基于TM与MODIS遥感数据的农业旱情监测——以河北省为例

以河北省冬小麦种植区域为研究区,基于TM和MOD IS遥感数据,利用植被供水指数法确定了研究区旱情等级。首先,将其与遥感解译获得的冬小麦空间分布图叠加得到受灾冬小麦空间分布图;然后以1 km的距离在受灾冬小麦周围做缓冲区,并与通过人口密度模型获得的人口密度空间分布图叠加,得出受灾人口空间分布;最后基于光能利用率改进模型构建粮食产量回归统计模型,得到粮食产量。目的是从粮食产量和作物受灾影响人口两个方面对农业受干旱影响情况进行遥感监测和定量评价,以期为相关部门制定防灾、抗灾措施提供科学依据。结果表明,2004年研究区:(1)春季受灾面积小,仅占16.4%;(2)旱情较轻,以轻旱为主,占受灾面积的89%;(3)冬小麦种植面积约为23 965.0 km2,受灾面积约606.3 km2,主要位于唐山市和保定市;(4)粮食产量回归统计模型精度达到了87%,冬小麦产量约为11939247 t,单产约为498.8 t/km2。     

稻草制浆黑液生物＋混凝处理试验

通过对稻草制浆黑液厌氧、好氧、混凝处理组合工艺的试验研究,探索该工艺的可行性,考察了不同温度、不同有机负荷下,该类废水的生物处理效果以及后续混凝效果。结果表明：中温35℃是厌氧阶段最佳处理温度,好氧阶段不同负荷条件下,CODCr去除率基本相同;经厌氧－好氧处理,黑液CODCr和木质素去除率分别为80％和30％,色度去除不明显;混凝阶段CODCr和木质素去除率分别为70％和90％,色度去除率达90％以上,出水达到国家标准。     

有机膨润土对苯胺的吸附性能及应用研究

以溴化十六烷基三甲铵为改性剂制备有机膨润土,利用正交实验研究了有机膨润土吸附垃圾渗滤液中极性有机污染物苯胺的性能、条件及改性条件对吸附效果的影响。结果表明,有机改性膨润土对苯胺有很好的吸附效果,实验条件下对苯胺的去除率可达90％以上,绘制了有机膨润土吸附苯胺的吸附等温线,通过与吸附苯酚效果的比较,总结了有机膨润土吸附极性有机污染物的一般规律。     

羧甲基-β-环糊精对土壤中萘的洗脱去除作用

研究了不同浓度的羧甲基－β－环糊精溶液对不同组分土壤中萘的洗脱去除作用,同非离子表面活性剂脂肪醇聚氧乙烯醚的洗脱去除作用比较,讨论了其对洗脱效果的影响因素．结果表明:羧甲基－β－环糊精溶液对土壤中的萘有较好的洗脱去除效果,２０ｇ·１－１的羧甲基－β－环糊精溶液的洗脱率可达９０%以上;洗脱液浓度和土壤质地是影响洗脱去除率的主要因素;适当地增加洗脱液浓度对洗脱去除率有显著提高;与脂肪醇聚氧乙烯醚相比,以羧甲基－β－环糊精溶液作为增溶试剂,对土壤中的弱极性有机污染物进行洗脱处理具有更好的效果     

过硫酸盐去除石灰土介质中汽油BTEX的效果及乙醇的影响

为了认识岩溶区石灰土含水介质中化学氧化联合生物降解去除燃油苯系物的效果,以汽油中的苯、甲苯、乙苯和二甲苯(BTEX)作为污染物,通过批实验研究过硫酸盐(PS)联合硝酸盐去除汽油BTEX的效果,并认识不同浓度乙醇(EtOH)存在时带来的影响及化学氧化与反硝化联合修复的可能性.结果表明,在35 d内各组的BTEX去除率均达到91.00%以上,PS化学氧化能有效地去除BTEX.在不含EtOH及含EtOH初始浓度为500和5000 mg·L^-1的情况下,BTEX浓度在第65 d时分别为未检出、0.226 mg·L^-1、0.243 mg·L^-1,去除率分别为99.98%、99.00%、98.70%,其中,苯的去除率分别为99.98%、97.01%、93.32%.随着EtOH浓度的增加,苯的去除受到抑制,EtOH对BTEX的化学氧化具有阻碍作用.石灰土介质中高铁含量对PS具有活化能力,高含量有机质能促进PS分解,并导致pH值回升,出现反硝化作用和硫酸盐还原作用,有利于生物降解作用的恢复.     

