阿拉善查汗套海滩生态建设区最佳水文地质环境评价研究   总被引：1，自引：0，他引：1  

宝成  贾克力  范军  皇当俊  刘勇 《内蒙古农业大学学报(自然科学版)》2001,22(4):12-16

干旱沙漠区环境治理，水文地质环境是制约其它因素的关键。地下水位过高引起土壤盐渍化，地下水位过低则引起沙漠化。而正确确定地下水临界深度将成为查汗套海滩生态环境建设的瓶颈。本文提出地下水资源的允许开采量作为解决生态环境建设的重要途径之一，具有很好的资源效益和环境效益。  相似文献   

苗期不同滴灌方式对东北春玉米产量和水分利用效率的影响     

徐杰  李从锋  孟庆锋  葛均筑  王璞  赵明 《作物学报》2015,41(8):1279-1286

春旱是东北玉米产量增长的主要障碍因素之一,滴灌可有效缓解其对玉米生产的不利影响,不同滴灌方式的效果具有差异性。本文以常规雨养玉米为对照(CK),研究了传统滴灌(采用内嵌迷宫式滴灌管)和新型滴灌(采用自流插入式滴灌管)2种方式与不同埋管深度(0 cm、5 cm和10 cm)对玉米生长发育、产量和水分利用效率的影响。与对照相比,滴灌显著增产,增幅达9.5%~20.1%。传统滴灌不同埋管深度处理间产量差异不显著,而新型滴灌埋深5 cm产量显著高于地表滴灌,增幅为4.4%。同一埋深不同滴灌方式之间,新型滴灌埋深5 cm比传统滴灌增产8.8%,其他埋深差异不显著。与对照相比,滴灌处理出苗率提高11.3%,收获期穗数增加13.3%。新型滴灌埋深5 cm产量高于其他处理的原因是生殖生长期叶面积指数下降慢,显著提高收获期干物质重。与对照相比,滴灌处理水分利用效率提高8.1%~10.9%,其中新型滴灌埋深5 cm处理水分利用效率最高。因此,埋深5 cm新型滴灌是有效提高玉米产量和水分利用效率的灌溉方式。  相似文献   

土壤养分空间变异及合理取样数研究   总被引：46，自引：3，他引：46  

薛正平  杨星卫  段项锁  陆贤 《农业工程学报》2002,18(4):6-9

土壤养分存在明显的空间差异，田间土壤养分合理取样数取决于养分要素自身空间变异程度和人们对数据精度的要求。若空间变异大、精度要求高则需要较多采样数，反之需较少样点数。计算结果表明，极大多数养分要素的合理取样数较实际取样数有较大幅度减少，意味着可大幅降低采样及分析成本。据统计学空间自相关和半方差函数方法研究结果，养分要素存在一定的空间自相关性，但不同方向上的自相关性有明显差异，独立间距也因养分要素而异。研究结果可为精准农业土壤养分样点密度设定、养分要素等值线绘制及精准施肥提供支持。  相似文献   

地下滴灌土壤水运动和溶质运移数学模型的应用   总被引：11，自引：7，他引：11  

许迪  程先军 《农业工程学报》2002,18(1):27-30

利用建立的地埋点源土壤水运动和溶质运移数学模型描述地下滴灌条件下土壤水、肥运动的分布规律,将土壤质地结构、滴头出流量、滴头埋深和单次灌水历时等因素对土壤水分布的影响进行模拟分析。结果表明,在确定的土壤质地条件下,滴头出流量和埋深是影响地下滴灌系统性能的两个最重要的灌水设计参数,应尽量采用增加滴头数量而不是选用大流量滴头的方法来满足作物的需水要求。此外,合理的灌溉施肥时机应依据当地的土壤质地条件予以确定  相似文献   

浅谈长武王东试区“八五”土地利用规划   总被引：1，自引：1，他引：1       下载免费PDF全文

宋桂琴  巨仁  李领涛  赵爱秋 《水土保持通报》1993,(5):9-12

该文依据景观生态学原理和土地经济学特性(土地肥力、报酬递增性、土地经济供给的有限性)等理论及长武王东试区土地资源背景,论述了王东“八五”期间土地利用规划的要点:1.保持耕地面积的相对稳定;2.适度发展果园;3.加强现有林的抚育,增造灌木林;4.维持一定的牧草地面积,提高产草量;5.控制塬面村庄扩展。  相似文献   

渠井用水比对灌区降水响应及其环境效应分析     

李平  齐学斌  Magzum Nuroll  黄仲冬  梁志杰  乔冬梅 《农业工程学报》2015,31(11):123-128

渠井结合灌区适宜渠井用水比例关系灌区地下水环境和区域农业可持续发展。该文以人民胜利渠灌区为例,集合了灌区1954-2014年农业用水量及降水量、研究区域2008-2014年渠井用水比、地下水埋深、地下水水化学特征数据,分析了降雨量、地下水动态特征与渠井用水比例的相关性,以期探明渠井结合灌区渠井用水比对降雨的响应及其对土壤和地下水环境的影响。结果表明,典型渠井结合灌区渠井用水比与年降水量呈线性正相关;渠系上游地下水水位变化较下游更为剧烈,在用水水平、用水方式一致条件下,渠井用水比例越大,地下水埋深超过11 m区域增幅越小,较大的渠井用水比例对于上游地下水位下降减缓效果明显;平水期、枯水期,由于渠井用水比例不合理,地下水无序开采且超采严重,区域地下水碱化趋势明显;受气候变化影响,近5 a渠灌水量仅为多年均值的75.52%,未来区域降水量具有减小趋势,这势必进一步加剧农业水资源紧缺的形式。为了满足农业的正常生产,增加灌区地下水开采成为唯一解决途径,这势必加剧地下水的碱化趋势及地下水超采区的扩大。因此,确定灌区适宜的渠井用水比例对于灌区水资源的科学利用与农业的可持续发展具有重要意义。  相似文献   

