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1.
Irrigated agriculture allows for the increase of agrarian yields and stability in food supply and raw materials, being, at the same time, responsible for the reduction of water resources availability and for the pollution by salts and nitrate. This work aims to analyze the impact of changes in irrigation management (establishment of an on-demand flood irrigated system, assignment of irrigation allowances and water payment for surface and irrigation water consumption) in a traditional irrigated land on drainage flow, electrical conductivity and nitrate concentration in irrigation return flows between the year 2001 and the period 2005–2008. Changes in water management significantly modified quantity (lower drainage) and quality (electrical conductivity and nitrate) of irrigation return flows, keeping similar evolution paths during the year with water ameliorants in summer due to the use of good irrigation water quality. Salinity in irrigation return flows is not a current problem in the area as electrical conductivity values in water did not exceed the limit established for water used in irrigation or intended for human consumption. Despite the fact that changes in irrigation management and crop distribution have reduced nitrate concentrations in irrigation return flows by 43 %, the water still presents nitrate values exceeding the 50 mg NO3 ?/l. Thus, nitrate remains as the main agro-environmental problem in this irrigation area. However, the nitrate concentration trends detected in this work mark the possibility of reaching nitrate values below 50 mg NO3 ?/l in the case of maintenance of the conditions in this agricultural system. 相似文献
2.
Irrigated agriculture is a clear source of non-point pollution by salts and nitrogen species. The impact of such pollution should be quantified according to specific cases. The case of the Malfarás creek basin, a sprinkler irrigation district located in the semiarid Ebro valley in northeast Spain, has been evaluated. The main crops in the district were corn, barley and alfalfa, occupying 93 % of the irrigated area. The fate of water, salts and nutrients was evaluated by a daily water balance developed at a field scale for the natural year 2010. The yearly data of the whole set of 101 irrigated fields plus the non-irrigated area compared to the measured drainage produced a basin water balance with a low degree of error. The basin consumed 90 % of the total water input of which 68 % was used for crop evapotranspiration and the rest was lost due to non-productive uses. 16 % of the incoming water left the irrigation area as drainage water. The irrigated area was responsible for 87 % of the drainage. The average volume of drained water was 152 mm year?1 for the whole basin area. The irrigated area drained 183 mm year?1. The basin exported 473 kg of salt per hectare during 2010. This value was the lowest of the sprinkler irrigation areas in the Ebro valley, mainly due to the lower soil salinity. All the crops except barley received a nitrogen surplus of 10–50 % above their needs. The extra nitrogen entered the water cycle increasing the nitrate concentration in the aquifer water (150 mg L?1) and drainage water (98 mg L?1). In 2010 the mass of nitrogen exported by drainage was 49 kg per irrigated hectare. This value is too high for this type of irrigation system and implies that 17 % of nitrogen applied as a fertilizer was lost to drainage water. The key to decreasing the nitrogen leaching and pollution that it causes could be appropriate time-controlled fertigation along with better irrigation scheduling. 相似文献
3.
选择甘肃省临洮县洮惠渠灌区为试验研究区,通过直接观读、自动监测等技术手段,获取试验灌区的引水量、退水量、土壤墒情、降水量及蒸发量等水文基础数据。以水文监测基础数据为依据,采用引排差法、水分平衡法等相结合的方法,开展了农业灌溉耗水系数试验研究。初步试验结果表明:试验灌区灌溉期平均耗水系数为0. 730,典型地块灌溉期平均耗水系数为0. 671,2016年试验灌区降水量较常年偏少13. 0%~26. 3%,总体上属轻度干旱年份。该研究成果可为甘肃陇中黄土高原区水资源管理提供技术支撑。 相似文献
4.
In the Apalachicola-Chattahoochee-Flint (ACF) river basin in Alabama, Georgia, and Florida (USA), population growth in the city of Atlanta and increased groundwater withdrawal for irrigation in southwest Georgia are greatly affecting the supply of freshwater to downstream regions. This study was conducted to understand and quantify the effect of irrigation pumpage on the karst Upper Floridan Aquifer and river–aquifer interactions in the lower ACF river basin in southwest Georgia. The groundwater MODular Finite-Element model (MODFE) was used for this study. The effect of two drought years, a moderate and a severe drought year, were simulated. Comparison of the results of the irrigated and non-irrigated scenarios showed that groundwater discharge to streams is a major outflow from the aquifer, and irrigation can cause as much as 10 % change in river–aquifer flux. The results also show that during months with high irrigation (e.g., June 2011), storage loss (34 %), the recharge and discharge from the upper semi-confining unit (30 %), and the river–aquifer flux (31 %) are the major water components contributing towards the impact of irrigation pumpage in the study area. A similar scenario plays out in many river basins throughout the world, especially in basins in which underlying karst aquifers are directly connected to a nearby stream. The study suggests that improved groundwater withdrawal strategies using climate forecasts needs to be developed in such a way that excessive withdrawals during droughts can be reduced to protect streams and river flows. 相似文献
5.
