晋西黄土区旱井沉沙池结构形式试验设计

针对旱井集雨系统中急需解决的沉沙减淤问题，考虑到研究区的具体条件，在分析沉沙池中泥沙运移规律的基础上，设计出6种简单、实用的沉沙池结构形式。通过人工降雨试验，得出在系列变雨强条件下，在以5°左右的裸露夯实黄土面(保持土面初始含水率8%～15%，干容重1.40～1.60 g/cm³)作为人工集流场时，均以第Ⅴ和第Ⅵ种沉沙池的沉沙效果较好，沉沙效率分别为89.38%和92.28%，比对照提高约20%，是一种合理的结构形式。为今后旱井沉沙池的应用研究，做了有益的探讨。     

旱井集雨系统中沉沙池结构优化研究

针对当前旱井集雨系统中急需解决的沉沙减淤问题,利用人工降雨试验,得出了在各种雨强条件下,均以设置双重过滤网的沉沙池的沉沙效果最好,是一种简单、实用的优化结构形式,为今后旱井沉沙池的应用研究作了有益的探讨.     

位山引黄灌区沉沙高地的水土流失治理

引黄灌区大量泥沙堆积在沉沙池和输水渠两侧,形成了大面积的沉沙高地,既占用了大量土地又造成了区内水土流失和土壤肥力下降,从而制约了灌区经济的发展。以黄河中下游最大的引黄灌区位山灌区为例,通过深入了解灌区实际情况和对灌区多年来沉沙高地治理经验的总结,介绍了沉沙高地综合治理的模式,并对灌区沉沙高地综合治理效益进行了分析和预测。     

新型异向流沉沙池泥沙沉降特性试验与机理分析

为了探明二级泥沙处理设施--新型异向流沉沙池的泥沙沉降特性及其沉沙机理,该研究开展了不同流量和不同含沙浓度的系列试验,并对泥沙运动过程进行了力学分析,建立并求解了新型异向流沉沙池双向倾斜薄板上泥沙运动的一阶非线性微分方程。研究结果表明,对于中值粒径为0.021 mm的细颗粒泥沙的含沙水流,长96 cm、宽10 cm、高110 cm的新型异向流沉沙池对流量为45～360 L/h的泥沙截除率为40%～88.53%,约为相同体积的底板倾斜和底板水平的条形沉沙池的1.2～2倍;单位时间沉降至集沙箱的泥沙量是底板倾斜条形沉沙池的1.3～2.3倍;不同时刻双向倾斜薄板上的泥沙运动速度和加速度均大于单向倾斜斜板,倾角为锐角时,角度越大,速度越大。工程设计时,若地形高差满足要求,双向倾斜薄板的倾角（<90°）越大越有利于提高沉降效率,若高差不满足,倾角应不小于泥沙休止角。研究结果可为新型异向流沉沙池结构优化及应用提供参考。     

径流小区结构设计新探

径流小区结构设计新探陈明权（四川省蒲江县水利电力局，６１１６３０）在水土保持径流泥沙测验中，传统的径流小区无论是测泥水总量还是测泥水产生过程，都是把径流小区与集水沉沙池分开，在小区的下方边缘修建坡降为１％的集水槽，然后用输水管将径流泥沙输送至集水沉沙...     

水土保持生态工程建设中水资源的合理配置与利用——关于集雨节灌建设中几个问题的探讨

论述了集雨节灌在实现农业现代化、农民脱贫致富、水资源可持续利用、减少黄河下游泥沙淤积、水土保持生态工程建设、水利建设等方面的作用 ;集雨节灌建设中应对地表水和地下水统筹考虑、合理配置 ;雨水集蓄工程建设必须同时考虑集水含沙量 ,提出了一种采用拦沙原理设计沉沙池的方法 ,与采用沉沙原理设计的沉沙池可以进行优化比较设计 ;针对集雨节灌工程年费用计算时缺乏有关设施、设备的折旧年限、年折旧率、年大修费率的现状 ,提出了有关设施、设备的折旧年限、年折旧率、年大修费率 ,供年费用计算时参考。     

水土保持生态工程建设中水资源的合理配置与利用 ——关于集雨节灌建设中几个问题的探讨

论述了集雨节灌在实现农业现代化、农民脱贫致富、水资源可持续利用、减少黄河下游泥沙淤积、水土保持生态工程建设、水利建设等方面的作用;集雨节灌建设中应对地表水和地下水统筹考虑、合理配置;雨水集蓄工程建设必须同时考虑集水含沙量,提出了一种采用拦沙原理设计沉沙池的方法,与采用沉沙原理设计的沉沙池可以进行优化比较设计;针对集雨节灌工程年费用计算时缺乏有关设施、设备的折旧年限、年折旧率、年大修费率的现状,提出了有关设施、设备的折旧年限、年折旧率、年大修费率,供年费用计算时参考.     