Modelling the Balance of Metals in the Amended Soil for the Case of ‘Atmosphere–Plant–Soil’ System

Changing the concepts of economic development and introducing new amendments can hardly decrease the accumulation in the soil of such pollutants as metals, remaining there for a long time. The predictive models for describing the balance of metals in the soil, which are based on the ‘atmosphere–plant–soil’ system and reflect the complicated physical–chemical nature of the metals’ migration, expressed by coefficients obtained in long-term observations in natural conditions, allow for evaluating long-term concentration of metals in the soil. The model BALANS evaluates self-purification of soil, taking into account the uptake of metals of aerogenic origin by the soil together with amendments, their physical–chemical migration and the type of microrelief determining its intensity as well as the absorbed biomass of plants and the removal of metals with crops. In this model, the half-period of metals’ washing out from the soil, found for the microrelief characteristic of low places, exceeds 200 years for Ni, Cr and Pb and makes 90 and 150 years for Zn and Cu, respectively.     

The Role of Wind in Modeling of Oil Pollution Transport and Diffusion in the Persian Gulf

The Persian Gulf ecosystem is facing a variety of stresses as a result of being located within the richest oil province in the world, which hosts more than 67 % of the world oil reserve. In this paper, the distribution of oil pollution on the surface layer of the Persian Gulf is predicted for the different months after the release, based on the Coupled Hydrodynamical Ecological model for Regional Shelf seas (COHERENS). An Eulerian model for the Persian Gulf is set up using the Cartesian coordinate in the horizontal direction, and the sigma coordinate in the vertical direction. Based on this model, our analysis and simulation results indicate that the winds lead to diffusion of the contaminant concentration in the direction of the Arabian coast from the initial position of the spill. The results of this study can be used to provide appropriate solutions for preventing oil from spreading further in the region.     

An Integrated Assessment by Models for Energy Systems Analysis and Life-Cycle Assessment with a Case Study of Advanced Fossil-Fired Power Plants in China

We developed an integrated assessment (IA) using models for energy systems analysis and life-cycle assessment (LCA). Based on this assessment framework, we developed cost-benefit analysis (CBA) case studies for a hypothetical project designed to introduce advanced fossil-fired power generation technologies in China. Our MARKAL model for Japan confirmed that radical reductions (i.e., 80 % by 2050) of carbon dioxide (CO₂) could be attained from energy systems alone and that credit for emission allowances was required. We evaluated life-cycle costs and emissions of carbon dioxide, sulfur oxide, and nitrogen oxide gases for the energy technologies using an LCA model. Further, we applied a power generation planning model for six Chinese grids to provide a power mix structure, potentially producing credit by installing fossil-fired power generation technology and by using baseline grid emission factors with an average cost of electricity. Finally, by using dynamic emission reductions and additional costs from the two models, we conducted case studies of CBA for a hypothetical project to install the technologies in China. This was accomplished by evaluating emission reductions in monetary terms and by applying a life-cycle impact assessment model. A unique feature of our IA is its dynamic (time-varying) assessment of costs and benefits.     

Emission-based static traffic assignment models

Tailpipe emissions in the road transportation system are a major source of air pollution and greenhouse gases. One of the possible approaches is to influence drivers’ routing decisions such that the emissions and fuel consumption is minimized. In order to evaluate such condition, we develop environmental traffic assignment (E-TA) models based on user equilibrium (UE) and system optimal (SO) behavioral principles. Extending the traditional travel time-based UE and SO principles to E-TA is not straightforward because, unlike travel time, the rate of emissions increases with the increase in vehicle speed beyond a certain point. The results of various TA models show a network-wide traffic control strategy in which vehicles are routed according to SO-based E-TA, can reduce system-wide emissions. However, a system in which drivers make routing decisions to minimize their own emissions (E-UE system) results in a paradoxical situation of increased individual as well as system-wide emissions.     

Valuing Flood Risk Reductions

A choice experiment is used to estimate how Vietnamese households value a flood risk reduction. The empirical analysis is conducted on a sample of households located in the Nghe An Province, one of the provinces which is the most affected by floods in Vietnam. The results reveal that there is a high level of heterogeneity in preferences across households. We compute the willingness to pay (WTP) for a flood risk reduction, and we identify how it relates to different attributes of flood management policies (reduction of economic losses, reduction of human losses, political level in charge of implementing the flood management policy). In particular, the marginal WTP for reducing the flood fatality rate, which can be interpreted as the value of statistical life (VSL), varies from 2 517 million VND (approximately 120,818 USD) to 3 590 million VND (approximately 172,323 USD) depending on the model considered. The VSL represents between 77 and 111 times the annual household average income in our sample, a result in line with previous estimates in similar countries.