Simulated effects of crop rotations and residue management on wind erosion in Wuchuan,west-central Inner Mongolia,China

For decades, wind erosion has triggered dust and sand storms, buffeting Beijing and areas of northwestern China to the point of being hazardous to human health while rapidly eroding crop and livestock productivity. The EPIC (Environmental Policy Integrated Climate) field-scale simulation model was used to assess long-term effects of improved crop rotations and crop residue management practices on wind erosion in Wuchuan County in Inner Mongolia. Simulation results indicate that preserving crop stalks until land is prepared by zone tillage for the next year's crop in lieu of using them as a source of heating fuel or livestock fodder significantly reduces wind erosion by 60%. At the same time, grain and potato (Solanum tuberosum L.) yields were maintained or improved. Significant reductions in erosion, 35 to 46%, also resulted from delaying stalk removal until late January through late April. Yearly wind erosion was concentrated in April and May, the windiest months. Additionally, the use of alternative crop rotations resulted in differences in wind erosion, largely due to a difference in residue stature and quality and differences in biomass produced. As a result, altering current crop rotation systems by expanding corn (Zea mays L.), wheat (Triticum aestivum L.), and millet [Sorghum bicolor (L.) Moench] and reducing potato and pea (Pisum sativum L.) production significantly reduced simulated wind erosion, thus diminishing the severity of dust and sand storms in northwestern China. Saving and protecting topsoil over time will sustain land productivity and have long-term implications for improving conditions of rural poverty in the region.     

Dust storms: recent developments

Dust storms have a number of impacts upon the environment including radiative forcing, and biogeochemical cycling. They transport material over many thousands of kilometres. They also have a range of impacts on humans, not least on human health. In recent years the identification of source areas for dust storms has been an important area or research, with the Sahara (especially Bodélé) and western China being recognised as the strongest sources globally. Another major development has been the recognition of the degree to which dust storm activity has varied at a range of time scales, millennial, century, decadal, annual and seasonal.     

Modeling the Potential of the Northern China Forest Shelterbelt in Improving Hydroclimate Conditions1

Abstract: The forest shelterbelt (afforestation) project in northern China is the most significant ecosystem project initiated in China during the past three decades. It aims to improve and conserve the ecological environment in the project areas. The tree belt stands along the southern edge of the sandy lands, nearly paralleling to the Great Wall. This study used a regional climate model to simulate the potential of improving regional hydroclimate conditions resulting from the afforestation project. Two simulations with preafforestation and postafforestation land cover were performed over East Asia from January 1987 to February 1988. The model resolution is 60 km. The differences between the two simulations suggest that the northern China forest shelterbelt project is likely to improve overall hydroclimate conditions by increasing precipitation, relative humidity, and soil moisture, and by reducing prevailing winds and air temperature. The effects are more significant in spring and summer than fall and winter. Changes in many hydrologic properties (e.g., evapotranspiration, soil moisture, and water yield), however, differ between the dry Northeast China and the moist Northeast China. The hydroclimate effects are also found in the surrounding areas, featured by noticeably moister conditions in the area south of the afforestation project. The results imply that the shelterbelt project would reduce water yield in afforested Northwest and North China during spring, but increase water yield in the afforested Northeast China as well as in the southern surrounding area, offset some greenhouse effects, and reduce the severity of dust storms. Possible improvements of this study by using actual afforestation data, modeling with higher resolution, longer integration and more detailed processes, and analyzing the physical mechanisms are discussed.     

中国区域粮食生产与消费中的虚拟耕地平衡研究

从不同尺度分析了我国2008年粮食生产、消费中的虚拟耕地含量及虚拟耕地平衡空间分布规律.主要结论为:①2008年粮食生产虚拟耕地北方比南方多32396.8×107m2,人均粮食生产虚拟耕地量北方远远高于全国平均水平和南方,因粮食生产形成较为典型的虚拟耕地“北土南调”现象.②2008年粮食消费虚拟耕地北方比南方多6851.62×107m2.③从粮食生产与消费的虚拟耕地平衡空间分布规律来看,2008年虚拟耕地调出区全部位于我国北方地区,集中分布在两大地带:一是由黑龙江、吉林、内蒙古、新疆、宁夏5省(区)组成的我国北方边境沿线地带,二是由河南、安徽组成的中部区;调入区则集中在由东部沿海地区、中部省份和西部内陆省份组成的环状地带.     

