我国排灌机械行业战略管理的思考     

金立江 《排灌机械》2002,20(1):5-7

从经济全球化的要求出发，为迎接国际市场的挑战，结合我国排灌机械行业的现状，提出了行业战略管理的若干设想。  相似文献   

刚性暗管结构形式与排水性能关系的三维电模拟研究     

王少丽  张友义  瞿兴业 《灌溉排水学报》1995,(4)

作者选用电解液模型对农田排水暗管的五种结构处理进行了三维渗流测试，揭示了其渗流场的基本形态及势场变化规律，定性地描述了此五种暗管结构排水性能的优劣，同时采用能综合反映暗管排水性能的流量系数值，对不同结构在各种参数组合条件下的排水性能作了定量的分析对比，结合以往室内砂槽试验成果，提供了合理的暗管结构设计依据。此外，应用保角变换法求得了仅有纵缝和全管壁进水的两种结构的二维渗流量解析式，并通过对试验资料的统计分析和线性回归分析法推导出三维渗流量的近似计算式。  相似文献   

浅谈排灌标准在市场与生产中的作用     

王洋 《排灌机械》2004,22(5):46-48

为促进企业发展使之取得良好的经济效益，讨论了排灌机械行业贯彻与应用标准的情况，分析了标准的作用。自从我国加入世贸组织，国际贸易量日益增大，熟悉和掌握与之相关的标准，参与市场竞争更显得非常重要。指出了标准在市场与营销及生产中的制约作用和利害关系。  相似文献   

Use of saline–sodic waters through phytoremediation of calcareous saline–sodic soils     

M. Qadir  A. Ghafoor  G. Murtaza 《Agricultural Water Management》2001,50(3):197-210

Use of poor-quality groundwater has become inevitable for irrigation to compensate rapidly increasing water demands in many arid and semiarid regions. Salinity and sodicity are the principal soil and water quality concerns in such areas. Many saline–sodic and sodic soils have saline or saline–sodic subsurface drainage waters. Amelioration of these soils needs a source of calcium (Ca²⁺) that can replace the excess exchangeable sodium (Na⁺). Most of these soils, however, contain calcite (CaCO₃) of extremely low solubility. The native calcite does not supply adequate levels of Ca²⁺ for soil amelioration as do other chemical amendments. Phytoremediation may help ameliorate such soils through cultivation of certain crops tolerant to ambient soil salinity and sodicity. This amelioration strategy works through plant root action to help dissolve CaCO₃ to supply adequate Ca²⁺ without the application of an amendment. During a 3-year field experiment conducted under irrigated conditions, we evaluated phytoremediation against soil application of gypsum and farm manure, and water treatment with sulphuric acid on a calcareous saline–sodic soil (pH_s=8.0–8.4, EC_e=24–32 dS m⁻¹, SAR=57–78, CaCO₃=45–50 g kg⁻¹ for the top 0.15 m depth; Calcic Haplosalids). A saline–sodic water (EC=2.9–3.4 dS m⁻¹, SAR=12.0–19.4, RSC=4.6–10.0 mmol_c l⁻¹, SAR_adj=15.6–18.4) was used to irrigate the rice (Oryza sativa L.) and wheat (Triticum aestivum L.) crops grown in rotation. Active desalinisation and desodication processes were observed in all the treatments. After the final wheat crop, the 1.2 m soil profile EC_e was 7±0.5 dS m⁻¹ and SAR was 15±2 with non-significant treatment differences, indicating comparable soil amelioration effect of phytoremediation with other treatments. Better crop yields were obtained from the manure-treated plots, owing to its annual addition to the soil that possibly improved soil fertility. Phytoremediation needed minimum capital input because no initial investment was made to purchase the amendments.  相似文献   

适应排灌行业需要 建设岗位培训制度——由江苏理工大学流体机械工程技术中心连续15年举办培训班引发的思考     

吴一明 《排灌机械》2001,(4)

由排灌机械行业的现状 ,结合江苏理工大学流体机械工程技术中心 15年来举办培训班的实践 ,提出了培养一大批掌握现代科学技术的工程技术人员和高素质员工是促进排灌事业发展最直接、最有效的措施 ,而制定和完善岗位培训制度是这一措施规范化、制度化、科学化的保证。文章阐述了岗位培训的概念 ,对建立岗位培训制度的原则、框架和体系作了探讨。  相似文献   

