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1.
The future of the dolomitic springs after mine closure on the Far West Rand,Gauteng, RSA 总被引:1,自引:0,他引:1
Approximately 1.2 km of dolomitic limestone overlies the Far West Rand gold reefs southwest of Johannesburg, South Africa. This karst aquifer is partitioned into several groundwater compartments by predominantly north–south trending syenite dykes. Prior to mining, the primary water flow was westwards, decanting over dyke boundaries as a succession of springs along the Lower Wonderfontein Spruit. Dewatering of the overlying dolomitic aquifer for safety and economic reasons by deep gold mining operations, caused the water levels of four compartments to drop and their respective springs to dry up. By perforating dykes, formerly separated aquifers were hydraulically interconnected by mining. Using historical and recent data of water flow—surface and groundwater—and pumping rates, a geohydrological model is presented. The results suggest that the water tables will rise to their pre-mining levels within 30 years after mining ceases and that the dry springs will flow again, despite the compartments being connected by the extensive mining operations.
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C. J. U. SwartEmail: Phone: +27-18-7874435Fax: +27-18-7875972 |
2.
This paper investigates the impact ash fall would have on dairy farming, based on a study of ‘Tulachard’, a dairy farming
operation at Rerewhakaaitu, North Island, New Zealand. It includes analysis of the potential effects on the dairy shed and
milking machine, electrical supply and distribution, water supply and distribution, tractors and other farm vehicles, farm
buildings (haysheds, pump sheds, implement sheds, etc.), milk-tanker access to the farm and critical needs of dairy cows and
farm to keep milking. One of the most vulnerable areas identified in the study was the cooling of milk at the milking shed,
pending dairy tanker pick-up. The cooling system’s condenser is exposed to the atmosphere and falling ash would make it highly
vulnerable. Laboratory testing with wet and dry ash was conducted to determine its resilience to ash ingestion. It was found
to perform satisfactorily during dry testing, but during wet testing significant clogging/blocking of the condenser’s radiator
occurred, dramatically reducing airflow through the condenser. Specific mitigation recommendations have been developed that
include cleaning with compressed air and adapting farm management techniques to lessen usage of the condenser during an ash-fall
event. Specific recommendations for management of dairy farm operation are given to mitigate the effects of an ash-fall event.
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James W. ColeEmail: |
3.
Development of a conjunctive use model to evaluate alternative management options for surface and groundwater resources 总被引:4,自引:0,他引:4
A conjunctive use model has been developed to evaluate alternative management options for surface and groundwater resources. A simple water balance approach was used to estimate net recharge to the aquifer. The groundwater model FEFLOW takes net recharge as an input for the water balance calculation and simulates flow in the groundwater under all boundary stresses. The developed model was applied to an irrigated area in the Indus Basin, Pakistan, to predict groundwater levels up to 2010 in response to the possible need for intervention in irrigation and/or agricultural practices. A geographical information system (GIS) was used to assemble various types of spatial data. The study revealed that an increase in pumpage from the present rate would further strain the scarce water resources. Lining of watercourses and adjustment in cropping pattern could be adopted as alternatives for better management of surface and groundwater resources.
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Helmut EggersEmail: |
4.
Mark Giordano 《Hydrogeology Journal》2006,14(3):310-318
The rapid expansion in agricultural groundwater use in the last few decades has transformed rural economies in large parts of the developing world, in particular South Asia and North China. There has been no such “Groundwater Revolution” in most of sub-Saharan Africa and little is known about the actual role of groundwater use in supporting agricultural livelihoods in the region or opportunities to expand this role in the future. Published literature has been reviewed to paint a preliminary, region-wide picture of the contribution groundwater makes to agriculture, and in turn to rural livelihoods, within sub-Saharan Africa. The findings indicate that groundwater is used on only 1–2 million hectares of cropped area, directly contributing to the livelihoods of 1.5–3% of the rural population. Groundwater also plays a critical role in the vital livestock sector as well as an important indirect role in the supply of domestic water to agricultural households. While data are lacking, these latter two roles likely surpass the direct importance of groundwater to crop production. This suggests that an understanding of the value of agricultural groundwater use in support of rural livelihoods in sub-Saharan Africa should be based on different models than have typically been applied in Asia.
