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1.
The sustainability of the rice-wheat cropping system in an irrigated semi-arid area of Haryana State (India) is under threat due to the continuous rise in the poor quality groundwater table, which is caused by the geo-hydrological condition and poor irrigation water management. About 500,000 ha in the State are waterlogged and unproductive and the size of the waterlogged area is increasing. We analyse the hydrology and estimate seasonal net groundwater recharge in the study area. Rainfall is quite variable, particularly in the monsoon season, and the mean monthly reference evapotranspiration shows a high inter-annual variation, with values between 2.45 and 8.47 mm/day in December and May. Groundwater recharge analysis during the study period (1989-2008) reveals that percolation from irrigated fields is the main recharge component with 57% contribution to the total recharge. An annual groundwater table rise of 0.137 m has been estimated for the study area. As the water table has been rising continuously, suitable water management strategies such as increasing groundwater abstraction by installing more tubewells, using the groundwater conjunctively with good quality canal water, changes in cropping patterns, adoption of salt tolerant crops, changes in water-pricing policy, and matching water supply more closely with demand, are suggested to bring the water table down to a safe limit and to prevent further rising of the water table.  相似文献   

2.
Expansion of flood irrigation in the Lower Macquarie Valley of New South Wales, Australia, has been suggested as a major cause of increased groundwater recharge. The aim of this study was to estimate deep percolation under irrigation on two soils in the valley, in order to infer groundwater recharge. Three methods were used; water balance, Darcian flux calculations and chloride mass balance modelling. Chloride mass balance modelling and the water balance method gave comparable estimates of deep percolation for each soil. Chloride mass balance modelling was identified as the most reliable method for estimating deep percolation, but only gave an estimate for the entire growing season. These estimates were 214 and 104 mm for a cracking clay and red brown earth, respectively. While there is potentially greater error associated with estimates obtained using the water balance, this technique provided estimates of deep percolation for each individual irrigation. Results of the water balance indicated that deep percolation was greatest early in the growing season, following initial wetting of the soil, when the crop had a low leaf area index. Results calculated using Darcian flux equations were highly variable, and were therefore unreliable estimates of deep percolation. Groundwater recharge, inferred from estimates of deep percolation determined with the chloride mass balance model, was used to estimate the magnitude of potential annual groundwater rise. The potential groundwater rise during the 1992/1993 cotton growing season ranged from 465 mm beneath the cracking clay to 267 mm under the red brown earth. It is suggested that groundwater recharge and rise were highly dependent on the weather conditions prevailing during this period. Received: 24 January 1997  相似文献   

3.
Much environmental degradation, including salinity in the Mallee region of southeastern Australia, is associated with the loss of native vegetation and increased recharge. As a result, various agronomic practices have been proposed to reduce groundwater recharge. This study was conducted to evaluate the impact of these practices on recharge, in particular episodic recharge. A biophysically based model (WAVES) was used to estimate recharge rates under some typical crop and pasture rotations in the region using long-term meteorological data. Results show that: (1) recharge just below the root zone was episodic and that just 10% of annual recharge events contributed over 85% of long-term totals. Management options such as incorporating lucerne and deep-rooted non-fallow rotations can reduce both, mean annual recharge, and the number of episodic events, but not eliminate recharge completely; (2) winter fallows increased soil-water storage and some of the additional water was stored in the lower portion of the root zone or below it. This can increase the risk of recharge to groundwater system; (3) changes in land management may take a considerable period of time (>10 years) to have any noticeable impacts on recharge; and (4) recharge under lucerne was ≈30% of that under medic pasture.  相似文献   

4.
采用氯离子示踪技术确定干旱一半干旱地区地下水垂向入渗补给量对于揭示地下水补给的空间变化规律，完善地下水资源评价的理论与方法，具有重要理论与现实意义。利用天然环境氯离子示踪法评价了河北平原典型区地下水垂向入渗补给量，结果表明该方法在山前冲洪积平原水位埋深大的淡水区应用效果较好，鹿泉和栾城的补给量分别为44．72mm／a和31．31mm／a，占多年平均降雨量的8．2％和5．8％，以扩散流入渗为主；在中部冲湖积平原和滨海冲积海积平原由于天然环境氯离子浓度背景值高、水位埋深浅以及近海输入氯离子的波动性较大，该方法的应用受到一定程度的限制。  相似文献   

