河流生态环境需水及其健康评价研

将河流生态环境需水分为河流基本生态需水量、河流水污染防治需水、河流水面蒸发生态需水量、河流输沙需水,讨论了实现河流各项功能目标的各部分估算方法;提出了河流生态环境需水的阈值确定原则和方法,以及生态系统健康评价指标和评价标准;为河流健康评价提供了理论依据,对于提高河流健康评价的有效性及河流综合管理能力具有重要意义。     

基于PSR-改进模糊集对分析模型的河流健康评价

在分析河流健康概念的基础上,综合考虑能够反映河流健康系统完整性的形态、水文、水质及生物指标等方面因素,基于"压力状态响应"概念,设计了针对现阶段高强度人类活动状态下的渭河流域上游段的河流健康评价指标体系,按照河流近自然状态,确定了评价标准,建立了基于改进的模糊集对分析模型。基于构建模型对渭河流域林家村-魏家堡段河流健康进行了评价。结果表明,研究区域河流健康等级为三级,属于亚健康。提出了加强河流生态管理的对策。研究成果对河流生态修复与管理具有一定的理论技术参考价值。     

河流健康评价体系研究

在河流健康内涵分析的基础上,针对河流的自然功能、生态环境功能和社会服务功能,根据河流的基本特征和个体特征,建立由共性指标和个性指标构建的河流健康评价指标体系,并提出由河段至河流整体的评价方法。以西江为例,对建立的指标体系、评价方法进行了验证应用。成果为河流健康的定量评价、促进河流的科学管理提供科学依据。     

河流健康评价:内涵、指标、方法与尺度问题探讨

基于国内外最新研究进展,从河流健康的概念、评价方法、指标体系和尺度等方面综述了河流健康问题。大部分学者倾向于从河流的自然属性和社会属性来定义河流健康;河流健康评价方法包括模糊综合评价法、综合健康指数法和综合指标体系法,其中综合指标体系法是目前国内主要采用的评价方法;河流健康评价指标体系包括水文特征、水质参数、生物指标、河岸带指标、河流形态和社会服务状况6个方面,国内外指标体系存在着差异;探讨了河流健康评价尺度效应研究和尺度转换方法。最后阐述了河流健康评价中存在的概念、指标、尺度转换和评价结果运用等方面的问题。     

基于层次分析法的贵州省六硐河健康评估研究

河湖健康评估能够判断和评价河流的健康状态,不仅有助于河流管理决策者确定河流管理活动,还能够为河流保护和恢复提供科学依据。在分析贵州省六硐河河流健康内涵及指标体系的基础上,构建了由河流物理特征、水文水资源特征、水质状况、水生生物、社会服务功能等5个准则层和15个指标集组成的河流健康评价体系。将层次分析法和综合评估方法相结合,计算得到六硐河健康评估得分。结果表明,六硐河健康评估总得分82.32分,划分的8个河段的河流完整性得分范围在82.91～89.34分之间,整个六硐河流域总体处于健康水平,但仍然有部分河段部分指标处于不健康状态,应采取预见性措施达到有效控制河流生态系统破坏的发生或发展,显著降低生态系统朝着不可恢复状态发展的概率和生态修复投入。     

石葵河流域健康评价模型建立

为合理评估石葵河流域健康现状,构建了由河岸特征、河岸植被、河流水文特征、流域形态特征和社会经济5个标准层及19个评价指标组成的河流健康评价体系,并在此基础上构建各个指标所对应的评价标准。通过层次分析法对各个指标的权重进行计算,依据构建合理的评价模型对其综合评价。结果显示:石葵河流域健康综合评价指数EI为3.75,处于基本健康状态。分析存在的主要问题,并提出河流改善的建议,为石葵河的河流规划、管理和水资源合理开发利用提供了参考。      

北运河水量管理生态影响综合评价研究

北运河水利工程建设以及河流水量管理运行，在一定程度上影响了河流的水生态环境状况。建立了北运河水量生态影响评价的指标体系和评价标准，采用模糊层次模型对北运河水量管理生态影响进行了综合评价，其计算结果为0.81，判定级别为北运河处于“非常严重”级别下限，最后提出了综合治理措施保障北运河河流健康可持续利用。     

海河流域水资源保护规划总体布局研究

本研究考虑海河流域经济社会发展格局及水资源时空分布特点,以全国主体功能区规划和生态功能定位为依据,根据不同区域的资源环境特点及河湖生态系统特征,以水资源保护问题及需求为导向,结合规划近远期目标和控制指标要求,统筹谋划并构建了海河流域水资源保护"两廊、四区、六带"的宏观战略格局.作为海河流域水资源保护规划与管理的顶层设计内容,也将为构建海河流域河湖健康保障体系提供支撑.     

