南水北调西线一期工程区泥石流发育的非线性特征

通过对研究区103条泥石流沟发育状况统计显示,泥石流沟的数目、发育密度及规模在不同流域表现出不同特点;综合分析表明。泥石流沟的流域面积、主沟长度及平均沟床比降存在明显的分维特征,泥石流堆积物粒度组成具有很好的分形结构,这种良好的非线性关系在一定程度上揭示了研究区泥石流发育的非均一性和自相似性;分析得出了在沟谷流域面积〈5km^2,主沟长度〈5km及主沟平均沟床比降10％～60％时研究区内泥石流最易暴发的结论。     

金沟河流域和谐发展需协调的关系

为实现金沟河流域和谐发展目标,从外部环境和内部条件两个角度,分析了金沟河流域存在产权关系不清晰、流域管理与行政区域管理界定不清、水资源管理部门分散三大弊端,以及硬件建设缺失和软件服务不到位等主要问题,提出金沟河流域和谐发展的思路:在流域和谐发展方面进行有益的尝试,协调好流域长期发展与近期建设、水量调度与灌区灌溉、水资源优化配置与节水改造、地表水与地下水、流域管理与区域管理和水资源公益性与商品性等关系。     

沾河林区流域经营治理的探讨

对沾河湿地自然保护区，采取流域生态综合治理措施，通过挖截留沟，治理侵蚀沟等，调节水流作用；充分利用林间空地，实行立体开发，种植各种经济植物，林区内的农业用地根据市场需求。不断调整粮经作物种植比例，发展“两优一高”农林业。     

松嫩流域环境蠕变的若干事实

松嫩流域是中国东北部一块富饶的土地,物产丰饶,气候适宜,自然状况保护相对较好;20世纪后半叶,随着国民经济的高速发展,在一定程度上环境也遭到不同程度的破坏,有些还是很严重的;从环境蠕变的角度分析了松嫩流域环境所发生干旱、黑土退化、天然林减少、草场退化、西部地区沙漠化和荒漠化、湿地干涸缩小、江河污染鱼类减少、城市污染等变化;这些变化与气候变暖有很大的关系,须引起高度重视,尽早采取相应的防御措施。     

唐家堡河流域生态农业建设中的土地利用问题

唐家堡河流域位于甘肃省定西县的南部,祖历河、官川河支流上游。从地形地貌上属黄土高原丘陵沟壑区,从气候上属中温带半干旱气候,流域总面积96.4平方公里。近几年来,从各个方面对流域的治理和开发进行了研究。从农业生态经济的角度,本流域可以分为A区、B区和C区三个农业生态经济区。本文在上述研究的基础上,用目标规划的方法,对流域各区生态农业建设中的土地利用问题进行了初步的研究。     

绿曲富歌──来自乡宁县西廒村小流域内的报告

绿曲富歌──来自乡宁县西廒村小流域内的报告王建忠绿是生命，绿是希望，绿是辉煌。透过满坡满沟葱翠的绿色，透过满村满园飘香的果树，可以看到山西省乡宁县西廒村农民那一张张洋溢着喜气的笑脸；在欢蹦乱跳的猪羊畜群旁边，在各种机械的轰呜中，可以尽情地聆听和欣赏西...     

图们江流域的“UNDP”计划

图们江流域的“ＵＮＤＰ”计划谢挺夫，徐少义白山松水，峰险沟深。１４００多公里的边境线上，滚滚奔流的鸭绿江、图们江，象一把把咄咄逼人的利刃，将东北亚大陆板块拦采斩断。高山大川，这些大自然所设下的屏障，在共和国的历史上，曾做为抗美援朝、反修防修的前哨，将...     

实施非均衡经济发展战略培植巍山农村经济新产业

一、围绕两大经济带理清非均衡发展思路。结合巍山实际，按经济发展程度和地理区位把巍山划分：以永建、大仓、庙街、文华、巍宝五个坝区乡镇为红河流域经济带；以紫金、马鞍山、龙街、鼠街、牛街、青华六个山区乡为澜沧江流域经济带。根据两个经济带的地理、气候、交通、水利、劳动者素质、投入能力、土地水肥、基础设施状况等寻找更新更快的经济增长点，实打跨越式开发，重新调整和布局全县农村重点经济产业。     

岩鹰展翅谱沧桑

老鹰岩村的变化有多大 “安场有个老鹰岩,家家户户打草鞋。有朝一日绱子断,叮叮咚咚滚下岩”。当老鹰岩村七十多岁的老人易焱烈用颤抖的双唇说完这段顺口溜后,眼里噙满了耻辱的泪水。“这是过去人们编来鄙视咱们老鹰岩的啊！咱们穷是事实,但打草鞋卖营生的却很少,大多是靠编斗     

