共查询到19条相似文献，搜索用时 251 毫秒
1.
目前国内灌区灌溉水有效利用系数较低,提高灌区灌概用水效率意义重大。本文以黄河中上游某灌区为例,选取9个影响灌溉水有效利用系数的因素,采用主成分分析方法。结果显示,灌区灌溉用水效率正贡献率高的主要因素有四个：井渠结合灌溉面积比、渠道衬砌率、当年节水改造投资、节水灌溉面积;而负贡献率较高主要有常规水稻净灌溉定额、水稻种植比例。这些因素反映了灌区的种植结构、管理水平以及水利设施的现状。为此,在灌区要大力发展滴灌等节水技术;积极转变农业结构,例如：鼓励、引导农民发展高经济效益蔬菜、花舟、水果、草、牧;通过科技实验,推广节水技术,加大宣传力度,建立健全节水管理技术。 相似文献
2.
3.
4.
5.
农田水利工程建设是农业经济发展的必要基础,灌溉用水是农业生产中用水量最大的环节。要提高水资源利用率,改善田间灌溉面貌,提升农业生产效益,保证农业生产可持续发展,必须对灌区进行必要的水利设施配套建设,使灌区形成较为完善的灌溉工程体系,基本实现"旱能灌,涝能排",达到农业生产条件明显改善,农业综合能力明显提高,抗御自然灾害的能力明显增强的效果。充分利用现有的工程设施,合理调整归并,对灌区斗渠及田间渠道进行必要的改造衬砌,提高防渗能力,恢复渠道过流能力,提高灌溉保证率,改善落后的灌溉现状,有效促进作物种植向高标准农田稳步发展,缓解地方供水矛盾。 相似文献
6.
为了正确评价灌区用水效率及用水效益,构建了考虑回归水重复利用的灌区用水效率及效益指标。利用地表水-地下水耦合模型、SWAP模型和线性模型对柳园口灌区的水量和作物产量进行了分布式模拟,在此基础上,对柳园口灌区不同用水模式以及田间不同节水灌溉模式下的灌区用水效率及效益指标进行了计算,分析不同节水措施对灌区用水效率及效益指标的影响规律。结果表明,井渠结合调控模式和田间节水灌溉模式对柳园口灌区不同区域用水效率及效益的影响效果不同,但均能提高灌区总体的用水效率及效益。 相似文献
7.
阐述了节水灌溉信息化的重要性和必要性,探讨建设完善的灌区节水灌溉信息化管理系统。介绍信息管理系统、调度运行系统、水务公开系统、运行监控管理系统、遥测管理系统、灌溉用水预报系统、决策支持系统的基本结构和内容。实践证明,管理系统能够有效地提高灌区水资源的利用率和用水管理效率。 相似文献
8.
9.
首先分析了宁蒙引黄灌区近60年的气温变化特性,并据此划分基准期和变化期;分析了灌区种植结构的变化。然后采用彭曼公式和作物系数,分析了典型作物的物候期和灌溉需水的变化;并分析了灌区灌溉需水量和灌溉时间节律对自然和社会环境变化的响应。结果表明:变化期相较基准期,气温明显升高,灌溉需水在此影响下,有所前移;总种植面积增大,春小麦的种植面积大幅降低,玉米、葵花等其他作物增加,使得灌溉需水总量增多,并有所后延;在总种植面积增大、种植结构改变和气候变化的综合作用下,灌区灌溉需水量呈较大幅度的增加趋势,但汛前讯后需水比例变化不大。 相似文献
10.
以陕西省直交口抽渭灌区为例,在对灌区灌溉工程设施建设、节水灌溉发展状况研究的基础上,归纳灌区节水灌溉管理具体措施及取得成效,提出对策建议。分析认为：灌区节水灌溉发展以明渠引水为主,节水灌溉面积68万亩,占有效灌溉面积的60%。滴灌、管灌等高效节水灌溉面积达8.7万亩,占有效灌溉面积的7.7%,节水效果十分明显。以行政、工程与经济多种措施并举,采取切实可行的节水灌溉管理措施,推进了节水型灌区建设,加快用水方式由粗放向节约集约转变,提高水资源利用效率,年均节水达2 000万m3以上。远期应继续不断提高节水灌溉技术,制定合理对策,推进节水型现代化灌区建设。 相似文献
11.
以红壤丘陵景观中相对独立且整体性强的集水区为基本单元,重点研究了集水区内降水、蒸散、水量蓄存等地表水资源的年变化。结果表明,降水资源在集水区内的陆面拦截蒸散、塘堰蓄存、排出集水区三者中的分布比例约为7:2:1,在水土保持型坡地的植被拦截、土壤渗流、地表径流三者中的分布比例约为3:5:2;每公顷1m土体中的土壤贮水量,在丰水季节,水土保持型坡地要比非水保坡地高出864.0～1067.0m3,少水季节则高出647.0～855.0m3。研究结果还表明,以集水区为单元的农业灌溉用水量,一般为年降水量的12%左右,蓄存此水量的塘堰面积应占集水区土地总面积的11%左右,对于塘堰面积已占土地总面积10%左右的红壤丘陵区而言,抗御季节性干旱依靠扩大塘堰蓄水已不现实,其主要途径应是充分发挥水库工程和"土壤水库"的巨大抗旱潜力。 相似文献
12.
Influence of droughts on remote villages in the karst region of Guizhou Province,China: Causes and control 
下载免费PDF全文
下载免费PDF全文 Even though the precipitation is abundant in the Karst region of Guizhou Province, remote villages in this area frequently suffer severe droughts. This paper studied the causes of droughts in this region through field investigation and references collection. Based on the cause analysis, some suggestions were provided for hazard prevention and control from an engineering perspective. Besides occasional extreme weathers, the drought in this area is primarily caused by its unique geological structures of Karst plateau and underdeveloped agricultural techniques. Meanwhile, the vicious cycle between drought and poverty, which causes the deficiency of water conservancy facilities and hazard prevention awareness, is an important reason for the frequent occurrence of agricultural and socioeconomic drought. Considering the social and economic conditions of remote villages, the long-term control of drought can only be realized if current measures are capable of bring immediate effects and benefits. Therefore, the construction of well-planned and designed water conservancy system based on each village’s natural and social conditions are the priority for current hazard prevention. Generally, the exploitation of subterranean river should be considered as the first choice to stabilize the water supply for remote villages. Meanwhile, the construction and improvement of micro water conservancy facilities, such as small water tank, small pond and so on, can effectively support the water providence during droughts as well. 相似文献
13.
面向工程设计阶段,采用高拱坝施工动态仿真技术获取施工初-中期挡水度汛面貌数据,综合考虑水文、水力随机性因素,构建高拱坝施工初-中期导流风险模型,提出采用Monte Carlo方法耦合挡水度汛面貌数据和主要随机因素进行风险模型求解的方法。基于风险分析原理提出了导流洞设计的风险判别方法,给出导流洞尺寸设计优化的数学模型和具体步骤。通过金沙江上游某高拱坝工程案例分析的结果表明:所提风险模型及求解方法是适用的、有效的,该模型能够得到整个施工初-中期导流风险率,较为客观地反映高拱坝施工中期度汛可能存在的两种挡水情况,克服了初期导流风险模型的局限性;施工中期导流风险率随导流洞尺寸增大而减小,导流洞尺寸设计的可行方案集存在界限,即优化方案。研究成果可为高拱坝施工导流的风险决策和设计优化提供理论支撑。 相似文献
14.
SCS-CN and GIS-based approach for identifying potential water harvesting sites in the Kali Watershed,Mahi River Basin,India 总被引：6，自引：0，他引：6
The Kali sub-watershed is situated in the semi-arid region of Gujarat, India and forms a part of the Mahi River Watershed.
This watershed receives an average annual rainfall of 900mm mainly between July and September. Due to high runoff potential,
evapo-transpiration and poor infiltration, drought like situation prevails in this area from December to June almost every
year. In this paper, augmentation of water resource is proposed by construction of runoff harvesting structures like check
dam, percolation pond, farm pond, well and subsurface dyke. The site suitability for different water harvesting structures
is determined by considering spatially varying parameters like runoff potential, slope, fracture pattern and micro-watershed
area. GIS is utilised as a tool to store, analyse and integrate spatial and attribute information pertaining to runoff, slope,
drainage and fracture. The runoff derived by SCS-CN method is a function of runoff potential which can be expressed in terms
of runoff coefficient (ratio between the runoff and rainfall) which can be classified into three classes, viz., high (>40%),
moderate (20–40%) and low (<20%). In addition to IMSD, FAO specifications for water harvesting/recharging structures, parameters
such as effective storage, rock mass permeability are herein considered to augment effective storage. Using the overlay and
decision tree concepts in GIS, potential water harvesting sites are identified. The derived sites are field investigated for
suitability and implementation. In all, the accuracy of the site selection at implementation level varies from 80–100%. 相似文献
15.
利用地下水库蓄水是吉林省新的有效治水途径 总被引：2，自引：0，他引：2
利用地下水库蓄水是治水的一个有效的效途径。这项工作在我国属于起步阶段,在吉林省是一个空白。本文阐述了地下水库的基本概念、蓄水原理、基础条件、国内外现状,论述了吉林省利用地下水库蓄水的基础条件和巨大的蓄水效益远景。建议建设地下水库蓄水示范工程,推广利用地下水库蓄水,以缓解吉林省水资源严重缺乏的局面,并能大大提高水利化程度 。 相似文献
16.
Groundwater drought is a specific type of hydrological drought that concerns groundwater bodies. It may have a significant adverse effect on the socio-economic, agricultural, and environmental conditions. Investigating the effect of different climatic and anthropogenic factors on groundwater drought provides essential information for sustainable planning and management of (ground) water resources. The aim of this study is to identify the influencing factors on groundwater drought in north-western Bangladesh, to understand the forcing mechanisms. A multi-step methodology is proposed to achieve this objective. The standardised precipitation index (SPI) and reconnaissance drought index (RDI) have been used to quantify the aggregated deficit between precipitation and the evaporative demand of the atmosphere, i.e. meteorological drought. The influence of land-cover patterns on the groundwater drought has been identified by calculating spatially distributed groundwater recharge as a function of land cover. Groundwater drought is defined by a threshold method. The results show that the evapotranspiration and rainfall deficits are determining meteorological drought, which shows a direct relation with groundwater recharge deficits. Land-cover change has a small effect on groundwater recharge but does not seem to be the main cause of groundwater-level decline (depletion) in the study area. The groundwater depth and groundwater-level deficit (drought) is continuously increasing with little correlation to meteorological drought or recharge anomalies. Overexploitation of groundwater for irrigation seems to be the main cause of groundwater-level decline in the study area. Efficient irrigation management is essential to reduce the growing pressure on groundwater resources and ensure sustainable water management. 相似文献
17.
自强水库位于陕南秦巴山地中低山地貌区,水库为镇巴县备用水源地及旅游观光风景区,属小(1型水库。通过对库坝区地质构造、地层岩性、岩溶发育等工程地质条件分析可知,对工程建设及坝线选址有影响的工程地质问题主要为库区内发育逆冲叠瓦小断裂以及岩溶发育可能导致水库渗漏等。库区内无大型活动性断裂构造,构造较为稳定,且库区蓄水范围小,蓄水量不大,不易诱发地震。而拟选坝址位于自强河段,沟谷对称顺直,综合水库坝址区地形地貌、工程地质等条件进行坝线比选,推荐下游坝线为较为理想的坝线位置,可满足工程建设要求。 相似文献
18.
试论尾矿库安全监测的现状及前景 总被引：1，自引：0，他引：1
尾矿库作为矿山生产的重要元素,同时也是矿山的重大危险源和环境污染源。近年来,国内外尾矿库安全事故频频发生,且呈现不断上升的趋势,不但使企业经济蒙受损失,更对人民的生命财产安全与和谐的生态环境造成严重的危害,尾矿库的安全问题已经成为岩土工程防灾减灾的重要研究课题。本文论述了尾矿库的安全现状及其危害性,列举了国内外重特大尾矿库溃坝灾害的案例并对典型案例发生的原因进行了简要分析,说明了国内目前采用的几种尾矿库安全监测方法的原理、成效及其局限性,指出了实时全天候监测技术的必要性、特点以及所要面临的技术理论问题。 相似文献
19.
Paweena Panichayapichet Suwanchai Nitisoravut Arpa Wangkiat 《中国地球化学学报》2006,25(B08):119-120
Discharge of wastewater from the retaining pond of a Pb ore-flotation plant since 1967 and breaching of the retaining pond in April 1998 contaminated 17540 cbm of river bank sediment with 833 ton Pb, nearly 19 km along the Khli Ti Creek. High blood Pb concentration was detected in many inhabitants. Prohibition of water and aquatic biota consumption has caused difficulties for rural people to make their ends meet. The governmental agency closed the ore-floatation plant and built 2 rock check dams downstream. The dam was designed to slow down water velocity and precipitate particulate matter. Contaminated sediments that have been trapped in front of the dam were planned to be dredged and disposed in landfill. Until now, no dredging is performed because some experts claim that dredging will resuspend the contaminated sediment into the water column, and fresh sediment deposited during periods of high flow will cover the contaminated sediment. The aim of this study was to evaluate the ability of the rock check dam to prevent the transportation of Pb-contaminated sediment in the Khli Ti Creek. Sediment located before and after the rock check dam and 2 km downstream were collected in September 2003 and May 2005. During September 2003, Pb concentrations in sediment deposited before and after the rock check dam and 2 km downstream were 48840, 53741 and 36020 mg/kg, respectively. These results showed that Pb-contaminated sediment was transported over the first rock check dam but still remained after the rock check dam. Result of May 2005 sampling also showed the same trend, although with different ranges due to seasonal variation, types of collected sediment, sample preparation and analytical techniques. Pb concentrations in sediment were 209684, 306775 and 33760 mg/kg, respectively. 相似文献