Enhancing the Ability of a Soil Moisture‐based Index for Agricultural Drought Monitoring by Incorporating Root Distribution

Agricultural drought differs from meteorological, hydrological, and socioeconomic drought, being closely related to soil water availability in the root zone, specifically for crop and crop growth stage. In previous studies, several soil moisture indices (e.g., the soil moisture index, soil water deficit index) based on soil water availability have been developed for agricultural drought monitoring. However, when developing these indices, it was generally assumed that soil water availability to crops was equal throughout the root zone, and the effects of root distribution and crop growth stage on soil water uptake were ignored. This article aims to incorporate root distribution into a soil moisture‐based index and to evaluate the performance of the improved soil moisture index for agricultural drought monitoring. The Huang‐Huai‐Hai Plain of China was used as the study area. Overall, soil moisture indices were significantly correlated with the crop moisture index (CMI), and the improved root‐weighted soil moisture index (RSMI) was more closely related to the CMI than averaged soil moisture indices. The RSMI correctly identified most of the observed drought events and performed well in the detection of drought levels. Furthermore, the RSMI had a better performance than averaged soil moisture indices when compared to crop yield. In conclusion, soil moisture indices could improve agricultural drought monitoring by incorporating root distribution.     

The role of participation in the planning process: examples from Sweden

Participation in decision-making has successively developed into a guiding principle at both EU and national level. However, diverse perspectives exist on what the role of different interests in participative processes should be, and the legal rules regarding participation varies between different sectors; from clearly defined to virtually non-existent requirements. This may have adverse effects on the legitimacy of decisions and decision-making. This paper reviews the role of participation in the planning process in relation to natural resource development in Sweden, as guided by EU and international law. Based on the notion of effective participation, the study illustrates the potential clashes that may result from different conceptions of participation, for instance, at various levels of governance, as well as from disparate principles for implementation in different sectors.     

流域立法视角下生态流量保障的制度供给--以长江流域为例

生态流量保障的重难点在于流域生态流量不足问题的妥善解决。生态流量不足基于产生的原因可分为“自然型”和“人为型”。“人为型”生态流量不足的根源在于《水法》第4条规定的三生用水关系未得到妥善处理,实质上是水资源分配和管理不合理所致。具体表现为水资源保护理念镶嵌在制度表层、生态流量缺乏核心制度保障、流域规划匮乏强效监督机制、流域水资源分配信息公开不足、末端行政考核制度偏重水质管控、生态用水制度顶层设计与地方实施间落差巨大等。流域立法作为立法体系的中间环节,对上位法具有填补协调功能,对地方立法具有引领指导作用。建议在流域立法过程中,通过制度设计解构流域生态流量保障现存的制度困境,主要包括以下几个方面:一是完成流域特有保护理念到实体制度的转型。二是基于流域生态修复、水资源生态红线管控制度的开展以及有效衔接规划环境影响评价制度的需要,建立生态流量管控指标制度体系不可或缺。三是基于流域规划对三生用水的初始分配性,将生态流量供给纳入流域规划体系中,从水资源分配初始阶段保障生态流量,同时强化流域水资源规划制度的监督机制,健全规划制定的程序性规范,明确科学考察和调查评价人员的构成规则、方式及模式。四是依法加深政府信息公开程度保障公众的知情权、参与权及监督权。五是完善行政考核制度体系强化对生态流量供给的考核。     

宇宙环境中的某些化学问题

本文讨论了宇宙环境中的化学概况,特别是宇航环境化学和宇航适应问题。     

铬渣烧结矿炼制含铬生铁工业化生产试验研究

采用铬渣烧结矿作为熔剂,在３０ｍ＾３小高炉上进行了冶炼含铬生铁的工业化生产试验,铬河中六价铬的还原率接近１００％,总铬的金属化还原率大于９４％,平均每吨产品铁吃渣量为２．２９８ｔ,最高达２．７８５ｔ。炼制含铬最大于１０％铁含铬生铁,需同时配入铬铁矿增铬,保持１４８０Ｋ以上的炉温,控制较低的碱度,配入辅料降低炉渣溶点,可显著善炉渣的流动性,成功地实现渣,铁分离排放。监测了试验过程的二次污染,需控制高     

