中粉质壤土泥浆泵法修筑淤地坝人工排水管网布设优选研究     

颜婷燕  张武俊  许怀东  朱首军 《西北林学院学报》2014,29(5):53-58

以延安市志丹县前拐沟淤地坝筑坝现场修筑的人工试验小区为研究对象,使用土水比为1.0和1.5的泥浆,进行3种管道布设方式（横向管道、竖向管道、横竖向结合管道）、3种灌浆高度（30、60、90 cm）下的排水管网优选试验。结果表明,横竖结合管道的排水效果最好,竖向管道次之,且二者差距不大,横向管道最差,实际筑坝中宜优先选用竖向排水管道;在布设竖向管道和布设横竖结合管道2种情况下,管道排水均集中在试验最初的12 h内,且同种布设方式管道排水效果受灌浆高度的影响不大,可适当缩短1次灌浆后的静置时间和适当增大灌浆高度以缩短筑坝工期。  相似文献   

Effect of Microorganisms on Some Engineering Properties of Silt     

XU Zhao yang  ZHANG Li  ZHOU Jian 《保鲜与加工》2009,(2):80-84

The microbiology was introduced in foundation treatment. Several Carbonate mineralization microorganisms and polysaccharides viscose microorganisms were screened and the microorganisms No.ATCC 6453,3,polysaccharides viscose microorganisms 5 and 6 were used in silt modification. The engineering properties of silt before and after modification were compared by unconfined compressive strength test and indoor seepage test. The microstructures of silt incorporating different microorganisms were analysed by mean of scanning electron microscope and energy dispersive X ray (EDX) analysis. And the modification mechanism of silt has been revealed. These studies indicate that certain engineering properties of silt can be improved by incorporating microorganisms.  相似文献   

基质改良剂对滨海滩涂高钠盐粉土改良效果的试验研究     

夏清  郭相平  陈旭光 《灌溉排水学报》2012,31(6):107-110

采用桶栽试验,研究了不同施用量下,基质改良剂对江苏滨海高钠盐粉土理化性质及西红柿产量的影响。结果表明,与不使用改良剂处理(CK)相比,施用基质改良剂处理表层土壤干密度降低1.06%～9.39%,孔隙率增加1.10%～9.69%;土壤含盐量减少21.16%～25.64%;基质改良剂处理的土壤,其碱化度(ESP)、pH、土壤交换性Na+、土壤Na+和Cl-均较CK下降,且与基质施用量负相关;各处理土壤Ca2+和SO24-质量摩尔浓度分别较CK增加了150.00%～271.4%和3.8%～88.9%,且与施用量正相关。施用改良剂后,西红柿增产6.04%～30.95%,基质改良剂对江苏省滨海滩涂高钠盐粉砂土具有较好改良效果,其最佳施用量约为8.4～9.0t/hm2。  相似文献   

淤泥对弧形钢闸门启门力影响的计算方法   总被引：2，自引：0，他引：2  

徐国宾  高仕赵 《排灌机械》2012,30(3):304-308

为了估算泥沙淤积对弧形钢闸门启门力的影响,提出了一个计算公式.该公式将门前淤泥考虑为由粗细颗粒组成的宾汉体,同时考虑了泥沙附着力的力矩、梁格中附带泥沙重力的力矩、转动铰摩阻力的力矩、止水摩擦力矩、下吸力的力矩以及闸门重力和外加重力的力矩对弧形钢闸门启门力的影响.并利用该公式计算的弧形钢闸门启门力和西洱河二、四级电站泄洪闸门的实测资料进行对比得出：在门前泥沙淤积厚度较低的情况下,弧形钢闸门的启门力矩主要由闸门重力和外加重力决定,但是由泥沙引起的启门力矩变化也是不容忽视的,是导致闸门开启困难的影响因素之一,因此在设计过程中应充分考虑泥沙淤积对闸门启门力的影响,制定出合理的操作和维护方案,以防止闸门启闭困难情况的出现;该公式在计算门前有泥沙淤积情况下的启门力时,其计算精度能够满足工程实际需要.  相似文献   

