Application of CCME Water Quality Index to Monitor Water Quality: A Case Study of the Mackenzie River Basin, Canada

All six ecosystem initiatives evolved from many years of federal, provincial, First Nation, local government and community attention to the stresses on sensitive habitats and species, air and water quality, and the consequent threats to community livability. This paper assesses water quality aspect for the ecosystem initiatives and employs newly developed Canadian Council of Ministers of the Environment Water Quality Index (CCME WQI) which provides a convenient mean of summarizing complex water quality data that can be easily understood by the public, water distributors, planners, managers and policy makers. The CCME WQI incorporates three elements: Scope – the number of water quality parameters (variables) not meeting water quality objectives (F ₁); Frequency – the number of times the objectives are not met (F ₂); and Amplitude. the extent to which the objectives are not met (F ₃). The index produces a number between 0 (worst) to 100 (best) to reflect the water quality. This study evaluates water quality of the Mackenzie – Great Bear sub-basin by employing two modes of objective functions (threshold values): one based on the CCME water quality guidelines and the other based on site-specific values that were determined by the statistical analysis of the historical data base. Results suggest that the water quality of the Mackenzie-Great Bear sub-basin is impacted by high turbidity and total (mostly particulate) trace metals due to high suspended sediment loads during the open water season. Comments are also provided on water quality and human health issues in the Mackenzie basin based on the findings and the usefulness of CCME water quality guidelines and site specific values.     

成都盆地浅层土壤中砷来源的多元统计分析

对成都盆地3 061个浅层土壤样品以元素为变量进行砷回归分析,在回归模型的基础上进行R型因子分析,并选取因子载荷较大的元素作为特征元素组合。在结合元素地球化学性质、区域地质背景和因子得分等值线图的基础上,根据特征元素组合来研究砷的来源。研究结果表明:成都盆地浅层土壤中砷的来源有6种,其中龙门山一带晚三叠纪、侏罗纪、白垩纪沉积岩系和酸性岩浆岩及基性岩、超基性岩是成都盆地浅层土壤的主要来源。相对于后期人类作用而言,自然作用对成都盆地土壤中砷分布特征的影响占主导地位。     

准噶尔盆地生态系统优先性评价

生态系统是生物多样性的重要组成部分,更是物种多样性和遗传多样性赖以维持和保存的基础。为了有效地保护准噶尔盆地区域内的生态系统,综合应用生态学理论、植被长期研究成果和地理信息系统技术,总结了准噶尔盆地内生态系统类型,分析了各类生态系统特征和空间分布规律,探索了一种生态系统保护优先性评价方法,以期为区域生态保护建设提供依据...     

珠江流域极端降雨时空演变特征分析

基于珠江流域1960-2005年42个雨量站的日降雨资料,定义了3个极端降雨的指标(最大连续降雨量(MCP)、最大连续降雨天数(MCD)以及最大连续降雨强度(MCI))及通过将三者叠加得到的综合指数Z,运用线性回归模型以及Mann-Kendall法分析了珠江流域极端降雨的时空分布特征。研究结果表明:①珠江流域的MCP、MCD、MCI和Z值在总空间分布上呈东大西小的局势,全年和夏季MCP、MCD、MCI等Z值的高值出现在珠江三角洲、桂林市、百色市等地区,表明上述区域是极端降雨的高发区;②珠江流域近46年的极端降雨事件没有出现显著变异,未发现显著突变;③极端降雨事件的空间分布特征与地形有密切联系,流域内极端降水事件的多发区周围往往有山脉或高大地形环绕,由于山区或者丘陵区地势较高,因而易发生山洪等灾害。     

基于L-THIA模型的温榆河流域非点源污染负荷变化分析

为研究温榆河流域城市化过程中土地利用变化对非点源污染负荷的影响,基于GIS(地理信息系统)和RS(遥感),利用二次开发改进后的长期水文影响评价(L-THIA)模型,采用实地测得的EMC(事件平均浓度)数据,模拟了1992年和2009年非点源污染负荷量.结果表明,1992-2009年的城市化过程中商业用地、交通用地和住宅用地分别增加了13.95％、20.46％和85.76％,农业用地和水域分别减少40.04％和9.64％,导致非点源污染负荷量(总磷除外)明显增加.其中,总氮增加了3.31％,氨氮增加了12.20％,BOD5(5日生化需氧量)增加了11.87％,CODMn(化学需氧量)增加了7.62％,TOC(总有机碳)增加了15.46％,总磷下降了12.84％.交通用地、商业用地的非点源污染产出能力最强,应该成为非点源污染的重点控制区域.     

