塔河流域森林生态建设存在的主要问题及其策略

随着时间的推移,塔河流域生态环境恶化的现实已被越来越多的人们所认识。造成塔河中下游森林退化,生态环境恶化的主要原因除自然因素外,主要是人为不合理的社会经济活动的影响。目前塔河流域森林生态建设存在的主要问题有:第一水资源不合理的利用成为沙漠化和次生盐渍化的主要原因;第二传统的生活方式和掠夺式的生产方式使生态环境遭到破坏;第三耕地的增加,满足不了人口发展的需求,大面积的无序开荒,导致生态环境进一步恶化。为塔河中下游林地植被恢复、建设及防止退化的策略有:塔河中下游生态工程治理的原则;塔河中下游生态环境治理的基本思路;塔河流域生态环境治理的主要对策,合理利用水资源,坚持生产、生态建设并重,确保生态用水;要积极调整农村产业结构,正确处理林业和农业、林业和牧业以及林业和工业发展的关系;大力发展农村能源建设,从根本上解决农村薪材和生态保护之间矛盾;大力保护、恢复、发展荒漠林草植被,大力发展绿洲林业,建立荒漠生态环境和绿洲共同支撑的稳定的生态体系;积极实施林业生态工程和林果工程,建立较为完备和发达的生态和产业体系。     

新疆和田河绿色走廊演变机制及生态环境保护初析

和田河绿色走廊是塔里木盆地中南北穿越塔克拉玛干沙漠的三条绿色走廊之一，具有重要的政治经济、生态、交通意义。绿色走廊的演变受到构造运动、气候波动和人为干扰等因素的影响。其中，人为干扰是绿色走廊现代生态环境演变过程中最重要最活跃的控制因素。建议加强流域水资源总体规划与统筹管理，兼顾生产、生活和生态用水，逐步改变农村居民燃料能源结构，从而保护绿色走廊生态健康。     

塔里木河下游绿色走廊的生态问题与治理对策

从经济、军事和生态三个角度分析了保护塔里木河下游绿色走廊的必要性,概括了该区域的生态环境现状,即河水矿化度升高、地下水位下降从而导致植被的退化和沙漠化加剧的问题。最后提出了以水资源合理利用为前提和中心的治理对策。     

塔里木河中游段治理中的牧区水利建设

塔里木河中下游地区生态环境急剧恶化,最主要的原因是中游段河水近一半21×108m3被人为的散失,造成下游河水所剩无几,致使尾闾台特玛湖干涸。解决的根本办法是将中下游段两岸的农牧民迁出,实现人为耗水为零。近期切实可行的办法是积极开展牧区水利建设,改变牧业生产方式,集中高效利用塔河水资源,发展人工草地,改良天然草场,实现牧业生产生态环境的协调发展,人与自然和谐相处。     

环评中锅炉房大气污染源强的确定

在环境评价中,污染源强的确定对环境影响因素评价的分析结果有重要作用。对锅炉房污染物排放的分析表明,影响锅炉房大气污染物的主要因素有燃料的构成、发热量和燃烧方式等。确定锅炉房大气污染物的方法主要有物料衡算法、实测法和经验系数法。在这三种方法中,物料衡算法被普遍采用。在确定锅炉房大气污染物的排放量时,也可以采用物料衡算法和实测法相结合的方法。     

NUTRIENT CONCENTRATION CRITERIA AND CHARACTERIZATION OF PATTERNS IN TROPHIC STATE FOR RIVERS IN HETEROGENEOUS LANDSCAPES1

ABSTRACT: A method is demonstrated for the development of nutrient concentration criteria and large scale assessment of trophic state in environmentally heterogeneous landscapes. The method uses the River Environment Classification (REC) as a spatial framework to partition rivers according to differences in processes that control the accrual and loss of algae biomass. The method is then applied to gravel bed rivers with natural flow regimes that drain hilly watersheds in New Zealand's South Island. An existing model is used to characterize trophic state (in terms of chlorophyll a as a measure of maximum biomass) using nutrient concentration, which controls the rate of biomass accrual, and flood frequency, which controls biomass loss. Variation in flood frequency was partitioned into three classes, and flow data measured at 68 sites was used to show that the classes differ with respect to flood frequency. Variation in nutrient concentration was partitioned at smaller spatial scales by subdivision of higher level classes into seven classes. The median of flood frequency in each of the three higher level classes was used as a control variable in the model to provide spatially explicit nutrient concentration criteria by setting maximum chlorophyll a to reflect a desired trophic state. The median of mean monthly soluble reactive phosphorus and soluble inorganic nitrogen measured at 68 water quality monitoring sites were then used to characterize the trophic state of each of the seven lower level classes. The method models biomass and therefore allows variation in this response variable to provide options for trophic state and the associated nutrient concentrations to achieve these. Thus it is less deterministic than using reference site water quality. The choice from among these options is a sociopolitical decision, which reflects the management objectives rather than purely technical considerations.     

