宁南黄土丘陵干旱区小流域雨水资源潜力研究

针对黄土高原地区水资源严重短缺的态势和生态环境建设的需要,结合国家“十五”重大科技攻关项目“半干旱退化山区生态农业建设技术与示范”专项,以小流域为单元,以雨水资源为研究对象,根据宁南半干旱退化山区典型小流域土地利用现状和相关雨水集蓄资料,计算了彭阳中庄小流域雨水资源潜力,结果表明:(1)示范区雨水资源最大理论潜力为5491000m3,目前就地利用、异地利用和叠加利用3种利用方式的比例分别为36.85%∶1.47%∶61.67%;(2)示范区雨水资源可实现潜力为5479732.3m3,占全流域雨水资源潜力的99.79%;(3)目前试区雨水资源现实潜力量为3863997m3,仅占可实现潜力量的73.43%。从试区雨水资源的可实现潜力来看,还有较大的开发利用潜力。     

三江源区生物质资源沼气化利用潜力评价

分析和评价三江源区生物质能资源潜力,是建设庭院生态经济模式的基础。通过构建模型的方法,对三江源区的养殖业生产和牧区居民生活过程产生的畜禽粪便和人粪尿等生物质能源潜力进行了估算,分析结果表明,仅2011年,江河源区产生的牲畜粪便总量为5819．31万t ,人的粪便总量为135．92万t ,合计5955．23万t ,如果进行沼气化利用,可产生沼气11．23～18．84亿m3,相当于7．97～13．38亿kg的标准煤,对三江源生态移民点和灾后恢复重建点发展能源型庭院生态经济模式具有重要作用。     

新疆天山北麓奎屯河流域径流变化特征研究

奎屯河流域水资源总量为17.83×108m3,其中地表径流量为16.21×108m3,占水资源总量的90%以上。因此,研究径流补给来源及变化特征有助于掌握水资源的变化趋势,为水资源的开发利用提供可靠的依据。本文采用奎屯河流域各水文站径流系列资料,选取变差系数、年际极值比、集中度、集中期等参数,分析了奎屯河流域径流补给特性、来源、年内分配规律及年际变化特征。分析结果表明:奎屯河流域径流补给具有地带性和多样性特点,补给来源主要以冰川融水和雨水补给为主;年内分配极不均匀,集中程度高;年际变化相对稳定,变幅小,多年呈微弱增加趋势。     

新疆降水丰、旱特点及水资源的稳定度

通过205个气象、水文站的25年资料计算,得到新疆年平均降水总量为2425亿立方米,仅占全国降水总量的4%,而面积则占1/6,北疆面积约45万平方公里,年平均降水总量为1150亿立方米,南疆面积约120万平方公里,年平均降水总量1275亿立方米。新疆丰年降水总量为2569亿立方米,枯年降水总量为2340亿立方米。新疆山区年平均降水总量2048亿立方米,占全疆降水总量的84%,平原年平均降水总量为381亿立方米,占全疆降水总量的16%。新疆山区降水变差系数明显小于平原地区,尤其是天山山区其值为0.1—0.2,这与我国南方雨水充沛地区相当。     

河西走廊地下水资源

本文利用已有的水文地质资料 ,广泛收集、系统整理了河西走廊地区内最新的水资源利用、水利化现状、勘探实验及水文气象资料 ,在此基础上采用基流分割法、径流模数法、大气降水入渗法、和水均衡法对河西走廊不同区段的地下水天然资源量进行了最新的计算评价。经计算 1 999年河西走廊地下水资源总量为 5 5 8395 .5 5万 m3 /a,其中祁连山 -阿尔金山2 3840 0万 m3 /a,走廊区 2 4 670 2 .74万 m3 /a(已扣除重复量 ) ,北山 -阿拉善中低山区 (包括腾格里、巴丹吉林沙漠 ) 732 92 .81万 m3 /a。     

江苏口岸进口原木及其检疫状况

1 原木进口概况 中国是世界上木材及木制品的生产和消费大国,但同时人均森林占有量很少.1998年国家实施天然林保护工程,使国内木材市场出现较大的供应缺口.从1999年起,国家为了鼓励木材进口,对原木和锯材实行"零"关税政策,同时生产建设的扩大和人民生活水平的提高进一步刺激着木材消费,我国进口的木材数量迅速上升.1997年,进口原木为447.1万m3,1998年为482万m3,1999年为1013.6万m3,2000年为1361.17万m3,2001年为1686.31万m3,2002年为2433.31万m3,2003年1～10月份为2153.2万m3(其中俄罗斯原木为1216.3万m3,占原木进口总量的56.5%),估计全年进口量为2500万m3左右,木材进口额仅次于美国,居世界第2位.     

