河南省沿黄干流地区社会—生态—生产景观恢复力演化特征及情景模拟

[目的] 定量研究河南省沿黄干流地区2000—2018年社会—生态—生产景观恢复力的演化特征,指导沿黄地市社会生活,生态资源环境与农业生产活动的协调发展。[方法] 通过构建SEPLR （social-ecological-production landscape resilience,社会—生态—生产景观恢复力）评估框架,运用有序加权平均法设置情景偏好,绘制不同政策引导下恢复力预测图。[结果] ①从总体特征看,2000—2018年河南省沿黄干流地区SEPLR值为0.47～0.52之间,呈上升趋势,城市间空间差异逐渐增大,指数相似地区集中分布。②演化特征上,社会系统恢复力和生态系统恢复力缓慢增强,分别在0.14～0.65,0.08～0.30波动,生产系统恢复力变化微弱,在0.12～0.31波动;空间上,SEPLR及各子系统整体呈“中部强两边弱”的分布态势,层级结构具有集聚性。[结论] 河南省沿黄地市在“维持现状型”“生态优先型”“开发优先型”“农业优先型”4种政策情景下,“生态优先型”恢复力最高,未来黄河流域高质量发展应考虑“生态优先型”政策引导。     

临邑首站节能改造的可行性分析及实施

对临沧线及临济线各自单泵运行时输油泵节流损失较大的工况进行了论证,结果表明,两条管道具有分输的可行性,并且具有明显的节能潜力.结合现场具体情况,对两条管道进行了技术改造.能耗计算结果表明,实施分输措施后,每年节电近67×104kW·h,经济效益显著.     

2011—2050年RCP4.5新情景下东北春玉米种植布局及生产评估

【目的】研究东北地区春玉米适种区域及其生育期、产量对气候变化的响应。【方法】基于气候模式RegCM4输出的未来RCP4.5新气候情景逐日资料,采用经验频率法预测80%保证率下2011—2050年中国东北地区早、中、晚熟型春玉米种植区域时空变化,同时结合作物模型DSSAT4.5对黑龙江省晚熟品种的生育期、产量变化特征及该省因气候变化而新增的晚熟品种可能种植区内晚熟玉米的适种性进行模拟评估。【结果】RCP4.5情景下,2011—2050年东北三省≥10℃的积温呈增加趋势,早、中、晚熟型玉米品种种植界限均有不同程度的北扩或东移,可能种植范围扩大。黑龙江省2011—2050年间晚熟玉米新增可能种植区域内适宜种植晚熟品种;气候变化对原有种植区内晚熟品种生殖生长期的影响程度大于对营养生长期的影响,全生育期天数平均缩短2—11 d;产量变化存在明显空间差异,不考虑CO2肥效作用和考虑CO2肥效作用两种方案下的产量变化范围均介于±20%以内,但考虑CO2肥效作用时的产量较高。【结论】因气候条件变化而新增的春玉米种植区域的适种性需要综合考虑多方面因素来评估。未来40a玉米全生育期天数变化主要源于生殖生长期缩短,大气中CO2浓度增加带来的肥效作用可抵消一部分因温度升高产生的对玉米产量形成的不利影响。     

基于形态学空间格局分析与CA-Markov模型的武义县绿色基础设施时空格局变化及情景模拟

在全球城市化快速发展的背景下,绿色基础设施(GI)因其良好的生态环境效益而在城市规划与建设中受到重视。以浙江省金华市武义县为研究区,采用ArcGIS、GuidosToolBox、Conefor 2.6等软件对武义县1990、2005、2018年的3期土地利用类型图进行形态学空间格局分析,并设置城市发展优先、生态保护优先、自然发展3种情景,运用CA-Markov模型分别预测3种情景下的未来绿色基础设施空间格局。结果显示:1990—2018年武义县的绿色基础设施面积占武义县面积的比例在不断降低,重要核心区、孤岛面积不断减少,桥接区、孔隙、支线面积不断增大,景观破碎化问题加重。在2030年的情景模拟中,自然发展和城市发展优先情景下的武义县GI面积分别减少171.79 km² 和225.73 km²,核心区面积分别减少84.81 km²和126.76 km²。生态保护优先情景下,武义县GI面积增加25.52 km²,核心区面积增加69.60 km²。结果表明,如果一味追求粗犷式的经济发展,忽视生态保护,武义县的景观破碎化问题将进一步加剧。基于此,武义县应以生态保护优先为前提,适度开发中部、南部地区的旅游资源,以实现经济增长与环境相协调的可持续发展战略。     

Evaluation of effectiveness and efficiency of wild bird surveillance for avian influenza

This study aimed to assess which method of wild waterbird surveillance had the greatest probability of detecting highly pathogenic avian influenza (HPAI) H5N1 during a period of surveillance activity, the cost of each method was also considered. Lake Constance is a major wintering centre for migratory waterbirds and in 2006 it was the site of an HPAI H5N1 epidemic in wild birds. Avian influenza surveillance was conducted using harmonised approaches in the three countries around the lake, Austria, Germany and Switzerland, from 2006–2009. The surveillance consisted of testing birds sampled by the following methods: live birds caught in traps, birds killed by hunters, birds caught in fishing nets, dead birds found by the public and catching live Mute Swans (Cygnus olor); sentinel flocks of Mallards (Anas platyrhynchos) were also used. Scenario tree analysis was performed including sensitivity analysis, followed by assessment of cost-effectiveness. Results indicated that if HPAI H5N1 was present at 1% prevalence and assuming HPAI resulted in bird mortality, sampling dead birds found by the public and sentinel surveillance were the most sensitive approaches despite residual uncertainty over some parameters. The uncertainty over the mortality of infected birds was an influential factor. Sampling birds found dead was most cost-effective, but strongly dependent on mortality and awareness of the public. Trapping live birds was least cost-effective. Based on our results, we recommend that future HPAI H5N1 surveillance around Lake Constance should prioritise sentinel surveillance and, if high mortality is expected, the testing of birds found dead.     