Effect of humic acid on growth and crop nutrient status of wheat on two different soils     

R. U. Khan  M. Z. Khan  A. Khan  S. Saba  F. Hussain  I. U. Jan 《Journal of plant nutrition》2018,41(4):453-460

The effect of plant-derived humic acid (PDHA) and coal-derived humic acid (CDHA) on wheat growth was tested on two alkaline calcareous soils in pots. Humic acid derived from plant and coal materials was applied at the rate 0 (control), 50 and 100 kg/ha to wheat in pots carrying two soils viz. clayey loam soil and sandy loam soil separately. Data was collected on plant growth parameters such as spike weight, grain and straw weight, and plant nutrients (macronutrients and micronutrients). Results showed that spike weight increased by 19%, 15%, and 26%, and 11% with application of PDHA at the rate of 50 and 100 mg/kg in clayey loam and sandy loam soil, respectively. Grain yield show an increase of 21% and 11% over control with application of PDHA and CDHA at the rate of 50 mg/kg on both soils, respectively, and 10% and 22% with application of PDHA and CDHA at the rate of 100 mg/kg on both soils.  相似文献   

微生物砂浆防护粉土坡面的强度与抗侵蚀性影响因素分析   总被引：2，自引：1，他引：1  

邵光辉  冯建挺  赵志峰  刘鹏  李泽  周宁娜 《农业工程学报》2017,33(11):133-139

微生物砂浆表面防护处理是处理粉土边坡扬尘与水流侵蚀问题的新技术。采用微生物砂浆层对粉土表面进行防护处理试验,通过微型贯入试验、水稳定性试验以及模拟降雨冲刷试验,分析了微生物砂浆防护层厚度、CaCl_2和尿素混合胶结溶液浓度、喷洒处理遍数等参数变化对微生物砂浆表面防护层的强度、水稳定性和土壤剥蚀率等性能的影响规律。结果表明,微型贯入仪可用于微生物砂浆表面防护层的强度测定,防护层的强度、水稳定性随胶结溶液浓度和喷洒处理遍数的增长而提高,最小有效厚度为5 mm。采用浓度为0.50 mol/L胶结溶液喷洒4遍,厚5 mm的防护层能够达到贯入阻力310 kPa,防护强度比77.5,崩解率2.3%,浸水强度损失率5.4%,具备较高的强度和较好的抗崩解性与强度水稳定性。粉土边坡在微生物砂浆防护前后,土壤剥蚀率能够从大于29.6降至6.8 g/(m~2·s)以下。该研究表明,微生物砂浆层用于粉土表面防护具有较好的抗冲刷性;微生物诱导结晶的方解石形成包裹砂颗粒的胶结微结构,能够使表面防护砂浆层具备良好的抗水流侵蚀性。  相似文献   

基于混沌神经网络的流域坝系稳定性分析     

刘卉芳  曹文洪  王向东  孙中峰 《水土保持通报》2011,31(3):131-135

坝系相对稳定原理是淤地坝规划的理论基础。依据影响坝系稳定性的7个主要因素：坝控面积、坝数、总库容、可淤库容、坝前水深、防洪能力、淤地面积,以Matlab 7.0为平台,采用混沌神经网络（COBP）模型对马家沟流域13个坝系进行了稳定性分析。结果表明,13个坝系中有7个坝系处于不稳定状态,采用坝系稳定系数来校核COBP模型的计算结果,得出的结论一致,因此,可以判定采用神经网络方法得出的结果基本可信。此外,分析了7个坝系不稳定的原因,采用增加坝高和增加淤地坝数量的方法使7个不稳定坝系均达到稳定状态。通过对马家沟13个小流域淤地坝重新规划,形成的13个坝系全部处于稳定状态,可见COBP方法在确定流域坝系稳定方面具有实用的价值。  相似文献   

