建设模型黄土高原 维持黄河健康生命

模型黄土高原是为研究黄土高原水土流失规律、水土保持治理模式和治理效益 ,借助实体模拟理论和技术、测控技术和信息技术而构建的高科技试验研究模型体系 ,包括原型小流域观测、实体小流域模型和室内比尺模型。模型黄土高原建设的总目标与任务是 :在黄土高原地区选择不同类型区 ,构建野外和室内物理模型 ,开发数学模型 ,探索水土流失规律 ,提出水土流失治理模式 ,研究水土保持效益。开展模型黄土高原建设在基础理论、应用实践和技术及设备等方面都有一定的工作基础。介绍了近期已开展的工作和当前急需探索的关键技术问题     

黄土高原水土流失治理模式的层次结构及其演变

面对黄土高原不同历史时期形成的众多的水土流失治理模式,如何正确认识和客观评价,是长期困扰我国水土流失治理与区域持续发展的重大问题。该文根据黄土高原不同时期水土流失治理模式的构成内涵和任务目标,提出水土流失治理模式具有层次性、阶段性和区域适宜性的特点,并将水土流失治理模式划分为区域协调发展模式、小流域治理与发展模式、特定下垫面治理模式和特定问题治理模式4个层次,在此基础上分析了各个层次模式的适宜性。同时根据60多年来水土流失治理模式的演变,提出了水土流失治理模式的阶段性,明确了黄土高原水土流失主要治理模式及其阶段性规律。     

黄土高原重点小流域水土流失与综合治理效益遥感监测研究技术总结

黄土高原重点小流域水土流失与综合治理效益遥感监测研究技术总结李天杰（北京师范大学环保所，北京１００８７５）郭立民（山西省农业遥感应用科学研究所）朱启疆（北京师范大学地理系）编者按黄土高原重点小流域治理试验示范区水土流失及综合治理效益的遥感监测（７５－...     

大力发展小流域经济

<正> 从1980年开始小流域治理试点和在全国推广以小流域为单元进行综合治理以来,迄今已有13年了。在此期间,无论是试点、国家重点治理还是面上小流域治理,都经历了一个完善、发展的过程,由单纯防护型治理转向开发型治理,在全国产生了一批优质、高效小流域。小流域治理,使昔日水土流失严重、默默无闻的荒沟。变成了环境优美,种、养、加全面发展的小流域经济。下面就小流域经济问题谈点自己的看法。     

黄土高原小流域治理与生态建设

 分析黄土高原水土流失特征,介绍该区小流域综合治理与生态建设成就。根据黄土高原小流域治理理论与实践,提出了黄土高原国土整治的“28字方略”及水土保持型生态农业概念;研究了小流域生态系统健康评价方法及指标体系。建议退耕还林还草与沟道工程措施结合,加强生态系统自我修复功能的系统研究;在以小流域为单元的基础上,加强中尺度生态环境建设试验示范研究和科学评估生态恢复的环境效应等。     

参与式方法在小流域治理中的应用

以小流域为单元进行综合治理是当今世界各国防治水土流失的主要形式,而参与式方法的推广和运用,为小流域水土流失治理提供了一种有效途径。通过对世界银行贷款项目区参与式流域治理的应用与实施效果分析,探索参与式方法在我国黄土高原小流域治理中的作用。研究表明：运用半结构访谈和问题树的分析方法,可以有效找出制约地区发展的核心问题,为水土流失项目的开展以及不同治理模式的实施提供一个有效的途径;参与式流域治理不仅有助于实现生态环境的改善,促进农村经济社会的发展,同时对流域的生态-经济-社会可持续发展也具有重要意义。     