5.
Artificial recharge of aquifer storage can provide water during drought periods, reverse falling groundwater levels and reduce water losses associated with leakage and evaporation, as compared with surface water storage. We examine the technical and economic potential of artificial storage and recovery for drought mitigation in the Murrumbidgee Region of New South Wales, Australia. Potential locations for infiltration basins and injection/recovery wells are identified according to criteria such as water availability, aquifer suitability, recharge potential, and potential to provide a usable resource. The estimated annual artificial recharge potential is 180,000 ML through a combination of injection wells and infiltration basins. The cost estimates for artificial recharge vary from AU$ 62 ML−1 to AU$ 174 ML−1 depending on the choice of recharge method. Underground storage capacity can be developed at less than half the cost of surface storage facilities without undesirable environmental consequences or evaporation losses. The estimated benefits of artificial storage and recovery through infiltration basins are three to seven times the costs, during low allocation years.  相似文献   

6.
通过邹平县城北水文地质条件分析,建立了引黄补源条件下的邹平县城北地下水库补源模式数值模型,采用准三维非稳定流有限元法进行地下水库开发利用渗流场模拟,对地下水库在各种开采方案下的供水能力、流场演化趋势和资源优化开发模式进行预报评价。研究表明,坚持引黄补源,在保证总开采量平衡前提下,减少城东北地下水开采量,扩大渠网内地下水开采,将激发引黄渠道对地下水源地的补给、提高水源地效率、阻止城东北老开采区地下水位降落漏斗急剧下降。  相似文献   

7.
为了缓解大庆市水资源供需矛盾,提高城市供水安全保障程度,利用业已形成的大庆市西部地下水位降落漏斗,建立地下水库实施水资源人工调蓄。综合分析回灌水水源、回灌水水质、回灌水量、回灌方式等,设计大庆市西部地下水库人工回灌方案,通过数值模拟计算,模拟人工调蓄效果。模拟结果表明,人工回灌可使降落漏斗区地下水位有明显上升,采用压采的同时将注水井布设于龙虎泡管线南侧的注水方案,水位恢复效果最为明显,可使漏斗区地下水位回升11 m左右。  相似文献   

8.
Irrigation delivers major benefits in food security and human development. Irrigation also leads to waterlogging and salinity which threaten the sustainability of irrigated agriculture and pose major socioeconomic and environmental risks. The issue can be addressed by limiting net recharge to groundwater such that the water and salt keep natural equilibria. Often the information on net recharge within catchments is unavailable, particularly at lower spatial scales such as the farm or paddock; this offers little guidance for on-farm land and water management decisions—basic decisions that ultimately impact regional net recharge and waterlogging and salinity dynamics. This paper develops a cross disciplinary framework based on the concept of net recharge for setting paddock scale targets and to link these to the regional targets and community's goals for sustainable irrigation management. A management model, cast in a dynamic programming format to integrate a detailed hydrological model with an economic model was applied to estimate the productivity, profitability and sustainability of irrigated agriculture in a region of the Murray Darling Basin in Australia. SWAGMAN® Farm model was used to determine paddock scale net recharge. This interactive model enables an individual farmer to choose a profit optimizing crop mix while lowering net recharge; this in turn leads to a win-win outcome for all farmers. The net recharge metric can be used for the conversion of diffuse source groundwater recharge to a point source recharge at paddock scale, enabling the definition of private property rights to a common pool problem and assigning individual responsibilities for its management—a vexing issue and a new concept for the commons literature. Net recharge shows significant spatial and temporal variation which warrants a targeted/zonal approach to address the issue. Regional and targeted strategies and actions to address the issue are identified. Apart from its applied and action research orientation, the development of paddock scale net recharge metric is perhaps the most significant conceptual contribution of this research which can lead to shared management of groundwater aquifers.  相似文献   