CHEMISTRY OF COALBED METHANE DISCHARGE WATER INTERACTING WITH SEMI‐ARID EPHEMERAL STREAM CHANNELS1

ABSTRACT: The objective of this study was to examine the chemistry of Coalbed Methane (CBM) discharge water reacting with semi‐arid ephemeral stream channels in the Powder River Basin, Wyoming. The study area consisted of two ephemeral streams: Burger Draw and Sue Draw. These streams are tributaries to the perennial Powder River. Samples were collected bimonthly from three CBM discharge points and seven channel locations in Burger Draw and Sue Draw. Samples were also collected bimonthly from the Powder River above and below the confluence of Burger Draw. Before sample collection, the pH and electrical conductivity (EC) were measured in the field. Samples were transported to the laboratory and analyzed for alkalinity, major cations, and anions. From the measurement of sodium (Na), calcium (Ca), and magnesium (Mg), practical sodium adsorption ratio (SARp) and true sodium adsorption ratio (SARt) were calculated. Results suggest pH and EC of CBM discharge water was 7.1 and 4.3 dS/m, respectively. The CBM discharge water consisted of higher concentrations of sodium and alkalinity compared to other components. The pH of CBM discharge water increased significantly (p = 0.000) in the downstream channel of Burger Draw from 7.1 to 8.84 before it joined with the Powder River. Dissolved calcium concentration of CBM discharge water decreased significantly (p = 0.000) in the downstream channel water. Subsequently, SARp increased approximately from 24 to 29. The SARt also increased significantly (p = 0.001) in the downstream channel water. For instance, SARt of CBM discharge water increased from 32.93 to 45.5 downstream channels after the confluence of Sue Draw with the Burger Draw. The only significant difference in water chemistry above and below the confluence of Burger Draw with the Powder River was pH, which increased from 8.36 to 8.52. The significant increase in SAR values of CBM discharge water in Burger Draw and Sue Draw tributaries suggest a careful monitoring of salinity and sodicity is needed if CBM discharge water is used for irrigation in semi‐arid environments. Results discussed in this study will be useful to downstream water users who depend on water for irrigation.     

西南某水电站岩体质量分级研究

介绍了水利水电工程地质分类、RM R分类和Q系统分类等3种分级法的具体使用和评价标准,并以西南某水电站为例,将这3种分类方法对其坝区围岩分类的结果进行了对比和相关性分析,得出了该水电站围岩合理、科学的评价分类结果。依据此评价结果,绘出了坝区岩体质量分级图,准确显示了坝区的岩体质量特征,证实了3种分级法在该类岩体分级的适用性和统一性。在充分调查和资料掌握的基础上,对岩体工程地质分类在实际工程中的应用提出了具体的指标和实际的操作法。     

污染物排放相关指标计算方法的研究

针对传统的污染排放数据指标计算方法存在的问题,提出污染物排放指标应根据排污强度和经济指标确定的新思路,同时提出污染物排放指标数据的快速测算模型设计.建议通过环境监测数据或物料衡算数据确定每个排污单位的平均排污强度,作为计算机处理的参数,再由该排污单位申报每月的经济指标(产量或产值),输入计算机计算其产污量、排污量和去除量.实施计算机管理的关键是选取适当的数据计算模型.新思路应该能够规范计算程序,建立污染源动态数据库,对排污数据实行有效的统计分析.     

Water sharing agreements sustainable to reduced flows

By signing a water sharing agreement (WSA), countries agree to release an amount of river water in exchange for a negotiated compensation. We examine the vulnerability of such agreements to reduced water flows. Among all WSAs that are acceptable to riparian countries, we find out the one which is self-enforced under the most severe drought scenarios. The so-called upstream incremental WSA assigns to each country its marginal contribution to its followers in the river. Its mirror image, the downstream incremental WSA, is not sustainable to reduced flow at the source. Self-enforcement problems can be solved by setting water releases and compensations contingent to water flow. We apply our analysis to the Aral Sea Basin. We compute the upstream incremental compensations for the Bishkek agreement and asses its vulnerability with historical flows.