继续加强小流域试点工作 促进长江流域可持续发展

小流域试点是水土保持工作的前沿阵地 ,重点研究解决水土保持事业前进道路上的治理技术问题。长江流域实施小流域试点 2 0年来 ,探索出不同水土流失类型区的治理模式和技术 ,为流域水土保持工作指明了方向 ,建立健全了小流域水土保持管理体系 ,推进了面上水土流失治理工作的深入开展 ,并培养锻炼了一批水土保持技术骨干。面对当前经济快速发展和西部大开发的新形势 ,小流域试点工作应拓宽思路继续创新 ,依靠科技 ,加强基础数据观测和专题研究 ,加强技术总结 ,加强试点的成果管理和后续管理 ,重点建设一批示范小流域 ,以促进长江流域可持续发展。     

纸坊沟流域土壤入渗速率随空间和治理度之变异规律

由于黄土具有入渗速率高的特点,近年来许多专家学者建议将"全部降水就地拦蓄入渗"作为黄土高原国土整治的战略决策,而采取小流域为单元的方法进行水土流失综合治理与开发,在黄土高原乃至全国流域治理中取得了成功经验.     

进一步提高陕北小流域综合治理水平问题的商榷

<正>1 小流域综合治理中存在的问题新中国建立以后,特别是改革开放以来,小流域治理已成为陕北治理水土流失的主要形式.1983年陕北的无定河、黄甫川流域被列入国家重点治理区,延河、佳芦河也相继列入世界银行贷款水土保持项目进行重点治理.好机遇为陕北水土保持工作带来了勃勃生机,政府重视、政策调动加上资金投入力度的增大,使这一地区的小流域治理健康、持续发展,呈现出从未有过的好势头,在规模治理、综合治理、开发治理上都有大的突破,涌现出不少沟、坡、塬、峁、梁综合治理,林、草、果、粮全面开发,山、水、田、林、路一步到位的成功典型,充分显示了黄土高原治理开发的潜力和希望,为治理黄土高原水土流失、改善生态环境、建设生态农业闯出了路子,提供了可贵的经验.     

论小流域综合治理与规划的指导思想

黄土高原区域治理中各试区的科技攻关项目成果和水利部及各地方政府的试点和重点小流域规划和治理的实践表明：为了加快治理速度，取得更大的生态、经济和社会效益，在小流域综合治理和规划中，必须贯彻以强化降水就地拦蓄入渗为方略的８条指标思想。     

重庆长寿湖富营养化评价及氮磷平衡研究

利用营养状态卡森指数和综合营养状态指数评价长寿湖富营养状况,结果表明各监测点均达到富营养化水平。长寿湖富营养化主要影响因子氮磷的输入输出研究结果为:氮输入总量7914 6t/a ,主要来源为上游来水,占总量约70 % ;磷输入总量5 91 84t/a ,主要来源为农田径流,占总量约4 7% ;氮磷输出量分别为2 4 19 5t/a和12 0 2t/a,截留率分别为6 9 4 %和79 7%。结合该地的实际情况,指出了防止湖泊富营养化加重,当务之急为控制龙溪河上游水源污染物入湖负荷     

黄家二岔小流域能量流的系统分析Ⅱ．种植业子系统能量流分析

计算了小流域小麦、豌豆、马铃薯、胡麻、玉米的有机能、无机能投入和各种作物的籽粒、秸秆、根的能量产出，以此分析了各种作物的能量产投关系、种植业子系统能量流的现状与问题，并作了种植业投能结构和数量的优化分析。     

3S支持下的陇中黄土高原生态系统健康评价--以甘肃省榆中县为例

利用遥感影像、DEM和调查数据,在野外调查的基础上,利用3S技术,生成各参评因子的专题栅格图层.运用层次分析法,从影响生态系统健康的自然和人文因子的角度出发,选择活力、组织结构、负荷能力、恢复力、生态系统功能维持、外部投入及人群健康状况作为研究区生态系统健康评价的7个要素,构建生态系统健康评价指标体系.健康等级划分为:很健康、健康、中度健康、一般病态和疾病5级.研究结果表明,该县生态系统健康状况处于中等偏下水平,一般病态面积占到45%～50%,而且从1991年-2002年-2006年病态面积逐年增加,健康面积逐步缩小,反映出榆中县2006年生态系统健康状况较2002年和1991年有所下降.     