黄土高原窑窖集水工程技术探讨

在调查研究的基础上 ,指出了目前黄土高原窑窖集水工程建设中存在的主要问题 ,包括沿路水窖布设过多、集流场建设滞后以及目前窑窖施工、沉沙池设计中存在的关键技术问题等。在具体分析集流场集流潜力和用水量基础上 ,针对沿路水窖布局提出了科学密度指标体系。作者还对水窖工程技术存在问题提出了对策 ,并推荐迷宫式沉沙池以完善目前窑窖工程的技术环节。     

集沙仪结构参数对集沙效率的影响

通过分析近年来国内外集沙仪的研究成果,确定了影响集沙仪集沙效率的主要结构参数：集沙仪进沙口的高宽比、进沙通道长度、布袋材质等。根据集沙仪性能试验要求,对不同结构参数的集沙仪进行了风洞性能试验。试验结果表明：在6、9 、12、15、18 m/s 5个风速下,集沙仪对0.15～0.60 mm粒径土样的平均集沙效率高于混合土样和0.15 mm以下粒径土样的平均集沙效率,说明集沙仪更适合采集以跃移形式运动的土壤颗粒。结构因素对集沙效率影响的主次顺序为进沙口高宽比、进沙通道长度、布袋材质。进沙口高宽比是对集沙效率影响显著的结构因素。通过对试验结果的极差和方差分析,得出集沙仪最优组合的结构参数是高宽比为0.5、进沙通道长度为20 cm、白丝布,此时集沙仪的平均集沙效率为80.91%。     

“圆中环”沉沙排沙池浑水沉沙特性

"圆中环"沉沙排沙池是一种新型二级泥沙处理设施,以新疆呼图壁阿苇滩"圆中环"为原型,通过物理模型试验研究其浑水沉沙分布规律以及沉沙排沙效果。研究表明:"圆中环"的含沙量、沉沙范围和沉沙粒径在环向呈不均匀分布,135°~225°范围分布较大。但含沙量及沉沙粒径在径向与半径成反比,在距离圆心1/2半径处以内含沙量沿垂向与水深成反比,垂向分布不均匀,沉沙颗粒较粗,其余范围含沙量垂向分布较均匀,沉沙颗粒较细;在设计工况条件下,"圆中环"截沙率为90.9%,1 mm粒径范围截沙率为100%。试验证明:"圆中环"存在泥沙分选现象,水沙分离依靠重力沉降,溢流堰长是沉沙效率高的重要原因。"圆中环"沉沙粒径范围大,截沙率高,排沙耗水率较小,并能利用水力作用自动排出沉沙。研究结果可为"圆中环"优化结构形式及设计应用提供参考。     

Topographical surveying for improved assessment of sediment retention in check dams applied to a Mediterranean badlands restoration site (Central Spain)

Purpose

The effects of check dams used in restoration projects have been discussed in a number of papers in recent years. This paper studies the effectiveness of retaining sediments from check dams constructed in the badlands restoration site of Tórtoles, located in the Corneja River basin (Spain), using a new topographical method.

Materials and methods

In order to assess the sediment-retaining capacity of the check dams, we measured the volume of sediment trapped by 15 of the 123 check dams built in 1965. We carried out a detailed topographical survey using a Total Station, with an accuracy of ±1 cm, to measure cross sections of the sediment trapped by each check dam. The results were then compared with those of two simplified methods which consider the volume of retained sediment as a simple geometric figure.

