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1.
In irrigated agricultural landscapes, land-use conversion may have landscape-level social, hydrological, and ecological effects. We used geographic information systems (GIS) and interviews to analyze development effects on irrigation in the Henry's Fork Watershed, Idaho. Farmers developed irrigation there in the 19th century, and incidental recharge from canal seepage and flood irrigation raised groundwater levels and expanded wetlands. Cohesive culture in agricultural communities sustained irrigation systems until amenity-driven demographic shifts beginning in the 1970s led to development approved by local governments with land-use planning but no water-management authority. Although only 5% of irrigated land has been converted, development has fragmented irrigated landscapes and made canal-system operation more difficult, potentially reducing groundwater levels, wetland extent, and return flows critical to downstream irrigators and fish and wildlife. We discuss future scenarios, highlighting the need for increased communication among local and state governments regarding land use and water management in irrigated landscapes across the West. 相似文献
2.
Integrated Water Resource Management (IWRM) becomes increasingly important in arid watersheds, where water resources are
scarce and demands are rising under increased population pressure. In this case study, we present the results from the Elqui Valley
in Chile, where water resources are shared between agriculture, mining operations, hydropower generation and drinking water for
nearby cities. An IWRM model was applied to visualize water resources distribution in the catchment and determine irrigation and
water use efficiencies. After calibration with observed surface and groundwater measurements, the model showed large differences
in efficiencies between different irrigation sectors. Most notably, irrigation sectors with the highest irrigation security, i.e.,
higher water rights per hectare, were characterized with lower water use efficiencies. Frequent water deficits were present in sectors
downstream of the main reservoir, which was related to limited water rights per hectare, lower irrigation efficiencies and
higher water demands due to larger agricultural areas. In subsequent scenario analyses, the model was used to evaluate the impact
of improved irrigation and water use efficiencies in these downstream sectors, to confirm an important reduction in water deficits,
except for drought years when surface water resources are insufficient. In a third scenario, groundwater resources were allowed to
compensate for water deficits, effectively reducing these in most irrigation sectors, especially during droughts. Expansion of the
current agricultural area by 37% was evaluated, as a future scenario, and was found to be unsustainable, as aquifer levels are lowered
to such levels that make annual recharge insufficient. 相似文献
3.
降雨、灌溉入渗和潜水蒸发在卫宁平原地下水循环中有重要的作用。为了准确评价卫宁平原地下水垂向入渗补给量和蒸发量，通过设立中卫、中宁两个包气带原位试验点，观测期为2013年6月~2013年11月和2014年4月~2014年10月，获取了两个试验点不同埋深处的土壤水负压、温度、岩性及水分运移参数，并采用定位通量法计算试验点的地表蒸散发、入渗量和潜水面蒸发、入渗量。结果显示：在包气带岩性相同、灌溉期相同（7~10月）、总灌溉量相近条件下，作物的灌溉模式决定了灌溉对潜水的补给强度：玉米少次大量（150 mm·次-1）灌溉对潜水的补给量为373.65 mm，远远大于茄子多次小量（50 mm·次-1）的灌溉模式下的152.3 mm；而在包气带岩性相同、种植作物相同、灌溉模式不变的前提下，同时期潜水面净补给强度相近：中宁试验点2013年7~10月份潜水面净通量为32.88 mm，2014年同期为57.42 mm。在降雨情况或灌溉量较小（50 mm）的情况下，植被的生长会阻碍水分在包气带中的下渗；在灌溉量较大（100 mm和150 mm）的情况下，植被的生长会促进包气带水分的下渗。 相似文献
4.