9.
Increased water use in the Hebei Plain during the last decades has caused serious groundwater level decline and many geological problems which have become the biggest threat to social–economic sustainability. Thus, to determine the factors resulting in the groundwater decline and to develop a practical plan for long-term groundwater use appear to be necessary in this region. In this paper, a water balance model is used in conjunction with regression techniques to estimate the groundwater recharge coefficient and the specific yield (defined as the ratio of the volume of water that a saturated rock or soil will release by gravity drainage to the volume of rock or soil) and the groundwater withdrawn by different water use sectors and the corresponding drop in the water-table are analyzed. The decline in water-table by different crops and water economic benefit of crops are discussed in detail in order to suggest sustainable use of groundwater resources in the Hebei Plain. Finally, sample policy scenarios are developed to show how groundwater in the Hebei Plain could be used in a sustainable manner. In our study, it is found that agriculture is the major consumer of groundwater, with about 85% of the total groundwater withdrawals, and groundwater depletion is mainly caused by agricultural water use. Production of winter wheat exerts a great negative influence on the groundwater system. Winter wheat is the most water consuming crop and result in significant decline of groundwater table. Water economic benefit of winter wheat is lower than that of other crops and withdrawing winter wheat sown area is rational option to make sustainable use of groundwater. With far-sighted and regional planning, the limited water resource can be used sustainably to generate maximum social benefits. This paper will provide information necessary for land-use planning in a severe water shortage region where farmland is mainly irrigated by groundwater.  相似文献   

10.
利用长岭县50眼监测井1980-2005年的地下水位监测数据、降水量、蒸发量和人工开采量资料,采用Kriging方法对地下水位进行空间插值,得出地下水流场的时空变化特征。在充分考虑研究区地质、水文地质的情况下,利用因子关联分析和因子贡献度分析方法,对地下水流场时空变化特征的驱动力进行了研究。结果表明:11980-2005年地下水位呈现出整体东南高西北低的特征,地下水位先降低后增加,2000年为转折点。地下水经历基本均衡期、负均衡期和水位回升期,地下水流场在西北部和东南部均出现异变现象。2实际补给量、人工开采量和地下水位具有较好的关联性,二者对地下水位的贡献度呈相反规律。20世纪80年代,实际补给量和人工开采量对地下水位的影响程度相当;90年代,人工开采量对地下水位的影响程度较大。3气象因素(降水量和蒸发量)是研究区地下水流场异变的重要因素,而人工开采是主导因素。4合理的地下水资源开采对于地下水恢复有较好的促进作用,6 000~7 000万m~3开采量对于研究区是合理的。该研究对于认知区域地下水演化和地下水资源优化配置有较好的指导意义。  相似文献   

11.
Estimating groundwater recharge in response to increased atmospheric CO2 concentration and climate change is critical for future management of agricultural water resources in arid or semi-arid regions. Based on climate projections from the Intergovernmental Panel on Climate Change, this study quantified groundwater recharge under irrigated agriculture in response to variations of atmospheric CO2 concentrations (550 and 970 ppm) and average daily temperature (+1.1 and +6.4 °C compared to current conditions). HYDRUS 1D, a model used to simulate water movement in unsaturated, partially saturated, or fully saturated porous media, was used to simulate the impact of climate change on vadose zone hydrologic processes and groundwater recharge for three typical crop sites (alfalfa, almonds and tomatoes) in the San Joaquin watershed in California. Plant growth with the consideration of elevated atmospheric CO2 concentration was simulated using the heat unit theory. A modified version of the Penman-Monteith equation was used to account for the effects of elevated atmospheric CO2 concentration. Irrigation amount and timing was based on crop potential evapotranspiration. The results of this study suggest that increases in atmospheric CO2 and average daily temperature may have significant effects on groundwater recharge. Increasing temperature caused a temporal shift in plant growth patterns and redistributed evapotranspiration and irrigation water use earlier in the growing season resulting in a decrease in groundwater recharge under alfalfa and almonds and an increase under tomatoes. Elevating atmospheric CO2 concentrations generally decreased groundwater recharge for all crops due to decreased evapotranspiration resulting in decreased irrigation water use. Increasing average daily temperature by 1.1 and 6.4 °C and atmospheric CO2 concentration to 550 and 970 ppm led to a decrease in cumulative groundwater recharge for most scenarios. Overall, the results indicate that groundwater recharge may be very sensitive to potential future climate changes.  相似文献   

12.
基于SPEI的贵州省分区干旱时空演变特征   总被引：2，自引：1，他引：1  
[目的]干旱对贵州省水循环及水资源管理系统造成严重破坏,科学合理地认识干旱时空演变对抗旱减灾及社会稳定至关重要。[方法]利用贵州省18个气象站点1960 2012年逐月降水和平均气温数据计算标准化降水蒸散指数SPEI评估干旱,采用M-K趋势检验、B-G分割法、极点对称模态分解法ESMD和反距离权重插值法分析了贵州省分区分时段干旱时空演变特征。[结果]贵州省月、季和年尺度SPEI序列均呈波动下降趋势,其中夏季和冬季SPEI序列变化未通过显著性检验,且20世纪60 90年代,贵州省各分区干湿变化具有较强的一致性,21世纪各分区的干湿变化不具有明显的一致性;以黔西北年SPEI为例,基于ESMD分解法得到3个模态分量IMF和1个趋势项R,从R看出干旱指数整体上呈波动“减小-增大”趋势,分析IMF1-IMF3振荡可得黔西北地区干旱具有2.1、7.6和26.5a的周期特征,且年代际周期26.5a在干旱变化中起主导作用,ESMD法在非线性、非平稳时间序列周期及趋势分析中应用效果较好;依据B-G分割法检测结果,得到1960 1986年、1987 2003年和2004 2012年3个研究时段,2004 2012年黔西北地区的冬旱强度和黔西南地区的春旱频率达到最大,分别为1.82和77.78%,2004 2012年四季干旱强度明显增大,且1986 2012年贵州省高强度干旱呈现由北向南转移趋势,1960 2003年四季干旱高频区呈现由东南向西北转移趋势,1960 2012年各分区四季干旱频率呈现增加趋势。[结论]贵州省各分区呈干旱化趋势,且干旱频率和强度呈现不同程度的增加。  相似文献   

13.
近年来三江平原的平原-丘陵-湿地交融区土地利用方式变化显著,造成地下水水位下降、水资源紧缺等问题,然而揭示该区土地利用方式变化对水资源影响的报道较少,且难于精准描述地表、地下、湿地和绿水等水资源量时空变化。本文联合基于格子波尔兹曼法的分布式TOPMODEL和湿地水流运动模型构建平原-丘陵-湿地交融区水文模型,利用GIS和RS技术,结合地学信息图谱与空间自相关方法,分析了挠力河流域土地利用方式变化及其对水资源量影响。结果表明:根据耕地面积变化和动态度分布得1990—2013年间挠力河流域草地和林地面积变化不大,旱地面积轻微下降;挠力河流域中部与北部区域生产条件优越的未利用地和旱地转为水田;土地利用方式变化对水资源影响由强到弱的顺序为灌溉水田抽取地下水量、绿水储量、径流深、绿水流量、补给地下水量;水稻田不同生育期蒸发量不同,造成了挠力河流域5—6月期间绿水流量增加、绿水储量减少、径流深减少、补给地下水量增加和灌溉水田抽取地下水量增加等趋势,7—8月期间这一增加趋势逐渐减弱,8月后这一趋势结束;水田密集区域绿水流量大,绿水储量和径流深减少,而补给地下水量和灌溉水田抽取地下水量增加。  相似文献   

14.
气候变化对北京地下水资源的影响分析   总被引：2，自引：0，他引：2  
总结了北京地下水资源概况,对近60 a来北京气温、降水、蒸发的变化特征进行了分析。结果表明:北京气温在波动中增暖,增幅约为0.08℃/a,而年降水量表现为下降趋势,平均变幅为-3.45 mm/a;年总水面蒸发量表现为明显的下降趋势,平均变幅为-8.04 mm/a。降水减少加之超量开采给地下水资源带来不利影响,导致地下水位持续下降,局部浅层含水层疏干,1999-2013年,第四系地下水累计亏损量达65.82亿m3,年均亏损量4.39亿m3,地下水水质也随之变差。平原区地下水蒸发量由1960-1980年的年均4.95亿m3/a,降至2001年以来的年均0.44亿m3/a。气温对地下水的影响是间接和微弱的。  相似文献   