Results and discussion

According to our results, 258 m³ of sediment has been retained by the check dams. These results show a significant discrepancy between the topographical method and the two other methods, whose values are consistently lower (14 to 20 %). According to our survey, the mean value for the volume of sediment retained by each check dam is 17.23 m³, versus 13.86 and 14.74 m³ when applying the other methods. Although there is a strong correlation between the volume of retained sediment computed by the topographical method and the other two methods (r ² from 0.96 to 0.94), the differences between them increase with the increasing size of the check dams. Therefore, total differences are expected to be more significant with larger check dams. The erosion rates, calculated on the basis of the retained sediment in the Tórtoles check dams, are 16–21 % lower when using the simpler methods. The bed slopes of the streams were reduced 12.44 % because of the presence of the check dams.

Conclusions

After having completed a more detailed topographical survey of the sediment trapped in the check dams, our results are more likely to estimate erosion rates and sediment yield correctly, thus leading to a better understanding of the effects of check dams on badlands restoration.     

干旱内陆河流域平原区生态环境需水分析——以新疆自治区台兰河流域为例

从干旱区台兰河流域存在的环境问题出发,在确定流域平原区生态环境需水类型的基础上,构建了台兰河流域平原区生态环境需水定量模型,估算了流域平原区生态环境的规模。计算结果表明,台兰河平原区最大生态环境需水量为4.146×108m3,最小生态环境需水量为2.372×108m3,最适生态环境需水量为2.983×108m3,分别占台兰河平原区水资源总量(8.121×108m3)的51.05%,29.21%和36.73%。在不考虑河流输沙需水量的情况下,台兰河河流生态环境需水量平均为1.440×108m3。在考虑输沙需水量的情况下,河流生态环境需水量平均为2.604×108m3。明确了在确定流域生态环境需水量时,必须考虑研究区环境状况和生态保护目标,从而在不同区域和用水部门间进行调配,并针对流域不同的生态系统状况和对应生态系统类型确定了面向生态的水资源合理配置方案。     

Simulation of in-situ bioremediation of phenol contaminated sandy aquifers I. Effect of sand sizes

Laboratory scale porous media biofilm reactors were used to evaluate the effect of biofilm thickness on media porosity and permeability. Media tested consisted of three different sizes of sand (0.4, 0.3, and 0.2 mm). A set of fifteen columns was used in this experiment, five columns for each size of sand. Columns were operated under constant piezometric head (2.5 m) conditions, resulting in a decreasing flow rate with biofilm development. During the experiment, variations in the piezometric head, substrate concentration, and growth in biomass as well as volatile solids were monitored in space and time. Phenol (15 mg/L) was used as a growth substrate. The reductions in hydraulic conductivity were found to be 97% for the coarse sand (0.4 mm), 96% for the medium size sand (0.3 mm), and 93.7% for the fine sand (0.2 mm). The respective removal of phenol in these columns was 96% for the coarser sand, 97.9% for the medium size sand, and 98.8% for the finer sand. Steady-state effluent phenol concentrations occurred simultaneously with uniform hydraulic conductivity reduction after 50 days of operation. The concentration of volatile solids near the column inlets and outlets, after 58 days of operation, ranged between 9.8 and 4.04 mg/g for the coarse sand, 11.2 and 6.2 mg/g for the medium size sand, and 11.8 and 6.2 mg/g of sand for the fine sand, respectively. The number of colonies near the column inlets and outlets was 2800 × 10¹⁰/mL and 1480 x 10¹⁰/mL for the coarse sand, and 2840 × 10¹⁰/mL and 1520 × 10¹⁰/mL for the medium sand, and 2890 × 10¹⁰/mL and 2120 × 10¹⁰/mL for the fine sand.     

