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1.
黑河流域土地利用变化对地下水资源的影响 总被引：1，自引：0，他引：1
Land use and land cover changes have a great impact on the regional hydrological process. Based on three periods of remote sensing data from the 1960s and the long-term observed data of groundwater from the 1980s, the impacts of land use changes on the groundwater system in the middle reach of Heihe River Basin in recent three decades are analyzed by the perspective of groundwater recharge and discharge system. The results indicate that with the different intensities of land use changes, the impacts on the groundwater recharge were 2.602 × 10^8 m^3/a in the former 15 years （1969-1985） and 0.218 × 10^8 m^3/a in the latter 15 years （1986-2000）, and the impacts on the groundwater discharge were 2.035 × 10^8 m^3/a and 4.91 × 10^8 m^3/a respectively. When the groundwater exploitation was in a reasonable range less than 3.0 × 10^8 m^3/a, the land use changes could control the changes of regional groundwater resources. Influenced by the land use changes and the large-scale exploitation in the recent decade, the groundwater resources present apparently regional differences in Zhangye region. Realizing the impact of land use changes on groundwater system and the characteristics of spatial-temporal variations of regional groundwater resources would be very important for reasonably utilizing and managing water and soil resources. 相似文献
2.
黑河流域土地利用变化对地下水资源的影响 总被引：26，自引：0，他引：26
土地利用与覆被变化对区域水文过程具有深刻影响。利用1960s以来的三期遥感数据和1980年以来的地下水长期观测数据, 从地下水补给和排泄系统两方面, 分析了近30年来甘肃省黑河流域中游地区土地利用与覆被变化对地下水系统的影响, 结果表明：以1985年为界, 随土地利用与覆被变化强度不同, 前后15年土地利用变化对地下水系统补给的影响分别达到2.602亿m3/a和0.218亿m3/a, 对排泄系统的影响分别为2.035亿m3/a和4.91亿m3/a, 在保持区域人工开采量不超过3.0亿m3/a的合理幅度下, 土地利用变化对区域地下水资源变化起着决定作用;在区域土地利用与覆被变化和近10年来人类较大规模开采影响下, 甘肃省张掖盆地地下水资源变化出现了显著的区域差异性。认识土地利用变化对流域地下水系统的作用与区域地下水资源的时空变化特征, 对流域水土资源合理利用规划与管理有重要意义。 相似文献
3.
Northwest China includes Xinjiang Ugyur Autonomous Region, Qinghai Province, Gansu Province, Ningxia Hui Autonomous Region and Shaanxi Province, covering 308×104 km2. It is located in the warm-temperate zone and the climate is arid or semi-arid. Precipitation is very scarce but evaporation is extremely high. The climate is dry, the water resources are deficient, the eco-environment is fragile, and the distribution of water resources is uneven. In this region, precipitation is the only input, and evaporation is the only output in the inland rivers, and precipitation, surface water and groundwater change with each other for many times, which benefits the storage and utilization of water resources. The average precipitation in this region is 232 mm, the total precipitation amount is 7003×108 m3/a, the surface water resources are 1891×108 m3/a, the total natural groundwater resources are 1150×108 m3/a, the total available water resources are 438×108 m3/a, and the total water resources are 1996×108 m3/a and per capita water resources are 2278 m3/a. The water resources of the whole area are 5.94×104 m3/(a.km2), being only one-fifth of the mean value in China. Now, the available water resources are 876×108 m3/a, among which groundwater is proximate 130×108 m3/a. 相似文献
4.
对雷州半岛土壤渗透性进行了分析,并结合地形地貌、降雨入渗补给情况,识别地下水潜在补给区。雷州半岛土壤渗透性空间差异较大,饱和渗透系数变化范围为 0.04~8.83 m/d。总体而言,半岛南部、遂溪西北部渗透性较好,中部较差。土壤渗透系数受到土地利用类型、土壤粒径、土壤有机质等的影响。随着土壤中值粒径和有机质含量的增加,土壤渗透系数增加。不同土地利用类型,其土壤平均渗透性优劣表现为：荒地＞桉树林＞甘蔗＞菜地＞菠萝＞其他林地＞香蕉＞苗圃＞坡稻＞水稻田。降雨入渗补给系数南北高、中间低,随着土壤渗透系数增加而提高。半岛南部石茆岭和石板岭一带,地势高,坡度较缓,同时土壤渗透性和降雨入渗补给系数相对较高,为雷州半岛地下水潜在补给区。 相似文献
5.