长江流域农业生态经济区划的初步探讨

一、长江流域生态经济状况 长江是我国的第一大河,流域面积达180余万平方公里,约占全国土地面积的1/5。人口约3.52亿,约占全国人口的1/3;有近4亿亩耕地,约占全国耕地面的1/4。全流域自然气候条件十分优越,农业资源丰富,开发历史悠久,经济文化发达。80年代初,全流域农业总产值占全国农业总产值34.9％,其中,种植业占34.5％,林业占33.4％,牧业占38％,渔业占27.8％。全流域主要农产品产量占全国相应产品产量的比重为:粮食占40％以上,棉花占     

退耕还林工程经济影响评价与分析——以湖北省秭归县为例

根据湖北省秭归县退耕还林工程状况,建立了秭归县退耕还林工程经济影响评价指标体系,并用层次分析法,计算出各指标权重;用线性加权和函数法,通过影响指数计算模型,计算出秭归县退耕还林工程经济影响指数;调查整理秭归县退耕还林工程实施10年来的数据,运用前后对比法、过程监测法,结合影响指数,从退耕还林工程对地方经济发展、对居民收入、土地生产3个方面的影响对秭归县退耕还林工程经济影响进行了定性与定量评价分析。通过分析,说明了退耕还林工程在保证了秭归县总体经济稳步增长的情况下,合理调整产业结构,不断挖掘自身潜力,在短期内已经开始发挥出巨大的经济效益影响,且其影响正随着工程的稳步推进愈来愈大。     

气候因子对花生-脐橙两大经济圈的负面影响

花生是中国科学院红壤生态实验站所在地域附近农业的特产和经济收入的命脉;中国科学院三峡工程秭归生态实验站地域的脐橙,是库区农业的特产和经济收入的命脉,也是库区高山峡谷绿化造林防治水土流失的好办法。气候因子对花生—脐橙两大经济作物的负面影响极大;根据两大经济圈的现实气象资料和实地观察,探索了生态网络气象数据的处理。     

Coping with drought with innovative pricing systems: the case of two irrigation water management companies in France

In recent years, France has been facing particularly severe drought periods especially in summer. In a country where agriculture is the largest water user, some irrigation management companies have implemented innovative pricing systems to handle this situation. The objective of this article is to analyze the impact of these new management systems on farmers’ incomes, the revenue of the management companies, and the amount of water used. To do that, we develop a methodology using a stochastic model that simulates the representative farmer's optimal behavior in a context of climatic variability. An empirical application is made with a crop growth model and data collected from the Midi‐Pyrenees region. The results show that using these specific nonlinear pricing systems allow irrigation water managers to reduce the impact of drought on production. Moreover, the type of pricing implemented depends on the characteristics and capabilities of the water company. More particularly, these pricing systems can be used to anticipate agricultural water demand in order to avoid imbalance with water availability.     

Trade‐offs in the performance of alternative farming systems

Numerous alternative farming systems are proposed as solutions to the sustainability challenges of today's conventional farming systems. In this paper, we review the production, environmental, and socioeconomic performance of three widely discussed and promoted alternative farming systems—organic, smallholder, and urban agriculture. We show that both organic and smallholder agricultures have some benefits, but also entail important trade‐offs; organic has environmental benefits, and also livelihood, health, and nutritional benefits for producers and consumers, but is hampered by lower yields and higher prices. Smaller farms have higher yields and host higher biodiversity, but are hampered by lower incomes to farmers. Urban agriculture can take some pressure off rural landscapes, provide nutritional benefits to the urban poor, and engage urban dwellers in addressing food system challenges, but it simply cannot scale up to be a substantial solution in and of itself. We suggest that instead of focusing on alternative systems, we should identify pathways to sustainable farming for all systems, reforming conventional systems where they perform poorly, and transitioning to alternative systems in contexts where they perform best.     