甘肃省淤地坝水资源的利用潜力

[目的] 分析淤地坝拦泥蓄水及其水资源利用潜力,为淤地坝水资源利用及管理提供依据。[方法] 本文通过调查法对甘肃省多沙粗沙区淤地坝建设现状、拦沙数量及空间分布、水资源利用效益和利用潜力进行分析。[结果] 截至2019年底甘肃省共建成淤地坝1 600座,其中大、中、小型坝各为559,452,589座;坝控面积4 101 km²,总库容4.82×10⁸ m³,其中设计拦泥库容2.29×10⁸ m³。目前拦泥库容1.43×10⁸ m³,占设计拦泥库容的62.37%;拦泥库容中,大、中、小型坝各占80.86%,13.21%和5.93%;泾河流域、黄河干流、渭河流域、洮河流域各占71.46%,13.91%,12.72%,1.91%。由于流域产沙量减少,大型坝平均淤积17 a后（平均设计淤积年限15 a）剩余拦泥库容占设计拦泥库容的43.88%;中型坝平均淤积后（平均设计淤积年限10 a）剩余拦泥库容占设计拦泥库容的38.81%。全省淤地坝剩余拦泥库容8.62×10⁷ m³,可作为今后蓄水利用的潜在库容。目前,淤地坝蓄水主要用于应急抗旱、农业及果园高效节水灌溉、土地多种经营及经济综合开发、畜禽养殖、淤地坝田园综合开发利用等。庆阳、平凉、天水和定西市安定区今后可开发用于人饮备用水源地、提灌补灌工程水源地、水体养殖（鱼塘）的淤地坝数量共147座。[结论] 为满足当地乡村振兴与高质量发展对淤地坝的社会需求,对有蓄水用水需求的区域,应提高新建坝的设计标准,建设可长期蓄水的高标准淤地坝;对已建成的大中型淤地坝进行提质改造,保证淤地坝坝体、防洪及水资源利用的安全性,同时建立淤地坝风险管控预警机制,有效化解缺水地区淤地坝蓄水用水与防汛管理的矛盾。     

The Application of MnO2 in the Removal of Manganese from Acid Mine Water

The successive alkalinity-producing passive system (SAPPS) located in Gangneung, South Korea was designed to treat acid mine drainage. The performance of SAPPS has been monitored intensively for 3 years at the component level (influent, settling pond A, the successive alkalinity-producing system (SAPS), settling pond B, constructed wetland, and effluent). This study evaluated the ability of SAPPS to remove acidity and iron from influents at flow rates ranging from 17 to 160 m³/day. The concentration of soluble Fe_total was the highest, and the pH was the lowest at low flow rates (≤61 m³/day). When flow rates were over 80 m³/day, concentrations decreased and Fe_total was removed primarily at the SAPS stage. For flow rates of less than 61 m³/day, Fe_total was removed at the SAPS stage as well as in settling pond B and at the constructed wetland. Hydraulic retention times of 1 and 2 days were found to be appropriate and economical for use with the SAPS stage and for settling pond B and the constructed wetland, respectively The treatment of acid mine drainage by conventional SAPPSs is limited by the availability of alkaline materials. However, the new proposed system can address this weakness through the provisioning of a suitable alkalinity supply.     

Sediment Yield Deduction from Check–dams Deposition in the Weathered Sandstone Watershed on the North Loess Plateau,China

As the basic unit of erosion and sediment yield, it was critical to determine the amount of soil erosion and sediment yield in the small watersheds for sustaining a reasonable water resource and sediment regulation system. In this study, we determined the sediment yield from the dams‐controlled watershed on the North Loess Plateau. Three check dams in the watershed were investigated by drilling ten‐hole sedimentation cores. The corresponding flood couplets were dated according to thickness of deposition layers, distribution of sediment particle size and historical erosive rainfall events. On the basis of the check dams capacity curve, the soil bulk density and the thickness of couplets, the deposit mass of check dams, and then the sediment yield of watershed at different temporal and spatial scale were deducted. In total of the 33, 60 and 55 couplets were corresponded to individual flood events in the dam MH1# from 1976 to 1984, the dam MH2# from 1985 to 2007, and the dam MH4# from 1981 to 2009, respectively. The specific sediment yield for flood events was 1,188.5–11,527.9 Mg km⁻², 1,278.6–17,136.7 Mg km⁻², and 3,395.9–33,698.5 Mg km⁻², and the annual average sediment yield was 10,728.6 Mg (km² · a)⁻¹, 12,662.9 Mg (km² · a)⁻¹, and 16,753.3 Mg (km² · a)⁻¹ in dam MH1#, MH2# and MH4# controlled watershed, respectively. The sediment yields were inversely proportional to the dams – controlled areas. For the whole watershed, the annual average sediment yield was 14,011.1 Mg (km² · a)⁻¹ from 1976 to 2009. There were large amounts of sediments (42.3–50.5%) were intercepted gradually along the way from small watersheds to the river channel. And the minimum rainfall for sediment deposited in the dams was greater than 20 mm in this watershed. The results of this study suggested that the sediments retained behind check dams were helpful to quantifying the amount of erosion sediment yield and understanding the soil erosion evolution in the small and ungauged watersheds. Copyright © 2016 John Wiley & Sons, Ltd.     