在天山北坡以选取的典型区昌吉市和阜康市为例,利用动态相关法、典型流域开采模型法、可开采系数法分析确定地下水可开采量。对这3种方法分别分析了其计算过程中的制约因素,并将计算的结果和以往成果进行了比较。结果表明：动态相关法计算结果准确度较高,成果可靠性高,且在以往的新疆地下水资源评价成果中,至今还未采用过,故推荐动态相关法为新疆天山北坡平原区地下水可开采量确定方法的首选。 相似文献
6.
The groundwater table has been declining at a rate of 0.65 m/yr in Luancheng County since large scale groundwater extraction carried out in the 1960s. The drop of precipitation, substantial increase in agricultural output, variations of crop planting structure and construction of water conservancy projects in the headwater area all tie up with the decline of the groundwater table. On the basis of analyzing the hydrogeological conditions and the water resources utilization of Luancheng County, a three-dimensional groundwater flow model was developed to simulate the county’s groundwater flow through finite-difference method using Visual Modflow software. We divide the research field into four parts after analyzing the hydrogeological condition. Based on parameter calibration and adjustment using measured data, the hydraulic conductivity and specific yield were simulated. Using the calibrated model, we analyze the agricultural water saving potentiality and its influence on the groundwater. The results are as follows: (1) if we decrease the amount of water extracted by 0.14×108 m3, the average groundwater table of the five observation wells in December will rise by 0.33 m; (2) if we decrease the water by 0.29× 108 m3, the average groundwater table of the five observation wells in December will rise by 0.64 m; and (3) if we increase the water by 0.29×108 m3, the average groundwater table of the five observation wells in December will decline by 0.45 m. So we can draw a conclusion that controlling the agricultural water use is an important way to prevent the decline of groundwater table. 相似文献
7.
华北平原地下水动态及其对不同开采量响应的计算——以河北省栾城县为例 总被引：22，自引：1，他引：22
自从20世纪60年代大规模开采地下水以来,栾城县的地下水位以每年大约0.65 m的速度下降.降雨量的减少、农业产量的大幅度提高、种植结构的变化以及上游水利工程的修建,都与地下水位的下降有着密切联系.利用Visual Modflow软件,在分析该县水文地质条件与水资源利用的前提下,运用三维地下水流模型,通过有限差分方法对栾城县的地下水系统进行了模拟,结果表明:5个观测孔的地下水位计算值与实测值拟合程度很好,模拟出的地下水流场与实际情况基本一致.利用掌握的水文地质资料,进行参数分区,通过实测资料的校正、调参,模拟出各分区参数值.利用校正后的数学模型,对栾城县地下水对不同开采量的响应进行了计算,结果如下:在现状农业开采量1.01×108m3基础上分别减少14%(0.14×108m3)、29%(0.29×108m3)和增加29%(0.29×108m3)的情况下,到12月份5个观测孔的平均地下水位分别比现状地下水位上升了0.33 m,0.64 m和下降了0.45 m. 相似文献
8.
塔里木盆地南缘地下水脆弱性评价 总被引：22，自引：8，他引：14
干旱区地下水脆弱性是地下水系统本身固有的不稳定属性,是系统结构、功能状态在人类活动干扰及气候变化等自然因素作用下具有的敏感性、易变性和弹性的综合反映。可以以河川径流中冰雪融水比重、地表径流入渗占地下水补给比例、地下水补给强度、地表水的引用率等十项指标(IRRUDQELTS)进行定量评价。通过对塔里木盆地南缘地下水脆弱性评价,表明该区属地下水严重脆弱区,其脆弱程度远大于地下水开发利用程度较高的河西走廊,其中又以民丰县、皮山县为极端脆弱。 相似文献
9.
A recent decision to allow higher levels of urban development in central Oahu, Hawaii, has heightened the concern about possible loss of agricultural land and further drops in aquifer levels. This paper examines such potential impacts and offers a procedure for incorporating them into land use planning. First, a water-balance simulation model computes the change in groundwater recharge under changes in land use and irrigation technology. The resulting changes, together with estimated water demands for the agricultural, commercial and residential sectors, are then included in a multiobjective programming model that identifies optimal patterns of land use conversion under different objective trade-offs. Objectives treated are the minimization of agricultural land loss and of water demand, and the maximumization of recharge over withdrawal. The second objective pertains to water management during drought, while the third refers to sustainable groundwater management. Results show that, depending on the relative importance given each of these two objectives, land moving out of sugar cane will differ significantly in amount and by type of irrigation presently used. The relative importance of these objectives thus needs to be determined if water is to play a coherent and guiding role in land use planning. 相似文献
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11.