辽北地区典型河流水生态功能区水生态系统健康评价

以位于辽宁北部的清河、汎河流域11个水生态功能三级分区为基本评价单元，依据水生态系统健康的特点、内涵及研究区域的生态特征，构建了水生态系统健康评价层次分析指标体系。采用改进层次分析法结合模糊数学模型对清河、汎河流域水生态系统健康进行了评价。评价结果表明：汎河流域4个水生态功能区中，有3个处于“健康”状态（IV-5-2、IV-5-3、IV-5-4），1个处于“一般”状态（IV-5-1）。清河流域7个水生态功能区中，有1个处于“健康”状态（IV-5-11），2个处于“亚健康”状态（IV-5-10、IV-5-12），2个处于“一般”状态（IV-5-9、IV-5-13），2个处于“疾病”状态（IV-5-8、IV-5-14）。利用科学的评价模型结合水生态功能分区的水生态系统健康评价为流域的综合治理提供科学依据。     

典型北方季节性河流生态需水量研究

在供水方面北方河流存在着水资源缺乏、水质恶化等水环境问题,按照工、农、生三产水资源配比情况,北方地区农业种植业需水量占总供水量的70%以上,同时污染负荷以面源污染负荷为主。以京津冀绿色农副产品的保障基地河北省洋河流域为例,基于前期海河流域(洋河流域为海河流域的一条二级支流)河流生态需水量计算方法学研究结果,选取水文学及目标水质法计算洋河干流左卫、响水铺、鸡鸣驿和八号桥4个典型断面最小、适宜和理想生态需水量。通过Tennant法为参照,计算结果表明:①以COD指标为生态目标计算的最小、适宜和理想生态需水量分别为0.82、1.64、2.48亿m~3;②以NH~+_4-N指标为生态目标计算的最小、适宜和理想生态需水量分别为0.83、1.65、2.49亿m~3。同时综合考虑洋河流域对京津冀农副产品保障的灌溉功能定位,从洋河盆地的农业灌溉生态需水量角度切入,利用CROPWAT模型计算目标区域农作物需水量,提出了基于保障洋河流域作物灌溉问题生态需水量的计算,并制定了相应水库的调蓄方案。友谊水库作为洋河干流最大的水库,需向下游补灌60万m~3水源才能满足作物需水要求。     

Overland water and salt flows in a set of rice paddies

Cultivation of paddy rice in semiarid areas of the world faces problems related to water scarcity. This paper aims at characterizing water use in a set of paddies located in the central Ebro basin of Spain using experimentation and computer simulation. A commercial field with six interconnected paddies, with a total area of 5.31 ha, was instrumented to measure discharge and water quality at the inflow and at the runoff outlet. The soil was classified as a Typic Calcixerept, and was characterized by a mild salinity (2.5 dS m⁻¹) and an infiltration rate of 5.8 mm day⁻¹. The evolution of flow depth at all paddies was recorded. Data from the 2002 rice-growing season was elaborated using a mass balance approach to estimate the infiltration rate and the evolution of discharge between paddies. Seasonal crop evapotranspiration, estimated with the surface renewal method, was 731 mm (5.1 mm day⁻¹), very similar to that of other summer cereals grown in the area, like corn. The irrigation input was 1874 mm, deep percolation was 830 mm and surface runoff was 372 mm. Irrigation efficiency was estimated as 41%. The quality of surface runoff water was slightly degraded due to evapoconcentration and to the contact with the soil. During the period 2001–2003, the electrical conductivity of surface runoff water was 54% higher than that of irrigation water. However, the runoff water was suitable for irrigation. A mechanistic mass balance model of inter-paddy water flow permitted to conclude that improvements in irrigation efficiency cannot be easily obtained in the experimental conditions. Since deep percolation losses more than double surface runoff losses, a reduction in irrigation discharge would not have much room for efficiency improvement. Simulations also showed that rice irrigation performance was not negatively affected by the fluctuating inflow hydrograph. These hydrographs are typical of turnouts located at the tail end of tertiary irrigation ditches. In fact, these are the sites where rice has been historically cultivated in the study area, since local soils are often saline-sodic and can only grow paddy rice taking advantage of the low salinity of the irrigation water. The low infiltration rate characteristic of these saline-sodic soils (an experimental value of 3.2 mm day⁻¹ was obtained) combined with a reduced irrigation discharge resulted in a simulated irrigation efficiency of 60%. Paddy rice irrigation efficiency can attain reasonable values in the local saline-sodic soils, where the infiltration rate is clearly smaller than the average daily rice evapotranspiration.     