太湖流域水生态系统服务及其空间差异

以太湖流域土地利用资料、水文水质资料和统计资料为基础,对流域尺度上水生态系统服务功能及其空间差异性进行了评价与分析。结果表明,太湖流域水生态系统的水供给功能为3.70×1010 m3/a,水产品功能为6 681.180t/a,水路旅客周转量为4.604×108人/(km.a),水路货运周转量为2.90×1011t/(km.a),蓄水总量为4.53×109 m3/a,调节水量为7.69×109 m3/a,固碳量为4.28×106 t/a,释放O2量为1.14×107 t/a,净化污水量为6.30×109 t/a,年输沙量为1.22×106 t/a,造陆面积为189.851hm2/a;水生态系统服务功能总价值为9.10×1010元/a,不同服务功能价值量排序为:旅游>航运>调蓄>水质净化>固碳释氧>水供给>水产品>输沙造陆;太湖流域单位面积水生态系统服务功能价值为19.22元/(m2.a),且存在较大空间差异,其顺序为:浦西区>武澄区>浙西区>杭嘉湖区>湖西区>阳澄区>太湖区。     

Arsenic Contamination in Soils Affected by a Pyrite-mine Spill (Aznalcóllar, SW Spain)

On 1998, a settling pond of a pyrite mine in Aznalcóllar (SW Spain) broke open, spilling some 3.6?×?10⁶ m³ of water and 0.9?×?10⁶ m³ of toxic tailings into the Agrio and Guadiamar river basin 40 km downstream, nearly to Doñana National Park. The soils throughout the basin were studied for arsenic pollution. Almost all the arsenic penetrated the soils in the solid phase (tailings) in variable amounts, mainly as a result of the different soil structure. The chemical oxidation of the tailings was the main cause of the pollution in these soils. A study of the relationships between the main soil characteristics and arsenic extracted with different reagents (water, CaCl₂, acetic acid, oxalic–oxalate and EDTA) indicates a direct relationship with the total arsenic concentration. The highest amount of arsenic was extracted by oxalic–oxalate (24%–36% of the total arsenic), indicating the binding with the iron oxides.     

淤地坝保碳、减排、增汇作用与其能力评估

淤地坝是黄土高原地区重要的沟道治理措施,也是陆地生态系统中重要的储碳场所。评估淤地坝的碳汇作用与能力,可为研究其他水土保持措施碳汇提供重要借鉴,也为我国碳达峰、碳中和目标提供科学依据。以黄土高原淤地坝为研究对象,系统探讨淤地坝的碳汇效应与机理,提出淤地坝碳汇能力估算方法。结果表明:淤地坝具有保土保碳、减蚀减排和增绿增汇作用。在过去50年中黄土高原淤地坝保碳能力为2.16×10⁷ t C,减排能力为4.33×10⁶~8.66×10⁶ t C,增汇能力为6.84×10⁵ t C。淤地坝产生积极的碳汇效益,对提升生态系统碳中和能力、降低碳达峰的峰值发挥重要作用。淤地坝与其他主要水土保持措施都具有保土、减蚀等多种水土保持效益,可充分发挥保碳、减排、增汇等多种碳汇作用。推行碳汇水土保持工作、实施水土保持增汇行动,既可全面巩固陆地生态系统碳汇作用,又能持续提升生态系统增汇能力,对碳达峰与碳中和作出水土保持贡献。     

半隐蔽式沙柳沙障的防风阻沙效益

对毛乌素沙地15,25和35cm的3个高度,1m×0.5m,1m×1m,1m×2m,2m×2m,2m×3m5种规格的半隐蔽格状沙柳沙障内近地表风沙流的活动过程进行了对比研究,分析了不同规格沙障的防风阻沙效益。结果表明,设置沙柳沙障后地表土壤中细粒物质含量明显增加;与裸沙丘相比,沙柳沙障内的相对输沙率明显减少。根据当地的自然条件和经济状况,认为毛乌素沙地适宜于当地铺设的沙柳沙障规格为2m×2m。