《地理学报(英文版)》2019,(6)
From a critical zone perspective, the present paper aims to present the magnitude of groundwater recharge under different agricultural land-use types, reveal the process of water and solute transport in thick vadose zone, evaluate the "time lag" effect of recharge, and underscore the role of thickening vadose zone in recharge. The results indicated that different agricultural land-use types need to be further considered in recharge rate estimate. Under the typical irrigation condition in the piedmont plain, the recharge rate under flood irrigated winter wheat and summer maize(W/M_F), maize(M), non-cultivation(NC), native vegetation(NV), vegetables(V), and orchards(O) is 206.4, 149.7, 194.1, 46.4, 320.0, and 48.6 mm/yr, respectively. In the central plain, the value under W/M_F, M, NC, V, and cotton(C) is 92.8, 50.8, 85.0, 255.5, and 26.5 mm/yr, respectively. Soil water residence time(several years) and groundwater level response time(several months) should be distinguished to further understand the processes of groundwater recharge, because the soil water displacement velocities range from 0.2 to 2.2 m/yr while the rate of wetting front propagation is approximately 47 m/yr in the piedmont plain. The thickening vadose zone would prolong residence time of soil water and contaminant, which could postpone the time of or alleviate groundwater pollution, but have no significant influence on the magnitude of recharge in a long time scale. Recharge coefficient based on shorter time span(e.g. 2 or 3 years) should be used with caution as a parameter for groundwater resources evaluation, because it varies with total water input and target soil depth. Uncertainties in evapotranspiration and other water balance components should be evaluated in recharge estimation and the impact of land-use types on recharge should be emphasized. The critical zone science would greatly improve the understanding of groundwater recharge processes. The results of the present study will be helpful in sustainable groundwater resources management. 相似文献
5.
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
6.
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 2.602×108 m3/a in the former 15 years (1969-1985) and 0.218×108 m3/a in the latter 15 years (1986-2000), and the impacts on the groundwater discharge were 2.035×108 m3/a and 4.91×108 m3/a respectively. When the groundwater exploitation was in a reasonable range less than 3.0×108 m3/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
7.
Shifts in resource availability and resulting land use changes are important research themes for coupled human and natural systems and human dimensions of global environmental change. This study examines the relationship between groundwater depletion and agricultural land use change within a single county in the High Plains, where agro-economic systems and populations are dependent on access to reliable groundwater supplies. Results indicate a significant relationship between high proportionate decreases in groundwater and land being removed from irrigation. This case study strengthens the links among local, regional, and global environmental change, and contributes to a greater understanding of the High Plains in the context of regional sustainability and vulnerability concerns. 相似文献
8.
Although Ethiopia has abundant land for irrigation, only a fraction of its potential land is being utilized. This study evaluates suitability of lands for irrigation using groundwater in Ethiopia using GIS-based Multi-Criteria Evaluation (MCE) techniques in order to enhance the country's agricultural industry. Key factors that significantly affect irrigation suitability evaluated in this study include physical land features (land use, soil, and slope), climate (rainfall and evapotranspiration), and market access (proximity to roads and access to market). These factors were weighted using a pair-wise comparison matrix, then reclassified and overlaid to identify suitable areas for groundwater irrigation using a 1-km grid. Groundwater data from the British Geological Survey were used to estimate the groundwater potential, which indicates the corresponding irrigation potential for major crops. Results indicated that more than 6 million ha of land are suitable for irrigation in Ethiopia. A large portion of the irrigable land is located in the Abbay, Rift Valley, Omo Ghibe, and Awash River basins. These basins have access to shallow groundwater (i.e., depth of groundwater less than 20 m from the surface) making it easier to extract. The comparison between available groundwater and total crop water requirements indicate that groundwater alone may not be sufficient to supply all suitable land. The study estimates that only 8% of the suitable land can be irrigated with the available shallow groundwater. However, groundwater is a viable option for supplementing surface water resources for irrigation in several basins in the country. 相似文献
9.
Keesari Tirumalesh Roy Annadasankar Mohokar Hemant Pant Diksha Sinha U. K. 《Natural Resources Research》2020,29(3):1951-1973
A thorough study on understanding of groundwater recharge sources and mechanisms was attempted by integrating the hydrogeological, geochemical and isotopic information along with groundwater dating and end-member mixing analysis (EMMA). This study was necessitated due to prolonged dryness and unavailability of freshwater in semi arid Deccan trap regions of Central India. In addition, groundwater resources are not characterized well in terms of their geochemical nature and recharge sources. The hydrogeochemical inferences suggest that aquifer I consists of recently recharged water dominated by Ca–Mg–HCO3 facies, while groundwater in aquifer II shows water–rock interaction and ion exchange processes. Presence of agricultural contaminant, nitrate, in both aquifers infers limited hydraulic interconnection, which is supported by unconfined to semi-confined nature of aquifers. Groundwater in both aquifers is unsaturated with respect to carbonate and sulfate minerals indicating lesser water–rock interaction and shorter residence time. This inference is corroborated by tritium age of groundwater (aquifer I: 0.7–2 years old and aquifer II: 2–4.2 years old). Stable water isotopes (δ2H, δ18O) suggest that groundwater is a mixture of rainwater and evaporated water (surface water and irrigation return flow). EMMA analysis indicates three groundwater recharge sources with irrigation return flow being the dominant source compared to others (rainwater and surface waters). A conceptual model depicting groundwater chemistry, recharge and dynamics is prepared based on the inferences.