泾惠渠灌区渠首地表水资源可利用量长期变化及其潜力研究

以泾惠渠灌区渠首——泾河张家山站长系列水文数据为研究对象,利用滑动平均、Tenant、回归分析及概率统计等方法分析了泾河来水形势、河道内生态环境需水量以及汛期不可利用水量,深入研究了泾惠渠灌区渠首水资源可利用量、灌区可引水量及引水潜力等问题。研究结果表明:泾河流域张家山站实测年径流量呈现出明显递减趋势,多年平均实测径流量从20世纪60年代的17.15亿m3下降到近十年来的9.95亿m3,实测径流距平最小达到-29.6%;河道内全年水资源可利用率基本维持在50%～60%左右;随着河道水资源利用的沙限的提高,灌区渠首可引水量及可引水量潜力均相应有所增加。按照目前泾河来水水源形势,灌区仍有1.66～2.10亿m3左右引水潜力可以挖掘。     

温室集雨与集雨水高效利用研究

在半干旱偏旱区设置了清除土表杂草、红沙覆盖、废膜覆盖和日光温室棚面4种不同的集流面处理,结合日光温室秋冬茬黄瓜、番茄不同灌水量试验,通过水的转化效率探讨不同集流面的使用价值和提高水转化效益的适宜灌水量.结果表明:温室棚面的年产流率最高为85.4%,其次为废膜集流面45.4%,清除土表杂草集流面的年产流率仅有8.2%.从单方水集流费用看,清除土表杂草>红沙集流面>废膜集流面>日光温室棚面,平均集流费用为2.18元/m3,单座温室棚面(450 m2)集流面加上温室间隔区废膜集雨(600 m2),集雨水总量可达到197 m3,能够满足温室一茬黄瓜和一茬番茄的需水量.     

国内外集雨农业研究进展与展望

从集雨农业科学研究的历史、雨水收集蓄存技术、集雨系统的分类、集雨模型和收集雨水的高效利用等方面详述了近一个世纪以来国内外的研究进展情况,指出了目前所存在的问题有:(1)对区域可收集雨水资源潜力的评估与计算研究不够;(2)多注重雨水汇集、雨水蓄存、雨水利用等各单项技术的研究,而没有把它们当作一个整体来进行研究,对这些技术的集成研究不够;(3)重视了雨水集流量的研究,而忽略了雨水集流度的研究;(4)未将生态需水纳入集雨模型。对未来集雨农业研究进行了展望。     

吴起县2015年水资源承载力评价

通过对吴起县生态和社会经济的全面调查,基于水量平衡理论,预测了吴起县2015年各行业的用水量,并运用水资源平衡指数对该县未来的水资源承载力进行了评价.结果表明:以目前的产业结构及发展趋势,到2015年时,吴起县农业用水量为0.295 4×108 m3,畜牧用水量为0.001 2×108 m3,林草地用水量为1.106 3×108 m3,工业用水量为0.073 8×108 m3,生活用水量为0.019 6×108 m3,总需水量为1.496 3×108 m3,占实际可利用水资源总量(1.901 4×108 m3)的78.7%,年内基本能满足水资源消耗的要求;以维持植被年内生长,避免土壤干层为目标的林地最小生态需水量为2.861 2×108 m3,水资源平衡指数为-1.5,水资源今后将难以承载生态和经济的发展规模.林业、农业及工业生产用水占用水总量的98.62%,说明在目前广泛进行黄土高原地区植被恢复,同时大力促进西北地区经济发展的情况下,县域范围今后水资源亏缺的主要压力来自于生态和经济建设耗水.因此,这一地区的水资源承载力研究,应以解决水资源在修复生态和促进经济发展之间相互挤占的矛盾为目的,合理配置,实现生态与经济综合效益最大化.     

内蒙古黄土高原区降水规律与集雨利用潜力分析

在黄土高原干旱少雨,地下水埋深较深的地区,通过建立水窖集雨供人畜饮用和作物补充灌溉具有重要意义。本研究利用沙圪堵镇的准格尔旗气象站1959—2000年气象资料,进行降水规律分析。结果表明,位于内蒙古黄土高原区的准格尔旗年均降水量为392.1mm,最大年降水量为635.5mm,最小降水量仅为142.5mm。年降水量在500mm以上的保证率为19%,接近五年一遇,年降水量400mm以上的保证率为44%,可基本上满足短季耐旱作物的生长之需;降水量在300mm之下的频率为21%,不能满足作物生长对水分的需求。有1/3的年份年降水量300—400mm之间,作物生长所需水分亏缺的部分,需要适当补灌。由于4—5月作物播种和苗期降水量少,存在生长障碍,如能在前一年集雨次年春天补充灌溉将有利于全苗和增产。对于10mm以上的降水,保证率80%以上的降水量仅为135mm,保证率60%的降水量为200mm。中雨雨量为达到300mm的保证率只有30%。对于大雨过程,总降水量200mm只有15%的可能性,100mm以上的保证率为60%。如果降水10mm以上才能集到雨水,100m2的集雨面,只有60%的年份产水量大于20方。不同集雨面的集流效益不同,在建立集雨水窖时,要根据水窖体积和集雨面材料的集流效率,合理确定集雨面,保证80%以上的年份达到满意的集雨效果。另外,根据降水规律可利用自然地面进行田间集雨,利用土壤库容保存降水供作物生产之用。     