15.
Castilla-La Mancha in Central Spain is a semi-arid area of extremely high interannual and seasonal rainfall variability. Average annual rainfall for the catchment of the Upper Guadiana using data from 60 rain gauges for October 1956–September 1991 varied from a minimum of 326 mm in October 1982–October 1983 to a maximum of 642 mm in October 1968–September 1969. The mean annual rainfall for the period was 495 mm with a coefficient of variation for annual rainfall of 26.4%. In addition to this the spatial variability of rainfall is particularly high. For example total annual rainfall varied from 200 to 1200 mm for the hydrological year October 1968–September 1969 over a distance of only 50 km. The mean annual rainfall for all 60 stations for the period 1956–1991 was 460 mm with a coefficient for spatial variation of 15%. Dryland farming which relies on these uncertain precipitation inputs is a high risk activity [Tarjuelo, J.M., de Juan, J.A., Valiente, M., Garcia, P., 1996. Agric. Water Manage. 31, 145–163] and over recent decades intensive irrigation has increased dramatically in order that precipitation inputs can be supplemented as required thereby allowing more stable agricultural productivity. The paper uses a coupled hydrology and vegetation growth model – PATTERN [Mulligan, M., 1996. Modelling hydrology and vegetation change in a degraded semi-arid environment. PhD. Thesis, University of London] to explore the relationship between irrigation and productivity for different soils typical of the Upper Guadiana catchment. Analysis of the model results shows that irrigation efficiency is highly sensitive to both soil texture and irrigation volume. Optimally efficient irrigation in terms of water losses occurs at the lowest volumes of applications. Fine grained soils are better suited to irrigation than coarse grained soils as losses to recharge are minimised. Coarse grained soils have large recharge losses and irrigation is also more sensitive to small changes in texture for coarser soils. Irrigation losses through recharge are also very sensitive to the interannual and spatial variability of rainfall.  相似文献   

16.
Summary Field experiments were conducted at two sites with differing root zone water holding capacities. Corn grain yield was measured as a function of water management treatments. Stress development in given treatments was generally limited to one of three periods (planting-to-12-leaf, 12-leaf-to-blister-kernel, and blister-kernel-to-physiologic-maturity) during the growing season. Stress levels were defined as low (L), moderate (M) or severe (S) and were based on degree of soil water depletion and an allowable level of leaf xylem pressure depression in midafternoon.Yield vs seasonal ET exhibited linear relationships. Slope of an estimated upper bound function was 0.28 T/ha-cm of water use. Maximum seasonal grain yields were consistently produced with an L-L-L stress sequence allowing about 30–40% depletion of the root zone available water capacity (to 122 cm depth) between irrigations. A trickle irrigated treatment that maintained near zero soil water potential averaged about 4% more yield than the 30–40% depletion criteria, but this difference was not significant at P=0.05.Results, when normalized as relative yield (Y/Ym) vs relative seasonal evapotranspiration (ET/ETm), indicated an upper bound slope of 1.50% yield loss per 1% decline in seasonal ET from the ETm level. When stress was concentrated in the 12 leaf to blister kernel period, the yield reduction slope was 2.60%.Average observed Y/Ym ratios were 0.95 for M-L-L, 0.92 for S-L-L, 0.85 for L-M-L, 0.62 for L-S-L, 0.62 for L-S-L, 0.90 for L-L-M, and 0.69 L-L-S stress sequences.If water stress is limited to one growth period per season an upper bound yield attainment is likely if irrigations relieve stress before available root zone storage capacity is 90–95% depleted in the planting to 12 leaf period, 80–90% depleted in 12 leaf to blister kernel period or when a programmed depletion to 100% available water exhaustion near physiological maturity is achieved in the later grain fill period.Yield reduction of less than 5 % from potential levels appears likely in the climatic setting of this study when root zone available water depletions are limited to 60–70% in the early vegetative period (assumes near field capacity moisture at planting), 30–40% in the 12 leaf to blister kernel period, and 50–60% in the later grain fill period.This work was supported by North Dakota Agricultural Experiment Station Projects 1432 and 1435 and by funds provided by the U.S. Department of Interior, Water and Power Resources Service  相似文献   

17.
In arid and semi-arid regions irrigation is usually needed to provide enough water for crop growth in cultivated areas. As surface waters are scarce, especially in summertime when the water is needed, groundwater is heavily used to supply the water demand. Overexploitation of the aquifer in dry years causes depletion of the groundwater storage and systematical lowering of the piezometric levels. This is a particular problem in aquifers developed in closed basins where lateral inflow is nearly absent and replenishment is constrained by rainfall recharge. In this paper, simple indicators derived from meteorological data, abstraction rates and piezometric time series are compared with the groundwater storage depletion as obtained from a calibrated groundwater flow model. Application of the method to the overexploited Shahrekord basin in Iran shows that for the simulated period 1989-2003 an accumulative index of the difference of aquifer recharge, as calculated by a soil moisture balance method, and groundwater abstraction has a correlation coefficient of nearly one with model calculated storage. Indicators based on the filling index derived from piezometric time series or on the ratio of aquifer discharge to recharge have slightly lower correlations. The accumulated index indicator can be used to follow aquifer storage in the future without the need to run the full groundwater flow model. This simple approximation is restricted to aquifer systems with a limited lateral inflow and outflow.  相似文献   