泥石流与主河交汇的试验研究   总被引：3，自引：1，他引：3  

郭志学  方铎余斌 《水土保持学报》2003,17(5):175-177

泥石流入汇主河属于复杂的非牛顿流体与牛顿流体汇流问题,由于其机理的复杂性,一直缺少这方面的研究。本文在试验的基础上,分析了泥石流入汇主河后,汇口附近各水力参数的变化规律。探讨了泥石流入汇后下游水位相对壅高与流量比以及交汇角的关系,得出相对壅水高度随流量比及交汇角的增大而增大的结论。分析了交汇口附近淤积量及淤积率与流量及流量比的关系。30°,60°和120°交汇角情况下,淤积量总体趋势是随支流流量及流量比的增大而增大,淤积率随总流量增大而减小,在主支流量相当时出现最大值;90°交汇时,淤积量随支流流量及流量比的增大而减小,淤积率随总流量增大而增大,在主支流量相当时出现最小值。  相似文献   

Methane emissions from different vegetation zones in a Qinghai-Tibetan Plateau wetland   总被引：1，自引：0，他引：1  

Mitsuru Hirota  Yanhong Tang  Shigeki Hirata  Wenhong Mo  Shigeru Mariko 《Soil biology & biochemistry》2004,36(5):737-748

We measured methane (CH₄) emissions in the Luanhaizi wetland, a typical alpine wetland on the Qinghai-Tibetan Plateau, China, during the plant growth season (early July to mid-September) in 2002. Our aim was to quantify the spatial and temporal variation of CH₄ flux and to elucidate key factors in this variation. Static chamber measurements of CH₄ flux were made in four vegetation zones along a gradient of water depth. There were three emergent-plant zones (Hippuris-dominated; Scirpus-dominated; and Carex-dominated) and one submerged-plant zone (Potamogeton-dominated). The smallest CH₄ flux (seasonal mean=33.1 mg CH₄ m⁻² d⁻¹) was observed in the Potamogeton-dominated zone, which occupied about 74% of the total area of the wetland. The greatest CH₄ flux (seasonal mean=214 mg CH₄ m⁻² d⁻¹) was observed in the Hippuris-dominated zone, in the second-deepest water area. CH₄ flux from three zones (excluding the Carex-dominated zone) showed a marked diurnal change and decreased dramatically under dark conditions. Light intensity had a major influence on the temporal variation in CH₄ flux, at least in three of the zones. Methane fluxes from all zones increased during the growing season with increasing aboveground biomass. CH₄ flux from the Scirpus-dominated zone was significantly lower than in the other emergent-plant zones despite the large biomass, because the root and rhizome intake ports for CH₄ transport in the dominant species were distributed in shallower and more oxidative soil than occupied in the other zones. Spatial and temporal variation in CH₄ flux from the alpine wetland was determined by the vegetation zone. Among the dominant species in each zone, there were variations in the density and biomass of shoots, gas-transport system, and root-rhizome architecture. The CH₄ flux from a typical alpine wetland on the Qinghai-Tibetan Plateau was as high as those of other boreal and alpine wetlands.  相似文献   

Development and practical test of a weighable groundwater lysimeter for floodplain sites     

Doerthe Bethge‐Steffens  Ralph Meissner  Holger Rupp 《植物养料与土壤学杂志》2004,167(4):516-524

Presently, the soil water balance of flood‐influenced soils in fluvial plains is insufficiently described. The new development of a weighable groundwater lysimeter is the basis for recording the water‐balance components precipitation, evapotranspiration, groundwater recharge, capillary rise, and interaction with the water course. Soil‐hydrologic measuring setups at two floodplain sites of the Elbe river serve for direct comparability of lysimeter measurements with data obtained on site. A groundwater control was designed for lysimeters that automatically adjusts the current groundwater level at the floodplain measuring setups and quantifies inflow into or outflow from the lysimeter. It turned out that the lysimeter developed is capable of identifying the individual water‐balance quantities at high accuracy. Contrary to previous assumptions, it was possible to prove groundwater recharge for the floodplain sites.  相似文献   

亚热带湿润地区城市公园重建强度对其土壤酸化和土壤中重金属的影响     

HOU En-Qing  XIANG Hui-Min  LI Jian-Li  LI Jiong  WEN Da-Zhi 《土壤圈》2015,25(1):82-92

Soil quality is a major concern in the management of urban parks. In this study, the soils at 0–3, 3–13, and 13–23 cm depths were sampled from six urban parks, differing in reconstruction intensity(mainly changes made during conversion of natural forests into parklands), in the Pearl River Delta, China to determine how reconstruction intensity influenced the extent of acidification and heavy metal levels in the soils of urban parks in a humid subtropical environment. High reconstruction intensity(HRI) was practiced in three parks and low reconstruction intensity(LRI) in three other parks. The LRI soils were strongly to extremely acidic(with low exchangeable Ca, Mg, and K concentrations) while the HRI soils were much less acidic. Both total and extractable concentrations of soil heavy metals were related to the specific management practices and age of the park, but did not differ significantly between LRI and HRI parks or among soil depths. Soil p H was significantly related to soil exchangeable cation concentrations and base saturation but was weakly related or unrelated to soil heavy metal levels. Our results suggest that high intensity but not low intensity reconstruction significantly reduces the extent of soil acidification in the urban parks in a humid subtropical environment.  相似文献