Mats Söderström 《Environmental Geology》1992,20(2):85-92
Spatial distribution of the salinity in groundwater used for irrigation and irrigated soil was investigated on Gammouda Plain, an important agricultural area in central Tunisia. Samples from 188 wells and irrigated fields were obtained in November 1988. Groundwater salinity ranges from 2 to 30 dS/m, and 50 percent of the sampled wells have a salinity higher than 3.5 dS/m. In most cases the soil samples have a salinity higher than 4 dS/m. Maps of salinity and leaching were produced by a geostatistical interpolation method based on ordinary kriging. In a great part of the plain, the estimated salinity levels indicate that there is a considerable risk for reduced yield potential for several of the most important crops grown. A rough estimation of the leaching fraction was computed from the soil and water salinity. Computer-based models of salinity ought to facilitate the general planning of irrigation management and crop selection. 相似文献
6.
7.
Determining groundwater degradation from irrigation in desert-marginal northern China 总被引：1，自引：1，他引：0
Brighid E. Ó Dochartaigh Alan M. MacDonald William G. Darling Andrew G. Hughes Jin X. Li Li A. Shi 《Hydrogeology Journal》2010,18(8):1939-1952
Groundwater degradation from irrigated agriculture is of concern in semi-arid northern China. Data-scarcity often means the causes and extent of problems are not fully understood. An irrigated area in Inner Mongolia was studied, where abstraction from an unconfined Quaternary aquifer has increased threefold over 20 years to 20 million m3/year; groundwater levels are falling at up to 0.5 m/year; and groundwater is increasingly mineralised (TDS increase from 400 to 700–1,900 mg/L), with nitrate concentrations up to 137 mg/L N. Residence-time (chlorofluorocarbons), stable-isotope and hydrogeochemical indicators helped develop a conceptual model of groundwater system evolution, demonstrating a direct relationship between modern water proportion and the degree of groundwater mineralisation, indicating that irrigation-water recycling is reducing groundwater quality. The investigations suggest that before irrigation development, active recharge to the aquifer from wadis significantly exceeded groundwater inflow from nearby mountains, previously held to be the main groundwater input. Away from active wadis, groundwater is older with a probable pre-Holocene component. Proof-of-concept groundwater modelling supports geochemical evidence, indicating the importance of wadi recharge and irrigation return flows. Engineering works protecting the irrigated area from flooding have reduced good quality recharge; active recharge is now dominated by irrigation returns, which are degrading the aquifer. 相似文献
8.
Chowdhury Sarwar Jahan Md. Ferozur Rahaman Riad Arefin Shamser Ali Quamrul Hasan Mazumder 《Journal of the Geological Society of India》2018,91(5):613-620
Demand for irrigation water increases day by day along with meteorological vagaries and extension of irrigated area in the drought-prone Barind area of Bangladesh. This increasing stress on water resource is gradually making the area water scare. The study is aimed at studying the morphometric parameters of the Atrai-Sib river basin in the Barind area and on their relevance in water resource management based on satellite images and SRTM DEM. Computation and delineation of linear and areal aspects of the river basin and its morphometric components reveals that stream order ranges from first to eighth order showing dendritic drainage pattern. The basin represents homogeneity of soil texture; possibility of flash flood after heavy rainfall with low discharge of runoff; and is not largely affected by structural disturbance. Moderate drainage density of the river basin area indicates semipermeable soil lithology with moderate vegetation. Mean bifurcation ratio of the basin is calculated as 3.92 and elongation ratio 0.75, which indicate elongated shape of the river basin with low to moderate relief bounded in the east and west by ‘moderate to steep’ sloping land area. It reveals a flatter peak of runoff flow for longer duration and gravity flow of water. The gentle but undulating slope of the basin represents ‘excellent’ category for groundwater management as the site is favorable for infiltration due to maximum time of runoff water percolation. The east facing slopes of the basin show higher moisture content and higher vegetation than the west-facing slope. The land use pattern of the area shows that major part (95.29%) comes under the cultivated land which will support future river basin development and management. Results obtained from the study would be useful in categorization of river basins for future water resource development and management, and selection of suitable sites for water conservation structures such as check dam, percolation tank, artificial recharge of groundwater through MAR technique etc. 相似文献
9.