瓦房店市水果生产标准化发展研究

瓦房店市是我国重要的水果生产基地,在国内水果生产领域占有重要地位。随着水果市场化的不断深入,如何满足和适应国内外市场需求成为瓦房店市水果生产的关键问题。从瓦房店市水果生产实际出发,阐述了实施水果生产标准化的必要性,提出了发展水果生产标准化的具体措施。     

金谷子耐旱TG118引种试种及推广应用

对引进的谷子新品种金谷子耐旱TG118进行品种比较试验和多点试种。结果表明：该品种抗旱、耐瘠、适应性强,稳产、高产、抗病抗风抗倒伏强,品质优良,粮草兼用,种植简单,省工易管;一般产量在6000kg/hm2以上,比当地主栽品种增产20%以上。最高产量达9450kg/hm2,适于在辽西北地区推广应用。     

对《种子法》存在问题的探讨

《种子法》是我国种植业第一部法律。自实施以来,为依法加强种子管理提供了有力的法律支撑,促进我国种子产业发生翻天覆地的变化。但随着依法管理工作的深入和种子产业的快速发展,《种子法》及配套规章的一些问题逐步显现出来。对《种子法》及配套规章存在的问题进行深入分析,对需要进一步补充的章节以及需要调整的内容进行深入探讨,以求更加完善和明确。     

Review of the Egyptian experience in implementing land drainage projects

About 30 years have passed since the Government of Egypt embarked on implementing a series of large scale drainage projects. At present, about 3.8 million acres have been provided with drainage systems on the basis of systematic pre-drainage investigations and designs. The target is to provide drains in approximately 6.4 million acres in the Nile Valley and Delta.The implementation of the subsurface drainage system is carried out by the public sector and private contractors under direct supervision of governmental regional departments. The implementation process depends on many factors related to the drainage material, machinery, manpower, site requirements, farmers and organizations involved. Problems and constraints are sometimes challenging, however, the annual rate of implementation has gradually increased to 170,000 acre/year.This paper discusses the different aspects involved in the implementation process of drainage systems. The development in materials, machinery and construction technologies will be reviewed. Institutional and management factors are going to be also considered.     

和谐社会理论建设的几点哲学思考

在新世纪,面对机遇和挑战,党的十六大把“社会更加和谐”作为全面建设更高水平的小康社会的一个重要目标。中国人素有社会和谐的理想;西方人自古也向往社会和谐;借鉴东西方两种和谐社会思想的经验、教训,构建社会主义和谐社会理论。     

A European irrigation map for spatially distributed agricultural modelling

We present a pan-European irrigation map based on regional European statistics, a European land use map and a global irrigation map. The map provides spatial information on the distribution of irrigated areas per crop type which allows determining irrigated areas at the level of spatial modelling units. The map is a requirement for a European scale assessment of the impacts of irrigated agriculture on water resources based on spatially distributed modelling of crop growth and water balance. The irrigation map was compiled in a two step procedure. First, irrigated areas were distributed to potentially irrigated crops at a regional level (European statistical regions NUTS3), combining Farm Structure Survey (FSS) data on irrigated area, crop-specific irrigated area for crops whenever available, and total crop area. Second, crop-specific irrigated area was distributed within each statistical region based on the crop distribution given in our land use map. A global map of irrigated areas with a 5′ resolution was used to further constrain the distribution within each NUTS3 based on the density of irrigated areas. The constrained distribution of irrigated areas as taken from statistics to a high resolution dataset enables us to estimate irrigated areas for various spatial entities, including administrative, natural and artificial units, providing a reasonable input scenario for large-scale distributed modelling applications. The dataset bridges a gap between global datasets and detailed regional data on the distribution of irrigated areas and provides information for various assessments and modelling applications.     

粉质仪和拉伸仪在面粉生产中的应用

在介绍粉质仪和拉伸仪结构和原理的基础上,探讨了粉质曲线中吸水率、形成时间、稳定时间、弱化度和评价值等指标与面粉品质的关系,以及如何根据拉伸曲线中面团最大拉伸阻力、延伸度和拉伸曲线面积等指标来评价面团品质,并结合生产实际,概述了粉质仪和拉伸仪在面粉生产中的作用。     

农村信息化服务的现状及建设措施

分析当前我国农村信息化服务的现状,提出加强农村信息化服务的新举措。     

车辆ABS控制算法的研究及探讨

对现代汽车的ABS控制算法作了一些简单的介绍,同时指出了它们的一些缺陷,相应地提出了几种对ABS的其它控制方法并加以探讨,其中着重论述了ABS门限值控制算法中参考车速的确定方法和基于附着系数的控制算法。