18.
Nitrogen (N2) fixation in an irrigated white clover-grass sward was estimated using the 15N isotope dilution technique following the addition of K15NO3 at 0.5 gN m–2 and 80 atom % 15N in a field study during the 1990–91 season. Two water salinity treatments (channel water; ECw = 0.07 and groundwater; 2.4 dS m–1) and four irrigation frequencies were included in a factorial design with four replicates. The channel water treatments were irrigated when pan evaporation minus rainfall equalled 50 mm, whereas the groundwater treatments were irrigated at deficits of 40, 50, 65 or 80 mm. Cumulative dry matter of the clover was significantly less in treatments irrigated with saline groundwater compared to channel water at day 164, and soil salinities (ECe) increased on average from 2.3 to 5.07 dS m–1. In contrast, salinity of the irrigation water had no effect on the cumulative yield of grass. Cumulative dry matter of the grass and clover were not affected by groundwater irrigation frequency. Total N accumulation by the grass did not differ significantly between treatments. However, total N accumulation in white clover was significantly less (P < 0.05) in all treatments irrigated with groundwater compared to channel water. Neither the N concentrations of the grass nor the clover differed significantly between the salinity treatments. Salinity and irrigation frequency had no effect on the proportion of clover N (Patm) derived from N2 fixation. The values of Patm were high throughout, and increased progressively from 0.78 at day 39 to 0.91 at day 164 (P < 0.01). However, the yield of fixed N was lower in clover when watered with groundwater compared to channel water (P < 0.01). Thus low to moderate soil salinity did not affect the symbiotic dependence of clover, but the yield of biologically-fixed N was depressed through a reduction in the dry matter yield of the legume.  相似文献   

19.
气候变化和人类活动对灌区地下水埋深的影响   总被引：1，自引：0，他引：1  
[目的]探析气候变化和人类活动对灌区地下水埋深的影响.[方法]利用年代波动性分析、突变检验、灰色关联分析、敏感性分析、双累积曲线法和相对贡献率分析了人民胜利渠灌区1952-2013年地下水埋深及其影响因素的变化和突变特征,并识别了地下水埋深与各影响因素间的响应特征.[结果]人民胜利渠灌区地下水埋深呈明显增加趋势(0.8...  相似文献   

20.
塔里木河干流流域气候变化特征及其突变分析   总被引：2，自引：2，他引：0  
以塔里木河干流流域为研究区域,选取流域内10个气象站点1961—2013年逐日地面气象资料,采用Penman-Monteith模型、气候倾向率、Mann-Kendall突变检验方法,分时段分析了塔里木河干流流域气候变化特征及其突变。结果表明,1塔里木河干流流域年平均气温为"突变点前增幅(0.09℃/10 a,p0.05)低于突变点后增幅(0.13℃/10 a,p0.05)",年干燥度为"突变点前减幅(4.05/10 a,p0.05)高于突变点后减幅(0.54/10 a,p0.01)",呈"冷干—暖湿—冷干"的变化趋势,1990年和1976年分别是年平均气温和干燥度的突变点。2塔里木河干流流域平均气温为"夏季春季秋季冬季"的时间分布,干燥度为"冬季秋季春季夏季"的时间分布,春季平均气温和干燥度均为"突变点前增幅(0.09℃/10 a,11.42/10 a)低于突变后增幅(0.52℃/10 a,14.01/10 a)",呈"冷干-暖湿-暖干"的变化趋势;夏、冬季为"突变点前变幅(0.02℃/10 a,-1.93/10 a;-0.25℃/10 a,-84.48/10 a)高于突变点后变幅(-0.01℃/10 a,-0.05/10 a;-0.12℃/10 a,22.14/10 a)",呈"冷干—暖湿—冷干"的变化趋势;秋季为"突变点前变幅(0.02℃/10 a,-56.76/10 a)低于(高于)突变点后变幅(0.05℃/10 a,-16.34/10 a)",呈"冷干—暖湿—冷湿"的变化趋势,2003年、1999年、1993年、1978年和1983年、1969年、1963年、1980年分别是四季平均气温和干燥度的突变点。3塔里木河干流流域年、季干燥度均在16以上。2000年后,年、夏、冬季冷干化明显,春季暖干化明显,秋季冷湿化明显,且秋、冬季平均气温减幅最大(0.53℃/10 a,p0.01;0.9℃/10 a,p0.01)。  相似文献   

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