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Mark GiordanoEmail: Phone: +94-11-2787404Fax: +94-11-2786854 |
5.
The hydrochemical evolution of an alluvial groundwater located along the Mediterranean seashore is analyzed with respect to
its agricultural and climatic environment, including degree of saturation of the soil; types of cultures, chemical fertilizers
and phytosanitary treatments; selective irrigations of the cultivated areas; precipitations. It is shown that the environmental
effect on the groundwater's vulnerability depends on two groups of factors:
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1. | Transfers from surface to groundwater of nitrates, chlorides, sulfates, and potassium, which are governed by: (a) the climatic conditions before the agricultural activities begin, (b) the kinds of agricultural activities and their distribution in time with respect to a given climatic context. Phenomena of retention and/or rapid diffusion are related to the sedimentary heterogeneities of the reservoir and to the differences of ternperatures between irrigation waters and precipitations. |
2. | Cationic exchanges related to the presence of clays of Montmorillonite-Kaolinite type. |
6.
Recharge to a saline, unconfined shallow-water-table aquifer is normally considered as an irrecoverable loss of water, but
such thinking could be reviewed empirically. The use of an appropriate groundwater harvesting system does not only provide
an opportunity to recover this lost water, but can also help in catchment salinity management and improvement. Agricultural-based
land-drainage systems such as those that use serial biological concentration (SBC) of salts, provide examples of such harvesting
methods. The impact of groundwater harvesting has been assessed on the hydro-salinity of a saline catchment in southeastern
Australia through modeling. For both the below average rainfall and very wet years, the “do nothing” scenario resulted in
increasing salinization in the catchment. However, after introducing a SBC system, groundwater salinity showed a decreasing
trend while hydraulic heads tended to stabilize around the depth of subsurface collector wells. However, for a successful
groundwater harvesting system, proper understanding of the groundwater flows and salt mobilization associated with a catchment
is necessary. The outcomes of this modelling study have the potential to address similar issues (salinization) and/or needs
(water harvesting) existing elsewhere in the world, particularly in semi-arid regions.
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Muhammad Nadeem AsgharEmail: |
7.
The aim of this paper is to use an economic framework to derive decision making rules for river basin management with a focus on groundwater resources. Using an example from northern Nigeria, the paper provides an example of how decision making for sustainable water resources management may be facilitated by comparing net benefits and costs across a river basin. It is argued that economic tools can be used to assess the value of water resources in different uses, identify and analyze management scenarios, and provide decision rules for the sustainable use and management of surface and ground water resources in the region.
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Gayatri AcharyaEmail: |
8.
南、北盘江流域枯水期水化学特征及离子来源分析 总被引:1,自引:0,他引:1
为进一步了解珠江上游南、北盘江流域水化学现状,对其枯水期36个河水样品进行水化学特征分析,结果表明:枯水期河水pH值在7.85~8.75之间,呈弱碱性,TDS均值为358 mg·L-1。河水中阴离子组成以HCO3-、SO42-为主,当量浓度占比均值达到65%与26%,阳离子中Ca2+和Mg2+是绝对的优势离子,当量浓度占比均值分别为65%和24%。与丰水期相关研究对比分析发现Ca2+、Mg2+、Na+、SO42-、HCO3-、Cl-的枯水期浓度普遍高于丰水期,K+、NO3-丰、枯水期浓度变化不大。Piper图、岩性端元分析以及离子浓度比值分析表明,研究区水化学主要受碳酸和硫酸共同参与下的碳酸盐岩风化控制。南、北盘江流域都受到农业施用的钾肥和氮肥的影响,此外,北盘江主要受到煤炭开采以及燃煤工业的影响,南盘江主要受到源头及上游河段化工企业废水和沿途市县的生活废水的影响。与前人数据对比发现,15年间人为活动对流域水化学的影响加剧。 相似文献
9.