相似文献10.
l introductionYucheng area is located in the downstream alluvial plain of the Yellow hiver in Shandong provillce,Nortll China. bouenced by the conhnenlal monsoon clllnate in wann tCmperate zone, fainfall isdistributed very unevenly in bine. AVerage annual precipitation amounts to 600 ~ with 70%concentrahng from June to September The mother material of soil is conStituted by river alluvium andmainly consistS of mealy sand and light loam. Vadose zone consistS of mealy san4 its dry bulk densi… 相似文献
11.
基于改进层次分析法的干旱扬水灌区水土环境变迁响应评估 总被引：1，自引：0，他引：1
受大量的外调水资源和人工灌溉的影响,干旱扬水灌区的水土环境变迁过程具有独特性,其对区域环境要素的响应是长期、潜在而缓慢的,该过程可通过科学的评估与分析描述其发展的趋势。评价过程是否合理,评价结果是否准确是灌区可持续发展的关键。通过应用改进的层次分析法,对干旱扬水灌区水土环境变迁响应进行了评价。结果表明:干旱扬水灌区水土环境变迁响应因子都属于"微敏感"因子;地表水对水土环境的变迁响应相对较为强烈,其次为地下水、区域气候,而土地利用最为迟缓; 18个响应因子中最为敏感的是灌区提水量及灌溉用水量,次之为地下水水位及回归水水质。该评价模型的评价结果与当前灌区水土环境变化现状相吻合,验证了改进层次分析法在干旱扬水灌区水土环境变迁响应评价中的有效性和可操作性,可为灌区的建设和管理提供科学合理的参考依据。 相似文献
12.
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
13.
14.
Duncan F.M. McGregor Andrew Adam‐Bradford Donald A. Thompson David Simon 《Singapore journal of tropical geography》2011,32(3):382-398
This paper outlines pressures on agricultural land in periurban Kumasi, Ghana. A survey of agricultural practices underlines the recent and rapid transition from agricultural to urban land use in the periurban interface, and shows how farmers are reacting by reducing fallow periods. Farmers are also intensifying agriculture near streams and rivers through increased use of irrigation, in response to growing urban markets for a wider range of vegetables. We identify specific problems of water resource pollution and waste management, with particular reference to farmland irrigation. We report results of composting interventions as a community‐based waste management strategy. We consider integrated organic waste recycling as a generic strategy to help protect periurban natural resources, to enhance food production through nutrient recycling, and to improve community sanitation. 相似文献
15.
Recharge to mountainous carbonated aquifers in SE Spain: Different approaches and new challenges 总被引：1，自引：0，他引：1
J.M. Andreu F.J. Alcalá Á. Vallejos A. Pulido-Bosch 《Journal of Arid Environments》2011,75(12):1262-1270
As in most semiarid regions, the main source of freshwater in SE Spain is its aquifers, and their exploitation has enabled the development of highly profitable irrigated agriculture and tourism industries. The application of sustainable water management plans requires aquifer recharge to be quantified and its spatial pattern evaluated. This paper gives a comprehensive review of various recharge studies in mountainous carbonated aquifers, the most important groundwater reservoirs in SE Spain. Quantification of potential recharge rates and their spatial variability are illustrated using satellite-based modeling and tracer techniques. Actual recharge figures from the application of a lumped model based on water table fluctuations are also presented. Potential recharge relative to actual recharge is around 1 in small aquifers and flat areas and may increase up to 1.3 in heterogeneous mountainous aquifers with deep water levels due to losses of recharge in transit in the vadose zone. The complex interaction between climate, geology, aquifer geometry, topography, soil properties and the degree of karstification prevents the systematization of any particular technique to quantify potential recharge. The use of water table fluctuation methods for actual recharge evaluation requires daily time steps to compute unnoticed small recharge events. Therefore, the monitoring of environmental variables and the use of complementary techniques for comparison are recommended. Despite their importance for the correct assessment of recharge in the region, uncertainty analyses are still scarce, and the natural variability of recharge is unknown in most cases. Effort is required to improve the spatial and temporal characterization of recharge through the integration of interdisciplinary sciences. 相似文献
16.