基于生活水平维度的县级贫困度量研究——以武陵片区北部为例

提高贫困人口瞄准和识别的准确度是农村扶贫开发需要解决的首要问题,近年来从多个角度进行多维贫困的精准度量与分析成为国内外扶贫领域的研究热点。该研究以Sen的能力方法理论为基础,以Alkire和Foster的多维贫困指数(MPI)测算指标体系为参考,结合研究区实际情况,建立了生活水平维度贫困指标体系,利用武陵片北部11个县的贫困农户调查数据进行了基于"A-F"双临界值法的县级贫困人口量算,并通过"维度加总-分解"算法进行了空间分异分析。结果显示:生活水平维度中通电与资产指标对研究区贫困发生率和多维贫困指数影响最小,燃料类型指标影响最大;11个县贫困程度由大到小依次为:巴东县石柱土家族自治县秭归县建始县来凤县恩施市鹤峰县利川市丰都县咸丰县黔江区;依据房屋结构、燃料类型、饮水情况3个指标可将11个县分为甲乙丙3种类型,不同类型县的主要致贫因素不同,当地政府应根据各县具体情况采取差异化扶贫政策。     

加快推进农村土地资产经营的政策研究

开展农村土地资产经营的实际困难：资金扶持力度不够,农村金融产品缺乏;月艮务平台不健全,管理机制不完善。近年来,国内部分地区通过发展农村土地金融、、建设农地流转平台对推进农村土地资产经营进行了有益探索。加快推进农村土地资产经营的政策建议：（i）进—步加快农村土地金融服务及制度创新,开展农村土地经营权抵押和股权质押融资创新;尝试开办土地银行业务和土地资产证券化业务,（2）进一步加快完善农地流转平台,将农地流转平台裹在基珐．实现下沉服务,拓展平台照备功能,打造“一站式”服务。     

青海湖区生态环境综合治理对策研究

青海湖是国家级自然保护区，是国际重要湿地之一。近30年来，围绕湖水持续下降这一主题，又使青海湖成为中国乃至世界特级生态告急区之一。针对青海湖面临的生态危机，展开广泛的研究，提出：封湖育鱼、封山育草、保护水源涵养林，实施湖区封闭，引水济湖，人工增雨等措施，协调好人与生态环境的关系，坚持可持续发展观和科学观，创出适合青海湖区发展的新路子。     

Agrarian reform and cooperation between settlers in the Midwest of Brazil: An institutional approach

Cooperation is an important factor in improving the efficiency of agrarian reform, but hardly occurs, which is a serious problem in Brazil. This research tries to explain why cooperation is so difficult in Brazilian settlements. It focuses on the Midwest of Brazil, a region with a high concentration of land, located in the main region for production of commodities. Research combines a New Institutional approach with aspects from the economic sociology. The model developed in the paper is original and highlights factors responsible for cooperation. Research differentiates institutional arrangements according to asset specificity and sunk costs. Beside associations for representation with public authorities, where cooperation is easier, cooperative arrangements need specific investments from the settlers, who require warranties before participating. Institutions serve as warranties for adopted governances. In the case of cooperation in Brazilian settlements, these warranties should come from informal institutions, which can be a problem in some communities. Leadership of a producer can also have an important role in hierarchical networks.     

Assessing cost‐effectiveness when environmental benefits are bundled: agricultural water management in Great Barrier Reef catchments

Using economic analysis to prioritise improvements in environmental conditions is particularly difficult when multiple benefits are involved. This includes ‘bundling’ issues in agricultural pollution management, where a change in management action or farming systems generates multiple improvements, such as reductions in more than one pollutant. In this study, we conceptualise and compare two different approaches to analysing cost‐effectiveness when varying bundles of benefits are generated for a single project investment. Each approach requires data to be transformed in some way to allow the analysis to proceed. The index approach requires the transformation on the benefits side so that the effects of multiple pollutant changes can be combined into a measure for each project which can then be compared to costs. By comparison, the disaggregation approach requires the transformation on the costs side where costs for each project have to be apportioned across the different pollutants involved. The paper provides novel insights with an application to agricultural water quality improvements into the Great Barrier Reef in Australia, demonstrating that while both approaches are effective in prioritising projects by cost‐effectiveness, the disaggregation approach provides more insightful results and values that may be relevant for use as upper value guidelines in future project selection.     

Roadmap for interactive exploration of sustainable development opportunities: The use of simple instruments in the complex setting of bottom-up processes in rural areas

Before embarking on the development of rural areas or regions it seems necessary to answer the following key questions: what goals of the parties involved can be realized, and where, when and how? To tackle these questions we have developed a ‘roadmap’, as part of an overall sustainable development procedure for physical planning and spatial management in rural areas. The roadmap is a tool for the process manager and the people involved. It helps to find the way in the exploration of the potential social, economic and ecological benefits of developing the area or region. The purpose of using the roadmap is to alleviate doubts about the advantages of cooperating in pursuit of sustainable development. A back-casting approach is applied to create appealing visions of the future and visualize mutual opportunities worth implementing. In this article we first describe the need for this new roadmap. We then describe its use, step by step and in some detail. An example of the exploration process is described and the strengths and weaknesses of the roadmap are discussed.