Soil carbon saturation: Evaluation and corroboration by long-term incubations

Although current assessments of agricultural management practices on soil organic C (SOC) dynamics are usually conducted without any explicit consideration of limits to soil C storage, it has been hypothesized that the SOC pool has an upper, or saturation limit with respect to C input levels at steady state. Agricultural management practices that increase C input levels over time produce a new equilibrium soil C content. However, multiple C input level treatments that produce no increase in SOC stocks at equilibrium show that soils have become saturated with respect to C inputs. SOC storage of added C input is a function of how far a soil is from saturation level (saturation deficit) as well as C input level. We tested experimentally if C saturation deficit and varying C input levels influenced soil C stabilization of added ¹³C in soils varying in SOC content and physiochemical characteristics. We incubated for 2.5 years soil samples from seven agricultural sites that were closer to (i.e., A-horizon) or further from (i.e., C-horizon) their C saturation limit. At the initiation of the incubations, samples received low or high C input levels of ¹³C-labeled wheat straw. We also tested the effect of Ca addition and residue quality on a subset of these soils. We hypothesized that the proportion of C stabilized would be greater in samples with larger C saturation deficits (i.e., the C- versus A-horizon samples) and that the relative stabilization efficiency (i.e., ΔSOC/ΔC input) would decrease as C input level increased. We found that C saturation deficit influenced the stabilization of added residue at six out of the seven sites and C addition level affected the stabilization of added residue in four sites, corroborating both hypotheses. Increasing Ca availability or decreasing residue quality had no effect on the stabilization of added residue. The amount of new C stabilized was significantly related to C saturation deficit, supporting the hypothesis that C saturation influenced C stabilization at all our sites. Our results suggest that soils with low C contents and degraded lands may have the greatest potential and efficiency to store added C because they are further from their saturation level.     

利用多渠道多层次集资开展水土保持工作

近年来各地在多渠道多层次集资方面创造了不少经验。本文研究总结了各地的集资经验,认为增加投入是增强水土保持活力的物质基础,是水土保持工作能够持续稳定发展的关键。文章指出:在当前国民经济治理整顿期间,由于国家每年的水土保持资金不可能增加很多。因此,一要充分注意利用现有资金渠道;二要千方百计开辟和扩大资金渠道;三要改革资金使用办法。使有限的资金发挥更大的效益。     

Public Views on Family and Corporate Farms

ABSTRACT

Contemporary agricultural practices and the public's understanding of the same are not necessarily in synchrony. Beliefs about the economic contribution of agriculture, farming practices, and their impacts on the environment and community, and the motivations of farmers were explored via a mail survey of Illinois residents. Respondents were asked to consider farms by structure and describe what they perceive to be attributes or behaviors differentiating family or corporate farms. Respondents recognized the value of agriculture to the state. Overall, agriculture was ranked among the seven standard industry categories as that with the most important economic impact. However, this sector was ranked lower by residents in counties with or adjacent to population centers of a hundred thousand residents or more and by the non farm population. Although perceived distinctions between crop and livestock operations were not substantial, strong differences were perceived between corporate and family farms. Perceived factors differentiating the two farm types included ownership, operation size, business motivation, separation of management and labor, operator's concern for and participation with the local community and environment, heritage, source of labor, and locale of residence. Family farms were perceived in a much more favorable light than their corporate counterparts.     

Rheological Behavior of Undeveloped and Developed Wheat Dough

Undeveloped wheat dough is essentially wheat flour that has become fully hydrated without being deformed. The rheological properties of this material were compared to dough (developed dough) made using the standard method involving a farinograph. Flow behavior of undeveloped and developed dough samples made from hard and soft wheat flours were tested using creep tests, frequency sweep oscillatory tests, and temperature sweep oscillatory tests. All experiments showed that the undeveloped dough requires less resistance for deformation than developed dough. The differences are due to the energy input received by the developed dough and the influence of this factor in forming the protein matrix associated with developed dough. To attain a comparable state as the dough made in the farinograph, an energy input must be applied to the undeveloped dough material. Understanding the differences between undeveloped and developed dough may lead to new products, equipment, and processes in the bakery industry.     