Incorporating stakeholders’ preferences into a multi-criteria framework for planning large-scale Nature-Based Solutions

Hydro-meteorological risks are a growing issue for societies, economies and environments around the world. An effective, sustainable response to such risks and their future uncertainty requires a paradigm shift in our research and practical efforts. In this respect, Nature-Based Solutions (NBSs) offer the potential to achieve a more effective and flexible response to hydro-meteorological risks while also enhancing human well-being and biodiversity. The present paper describes a new methodology that incorporates stakeholders’ preferences into a multi-criteria analysis framework, as part of a tool for selecting risk mitigation measures. The methodology has been applied to Tamnava river basin in Serbia and Nangang river basin in Taiwan within the EC-funded RECONECT project. The results highlight the importance of involving stakeholders in the early stages of projects in order to achieve successful implementation of NBSs. The methodology can assist decision-makers in formulating desirable benefits and co-benefits and can enable a systematic and transparent NBSs planning process.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01419-4) contains supplementary material, which is available to authorized users.     

千岛湖流域杭州段人类活动净氮、净磷输入时空分布

为探究人类活动对流域氮磷输入的影响,基于人类活动净氮、净磷输入模型（NANI、NAPI）,分析了2008~2017年千岛湖流域杭州段氮磷输入的时空变化特征及驱动因素.结果表明：年际NANI值呈上升的趋势,10a平均值为2230kg/（km²·a）;年际NAPI值呈先上升后持续下降趋势（峰值出现在2011年）.各子单元空间差异性较为显著,NANI、NAPI值均呈西高东低、南高北低的分布特征.NANI主要输入组分年际间差异显著,2008~2014年NANI的最大贡献源为氮肥施用（37.3%~39.9%）,2015~2017年最大贡献源则为大气氮沉降（36.4%~38.4%）;NAPI主要输入组分年际间较为一致,最大贡献源为人类食品和动物饲料磷输入（44.1%~48.1%）,其次为磷肥施用（40.3%~43.4%）.影响因子中,农作物种植强度与NANI、NAPI的相关性最显著,分别为0.851和0.806.各子单元NANI、NAPI与入湖TN、TP负荷强度显著相关,NANI变化可解释其63.9%的河流TN负荷变化,NAPI变化可解释其73.3%的河流TP负荷变化.因此,千岛湖流域杭州段面源污染实际管控中应重点关注NANI、NAPI值较高的汾口镇、威坪镇及浪川乡,加强氮磷化肥污染防治,实行污染控源减排策略.     

石羊河流域降水稳定同位素变化的区域差异

为了了解干旱内陆河流域降水稳定同位素变化过程及其影响因素,基于石羊河流域荒漠区、绿洲区和山区8个站点2013年7月至2014年7月,497个降水样品氢氧稳定同位素数据及相应气象数据,研究了石羊河流域降水稳定同位素的时空变化、环境效应以及降水水汽来源.结果显示：石羊河流域局地大气水线斜率和截距表现出夏低冬高的变化趋势;降水稳定同位素表现出夏高冬低的变化趋势,从荒漠区、绿洲区到山区,稳定同位素值随海拔升高而降低,海拔效应为-0.22‰/100m,这是温度效应的另一种体现;流域降水稳定同位素表现出显著的温度效应,温度效应为0.43‰/℃,在天气尺度下受季风水汽和降水淋洗过程的影响表现出降水量效应;流域降水来源主要受西风水汽控制,夏季也会会受到季风水汽影响,冬季也受到极地气团影响.