Preliminary observations of environmental damage due to the Gulf War

Preparing for and conducting the Gulf War resulted in much damage to the environment of the region. The first and most visible effect is related to the damage caused by oil well fires in terms of air pollution as well as the potential damage to the petroleum reservoirs. The second detrimental effect has been caused by the oil spill in the Gulf water. Hundreds of miles of the western coastline of the Gulf are already covered with oil. Petroleum 'mats' have settled on coral reefs and have reduced Gulf water productivity. Foremost among the irreparable damages are changes to the terrain due to the digging of trenches, building walls of soil and otherwise disturbing the desert pavement in and around Kuwait. Disruption of the, usually, one-grain thick layer of pebbles on the desert floor exposes soil to wind action. Changing the contours of the normally flat land increases resistance to the wind and increases the potential of particle transport until the land is peneplained. This condition will increase the frequency and the ferocity of dust storms in the region. It will also result in the formation of new sand dunes; sand drifts already exist along roads in northern Kuwait. It is believed that the detrimental effects on the atmosphere will last for years, on the Gulf water for decades, and on the desert surface for centuries.     

Hydrologic Impact Assessment of Land Cover Change and Stormwater Management Using the Hydrologic Footprint Residence

Urbanization impacts the stormwater regime through increased runoff volumes and velocities. Detention ponds and low impact development (LID) strategies may be implemented to control stormwater runoff. Typically, mitigation strategies are designed to maintain postdevelopment peak flows at predevelopment levels for a set of design storms. Peak flow does not capture the extent of changes to the hydrologic flow regime, and the hydrologic footprint residence (HFR) was developed to calculate the area and duration of inundated land during a storm. This study couples a cellular automata land cover change model with a hydrologic and hydraulic framework to generate spatial projections of future development on the fringe of a rapidly urbanizing metropolitan area. The hydrologic flow regime is characterized for existing and projected land cover patterns under detention pond and LID‐based control, using the HFR and peak flow values. Results demonstrate that for less intense and frequent rainfall events, LID solutions are better with respect to HFR; for larger storms, detention pond strategies perform better with respect to HFR and peak flow.     

Land loss in coastal Louisiana (U.S.A.)

This paper examines causes and consequences of wetland losses in coastal Louisiana. Land loss is a cumulative impact, the result of many impacts both natural and artificial. Natural losses are caused by subsidence, decay of abandoned river deltas, waves, and storms. Artificial losses result from flood-control practices, impoundments, and dredging and subsequent erosion of artificial channels. Wetland loss also results from spoil disposal upon wetlands and land reclamation projects.Total land loss in Louisiana's coastal zone is at least 4,300 ha/year. Some wetlands are converted to spoil banks and other eco-systems so that wetland losses are probably two to three times higher. Annual wetland losses in the Barataria Bay basin are 2.6% of the wetland area. Human activities are the principal determinants of land loss. The present total wetland area directly lost because of canals may be close to 10% if spoil area is included. The interrelationship between hydrology, land, vegetation, substrate, subsidence, and sediment supply are complicated; however, hydrologic units with high canal density are generally associated with higher rates of land loss and the rate may be accelerating.Some cumulative impacts of land loss are increased saltwater intrusion, loss of capacity to buffer the impact of storms, and large additions of nutrients. One measure of the impact is that roughly $8–17 × 10⁶ (U.S.A.) of fisheries products and services are lost annually in Louisiana.Viewed at the level of the hydrologic unit, land loss transcends differences in local vegetation, substrate, geology, and hydrology. Land management should therefore focus at that level of organization. Proper guideline recommendations require an appreciation of the long-term interrelations of the wetland estuarine system.     

Eco-Environmental Evolution, Control, and Adjustment for Aibi Lake Catchment

Aibi Lake in north Xinjiang is a typical lake of the arid area, but with a peculiar wetland–arid area ecosystem. Due to the climate becoming drier and the disturbance of human activities, the eco-environment of Aibi Lake catchment has degraded. It was found in our study that there were spatial–temporal changes of vegetation cover, plant species, and soil physical and chemical properties in the catchment. In the upper section of alluvial–fluvial plains, the desertified steppe of Stipa and Artemisia spp. is developed with vegetation cover of some 50%. Haloxylon ammodendron desert occupies the lower section with vegetation cover of some 60%. In these regions with an intensive human disturbance, vegetation has degraded into herb vegetation of annual plant complexes. On the margins of the alluvial–fluvial fans, the lakeshore, and the surrounding regions where the river mouths join the lake, different azonal vegetation—Phragmites communis marsh, Phragmites communis meadow, and Tamarix shrubs—have developed with a vegetation cover of some 80%. On heavier, salinized land, succulent halophyte desert vegetation dominated by Halocnemum strobilaceum has formed with a fractional canopy cover of 10–15%. Haloxylon persicum, Aristida pennata, and other species with a vegetation cover of 30–50% grow in the sand desert zone on the periphery in the lake. In contrast with the 1950s, the vegetation cover around the lakebed and at the river deltas has slightly increased; however, the vegetation cover around the periphery of the lake has decreased and the plant species have still degraded. The surface soils on the windward area and the dried lakebed that have lost vegetation protection have become coarser, whereas the land on the leeward side of the lake has accumulated fine particles. In contrast with the 1980s, soil organic matter has declined markedly. The analyses of climatic data show that the number of days of drifting dust in Jinghe County and Bole City increased in the last 20 years. In the investigation, we found that intensively developed land, the bare lakebed, and abandoned cultivated land provided a great deal of material for drifting dust. In conclusion, we consider the eco-environmental degradation resulting from the inappropriate human activities and put forward recommendations for land-use adjustment and dust control.     