N. Janardhana Raju Prahlad Ram Sangita Dey 《Journal of the Geological Society of India》2009,73(2):178-192
The lower Varuna River basin in Varanasi district situated in the central Ganga plain is a highly productive agricultural
area, and is also one of the fast growing urban areas in India. The agricultural and urbanization activities have a lot of
impact on the groundwater quality of the study area. The river basin is underlain by Quaternary alluvial sediments consisting
of clay, silt, sand and gravel of various grades. The hydrogeochemical study was undertaken by randomly collecting 75 groundwater
samples from dug wells and hand pumps covering the entire basin in order to understand the sources of dissolved ions, and
to assess the chemical quality of the groundwater through analysis of major ions. Based on the total dissolved solids, two
groundwater samples are considered unsuitable for drinking purpose, but all samples are useful for irrigation. Graphical treatment
of major ion chemistry by Piper diagram helps in identifying hydro-geochemical facies of groundwaters and the dominant hydrochemical
facies is Ca-Mg-HCO3 with appreciable percentage of the water having mixed facies. As per Wilcox’s diagram and US Salinity laboratory classification,
most of the groundwater samples are suitable for irrigation except two samples (No’s 30 and 68) which are unsuitable due to
the presence of high salinity and medium sodium hazard. Irrigation waters classified based on residual sodium carbonate, have
revealed that all groundwaters are in general safe for irrigation except one sample (No. 27), which needs treatment before
use. Permeability index indicates that the groundwater samples are suitable for irrigation purpose.
Although the general quality of groundwater of the lower Varuna River basin is suitable for irrigation purpose, fifty seven
percent of the samples are found having nitrate content more than permissible limit (>45 mg/l) which is not good for human
consumption. Application of N-Fertilizers on agricultural land as crop nutrients along the Varuna River course may be responsible
for nitrate pollution in the groundwater due to leaching by applied irrigation water. The other potential sources of high
nitrate concentration in extreme northern, southern and southwestern parts of study area are poor sewerage and drainage facilities,
leakage of human excreta from very old septic tanks, and sanitary landfills. The high fluoride contamination (>1.5 mg/l) in
some of the samples may be due to the dissolution of micaceous content in the alluvium. Nitrate and fluoride contamination
of groundwater is a serious problem for its domestic use. Hence an immediate protective measure must be put into action in
the study area. 相似文献
10.
11.
2001-2018年石羊河流域植被变化及其对流域管理的启示 总被引：1，自引：0，他引：1
植被是流域生态系统的重要指标,植被景观管理也是流域综合管理的重要内容。综合利用长时间序列MODIS反射率和归一化差值植被指数（NDVI）产品及Landsat卫星遥感影像,基于谷歌地球引擎（GEE）平台,利用计算机自动分类的方法,监测了2001-2018年间石羊河流域的植被（包括灌溉土地）的逐年变化,结合降水、径流量和地下水位地面监测数据,分析了全流域植被指数、植被面积、灌溉土地范围的变化特征及其与水循环之间的互馈关系。研究发现,2001-2018年间,石羊河流域的植被面积以每年约135 km2的速率增加,其中,自然植被和灌溉土地分别以每年60.5 km2和74.6 km2的速率增加。除了金昌区的植被增加以灌溉土地为主外,其他区域都以自然植被的增加为主。特别是民勤地区,由于十多年的持续调水和有效退耕,地下水位近年来开始抬升,自然植被开始恢复。但与此同时,中游凉州区和永昌县的生态风险加大。未来可从灌溉规模控制、地表与地下水统一调度、景观分级和配置技术发展、优化产业结构、强化与流域外的连通性等方面加强流域综合管理,提高流域社会系统弹性,增强可持续发展能力。 相似文献
12.