天山北坡水资源开发对地下水资源的影响及其合理利用   总被引：3，自引：0，他引：3  

魏忠义 《干旱区资源与环境》1992,6(2):55-62

本文论述了包括乌鲁木齐市在内的天山北坡山前平原范围内的地下水资源数量、补给关系及开采利用条件,以及地下水开发后对该地区地下水位、数量、质量及泉水渗出等方面的影响,并对如何合理利用本地区地下水资源提出了意见。  相似文献   

Linking Land-use, Water Body Type and Water Quality in Southern New Zealand   总被引：3，自引：0，他引：3  

Lisa M. Galbraith  Carolyn W. Burns 《Landscape Ecology》2007,22(2):231-241

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.  相似文献   

The decline of Austrocedrus chilensis forests in Patagonia, Argentina: soil features as predisposing factors     

Ludmila La Manna  Mario Rajchenberg 《Forest Ecology and Management》2004,190(2-3):345-357

The forests of Austrocedrus chilensis in southern Argentina suffer mortality from “mal del ciprés”, whose causes remain unknown. The purpose of this work was to establish the relation of soil features with the occurrence of the disease. In Río Grande Valley, Chubut Province, Argentina, 14 areas with “mal del ciprés” were selected for study. The spatial pattern of the decline varied among the different areas and was classified as aggregated and disaggregated. In each area, symptomatic and asymptomatic plots were established and characterized by 11 edaphic and topographic variables. Three forest areas where the disease was totally absent were also included. Site features were related to the occurrence of the decline using principal component analysis and cluster analysis. Results indicated that soil properties related to poor internal drainage, such as the proximity to water streams, non-allophanized soils of fine textures, and redoximorphic features, act as predisposing factors to the development of “mal del ciprés”. Poor soil drainage was strongly associated not only with the occurrence of the disease, but also with its spatial pattern. Symptomatic and asymptomatic plots presented similar edaphic features in areas with a disaggregated distribution of the decline and were grouped together in the multivariate analysis. This result suggests that large areas with such a pattern are prone to develop the decline.  相似文献   

Water balance and maize yield following improved sesbania fallow in eastern Zambia   总被引：1，自引：0，他引：1  

E. Phiri  H. Verplancke  F. Kwesiga  P. Mafongoya 《Agroforestry Systems》2003,59(3):197-205

Sesbania [Sesbania sesban (L.) Merr.] fallows are being promoted as a means for replenishing soil fertility in N-depleted soils of small-scale, resource-poor farmers in southern Africa. Knowledge of soil water distribution in the soil profile and water balance under proposed systems is important for knowing the long-term implications of the systems at plot, field and watershed levels. Soil water balance was quantified for maize (Zea mays L.) following 2-year sesbania fallow and in continuous maize with and without fertilizer during 1998–1999 and 1999–2000 at Chipata in eastern Zambia. Sesbania fallow increased grain yield and dry matter production of subsequent maize per unit amount of water used. Average maize grain yields following sesbania fallow, and in continuous maize with and without fertilizer were 3, 6 and 1 Mg ha⁻¹ with corresponding water use efficiencies of 4.3, 8.8 and 1.7 kg mm⁻¹ ha⁻¹, respectively. Sesbania fallow increased the soil-water storage in the soil profile and drainage below the maximum crop root zone compared with the conventionally tilled non-fertilized maize. However, sesbania fallow did not significantly affect the seasonal crop water use, mainly because rainfall during both the years of the study was above the normal seasonal water requirements of maize (400 to 600 mm). Besides improving grain yields of maize in rotation, sesbania fallows have the potential to recharge the subsoil water through increased subsurface drainage and increase nitrate leaching below the crop root zone in excess rainfall seasons. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

香港南莲园池排水系统的人性化景观设计     

郑焯源  宋伟玲 《广东园林》2014,(1):39-41

园林排水工程设施是园林建设的重要组成部分。随着人们审美及技术水平的日益提高,园林排水系统设计不仅需要关注功能使用,还要力求营造出更好的园林景观效果。文章以香港南莲园池为例,探讨了园林排水系统设计和园林造景艺术紧密结合的某些细节及其人性化设计的手法。  相似文献