锅炉烟尘污染与治理

中原油田黄河以北广大地区燃煤锅炉分布广泛,污染物排放量相对较大。为减少大气污染,采取了以下治理措施:提高运行操作水平;选择适宜的燃烧设备;选择效果较好的除尘设施;选择适宜的煤质等。采用上述综合措施后,不仅降低了锅炉的排烟量也降低了锅炉的烟尘排放浓度,锅炉烟尘排放达标。     

基于GIS的关中地区人居环境自然适宜性研究

选取地形、气候、水文、植被等自然因子,建立1km×1km栅格单元的人居环境基础数据库,构建了基于人居环境指数的关中地区人居环境自然适宜性评价模型.并采用GIS技术定量评价了关中地区的人居环境自然适宜性,揭示了关中地区人居环境的自然格局与地域特征.研究表明,关中地区人居环境指数整体呈现由南向北递减趋势,人居环境指数可综合反映区域人居环境的自然适宜程度,关中地区人口明显集中分布于人居环境适宜程度较高的地区.评价结果显示,关中地区人居环境一般适宜区和比较适宜区面积最大,约5.5489×104km2,接近全区总面积的99.98%,相应人口约为2294.95万人,占全区总人口的99.98%;人居环境临界适宜地区8km2,占全区总面积的0.02%,相应人口2200人,零星分布在陇县西北的黄土高原地区;关中地区人居环境高度适宜地区面积3km2,人口1400人,由于适宜度高、面积小,导致人口密度最大,达467人/km2.     

HYDROLOGIC IMPACTS OF ALTERNATIVE APPROACHES TO STORM WATER MANAGEMENT AND LAND DEVELOPMENT1

Low impact development (LID) and other land development methods have been presented as alternatives to conventional storm water management and site design. Low impact development encourages land preservation and use of distributed, infiltration‐based storm water management systems to minimize impacts on hydrology. Such systems can include shallow retention areas, akin to natural depression storage. Other approaches to land development may emphasize land preservation only. Herein, an analysis of four development alternatives is presented. The first was Traditional development with conventional pipe/pond storm water management and half‐acre lots. The second alternative was Cluster development, in which implementation of the local cluster development ordnance was assumed, resulting in quarter‐acre lots with a pipe/pond storm water management system and open space preservation. The “Partial” LID option used the same lot layout as the Traditional option, with a storm water management system emphasizing shallow depression storage. The “Full” LID used the Cluster site plan and the depression storage‐based storm water management system. The alternatives were compared to the hydrologic response of existing site conditions. The analysis used two design storms and a continuous rainfall record. The combination of land preservation and infiltration‐based storm water management yielded the hydrologic response closest to existing conditions, although ponds were required to control peak flows for the design storms.     

Particulate matter concentration and air quality affected by windblown dust in the Columbia plateau

The USEPA has proposed to regulate PM(coarse) (particulate matter 2.5 to 10 microm in diameter). Exceedance of the proposed National Ambient Air Quality Standard (NAAQS) for PM(coarse) is expected within the Columbia Plateau of the Pacific Northwest United States based on the high frequency of dust storms and the large contribution of crustal material to fugitive dust in the region. The objective of this study was to explore the implication of the proposed NAAQS for PM(coarse) on air quality. Concurrent observations of both PM10 (particulate matter 相似文献   

An Integrated Approach to Reservoir Management: The Williston Reservoir Case Study

/ The management of industrial reservoirs for hydroelectric energy can cause severe impacts to surrounding communities. This study examines the generation of dust along the northern foreshore zones of Williston Reservoir in northern British Columbia. The dust is generated in the spring when the reservoir levels are low and impacts a relocated First Nations' village (Tsay Keh) at the north end of the reservoir. Data were gathered to provide an overview of the physical conditions that contribute to the dust problem, including a social survey, soil analysis, and vegetation inventory. The study provides a scoping method to assess a large-scale and complex problem with respect to dust management along a large reservoir. Methods for dust control include short- and long-term solutions that integrate the use of native vegetation along the foreshore zones of the reservoir.     