Hamdi Monji Louati Dhouha Majdoub Rajouene Abida Habib 《Arabian Journal of Geosciences》2016,9(15):653
In Sidi Bouzid plain, rainfall alone is insufficient to satisfy crop water requirements. Within this framework, and in order to improve water resources in the region, the Tunisian State adopted non-conventional water mobilization techniques, among which artificial spate irrigation. The objective of the study is to evaluate the impact of spate irrigation of flood water on the mitigation of agricultural drought and the enhancement of groundwater recharge. Annual and monthly rainfall data as well as flood water volumes were monitored. The study focused on the groundwater drawdown monitoring. Results showed a high flood water contribution to crop water requirements that exceeded rainfall. This water prevented drought in the spate perimeters. The groundwater drawdown was found to fluctuate over time, with an average decreasing rate of 0.4 to 0.5 m/year. Groundwater recharge was found to be highly correlated with flood water contribution through spate irrigation (R 2 = 84 %). Out of the spate zone, a high decrease in the groundwater level was noted. The lowest rate of 1 m/year was that of the farthest piezometer from the spate perimeters. This is influenced by the excessive pumping out of the spate zone. In 1980, groundwater flew from the west to the east. In 2015, the flow movement from the east to the center of the plain did not change due to the presence of the spate perimeters. Nevertheless, excessive pumping around sabkhas changed the flow directions at the outlet zone. A variation in groundwater salinity was observed in both space and time. In 1975, salinity was very low. The outlet zone was the most affected where the drawdown reached several meters, causing saltwater intrusion from the surrounding sabkhas. 相似文献
13.
The preliminary study of streams and rivers from the Roşia Montană area revealed that the concntration of heavy metals— Cd,
Mn, Cu, Pb, and Zn—are above accepted limits. The gold extraction method is based on flotation. The most important pollution
sources are mine tailings. The determinations were performed for samples collected in: April 2004, July 2004, September 2004,
November 2004, February 2005 and May 2005. The highest concentrations were found for cadmium in September 2004: 0.17 mg/L;
for copper in September 2004: 1.38 mg/L; for manganese in July 2004: 239.4 mg/L; for lead in May 2005: 0.54 mg/L; and for
zinc in September 2004: 35.37 mg/L;. This study involved three small rivers (streams) that flow into the Mureş River and finally
into the Danube River, having a great impact on human health and environmental stability in the area. In May 2005, a sample
of drinking water from the mining district was also collected. 相似文献
14.
黑河中游水土资源开发利用现状及水资源生态环境安全分析 总被引：12，自引：1，他引：12
黑河流域水资源产生于南部祁连山区,主要消耗于中游农业灌溉区。对黑河流域水文资料分析计算发现,流域出山水资源量多年变化比较稳定,最枯年和最丰年水资源量之比为 1:2,丰枯变化幅度与长江以南丰水河流相当。多年平均水资源量为32．31×108 m3／a,近10年中游水资源开发利用量稳定在34×108 m3／a以上,仅中游地区对水资源的开发利用率达120％左右。目前国际上公认的人均水资源量紧缺线为 1000～1700 m3／a,黑河流域水资源开发利用具有反复转化多次重复利用的特点,用这个指标无法全面评价黑河流域水资源的安全状况。 相似文献
15.
Lou Puli 《GeoJournal》1985,10(2):133-139
China's agriculture has much more urgent demand on irrigation and drainage than that of other countries'. At present, the country has a total irrigated area of 46 million hectares, accounting for 46% of the total cultivated land. This paper gives a brief introduction to the progress of the water resources development and a concise analysis on irrigation and drainage demands in various zones. Some salient experiences and lessons gained in these issues in the past some thirty years in China are reviewed. 相似文献
16.
Influences of the unsaturated,saturated, and riparian zones on the transport of nitrate near the Merced River,California, USA 总被引：1，自引：0，他引：1
Joseph L. Domagalski Steven P. Phillips E. Randall Bayless Celia Zamora Carol Kendall Richard A. WildmanJr Janet G. Hering 《Hydrogeology Journal》2008,16(4):675-690
Transport and transformation of nitrate was evaluated along a 1-km groundwater transect from an almond orchard to the Merced River, California, USA, within an irrigated agricultural setting. As indicated by measurements of pore-water nitrate and modeling using the root zone water quality model, about 63% of the applied nitrogen was transported through a 6.5-m unsaturated zone. Transport times from recharge locations to the edge of a riparian zone ranged from approximately 6 months to greater than 100 years. This allowed for partial denitrification in horizons having mildly reducing conditions, and essentially no denitrification in horizons with oxidizing conditions. Transport times across a 50–100-m-wide riparian zone of less than a year to over 6 years and more strongly reducing conditions resulted in greater rates of denitrification. Isotopic measurements and concentrations of excess N2 in water were indicative of denitrification with the highest rates below the Merced River. Discharge of water and nitrate into the river was dependent on gradients driven by irrigation or river stage. The results suggest that the assimilative capacity for nitrate of the groundwater system, and particularly the riverbed, is limiting the nitrate load to the Merced River in the study area. 相似文献
17.