Sowing the seeds of hope: providing regional behavioral health supports to the agricultural population

In 1999, project leaders from seven states (i.e., Iowa, Kansas, Minnesota, Nebraska, North Dakota, South Dakota, and Wisconsin) began to share ideas and resources for providing behavioral health assistance (i.e., mental health counseling and addictions services) to stressed farmers, ranchers, farm workers, and their families. The seven states are among those most impacted by the farm crisis of the 1980s and again by low commodity prices and disasters such as droughts and floods in the 1990s. Project leaders conferred in monthly telephone conference calls and by 2001 began meeting in semi-annual face-to-face meetings to formally agree on a mission, program components, and management structure. Administrative functions were transferred from the Wisconsin Office of Rural Health and Wisconsin Primary Healthcare Association, to AgriWellness, Inc., a regional nonprofit corporation founded to provide technical assistance, grant writing, training of service providers, and other administrative supports. The Sowing the Seeds of Hope program has become a model for the provision of behavioral health supports for the agricultural population, including development of farm stress telephone hotlines, provision of confidential and affordable outpatient mental health and substance abuse counseling, training of professional providers in agricultural behavioral health, training of indigenous farm and rural residents as outreach workers who can respond to disasters of all types, and weekend educational retreats for farm residents. The program has achieved economy of scale by sharing expertise across state boundaries and the formation of a regional administrative structure. Yet, many challenges exist, the greatest of which is obtaining ongoing permanent support for the increasing numbers of uninsured and underinsured people involved in agriculture.     

Improving food provision in a Guyanese home for the elderly: a participatory approach

OBJECTIVES: To conduct a needs assessment of all aspects of food provision in a residential home and to evaluate a subsequent nutrition intervention. DESIGN: An intervention study using a before and after design. A participatory approach was adopted and quantitative and qualitative methods used throughout. The intervention involved a revised menu, kitchen equipment, and establishing wholesale shopping and food donations. SETTING: A residential home for senior citizens in Guyana. RESULTS: Meals at the home were nutritionally inadequate and deeply unpopular with the residents. Intakes of fruits and vegetables were low and the home was heavily reliant on donated soya mince and rice. Meals were served within an eight-hour period to accommodate the staff's hours of work. Cutbacks in the food budget indicated that the financial state of the home explained some of the problems. The intervention was unable to address all problems identified, but led to substantial improvements in the nutritional adequacy of the food provided following the inclusion in the menu of a number of nutrient-dense foods such as chicken liver. The new menu was acceptable to the cooks and largely popular with the residents, although some problems persisted. CONCLUSIONS: The results show that improvements in the nutrient profile of the diet could be achieved with a flexible, community-based, participatory approach that addressed all elements of a home's food provision system. The changes also proved largely popular with the residents, thus potentially contributing to their quality of life.     

Anthropogenic Mercury Deposition to Arctic Lake Sediments

The history of atmosheric mercury inputs to remote arctic regions can be measured in lake sediment cores using lead-210 chronology. In this investigation, total mercury deposition is measured in sediments from Imitavik and Annak Lakes on the Belcher Islands in southeastern Hudson Bay, an area in the southern Canadian Arctic with no history of local industrial or agricultural sources of contamination. Both lakes received background and atmospheric inputs of mercury while Annak also received mercury from raw domestic sewage from the Hamlet of Sanikiluaq, a growing Inuit community of about 550 established in the late 1960's. Results from Imitavik show that anthropogenic mercury inputs, apparently transported through the atmosphere, began to appear in the mid-eighteenth century, and continued to the 1990's. Annak had a similar mercury history until the late 1960's when disposal of domestic sewage led to increased sediment and contaminant accumulation. The high input of mercury to Annak confirms that Sanikiluaq residents are exposed to mercury through native food sources.