标准景观情景方法及其在新农村建设规划中的应用

目前中国新型城镇化规划与新农村建设过程中,决策者急需通过科学的方法来获取对未来充分的认识,以制定合理的规划,为了解决传统趋势外推法的局限性,该文提出了一种标准景观情景方法。该文通过分析传统趋势外推法的优劣特点,在国内外情景学研究的基础之上提出标准景观情景方法,阐述了该方法应用于景观生态领域的优势与特点,构建了方法理论体系,并且将其应用于金井镇案例区,验证了其可行性与实用性。结果表明:通过该研究方法向决策者展示了未来2种不同的景观情景,并与传统趋势外推法模拟结果形成对比,提出了基于不同发展方向的相关政策启示。该方法适用于新型城镇化规划与新农村建设,同时应用到自然资源管理、环境规划、农业政策制定等领域也具有一定的指导意义。     

黄土丘陵沟壑区小流域水沙侵蚀过程的情景模拟分析

在黄土丘陵沟壑区小流域侵蚀水沙耦合数学模型基础上,以黄河中游典型流域岔巴沟流域为研究对象,根据工程水文学设计暴雨的方法生成各种假设暴雨过程,在固定下垫面不变的条件下,进行模拟计算并分析流域100年一遇、50年一遇和10年一遇设计暴雨的产流产沙效应。在几种不同的假设植被覆盖度下,分别模拟计算同一场典型暴雨在不同植被覆盖条件下的水沙侵蚀过程。模拟结果表明：1）根据岔巴沟流域100年一遇（P=0．01）、50年一遇（P=0．02）和10年一遇（P=0．1）设计暴雨3种情景下的水沙计算特征可知,100年一遇降雨（P=0．01）对应的洪峰流量和沙峰分别为805m^3／s和77．5万kg／s,50年一遇降雨（P=0．02）对应的洪峰流量和沙峰分别为595m^3／s和50．2万kg／s,10年一遇降雨（P=0．1）对应的洪峰流量和沙峰分别为108m^3／s和12．1万kg／s,根据以上计算结果可大致推断1970-2000年的绝大多数侵蚀观测场次的水沙重现期在10年一遇和50年一遇之间;2）该流域植被覆盖度的减水减沙效应显著,增加25％植被覆盖将减少水量73％和沙量84％,而减少25％的植被覆盖将增加29．9％的径流和18．6％的泥沙。不同降雨和植被覆盖条件下的水沙侵蚀过程情景模拟分析结果可为黄土高原丘陵沟壑区流域水土保持工程规划与设计提供依据。     

Effects of rising atmospheric CO2 on crop evapotranspiration in a Mediterranean area

In the assessment of plant response to the climate changes, the effects of CO₂ increase in the atmosphere and the subsequent rise of temperatures must be taken into account for their effects on crop physiology. In Mediterranean areas, a decrease of water availability and a more frequent occurrence of drought periods are expected. The objective of this study was to assess the impact of elevated CO₂ concentration and high temperature on reference evapotranspiration (ETo) and crop evapotranspiration (ETc) in the Mediterranean areas. The Penman-Monteith equation was used to simulate the future changes of reference evapotranspiration (ETo) by the recalibration of the canopy resistance parameter. Besides, crop coefficients (Kc) were adjusted according to the future climate trend. Then the modified empirical model (ETc = ETo × Kc) was applied providing an effective quantification of the climate change impact on water use of irrigated crops grown in Mediterranean areas. In the studied area, water use assessment was carried out for the period from 1961 to 2006 (measured data) and for a period from 2071 until 2100 (simulated data), showing a future climatic scenario. Water and irrigation use of crops will change as a function of climate changes, thermal needs of single crops and time of the year when they grow. Climate simulation model foresees the tendency for a significant increase of temperatures and a decrease of total year rainfall with a change of their distribution. The temperature increase and the concomitant expected rainfall decrease lead to a rise of year potential water deficit. About the autumn-spring crops, as wheat, a further increase of water deficit, is not expected. On the contrary, for spring-summer crops as tomato, a significant increase of water deficit and thus of irrigation need, is foreseen. Actually, for crops growing in that period of the year, the substantial rise of evapotranspiration demand cannot be compensated by crop cycle reduction and partial stomatal closure.     

消费者对国产婴幼儿奶粉质量安全风险感知偏差及其影响因素

为了解和调整消费者对国产婴幼儿奶粉质量安全风险感知偏差,基于情景模拟实验法获取559位消费者数据,采用有序Logistic模型,对消费者的国产婴幼儿奶粉质量安全风险感知偏差及其影响因素展开实证研究.结果表明:1)89.98％的消费者主观感知到的国产婴幼儿奶粉质量安全风险高于客观风险水平,存在风险感知偏差.2)产品知识、...     

不同森林管理预案下友好林业局森林景观的动态变化

森林作为最大的陆地生态系统,是生物圈中重要的一个环节,它不仅能够为人类提供木材,而且在涵养水源、保持水土、防风固沙、维护大气成分平衡等方面均发挥着重要的生态作用(代力民等,2005).