A diagnosis of the groundwater quality of 70 wells sampled during two climatic regimes (dry and raining seasons) from a semiarid area in Rajasthan, India, had been carried out using standard methods. Analysis of the results for various hydrochemical parameters wherein the geological units are alluvium, quartzite and granite gneisses showed that all the parameters did not fall within the World Health Organisation’s acceptable limits for irrigation and drinking water purposes. The order of major cations and anions obtained during the dry and raining seasons are Na+ ? Mg2+ ? Ca2+ ? K+ and Cl?? HCO3 ? ? SO4 2?? CO3 ?> F? ? NO3 ?, respectively. A maximum value of nitrate of 491.6 mg/l has been examined and its contamination is due to discriminated highly impacted groundwater samples by agricultural activity and small-scale urbanization. Fluoride (F?) concentration is 6.50 mg/l as a maximum value, whereas values in about 26 % of the samples are more than the permissible limit (1.5 mg/l) for drinking water. The cumulative probability distributions of the selected ions show two individual intersection points with three diverse segments, considered as regional threshold values and highly impacted threshold values for differentiating the samples with the effects of geogenic, anthropogenic and saline water mixing. The first threshold values indicate the background hydrochemical constituents in the study area. The second threshold value of 732 mg/l for bicarbonate indicates that sandy aquifer is being dissolved during wet period, whereas NO3 ? concentration of more than the initial threshold value (=75 mg/l) indicates discriminated highly impacted groundwater samples by agricultural activity and urbanization in dry season. Various parameters such as soluble sodium percentage (SSP), salinity (electrical conductivity (EC)), sodium adsorption ratio (SAR), residual sodium carbonate (RSC), Kelley’s ratio (KR), permeability index (PI), residual sodium bicarbonate (RSB) and magnesium absorption ratio (MAR) for the well samples show that, overall, 46 % of groundwater samples are not suitable for irrigation. Further, chloro-alkaline indices (CAIs) were used for distinguishing regional recharge and discharge zones whereas corrosivity ratio (CR) utilized for demarcating areas to use metallic pipes for groundwater supply. In general, groundwater quality is mainly controlled by the chemical weathering of rock-forming minerals. The information obtained represents a base for future work that will help to assess the groundwater condition for periodical monitoring and managing the groundwater from further degradation. 相似文献
10.
Guofeng Zhu Yu Zhang Yuanqing He Junju Zhou Hanxiong Pan Huiwen Guo Huiying Ma Xinggang Ma Lei Feng 《Environmental Earth Sciences》2018,77(22):765
97735 artificial reservoirs have been built in China since 1950s, which could guarantee the supply of urban water and agricultural irrigation. In arid oasis area, only the water of reservoir is available as water resource. The study of hydrochemical characteristics is the prerequisite for evaluating the water quality of domestic water and irrigation water. In the Hongyashan Reservoir, the middle of the Shiyang River Basin and the Tengger desert and Badain Jaran desert, water samples were taken at different points of the lake for about 3 years. The chemical characteristics of the lake water and their influencing factors were studied. The results of the samples for the test have shown that water of the Hongyashan Reservoir is weakly alkaline. And the main compositions of ions in the water are Ca2+ and \(\text{HCO}_{3}^{ - }\), hydrochemical type is Ca–HCO3. In terms of the seasonal variation of Hongyashan Reservoir, except for \(\text{NO}_{3}^{ - }\), the ions in the rest of the water showed roughly the same changeable characteristics in that the composition of ion is higher in summer and autumn, but lower in winter and spring. This is consistent with the seasonal variation in runoff ions throughout the Shiyang River Basin. Ionic characteristics are consistent with the ionic values of dry lakes in the world, which are suitable for urban water and water for irrigation, but are slightly higher than the global lake background standard. