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1.
Karez is an indigenous method of irrigation in which groundwater is tapped by a tunnel. After running for some distance the tunnel comes out in the open and the water is conducted to the command area. Karez irrigation is practised in 22 countries from China to Chile including Pakistan. In Pakistan it is confined to the province of Balochistan which has a tribal society.Karez is an old and stable irrigation system of Pakistan. It is a community enterprise managed by tribal tradition and run by social control. Spacing of the karez, their types, life, length, discharge, land development and allocation, water distribution and management are important aspects of karez irrigation which have been discussed in this paper. Differences in karez maintenance and management produced by differences in tradition and customs of various tribes inhabiting Balochistan are brought out. Furthermore recent changes in Karez irrigation caused by changes in the socio-economic conditions are also analysed. 相似文献
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选择长江中下游单季中稻为研究对象,结合45个气象站1961~2010年逐日气象资料,基于统计降尺度模型(SDSM),生成HadCM3气候模式A2和B2两种情景下各站点参考作物腾发量和降水数据。基于联合国粮食及农业组织(FAO)推荐的作物系数法,并考虑有效性降雨和不同地区深层渗漏量,分析历史和未来的水稻灌溉需水时空变化特征。结果表明:过去50年,除了太湖流域以外的长江中下游大部分区域的参考作物腾发量和水稻需水量都呈显著下降趋势,而显著下降的水稻灌溉需水量主要位于鄱阳湖流域;未来两种情景下,参考作物腾发量、水稻需水量和水稻灌溉需水量均值都呈下降趋势,但水稻灌溉需水量降幅最小;水稻需水量和水稻灌溉需水量在长江中下游地区的变化趋势具有明显的空间异质性,水稻需水量大幅减少的区域由太湖流域向汉江和洞庭湖流域扩展。未来水稻灌溉需水量减少的区域主要分布在太湖流域、汉江流域东部和洞庭湖流域北部,并随时间推移呈扩大趋势。 相似文献
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为进行某铁路隧道的设计与施工,获取相关的水文地质参数,进行了3个钻孔的抽水试验,以获取相关的水文地质参数。运用地下水径流模数法、大气降雨入渗法和地下水动力学法对隧道涌水量进行了计算,计算结果显示：地下径流模数法的计算值偏小,降水入渗法的计算值适中,地下水动力学法的精度较高,但计算的涌水量值较大;三种方法比较,决定结果采用大值,即涌水量正常值取6150m^3/d,最大涌水量值取9770m^3/d。提出了采用双向自流排水,适当布设施工监控设备的工程建议。 相似文献
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Groundwater resources use and management in the Amu Darya River Basin (Central Asia) 总被引：2，自引：0，他引：2
Shavkat Rakhmatullaev Frédéric Huneau Jusipbek Kazbekov Philippe Le Coustumer Jamoljon Jumanov Bouchra El Oifi Mikael Motelica-Heino Zbynek Hrkal 《Environmental Earth Sciences》2010,59(6):1183-1193
This paper analyses groundwater resources use and management in the socio-economic context of the Amu Darya River Basin which
covers a part of the following landlocked Central Asian countries: Afghanistan, Tajikistan, Turkmenistan and Uzbekistan. These
agrarian nations for sustaining their vital agricultural productions started to use groundwater during the recent drought
years (1998–2001) because of its relatively good quality and quantity and as an alternative to highly mineralized surface
waters. Present extent of groundwater resources use is discussed with consideration to their reserves, quality, and institutional
management and transboundary aspects within the basin. After the collapse of the centralized water resources management system
and infrastructure of the former Soviet Union, new underdeveloped systems are being practiced over the whole Amu Darya River
Basin. The critical situation of groundwater management in Afghanistan is also discussed. This work attempts to document the
management and use of groundwater in the Amu Darya Basin and present time management realities, with fragmented and weak national
and regional regulation on groundwater. Special attention is given to groundwater resources in irrigated agriculture, which
increased use in all countries of the basin is due to quick access to underground resources and relatively good quality and
quantity. 相似文献
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基于蒸散发互补相关原理,定量分析和预测了引黄灌溉发展对甘肃景泰灌区年潜在蒸散量的影响。景泰灌区从1972年开始引黄灌溉,年蒸发皿蒸发量和潜在蒸散量随着灌溉引水消耗的增大而减小,其中空气动力学项下降的趋势非常明显,潜在蒸散量的变化主要受到风速下降和相对湿度增大的影响,与引黄灌溉有密切关系。根据互补相关平流-干旱模型分析了年潜在蒸散量随灌区耗水量的变化规律,并在假定年降水量和年潜在蒸散量中辐射项保持多年平均值的情况下,预测了不同耗水量情景下的年潜在蒸散量。 相似文献
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1985-2013年黑河中游流域地下水位动态变化特征 总被引：2，自引：0，他引：2
在气候变化和人类活动的影响下, 黑河流域地表水和地下水的时空分布特征发生了很大变化. 研究水系统演化及其驱动机制对流域水资源可持续管理非常关键. 基于甘肃河西黑河中游流域地下水位动态、水文气象、土地利用和灌溉统计数据, 研究了1985-2013年黑河中游流域地下水位时空变化. 结果表明: 地表水的不合理分配和耕地的扩展导致了地下水的过量开采和地下水位的剧烈变化. 1985-2004年区域地下水位以下降为主; 2005-2013年呈现下降和回升两极发展趋势, 冲洪积扇群带地下水最大下降达17.41 m, 而黑河干流沿岸地下水位最大回升了3.3 m, 地下水埋深普遍增加了1.0~3.0 m. 尽管地下水位在2005-2013年表现出回升趋势, 但干流中游盆地地下水系统处于严重负均衡状态, 制定合理的“生态分水”方案和水资源综合管理规划非常紧迫. 相似文献
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钻孔样本间因存在地层层序不一致而导致无法确定建模时各地层拓扑关系,是采用钻孔数据建立三维地质模型的难点。拟通过下述方法解决这一难点：在已知的主地层层序表情况下,由主地层层序表结合钻孔信息推测出其他地层层序表,建立地层层序表集,再通过运用空间分析的手段来确定钻孔样本与各张地层层序表的归属关系,采用最大数目地层连接法来自动确定两个地层层序表间相互连接关系,并得到合并表;然后结合这种连接法,将全部地层层序表合并为一张最终地层层序表,从而确定所有地层拓扑关系;所有钻孔数据按照最终表进行标准化,之后运用表面建模方法进行三维地层建模。在诸永高速公路K120+030～K120+300段滑坡区域的三维地层建模中,运用该方法验证了其有效性。 相似文献
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《China Geology》2023,6(2):187-207
The Qiangtang Basin of the Tibetan Plateau, located in the eastern Tethys tectonic domain, is the largest new marine petroliferous region for exploration in China. The scientific drilling project consisting primarily of well QK-1 and its supporting shallow boreholes for geological surveys (also referred to as the Project) completed in recent years contributes to a series of new discoveries and insights into the oil and gas preservation conditions and source rock evaluation of the Qiangtang Basin. These findings differ from previous views that the Qiangtang Basin has poor oil and gas preservation conditions and lacks high-quality source rocks. As revealed by well QK-1 and its supporting shallow boreholes in the Project, the Qiangtang Basin hosts two sets of high-quality regional seals, namely an anhydrite layer in the Quemo Co Formation and the gypsum-bearing mudstones in the Xiali Formation. Moreover, the Qiangtang Basin has favorable oil and gas preservation conditions, as verified by the comprehensive study of the sealing capacity of seals, basin structure, tectonic uplift, magmatic activity, and groundwater motion. Furthermore, the shallow boreholes have also revealed that the Qiangtang Basin has high-quality hydrocarbon source rocks in the Upper Triassic Bagong Formation, which are thick and widely distributed according to the geological and geophysical data. In addition, the petroleum geological conditions, such as the type, abundance, and thermal evolution of organic matter, indicate that the Qiangtang Basin has great hydrocarbon-generating potential.©2023 China Geology Editorial Office. 相似文献
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Estimating groundwater recharge beneath irrigated farmland using environmental tracers fluoride, chloride and sulfate 总被引：2，自引：0，他引：2
Accurate recharge estimation is essential for effective groundwater management, especially in the North China Plain, where irrigation return flow is significant to vertical recharge but brings difficulty for recharge estimation. Three environmental tracers (F?, Cl? and SO4 2?) were used to estimate vertical recharge based on the mass balance and cumulative methods. Four boreholes were dry-drilled to 5–25 m depth beneath irrigated farmland and one was drilled to 5 m beneath non-irrigated woodland; soil samples were collected in all boreholes at set depths. The results indicated that F?, Cl? and SO4 2?were suitable tracers beneath the non-irrigated woodland, yielding recharge rates of 16.9, 18.8 and 19.4 mm/year, respectively. Recharge estimation was not straightforward when taking account of crop type, irrigation and/or fertilizer use. After comparing with previous research, conclusions were drawn: Cl? was an appropriate tracer for irrigated farmland when taking account of Cl? input from irrigation and absorption by crops; recharge rates were 65.9–126.8 mm/year. However, F? was a more suitable tracer for irrigated regions where account is made of the proportion of precipitation to irrigation return flow, provided low F? concentrations can be measured reliably. 相似文献
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The internal structure and the integrity of the containment walls are aspects of landfill site management that need to be continuously monitored. Monitoring currently involves construction of boreholes and chemical analyses of surface samples which are time-consuming and expensive. The applicability of ground penetrating radar (GPR) as an aid to monitoring these processes has been investigated. GPR surveys have successfully resolved the shallow depth soil and geological structure, identified the structure and history of the waste input, defined the water table in three dimensions and identified leachout breakout points in the impermeable lining of the landfill edges. Integration of the results of GPR surveys with data from surface surveys and boreholes could provide landfill operators, environmental agencies and commercial companies with a cost-effective monitoring methodology and a mechanism for enhancing contaminant migration modelling. 相似文献
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R. K. Ray T. H. Syed Dipankar Saha B. C. Sarkar A. K. Patre 《Hydrogeology Journal》2017,25(8):2513-2525
Extracted groundwater, 90% of which is used for irrigated agriculture, is central to the socio-economic development of India. A lack of regulation or implementation of regulations, alongside unrecorded extraction, often leads to over exploitation of large-scale common-pool resources like groundwater. Inevitably, management of groundwater extraction (draft) for irrigation is critical for sustainability of aquifers and the society at large. However, existing assessments of groundwater draft, which are mostly available at large spatial scales, are inadequate for managing groundwater resources that are primarily exploited by stakeholders at much finer scales. This study presents an estimate, projection and analysis of fine-scale groundwater draft in the Seonath-Kharun interfluve of central India. Using field surveys of instantaneous discharge from irrigation wells and boreholes, annual groundwater draft for irrigation in this area is estimated to be 212 × 106 m3, most of which (89%) is withdrawn during non-monsoon season. However, the density of wells/boreholes, and consequent extraction of groundwater, is controlled by the existing hydrogeological conditions. Based on trends in the number of abstraction structures (1982–2011), groundwater draft for the year 2020 is projected to be approximately 307 × 106 m3; hence, groundwater draft for irrigation in the study area is predicted to increase by ～44% within a span of 8 years. Central to the work presented here is the approach for estimation and prediction of groundwater draft at finer scales, which can be extended to critical groundwater zones of the country. 相似文献
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油铀兼探的找矿思路在松辽盆地的应用——以中央拗陷区南部为例 总被引：1，自引：0，他引：1
以"油铀兼探"的找矿思路,带动松辽盆地中南部开展砂岩型铀矿调查选区及钻探验证工作.将异常强度250 API和450 API确定为划分潜在铀矿孔、潜在铀矿化孔和正常孔的关键技术指标,对中央拗陷区南部1572个钻孔进行异常筛查工作.排查发现潜在铀矿孔362个,潜在铀矿化孔223个.对191号钻孔和36号钻孔进行钻探验证,发现1个工业孔、1个异常孔.认为区内寻找砂岩型铀矿的有利地段为油田区反转构造形成的隆起区边部四方台组河流相砂体,并总结了中央拗陷区南部6种主要控矿因素. 相似文献
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Mohammad Sharifikia 《Natural Hazards》2013,65(1):201-217
The Sistan area is located in the east of Iran, enclosure to Afghanistan border. It is a densely populated enclave in the scarcely populated arid area of the eastern part of Iran, where the life strongly depends on the shallow water of Hamoun Lake and wetlands in the delta of the Helmand River flows from the Hindukush Mountains in western Afghanistan. As the water resources are scarce in this arid region, the availability of freshwater in Hamoun Lake has caused many socioeconomic and environmental effects in study area during several years. Various categories of socioeconomic criteria have been defined that are influenced by the Hamoun wetland, namely employment, economic value of fish catch, reeds harvest and birds hunt, food supplying and its influence on the microclimate of the region and the severity of the sandstorms, health and finally provision of recreational opportunities in the region. On the other hand, the high evaporation rates in a very dry region and climatic fluctuations make very vulnerable ecosystem, causing several environmental challenges into human activities. Prolonged droughts due to decrease in annual rainfall in the Hirmand watershed based on climate change in the last decade have been recorded in this environmental hazardous area. Drying up of Hamoun Lake and dead reed system in the wetlands was monitored in the present study using the time series of satellite imagery. The lifelessness of Hamoun Lake has caused several environmental effects such as sandstorm and dust hazard, destroying vegetation, vanishing crop production, damage to fish and bird habitat, extensively decreasing reeds harvesting, reducing livestock and increasing wildlife death rates, increasing air pollution and consequently health problems, salty soil movement over the agriculture fields, etc., which have been identified as the outcome of this research. 相似文献
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Isotopic constraints on the origin of groundwater in the Ordos Basin of northern China 总被引：7，自引：2，他引：5
Jiansheng Chen Xiaoyan Liu Chiyuen Wang Wenbo Rao Hongbing Tan Haizhou Dong Xiaoxu Sun Yongsen Wang Zhiguo Su 《Environmental Earth Sciences》2012,66(2):505-517
Despite its extreme aridity, the Ordos Basin in northern China is rich in groundwater. Many artesian wells or springs with
large fluxes are utilized for drinking, irrigation and industrial production. In a search for the origin of the groundwater,
a detailed investigation of the stable isotopes of oxygen and hydrogen in the local precipitation, the river water, the springs,
the well water, as well as the soil water extracted from six soil profiles in the Ordos Basin, was carried out. The data show
that δD, δ18O and TDS values of the river water are similar to those of groundwater, while the TDS values of the soil water are about
ten times greater than those of groundwater. Furthermore, the mean isotopic compositions of the local precipitation are significantly
higher than those of river water and groundwater. Based on the chloride mass balance method, the estimated recharge rates
range from 5.2 to 17.2 mm/year, with a mean value of 10.5 mm/year. The results show that the main source of recharge of the
groundwater in the Ordos Basin is not the local precipitation, but must come from a region where the precipitation is characterized
by much lower δD and δ18O values. In addition, the groundwater in the Ordos Basin contains a component of mantle-derived 3He and crust-derived 4He suggesting that the groundwater may partly derive from flows through basement faults beneath the Ordos Basin. 相似文献
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The within-Iranian backarc basins, including the largest Sebzawar Basin, opened in the Mid-Cretaceous. Spreading in this basin
was completed by the end of the Cretaceous. The basin closed in the Eocene with the formation of subduction zones and volcanic-plutonic
belts. Data on North Afghanistan and the Central Pamirs have allowed us to reconstruct the eastern continuation of the Sebzawar
Basin up to the west of the Central Pamirs. No fragments of oceanic crust are retained in Afghanistan and the Pamirs, but
by analogy with the Sebzawar Basin, thick Paleogene flysch sequences and volcanic-plutonic complexes indicate setting of the
active margin and subduction. It is suggested that the belt of mantle seismicity that extends for 550 km to the south of the
Central Pamirs is related to the plunging and deformation of the lithosphere once underlying the Cretaceous-Paleogene basin.
The extremely vigorous seismicity of the Hindu Kush megasource at the western termination of the seismic belt is caused by
a number of specific tectonic features that predetermined the early onset of plunging of the subducted sheet (slab). In the
megasource, the slab sank to a depth of 300 km and became vertical; its active deformation has proceeded up to the present.
In the eastern part of the seismic belt, the slab started to plunge much later and therefore has retained a gentle slope,
so that the depth of the hypocenters is shallower (down to 200 km), and earthquakes are less strong. 相似文献
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Geochemical and isotopic characterization of groundwater and lake-water samples were combined with water and total dissolved solids balances to evaluate sources of groundwater quality deterioration in eastern Hetao Basin, Inner Mongolia, China. Groundwater quality is poor; 11 of 13 wells exceed drinking-water guidelines for at least one health-based parameter and all wells exceed aesthetic guidelines. The well water is largely derived from Yellow River irrigation water. Notably high uranium concentrations in the Yellow River, relative to world rivers, suggest groundwater uranium and other trace elements may originate in the river-derived irrigation water. Complex hydrostratigraphy and spatial variation in groundwater recharge result in spatially complex groundwater flow and geochemistry. Evapotranspiration of irrigation water causes chloride concentration increases of up to two orders of magnitude in the basin, notably in shallow groundwater around Wuliangsuhai Lake. In addition to evapotranspiration, groundwater quality is affected by mineral precipitation and dissolution, silicate weathering, and redox processes. The lake-water and TDS balances suggest that a small amount of discharge to groundwater (but associated with very high solute concentrations) contributes to groundwater salinization in this region. Increasing salinity in the groundwater and Wuliangsuhai Lake will continue to deteriorate water quality unless irrigation management practices improve. 相似文献