黑河流域中游荒漠区沙尘暴、扬沙和浮尘监测及其与气候因子的关系

[目的] 分析黑河流域中游荒漠区沙尘暴、扬沙以及浮尘频次和时长的月变化和年变化,并分析其与主要气候因子的关系,为区域沙尘天气的早期预警和荒漠区的经营和管理提供依据。[方法] 利用黑河流域红沙窝荒漠化综合防治试验站的2010—2019年的沙尘天气监测数据和气象数据进行分析。[结果] 沙尘频次和时长主要集中在春季,其次是冬季,春冬两季的频次和时长各占全年的82.3%和79.4%。10 a间沙尘暴和扬沙频次总体变化趋势逐渐减少,而浮尘频次总体变化趋势逐年增加;沙尘时长总体变化趋势逐年增加。沙尘频次月变化与土壤湿度（10 cm）和大气湿度之间呈极显著负相关（p<0.01）,与风速之间呈极显著正相关（p<0.01）。扬沙年际发生频次与土壤温度（5 cm）之间呈显著负相关（p<0.05）,与大气温度之间呈极显著负相关（p<0.01）。[结论] 近10 a来,黑河流域中游荒漠区的沙尘天气主要发生在春季和冬季,破坏性较大的沙尘暴和扬沙逐年减少,而浮尘逐年增加。沙尘频次的月变化主要影响因素是浅层土壤湿度、大气湿度和风速。春季的浅层土壤湿度影响了沙尘暴和扬沙年际频次变化,浅层土壤温度影响了浮尘年际频次变化;冬季的浅层土壤温湿度和降水量影响了沙尘暴的年际频次变化,浅层土壤温度和大气温度影响了扬沙的年际频次变化。     

侵蚀作用对黄土丘陵沟壑区有机碳迁移-沉积的影响

土壤有机碳(SOC)作为陆地碳库的重要组成部分,不仅对土壤肥力产生重要影响,而且在一定程度上影响着全球变暖趋势,为了深入探究土壤侵蚀与有机碳的关系,利用137 Cs核示踪法,以黄土丘陵沟壑区典型流域王茂沟坡耕地、林地、草地和梯田四种土地利用为研究对象,分析了不同坡面下土壤侵蚀对SOC迁移和沉积的影响规律.结果表明:与该...     

Ecological impacts of small hydropower plants on headwater stream fish: from individual to community effects

Hydroelectricity is increasingly used worldwide as a source of renewable energy, and many mountain ranges have dozens or hundreds of hydropower plants, with many more being under construction or planned. Although the ecological impacts of large dams are relatively well known, the effects of small hydropower plants and their weirs have been much less investigated. We studied the effects of water diversion of small hydropower plants on fish assemblages in the upper Ter river basin (Catalonia, NE Spain), which has headwater reaches with good water quality and no large dams but many of such plants. We studied fish populations and habitat features on control and impacted reaches for water diversion of 16 hydropower plants. In the impacted reaches, there was a significantly lower presence of refuges for fish, poorer habitat quality, more pools and less riffles and macrophytes, and shallower water levels. We also observed higher fish abundance, larger mean fish size and better fish condition in the control than in impacted reaches, although the results were species‐specific. Accordingly, species composition was also affected, with lower relative abundance of brown trout (Salmo trutta) and Pyrenean minnow (Phoxinus bigerri) in the impacted reaches and higher presence of stone loach (Barbatula quignardi) and Mediterranean barbel (Barbus meridionalis). Our study highlights the effects of water diversion of small hydropower plants from the individual to the population and community levels but probably underestimates them, urging for further assessment and mitigation of these ecological impacts.     

柴达木盆地农业节水灌溉的几种技术探讨

随着我国水资源供需矛盾的日益尖锐和水资源环境的日趋恶化,节水已成为我国解决水问题的有效途径之一。本文介绍几种节水技术,并分析利弊,反映柴达木盆地农业节水新观点、新思路,为农业节水更好的发展提供参考。     