Response of soil water dynamics to precipitation years under different vegetation types on the northern Loess Plateau,China

Implementation of the Grain-for-Green project has led to rapid land cover changes and resulted in a significantly increased vegetation cover on the Loess Plateau of China during the past few decades. The main objective of this study was to examine the responses of soil water dynamics under four typical vegetation types against precipitation years. Soil water contents(SWCs) were measured in 0–4.0 m profiles on a hillslope under the four vegetation types of shrub, pasture, natural fallow and crop in a re-vegetated catchment area from April to October in normal(2010), dry(2011), wet(2014) and extremely wet(2013) years. The results indicated that precipitation and vegetation types jointly controlled the soil water temporal dynamics and profile characteristics in the study region. SWCs in 0–4.0 m profiles of the four vegetation types were ranked from high to low as cropfallowpastureshrub and this pattern displayed a temporal stability over the four years. In the extremely wet year, SWC changes occurred in the 0–2.0 m layer under shrub and pasture while the changes further extended to the depth of 4.0-m deep layers under fallow and crop. In the other three years, SWCs changes mainly occurred in the 0–1.0 m layer and kept relatively stable in the layers deeper than 1.0 m for all the four vegetation types. The interannual variation in soil depth of SWCs was about 0–2.0 m for shrub and pasture, about 0–3.4 m for fallow and about 0–4.0 m for crop, respectively. The dried soil layers formed at the depths of 1.0, 0.6, 1.6 and 0.7 m under shrub, and 1.0, 1.0, 2.0 and 0.9 m under pasture, respectively in 2010, 2011, 2013 and 2014. The infiltrated rainwater mostly stayed in the 0–1.0 m layer and hardly supplied to soil depth 1.0 m in normal, dry and wet years. Even in the extremely wet year of 2013, rainwater recharge depth did not exceed 2.0 m under shrub and pasture. This implied that soil desiccation was difficult to remove in normal, dry and wet years, and soil desiccation could be removed in 1.0–2.0 m soil layers even in the extremely wet year under shrub and pasture. The results indicated that the natural fallow was the best vegetation type for achieving sustainable utilization of soil water and preventing soil desiccation.     

Potential of rooftop rainwater harvesting to meet outdoor water demand in arid regions

The feasibility of rooftop rainwater harvesting(RRWH) as an alternative source of water to meet the outdoor water demand in nine states of the U.S. was evaluated using a system dynamics model developed in Systems Thinking, Experimental Learning Laboratory with Animation. The state of Arizona was selected to evaluate the effects of the selected model parameters on the efficacy of RRWH since among the nine states the arid region of Arizona showed the least potential of meeting the outdoor water demand with rain harvested water. The analyses were conducted on a monthly basis across a 10-year projected period from 2015 to 2024. The results showed that RRWH as a potential source of water was highly sensitive to certain model parameters such as the outdoor water demand, the use of desert landscaping, and the percentage of existing houses with RRWH. A significant difference(as high as 37.5%) in rainwater potential was observed between the projected wet and dry climate conditions in Arizona. The analysis of the dynamics of the storage tanks suggested that a 1.0–2.0 m~3 rainwater barrel, on an average, can store approximately 80% of the monthly rainwater generated from the rooftops in Arizona, even across the high seasonal variation. This interactive model can be used as a quick estimator of the amount of water that could be generated, stored, and utilized through RRWH systems in the U.S. under different climate conditions. The findings of such comprehensive analyses may help regional policymakers, especially in arid regions, to develop a sustainable water management infrastructure.     