新疆和田地区地下水资源及其可持续开发利用 总被引：13，自引：5，他引：8
和田地区地下水具有一定的开发潜力,但地下水的可开采资源量依地表水的开发程度不同而变化。如果地表水引水率维持现状,则地下水最大可开采量为地下水天然补给量的55.8%,截取的蒸发蒸腾量为604%,同时泉水的消减率为35.56%。若地表水的引水率达80%,渠系利用系数提高到0.55时,地下水最大可采量为天然补给量的59.7%,截取的蒸发蒸腾量为70%,而泉水的消减率为49.4%。地下水的开发必须与保护并重,首先应加强昆仑山区的冰雪资源和水源涵养林的保护,合理开发平原区地下水与地表水;其次应积极预防地下水的污染及可能产生的生态环境负效应;同时必须加强基础建设和能力建设,提高全民节水意识。 相似文献
12.
Competitive use of transboundary freshwater resources is becoming one of the key factors influencing regional peace and political relationship among states. In China, 18 major international river basins are concentrated in three regions, of which the total annual outflow at the border is 7320×108 m3, occupying 26.8% of the total annual runoff of China, and the inflow at the border is only 172×108 m3. In this paper, we analyzed the major drivers affecting shared water vulnerability in China, namely: (1) changes in physical conditions affecting the availability of water; (2) competing objectives between economic development and ecological conservation; (3) lack of emergency response mechanisms; (4) unsound administrative institutions; and (5) shortcomings in the development of regional cooperation based on transboundary waters. We concluded by identifying four pathways for reducing vulnerability: (1) encouraging scientific research cooperation; (2) constructing information-sharing channels; (3) establishing early-warning mechanisms; and (4) promoting further coordination and negotiation. 相似文献
13.
One-dimensional models of groundwater flow, sediment thermal history and petroleum generation within continental rift basins 总被引：1，自引：0，他引：1
We investigate the effects of convective heat transfer on the thermal history of sediments and petroleum formation within continental rift basins using one-dimensional mathematical modelling. The transport equations used in this study to describe vertical groundwater flow and conductive/convective heat transfer are solved by the finite element method. Sediment thermal history is quantitatively represented using first-order rate kinetic expressions for kerogen degradation and an empirical fanning Arrhenius model for apatite fission track annealing. Petroleum generation is also represented in the model by a suite of first-order rate kinetic expressions. The analysis provides insights into how pore fluid circulation patterns are preserved in the rock record as anomalies in palaeogeothermometric data within continental rifts. Parameters varied in the numerical experiments include the ratio of conductive to convective heat transfer (thermal Peclet number; Pe) and the composition of the disseminated organic matter in the sediment (type II and III kerogen). Quantitative results indicate that vertical groundwater flow rates on the order of a mm/yr cause a change in computed vitrinite reflectance of the rocks and a shift in the depth to oil generation by as much as 3000 m. Differences in thermal gradients between recharge and discharge areas (Pe= 0.6) also change the width of the zone of oil generation by a factor of two. Even more dramatic, however, are the large changes in predicted apatite fission track length distributions and model ages between recharge and discharge areas. For example, a sediment package buried to a depth of 2400 m over 200 Myr within the groundwater recharge column had a fission track length distribution with a computed mean and standard deviation of 12.83 μm and 0.77 μm, respectively. The fission track model age for this sediment package was 209 Ma. The same sediment package in the discharge area has a distribution with a mean track length of 5.68 μm, a standard deviation of 3.37 μm, and a fission track model age of 2.6 Ma. Transient groundwater flow simulations, in which fluid circulation ceases after a period of time within the rift basin, are also presented to illustrate how disturbances in palaeogeothermometric parameters are preserved on geological time-scales. Vitrinite reflectance profiles require about 10 Myr to return to conductive conditions within groundwater recharge areas while the convective disturbances are preserved indefinitely along the discharge column, as long as further subsidence does not occur. Ancient groundwater flow systems are preserved as anomalies in computed apatite fission track model ages and distributions much longer after groundwater flow stops, relative to organic-based geothermometers. Significant differences exist in model ages between recharge (145 Ma) and discharge (90 Ma) areas 200 Myr after flow has ceased. However, calculated fission track histogram distributions are virtually identical in recharge and discharge areas after about 50 Myr. Our study suggests that ancient groundwater flow systems can be detected by comparing thermochronometric data between suspected recharge and discharge areas within continental rifts. Vitrinite reflectance profiles, observed offsets in the depth to the onset of petroleum generation, and apatite fission track annealing studies are all well suited for detecting groundwater flow systems which have been relatively long lived (107 years). Apatite fission track age data are probably best suited for identifying ancient groundwater flow systems within rifts long (>200 Myr) after flow ceases. 相似文献
14.