淤地坝在流域水土保持措施中的贡献研究   总被引：1，自引：0，他引：1  

刘卉芳  曹文洪  秦伟  张晓明 《中国农村水利水电》2011,(1):55-58

淤地坝既能拦截泥沙、保持水土、又能淤地造田、增产粮食,在黄土高原地区已经有上百年的历史。研究淤地坝在流域水土保持措施中的贡献,已成为泥沙研究和水土保持研究的一项重要课题。本次研究以黄土高原典型流域马家沟为例,分析淤地坝在水土保持措施中的的贡献,研究结果表明：1990~2007年年均减沙量最大的是淤地坝,其次是梯田,依次为林地和草地。坝地的减沙量贡献率在1990~2000年为41.51%,在2001~2007年平均达到了46.58%。  相似文献   

Gross nitrogen transformations and N_2O emission sources in sandy loam and silt loam soils     

LANG Man 《干旱区科学》2021,13(5):487-499

The soil type is a key factor influencing N(nitrogen) cycling in soil; however, gross N transformations and N_2O emission sources are still poorly understood. In this study, a laboratory ~(15)N tracing experiment was carried out at 60% WHC(water holding capacity) and 25℃ to evaluate the gross N transformation rates and N_2O emission pathways in sandy loam and silt loam soils in a semi-arid region of Heilongjiang Province, China. The results showed that the gross rates of N mineralization, immobilization, and nitrification were 3.60, 1.90, and 5.63 mg N/(kg·d) in silt loam soil, respectively, which were 3.62, 4.26, and 3.13 times those in sandy loam soil, respectively. The ratios of the gross nitrification rate to the ammonium immobilization rate(n/ia) in sandy loam soil and silt loam soil were all higher than 1.00, whereas the n/ia in sandy loam soil(4.36) was significantly higher than that in silt loam soil(3.08). This result indicated that the ability of sandy loam soil to release and conserve the available N was relatively poor in comparison with silt loam soil, and the relatively strong nitrification rate compared to the immobilization rate may lead to N loss through NO_3~– leaching. Under aerobic conditions, both nitrification and denitrification made contributions to N_2O emissions. Nitrification was the dominant pathway leading to N_2O production in soils and was responsible for 82.0% of the total emitted N_2O in sandy loam soil, which was significantly higher than that in silt loam soil(71.7%). However, the average contribution of denitrification to total N_2O production in sandy loam soil was 17.9%, which was significantly lower than that in silt loam soil(28.3%). These results are valuable for developing reasonable fertilization management and proposing effective greenhouse gas mitigation strategies in different soil types in semiarid regions.  相似文献   

Spatial variability of switchgrass (Panicum virgatum L.) yield as related to soil parameters in a small field     

Nicola Di Virgilio  Andrea Monti  Gianpietro Venturi 《Field Crops Research》2007

The harvested biomass of switchgrass (Panicum virgatum L.) is generally much lower than its potential; this may be due to several factors including not recovering all the biomass at harvest, weed competition, pests, disease and spatial variation of soil features. The objective of this research was to quantify the yield spatial variation of switchgrass and relate it to soil parameters, in a field of about 5 ha, in 2004 and 2005. Several thematic maps of soil parameters and biomass yield were produced using GIS and geostatistical methods. Soil parameters changed consistently within very short distances and biomass yield varied from 3 to more than 20 Mg ha⁻¹. This remarkable variation indicates that the potential for increasing switchgrass productivity is a real prospect. Furthermore, spatial variation of yield showed similar patterns in the 2 years (r = 0.38^**), and therefore a major influence of site characteristics on switchgrass yield can be assumed to occur. Significant correlations were found between biomass yield and soil N, P, moisture and pH as well as between soil parameters. Some soil parameters such as sand content showed patchy spatial distribution. Conversely, a reliable spatial dependence could not be identified for other parameters such as P. Further research is needed.  相似文献