伊犁河流域地表水资源优势及开发利用潜力研究

伊犁河流域是新疆地表水系最发达、径流最发育、水资源最丰富的内陆河流域,具有流域降水丰沛,径流补给充分,径流量大;水系发达,河川密布;水量变化较小、泥沙含量较少、水质较好的资源优势。但受经济发展水平及产业结构层次的限制,伊犁河流域水资源总体上仍处于利用效率低下、生产经营方式落后、综合利用潜力巨大的初级开发阶段。依据部颁SL201-9《江河流域规划编制规范》和流域整体规划目标,经过水资源多目标开发平衡分析与评价,给出了伊犁河流域水资源综合开发和合理配置远景规划方案。     

加强交通运输网络建设,促进柴达木地区发展

柴达木地区是我国 2 1世纪实现可持续发展重要的战略资源接替重点地区 ,也是西部大开发战略实施的重点建设地区。区域现代交通运输网络已初步形成 ,但远不能满足和保障大开发战略实施和可持续发展的需要 ,需要在未来的发展中继续加强交通运输设施建设 ,并实现适度“超前”发展 ,进一步提高各类运输方式的等级和质量 ,特别是铁路运输、管道运输的建设与发展     

Organic Seed-treatment as a Substitute for Chemical Seed-treatment to Control Common Bunt of Wheat

Common bunt of wheat, caused by Tilletia laevis and T. tritici, is a major seed and soil-borne disease in West Asia and North Africa. The use of resistant cultivars and chemical seed-treatments are the current control measures used to combat this disease. The aim of this study was to investigate alternative control measures to chemical seed-treatments that are environmentally friendly to support cultivar resistance. Several organic nutrients [skimmed milk powder, hucket (local skimmed milk) and wheat flour] at a concentration of 160g per kg of seeds were used as seed-treatments on two susceptible bread and durum wheat cultivars (Bau and Sebou, respectively) to examine their effectiveness in controlling the disease. Field trials over four years showed that skimmed milk powder, hucket, and wheat flour reduced common bunt infection levels by 96%, 93% and 62%, respectively. In most cases, the effectiveness of the skimmed milk powder and hucket was equal to the chemical seed-treatment; thus, these organic nutrients offer an effective and environmentally safe alternative to chemical treatments. However, a study of their economic value as well as of their effect on seed germination, and field emergence is needed.     

Linking Land-use, Water Body Type and Water Quality in Southern New Zealand

Land-use and vegetation cover have been linked to the nutrient levels (nitrogen, phosphorus) of surface waters in several countries. However, the links generally relate to streams and rivers, or to specific types of standing water, for example shallow lakes in a geologically defined region. We measured physical variables and nutrient chemistry of 45 water bodies representative of the wide range of lentic wetland environments (swamps, riverine wetlands, estuaries, reservoirs, shallow lakes, deep lakes) in Otago, New Zealand, and related these to catchment variables and land-use in order to assess the potential influence of catchment modification on water quality of these diverse wetlands. Catchment boundaries and land cover were derived from maps using ArcView GIS software. Our predictions that concentrations of nutrients and other components of water quality would correlate positively with the nature and intensity of catchment modification were confirmed in multivariate analyses. Physical and chemical measures were positively related to the extent of modification in the catchment (percentage of the catchment in pasture, planted forest, scrub and urban areas), and negatively related to lack of catchment modification (more of the catchment in bare ground, tussock grassland and indigenous forest). The strong negative correlations between nutrient concentrations, suspended sediment, water colour and the percentage of tussock cover in the catchment imply that increased conversion of the␣native tussock grassland to pastoral farming in␣Otago will increase nutrient concentrations and␣reduce water quality of the diverse lentic ecosystems.     

塔里木盆地沙漠化防治措施及其效益

土地沙漠化是干旱,半干旱地区普遍存在的一个重大环境问题。塔里木盆地是我国沙漠化危害最严重的地区之一,但干旱多风的自然条件引起的沙漠化,仅占现代沙漠化面积的１５．１３％,说明沙漠化土地是可以治理的,本文概述了农田林网,林网内农林复合经营,防沙林带,灌草带,造林固沙等沙漠化防治措施及其效果。     

准噶尔盆地南缘荒漠鼠类的微栖息地选择

依据地形及其内植被组成特征,划分出５种微栖息地类型。通过在不同物候期的观测表明,４种共存的鼠种间存在着明显的微栖息地分离。二足型跳鼠选择在开阔的空间活动四足型沙鼠则主要在多年生灌丛下取食。二种类型的鼠类微栖息地选择都不同程度地与同的多年生灌木