干旱区水土资源时空变化的定量研究 总被引：11，自引：9，他引：11
水资源是制约干旱区土地资源开发利用的主要自然因素，水、土资源利用在时间和空间上平衡与否的矛盾影响着干旱区生态环境与社会发展。用定量化的数学模型表示二者的互相影响，能描述、解释和预测二者关系并能为制定对策提供依据。本文首先分析了干旱区土地利用与水资源的相互影响，然后对水土资源相互影响下时空变化的模拟方法和理论进行了综述。一方面从蒸散的计算、模拟地下水补给、模拟区域尺度上土地利用影响、模拟土地管理措施影响、模拟抽取地下水影响、以系统方法模拟土地利用影响等几方面对土地利用影响下水资源的时空变化模拟进行了综述。同时对水资源影响下土地利用变化的模拟从主要考虑水文作用的水文－植被模型的建立应用及引入人为因素为驱动力的土地利用变化模拟两方面做了综述。文章最后进一步概括了干旱区水土资源时空变化模拟的趋势并就此方面的研究提出了三点展望意见。 相似文献
15.
通过对长武黄土塬区不同林龄苹果林地下0~20 m深剖面土壤湿度及土壤水氯离子浓度测定,定量分析了黄土塬区苹果种植对厚深黄土剖面土壤水分及地下水补给的影响。结果表明：随着林龄增加,苹果林地深剖面土壤水分由浅及深逐年降低,深层土壤储水量呈倒“S”曲线趋势下降,27龄之后进入稳定期。丰水年份形成的活塞流是黄土塬区深层渗漏以及地下水补给的主导方式,农田下地下水年均潜在补给量为30.2 mm,占年均降水量的5.2%。农田转换为苹果林地后形成的深厚土壤干层将阻断降水对地下水的补给,减弱地下水补给过程中活塞流的主导作用。需通过政策引导协调农果面积比例,保证地下水资源持续补给,达到可持续利用的目的。 相似文献
16.
2003—2017年植被变化对全球陆面蒸散发的影响 总被引：1，自引：0，他引：1
蒸散发是陆面水循环的关键环节和过程,是研究水循环对人类活动和气候变化响应的关键要素。过去十几年,全球下垫面的植被变化剧烈,但如何影响全球陆面蒸散发仍未得到清晰的揭示。本文采用500 m分辨率MODIS数据驱动PML-V2模型,定量解析了2003—2017年植被变化对全球陆面蒸散发的影响。结果显示：在全球尺度上,植被变绿使得全球蒸散发呈现显著的增加趋势,使陆地水循环加快;区域尺度上,植被变化对蒸散发的影响则存在明显的地带性和非地带性特征,如在北美洲中北部、欧洲、中国东部、非洲南部和澳大利亚东北部等地区,蒸散发总量的增加主要是由植被蒸腾增加而引起的。分析不同植被功能类型区的贡献显示,下垫面变化对灌木和耕地影响尤为明显,并在2012年以后呈现增强趋势;这2个植被类型区的全球年总蒸散发累积增加量为0.41×103 km3 a-1,约为黄河流域多年平均径流量的8倍。该研究结果有助于进一步加强关于下垫面变化对陆地水循环的影响及其可能带来的局部气候变化的认识。 相似文献
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In order to find out the variation process of water-sediment and its effect on the Yellow River Delta, the water discharge and sediment load at Lijin from 1950 to 2007 and the decrease of water discharge and sediment load in the Yellow River Basin caused by human disturbances were analyzed by means of statistics. It was shown that the water discharge and sediment load into the sea were decreasing from 1950 to 2007 with serious fluctuation. The human activities were the main cause for decrease of water discharge and sediment load into the sea. From 1950 to 2005, the average annual reduction of water discharge and sediment load by means of water-soil conservation practices were 2.02×109 m3 and 3.41×108 t respectively, and the average annual volume by water abstraction for industry and agriculture were 2.52×1010 m3 and 2.42×108 t respectively. The average sediment trapped by Sanmenxia Reservoir was 1.45×108 t from 1960 to 2007, and the average sediment retention of Xiaolangdi Reservoir was 2.398×108 t from 1997 to 2007. Compared to the data records at Huanyuankou, the water discharge and sediment load into the sea decreased with siltation in the lower reaches and increased with scouring in the lower reaches. The coastline near river mouth extended and the delta area increased when the ratio of accumulative sediment load and accumulative water discharge into the sea (SSCT) is 25.4–26.0 kg/m3 in different time periods. However, the sharp decrease of water discharge and sediment load into the sea in recent years, especially the Yellow River into the sea at Qing 8, the entire Yellow River Delta has turned into erosion from siltation, and the time for a reversal of the state was about 1997. 相似文献
19.