甘肃旱地农业发展与研究前沿

甘肃省72%的耕地属于旱地雨养农业,发展旱地农业对甘肃脱贫攻坚和高质量发展具有重要意义。20世纪90年代以来,甘肃旱地农业以“雨水富集、提升利用效率”为核心的集水农业发展思路得到快速传播,发展了丰富多样的旱地农业高效用水方法和技术,并在21世纪展现出明显成效。2000—2021年间,全省粮食生产总量从713万t增加到1 231万t,人均粮食产量从278 kg增加到491 kg,超过全国人均水平。2021年省政府提出优势特色产业三年倍增行动,快速推进多产业协同发展,为旱地农业高质量发展树立了典型案例。在总结过去20年甘肃旱地农业主要发展经验和成就的基础上,提出了未来需要重点研究的前沿科学问题。     

水资源联合调度模型在额济纳绿洲生态环境建设中的应用

对日趋缺水的额济纳绿洲,进行河水与地下水进行联合运用的目的是:减少水资源浪费,恢复生态水位,保护绿洲。按照国家水利部(1997)496号文件:《现状工程条件下黑河干流水量分配方案》(简称“97甘蒙分水方案),不同保证率下分配给内蒙古的水量。根据狼心山水文断面入境水量丰枯变化的分析结果,建立水资源联合调度模型,对四种不同来水方案进行计算。结果表明,执行“甘蒙分水”,采用内蒙长衬砌渠道输水,当保证率P=50%时,入境狼心山水量为7.527×108m3,到2020年地下水位埋深回升到2.35m,相应绿洲面积将扩大到5005.01km2,绿洲植被总盖度可达到58%。基本满足天然非灌溉林草的需水,逐步回补到生态要求的限定水位,使绿洲逐步得到恢复。     

乌拉盖河及其主要支流的水资源评价与合理利用的探讨

乌拉盖河是内蒙古高原最大的一条内流河,发源于大兴安岭山地,向西流经乌珠穆沁草原中部。水资源充沛而稳定。流域内多年平均径流量为１．１３亿立方米,Ｐ＝５０％保证率年径流量为０．８８亿立方米。根据本流域的中长期发展预测,到２０００年及２０２０年,人口、养畜、农田与草地建设、工业等均有大幅度增长,工农牧业产值将由２．８亿元达到２０００年的５．４亿元及２０２０年的１９．５亿元。按照合理的用水定额和水资源供需平衡分析,预计到２０００年,总需水量将达到０．６８亿立方米;到２０２０年,总需水量１．２亿立方米。因此,本流域的发展中,必须多方开发各项水资源,合理用水,节约用水,科学管理水资源。使乌拉盖河成为草原区可持续发展的资源与环境保障。     

Transmission of Phytophthora ramorum in Mixed-Evergreen Forest in California

ABSTRACT During 2001 to 2003, the transmission biology of Phytophthora ramorum, the causal agent of sudden oak death, was studied in mixedevergreen forest, a common forest type in northern, coastal California. Investigation of the sources of spore production focused on coast live oak (Quercus agrifolia) and bay laurel (Umbellularia californica), dominant hosts that comprised 39.7 and 46.2% of the individuals at the study site, respectively. All tests for inoculum production from the surface of infected coast live oak bark or exudates from cankers were negative. In contrast, sporangia and chlamydospores were produced on the surface of infected bay laurel leaves. Mean number of zoospores produced from infected bay laurel leaves under natural field conditions during rainstorms was 1,173.0 +/- SE 301.48, and ranged as high as 5,200 spores/leaf. P. ramorum was recovered from rainwater, soil, litter, and streamwater during the mid- to late rainy season in all 3 years of the study. P. ramorum was not recovered from sporadic summer rains or soil and litter during the hot, dry summer months. Concentrations of inoculum in rainwater varied significantly from year to year and increased as the rainy season progressed for the two complete seasons that were studied. Potential dispersal distances were investigated for rainwater, soil, and streamwater. In rainwater, inoculum moved 5 and 10 m from the inoculum source. For soil, transmission of inoculum was demonstrated from infested soil to bay laurel green leaf litter, and from bay laurel green leaf litter to aerial leaves of bay laurel seedlings. One-third to one-half of the hikers tested at the study site during the rainy season also were carrying infested soil on their shoes. In streamwater, P. ramorum was recovered from an unforested site in pasture 1 km downstream of forest with inoculum sources. In total, these studies provide details on the production and spread of P. ramorum inoculum in mixed-evergreen forest to aid forecasting and managing disease transmission of this environmentally destructive pathogen.     

石嘴山市水资源供需形势及其保障对策

石嘴山市供水以引扬黄河水为主,地下水为辅,在不开辟新的水源的条件下,未来年供水总量很难超过12亿m3。石嘴山市若保持现有水资源利用模式,按照"十一五"规划实现工农业生产、工业新上项目、城市化和生态环境保护等目标测算,到2010年年需水量将达到14亿m3以上;即使将农业用水保持在2005年的水平,到2010年年需水量也达到13亿m3以上,水资源缺口将长期存在。需要开源节流,以提高水资源利用效率为突破口,建立节水型工农业体系和全面节水型社会,摆脱水资源对经济发展的硬约束。