Groundwater pumped from the semi-confined Complex Terminal (CT) aquifer is an important production factor in irrigated oases agriculture in southern Tunisia. A rise in the groundwater salinity has been observed as a consequence of increasing abstraction from the aquifer during the last few decades. All sources of contamination were investigated using hydrochemical data available from the 1990s. Water samples were taken from wells tapping both the CT and the shallow aquifers and analyzed with regard to chemistry tracers. Hydrochemical and water quality data obtained through a sampling period (December 2010) and analysis program indicate that nitrate pollution can be a serious problem affecting groundwater due to the use of nitrogen (N) fertilizers–pesticides in agriculture. The concentration of nitrate in an groundwater-irrigated area in Gafsa oases basin was studied, where abstraction from an unconfined CT aquifer has increased threefold over 25 years to 34 million m3/year; groundwater levels are falling at up to 0.7 m/year; and groundwater is increasingly mineralised (TDS increase from 500 to 4,000 mg/L), with nitrate concentrations ranging from 16 to 320 mg/L. 相似文献
18.
塔里木河流域2005年四源流对干流供水径流情势分析 总被引：14，自引：9，他引：5
2004年塔里木河流域四条源流出山口天然径流量272.1×108m3,属丰水年,比多年平均值224.9×108m3多47.20×108m3,增加21.0%;比20世纪90年代平均241.9×108m3多30.20×108m3,增加12.8%,在1957-2005年49 a水文系列中排名第5位.其中,阿克苏河、叶尔羌河、和田河3条源流与多年均值比较,增幅达22%～25%,开都-孔雀河为平略偏丰.四条源流入塔里木河总水量为56.88×108m3,占四条源流出山口天然径流总量的20.9%.根据现今塔里木河综合治理,仍需要制定长远的全面流域规划,以生态系统建设为根本,从工程上、宏观水量控制管理上、经济上和科技手段上,保障实现塔里木河流域水资源的可持续开发利用. 相似文献
19.
G. Stamatis 《Environmental Geology》1999,38(2):126-140
Peneos is the mainstream for the drainage of Thessaly's basin. It contributes significantly in recharging the aquifers, as
well as to the direct irrigation water, since there is intense agricultural activity in the basin of Thessaly. The investigation
of the hydrochemical conditions of the surface water system of Peneos showed that the chemical composition is related to the
lithology of the aquifers of the basin, the anthropogenic influence and the biological activity. The chemical composition
of this system changes in time and space. The salinity decreases during the winter period, in contrast to the summer period
when it increases drastically. The lower values of TDS appear in the upstream part of the river (95–124 mg/l) whereas downstream,
the values of TDS increase significantly (400–632 mg/l). The hydrochemical type Ca-Mg-HCO3 dominates the largest part of the river while it changes to NA-Cl in the estuary. The concentrations of the dissolved species
in the main Peneos river are higher than in the spring waters. Peneos is the most polluted river in Greece. The concentration
of the pollutants is higher at the downstream part of the river, but is lower than the accepted upper limits. The use of the
surface water of the system of Peneos river for irrigation purposes based on the SAR factor is acceptable because the absorption
ratio for Na and salinity are low and medium respectively.
Received: 27 October 1997 · Accepted: 21 September 1998 相似文献
20.
To estimate the water saving potential of an irrigation area and create a scientific water saving plan, the irrigation water use efficiency and water productivity of the Hulanhe irrigation area for 2007–2014 were calculated, and the water saving potentials of different water saving plans were determined from the perspectives of engineering and crop water saving. The results showed that the evapotranspiration calculated from the surface energy balance algorithm for land model (SEBAL) agreed well with the measured results. The irrigation water use efficiency in the Hulanhe irrigation area was positively correlated with precipitation of irrigated land and was negatively correlated with the net irrigation water volume. The engineering water saving potential ranges for periods of 5, 8, 11, and 15 years were (1.702?×?108, 5.103?×?108) m3, (1.783?×?108, 5.184?×?108) m3, (1.865?×?108, 5.266?×?108) m3, and (2.301?×?108, 5.702?×?108) m3, respectively, and the water saving potential increased year over year. Low amounts of precipitation of irrigated land corresponded with small amounts of net irrigation water and greater water saving potential. Based on the cumulative frequency of the water productivity calculated for the Hulanhe irrigation area from 2007 to 2014, the target water productivity for short (50% of the multi-year average cumulative water productivity) and long (70% of the multi-year average cumulative water productivity) terms were 1.03 kg/m3 and 1.22 kg/m3, respectively, and the cumulative crop water saving potentials for short and long terms were 1.18?×?108 and 2.74?×?108 m3, respectively. These results provided a theoretical reference for creating water saving plans for irrigation areas. 相似文献