太湖流域土地利用变化对流域产水量的影响 总被引：38，自引：2，他引：38
根据土地详查和土地利用总体规划资料，分析太湖流域近２０年土地利用的现状特点和将来变化趋势。并以 １９９１年降雨类型分别计算了 １９８６、１９９６和 ２０１０年土地利用状况下流域的产水量。结果表明，太湖流域土地利用变化的主要特点是耕地面积的减少和建设用地面积的增加。同样降雨类型，１９９６年流域下垫面状况下的产水量比 １９８６年的多１０．１８ × １０８ ｍ３，２０１０年产水量将比 １９８６年多 １２ × １０８ｍ３。太湖流域土地利用变化对流域产水量有较大影响，这与２０世纪９０年代以来太湖持续高水位的现象相吻合。 相似文献
20.
Sediment cores from Chappice Lake, a hypersaline, groundwater-fed lake in southeastern Alberta, have been used in previous studies to reconstruct Holocene climate using lake levels as a source for proxy climate data. This assumes that the lake is fed by a shallow groundwater system sensitive to changes in climate. In this study we use the dynamics and chemistry of groundwater entering the lake to test this hypothesis.Groundwater inputs calculated from historical records using a simple water budget were highest during periods when the precipitation deficit was high. Over specific time intervals, the expected relationship between lake volumes and climate were not always found. Feedback loops between lake levels and groundwater input, and time lags within the system are the mechanisms proposed to explain these discrepancies.Field measurements suggest discharge of a local surficial groundwater system. Slug tests reveal a high conductivity system (K = 10-5 m/s) surrounding the lake. Hydraulic heads measured in standpipe, multilevel and minipiezometers installed around Chappice Lake show that the lake is situated in a closed hydraulic head contour. Hydraulic heads and water table elevations show strong annual fluctuations corresponding to seasonal changes in recharge. Horizontal hydraulic gradients measured in areas of groundwater springs indicate a strong horizontal component of flow towards the lake. Vertical hydraulic gradients are low and indicate the upward flow of water consistent with the discharge of a shallow, surfical groundwater system.Groundwater sampled from deposits surrounding Chappice Lake and springs feeding the lake have compositions similar to both shallow surficial aquifers and bedrock aquifers suggesting that the lake may be receiving inputs from both sources. However, evaporation simulations using PHRQPITZ, show that the evaporation of water typical of bedrock aquifers result in a mineral assemblage and brine composition different from that found at Chappice Lake. This suggests that discharge of a regional groundwater system can be eliminated as a dominant source over the lake's history. Evaporation simulations suggest that evaporation of groundwater from shallow surficial deposits can best explain the present mineral assemblage and brine chemistry and were likely the dominant source of water to the lake.Bedrock and shallow surficial groundwater sources have different chemistries and isotopic compositions. In hydrogeological settings such as Chappice Lake where more than one source may contribute to the lake, the relative importance of the different sources may change with changes in climate. If the source water composition to the lake changes, identifying changes in climate or hydrology based on changes in the composition of the lake preserved in sediment core will be made more difficult. This may complicate paleoclimate and paleohydrological reconstructions that rely on mineralogical and isotopic data. 相似文献