不同利用方式对江西省农田土壤碳氮磷生态化学计量特征的影响

根据江西省2013年采集的16582个农田耕层(0～20 cm)土壤样点数据,运用实地调查、经典统计学与地统计学等相结合方法,研究了江西省耕地土壤碳氮磷生态化学计量特征的空间变异性及不同农田利用方式对其的影响.研究结果表明:江西省耕地土壤有机碳(SOC)、全氮(TN)和全磷(TP)平均含量分别为17.90、1.58和0.52 g·kg~(-1),土壤碳氮比(C∶N)、碳磷比(C∶P)和氮磷比(N∶P)平均值分别为11.72、38.29和3.38,土壤C∶N∶P比平均值为34.44∶3.03∶1,说明P是江西省耕地土壤主要的限制因素.此外,由于碳、氮、磷三者之间并不存在显著的两两相关性,表明江西省耕地土壤中不存在稳定的"Redfield ratio";半方差函数表明,江西省土壤碳、氮、磷生态化学计量特征具有中等程度的空间变异性,其空间变异特征主要受到随机性因素的影响;经ANOVA检验显示,不同农田利用方式对土壤碳氮磷生态化学计量特征影响显著(p0.05),土壤SOC和TN平均含量依次表现为:两季水田水旱轮作一季水田一季旱地两季旱地,土壤TP平均含量依次表现为:两季旱地两季水田一季水田一季旱地水旱轮作,土壤C∶N依次表现为:两季水田两季旱地一季水田水旱轮作一季旱地,土壤C∶P平均值依次表现为:水旱轮作两季水田一季水田一季旱地两季旱地,土壤N∶P平均值依次表现为:水旱轮作一季旱地两季水田一季水田两季旱地.总体而言,土壤碳、氮、磷生态化学计量比的变化特征是农田利用方式和环境因子综合作用的结果,土壤C∶N∶P比对土壤碳、氮、磷储量及养分的限制性具有重要的指示作用.     

旋风水膜除尘器的捕尘性能和结构设计

借助于Leith和Licht的边界层分离理论 ,对轴向出风旋风水膜除尘器的捕尘性能进行了分析 ,得出了捕尘效率的理论公式、径高比等无量纲准数     

GIS ASSESSMENT OF THE VULNERABILITY OF THE ROSETTA AREA, EGYPT TO IMPACTS OF SEA RISE

A study of the area, including Rosetta city and the estuary of the river Nile (Rosetta branch), has been carried out for assessment of the impact of sea level rise (slr). A geographic information system (GIS) has been built including layers of land use, topography, archeological sites, land cover and population. Analysis of data has been carried out to assess vulnerability of various land use and land cover classes to the impact of sea level rise.Because the area under study has geomorphic relief profiles just over the sea level, inundation of total land could reach 26% of total study area due to only half a meter rise in sea level. This lost area includes 32% of urban clusters mainly used for human shelter and contains 52% of present monuments, 25% of valuable high quality dense palm trees cultivation, 75% of beaches and 19% of lands suitable, 25% of valuable high quality dense palm trees cultivation, 75% of beaches and 19% of lands suitable for agricultural reclamation (although suffering from salt water intrusion and soil salinization). This is expected to cause a significant impact on the present population, economic activities, total regional revenue, and also on tourism. At 1.1 m sea level rise, 72% to total study area could be inundated. This area contains all beaches, half of the palm cultivation, 43% of total urban clusters, which includes 81% of the monumental sites and historic buildings.Other environmental problems such as solid waste management, sanitary disposal network, deteriorating conditions of some monumental structures, in addition to the sea level rise act negatively on the environmental quality of the urban community. Future plans for urban expansion in the area must be studied carefully in order to preserve valuable palm lands and maintain and protect monuments and historic sites which help the promotion of tourism. An environmental management program is essential for upgrading tourism, promoting urban development and protecting coastal lands.     

1971-2016年新疆极端温度时空变化特征分析

基于新疆地区42个气象站点1971-2016年逐日温度数据资料,选取世界气象组织(WMO)推荐的10个极端温度指标,使用线性趋势法、克里金插值法和Mann-Kendall突变检验等方法,分析该地区极端温度指数在时间和空间上的变化规律.结果 表明:新疆地区1971-2016年间4个极端高温指数均呈现出明显的上升趋势,除极...     

多棱插接式钢管塔风振阻尼技术研究

多棱插接式钢管塔具有制作安装方便、占地面积小等独特优势,正在得到越来越多的应用。但这种结构属于风敏感结构,风振特性是设计必须考虑的关键因素。钢管塔结构为空间薄壁壳体结构,其结构分析设计尤其是风振反应分析和风振控制与传统的杆系塔架结构有很大的不同。在静动力分析的基础上,提出利用钢球减振器对钢管塔进行风振控制,基于状态空间描述法模拟了钢管塔受控前后的位移时程反应,时域与频域分析结果表明该减振装置可以使结构的阻尼增加3~5倍,结构的风振反应可减小30%。本文的研究为钢管塔结构的合理设计提供了基础,有助于其在我国的推广应用,同时为行业规范和高耸结构设计规范的修订提供必要的理论基础。