Mapping Threats to Power Line Corridors for Connecticut Rights-of-Way Management

Trees are a major threat to power line security across forested regions of the world. We developed a decision support system for identifying locations in Connecticut, USA where trees have grown tall enough to make contact with transmission lines during storms. We used the Random Forest algorithm, danger tree presence/absence data, and 25 raster environmental datasets to develop (1) an understanding of the abiotic environmental settings that host danger trees and (2) a spatially explicit map of danger tree distributions across Connecticut power line corridors. Danger trees were prevalent in locations (1) with an infrequent history of storms; (2) forested and residential land uses; and (3) low to middle elevations. Products from this research can be transferred to adaptive right-of-way management because they present managers with key information on where danger trees are likely to occur, and the methods presented herein have great potential for future application to other regions managers seek to identify high priority areas for danger tree removal.     

TIM: Assessing the sustainability of agricultural land management

TIM (Threat Identification Model) is a framework for the ex ante assessment of agricultural land management sustainability at the land unit scale that identifies sources of unsustainability within agricultural land management systems. The model explicitly links defined hazards to land productivity and environmental integrity, land resource data and information, and land management practice options using expert and local knowledge on land management and its potential effects. The model was tested in the Crystal Creek Subcatchment, a narrow coastal strip of land situated in north Queensland, Australia. This area was chosen due to the expansion of the sugar industry onto increasingly marginal land in the area, which represents a threat to sustainable land use and a requirement for careful land-use planning and land management.TIM may be used in a relational database as a stand alone decision support system for land-management planning. Its usefulness in land-use planning is greatest when it is linked to a Geographic Information System (GIS) as shown in this paper. GIS allows TIM outputs, such as constraints to agriculture and site-specific best-management practices, to be identified in a spatially explicit manner.The main advantages of TIM are that it can be done ex ante, it removes the need to define sustainability assessment criteria and indicators, it utilises current understanding of the causes and effects of land degradation and how different land-management practices influence these, and links this knowledge to definite land-management options.     

西部大开发中的新疆生态环境建设

新疆地处祖国西北边陲，其国土面积、资源储备和战略地位都在西部开发中居于重要地位。长期以来，由于人们对自然资源的不合理利用，加之经济发展滞后，使得该地区的生态环境遭到严重破坏，土地沙漠化、水土流失、森林、草场严重退化。正确认识和评价新疆的生态环境现状及其承载力，制定遏制生态环境恶化的有效方法，促进生态系统的良性循环，实现人与自然的和谐统一，是西部大开发中实现新疆经济、社会可持续发展的基础。     

Reclaimed Mineland Curve Number Response to Temporal Distribution of Rainfall1

Warner, Richard C., Carmen T. Agouridis, Page T. Vingralek, and Alex W. Fogle, 2010. Reclaimed Mineland Curve Number Response to Temporal Distribution of Rainfall. Journal of the American Water Resources Association (JAWRA) 46(4): 724-732. DOI: 10.1111/j.1752-1688.2010.00444.x Abstract: The curve number (CN) method is a common technique to estimate runoff volume, and it is widely used in coal mining operations such as those in the Appalachian region of Kentucky. However, very little CN data are available for watersheds disturbed by surface mining and then reclaimed using traditional techniques. Furthermore, as the CN method does not readily account for variations in infiltration rates due to varying rainfall distributions, the selection of a single CN value to encompass all temporal rainfall distributions could lead engineers to substantially under- or over-size water detention structures used in mining operations or other land uses such as development. Using rainfall and runoff data from a surface coal mine located in the Cumberland Plateau of eastern Kentucky, CNs were computed for conventionally reclaimed lands. The effects of temporal rainfall distributions on CNs was also examined by classifying storms as intense, steady, multi-interval intense, or multi-interval steady. Results indicate that CNs for such reclaimed lands ranged from 62 to 94 with a mean value of 85. Temporal rainfall distributions were also shown to significantly affect CN values with intense storms having significantly higher CNs than multi-interval storms. These results indicate that a period of recovery is present between rainfall bursts of a multi-interval storm that allows depressional storage and infiltration rates to rebound.     

高炉煤气干法除尘技术的发展

我国是采用高炉煤气干法袋式除尘最早的国家之一,至今已有40多年的历史。本文介绍了高炉煤气干法除尘技术发展的三个阶段,即起步、发展,以及炉容1000m3以上级的提高阶段,认为采用干法除尘,才能节能减排,实现综合利用。     

加拿大污染场地土壤质量指导值对我国建设用地土壤污染风险管控标准制修订的启示

针对我国建设用地土壤污染风险管控标准存在的保护目标单一、毒理学基础数据库有待完善、缺少因地制宜的地方标准及统一的标准制定规程等问题,本文研究了加拿大联邦及其省级土壤质量指导值分级制定技术规程,梳理了加拿大污染场地修复目标值的确定方法。在此基础上,从保护人体健康与保护生态环境并重、提升建设用地土壤污染风险管控标准的基础研究水平、研究基于地方实际的建设用地土壤污染风险管控标准和出台统一的标准制定规程文件等四个方面提出对策建议,以期为我国建设用地土壤污染风险管控标准制修订提供参考。