集成,水资源合理配置与流域集成管理;并简述了各领域的主要方向。     

Cost-benefit analysis of vetiver system-based rehabilitation measures for landslide-damaged mountainous agricultural lands in the lower Northern Thailand

On May 23, 2006, the landslide-debris flow occurred in several places of the lower Northern Thailand. These destroyed about 4,000 houses resulting in about 10,000 people having to be permanently evacuated. They also damaged large areas of high potential agricultural growth in the highland and mountains in the region. The impact of the landslide was both in terms of disruption of agricultural production and lowering of land productivity. A cost-benefit analysis (CBA) was used to compare the net welfare gained from different land rehabilitation measures applied in landslide-damaged agricultural areas in the lower Northern Thailand. In this paper, ex ante CBA was conducted based on the interviews with knowledgeable stakeholders prior to land rehabilitation project and policy implementations. The alternative measures were as follows: Measure 1—planting of vetiver grass (Chrysopogon zizanioides (L.) Roberty) with waterway construction; Measure 2—planting vetiver grass with intercropping of durian seedling and sunn hemp (Crotalaria juncea L.) including waterway construction; Measure 3—planting vetiver grass with intercropping of durian seedling and banana (Musa sapientum L.) including waterway construction; and Measure 4—status quo (under natural ecological succession process). For a 20-year project period, the highest net present value (NPV) was obtained from Measure 2 followed by Measure 3. The NPV of Status Quo option was higher than Measure 1. This is because if the land were to be left to naturally regenerate as is the case under Status quo, farmers would benefit from the natural rehabilitation process by native pioneer plants. The appropriate measures as studied in this research can be competent representative model for rehabilitating the landslide-damaged areas in the lower Northern Thailand where rehabilitation systems have not yet been introduced.