水平衡下黄淮海平原区耕地可持续生产能力测算 总被引：6，自引：0，他引：6
为缓解黄淮海平原区地下水水位的持续下降,国家提出耕地资源休养生息的战略,而实施耕地资源休养生息的关键,是确保水平衡下的耕地资源可持续生产能力。本文从可持续理论和水平衡的条件出发,将黄淮海划分成12个自然条件、社会经济条件相对均一的农业生态区,采用不同农业生态区代表实验站限水高产的产量和管理经验,以水定产并逐步修正,得到了黄淮海平原区耕地可持续生产能力,并与现实产量对比得到产量差。结果表明：① 水平衡条件下黄淮海平原区耕地的可持续粮食生产能力为1.16亿t/年;② 可持续总产产量差为-67.85万t/年,由于限水灌溉造成的粮食产能损失为小麦331.84万t/年,玉米不存在产能损失;③ 小麦主要压产地区为黑龙港地区、鲁西平原、豫东平原以及京津唐平原,而徐淮低平原、豫东平原以及胶西黄泛平原具有一定的提产潜力。通过测算,进一步认识了黄淮海平原区耕地可持续产能状况,为区域粮食生产的合理布局以及农业限水限产提供可靠依据。 相似文献
17.
Planning for source water protection in Ontario 总被引：2，自引：0，他引：2
Ontario began developing a drinking water source protection planning process in 2000, after a rural community's water supply was contaminated by pathogens from agricultural runoff. An expert committee report has recommended legislating a new source protection “sphere of jurisdiction” for municipalities; however, no specific new municipal tools or authorities have been proposed as yet. This paper reports findings from an evaluation of the extent to which existing institutional arrangements for land use planning and water management facilitate or constrain source protection by municipalities. A case study of the Regional Municipality of Waterloo suggests there is the potential to link land use planning more strongly to water management through creative use of existing tools, forgoing the need for major institutional changes. 相似文献
18.
流域土地可持续利用规划方法及应用研究 总被引：13，自引：2，他引：11
土地利用既受自然环境条件的种种制约,又对生态环境,尤其是水资源和水环境,产生深刻影响。因此,进行系统规划优化土地利用结构、协调土地利用和其他经济活动及生态环境保护的关系是非常必要的。基于土地利用系统是一个本征性灰色系统,本文以灰色多目标规划(GMOP)方法为核心,提出了一套流域土地利用灰色多目标规划模型。该方法既可有效地处理信息的不完备性和系统的动态性,又可全面地表达土地利用的多目标性。在对密云土地利用规划研究中,通过应用交互式调整和情景分析方法,得到该模型在两种情景下的优化方案,并结合密云实际情况综合分析,进行了方案筛选。 相似文献
19.
This paper firstly analyzes the land use - land cover (LULC) in Lake Ziway watershed (Ethiopia) and quantifies the changing patterns from 1973 to 2014 using Landsat images. Secondly, the paper estimates sediment yields using the Soil and Water Assessment Tool (SWAT model). It also assesses and estimates water abstraction from Lake Ziway using survey data. The study shows that the conversions from woodlands into agricultural lands and settlement areas are the major detected LULC changes. Of the total area of the watershed, agricultural lands and settlement areas together increased from 57% in 1973 to 75% in 2014 at the expense of woodlands whose areas decreased from 26.16% to 6.63% in the study periods. The study also shows that water abstraction and sediment loads are increasing at Lake Ziway watershed. The major driving forces behind these LULC changes and the impacts on the lake natural condition are anthropogenic factors such as population growth, land policy changes and deforestation. Increasing demands for more land and water resources, i.e., land for settlements and cultivation, wood for fuel and charcoals, and water for irrigation and municipal water supply, are the underlying causes for the observed changes on the watershed resources. Thus, if the existing scenarios of human pressures are left neglected without management interventions, severe watershed degradations will continue to further affect the watershed's resources including the hydrology. Therefore, responsible government institutions should start mobilizing the local communities along with providing financial and material supports for watershed rehabilitation through afforestation and soil and water conservation activities. Additionally, the free-access practices for water use should be replaced by user-charge policy to regulate water abstractions in order to adequately sustain the water level of Lake Ziway and its feeder rivers. In this respect, this study provides firsthand information to policy makers and planners to put in place a comprehensive land and water use plan and regulations against the unruly human actions in the watershed before irreversible losses might happen to Lake Ziway and its watershed resources. 相似文献
20.
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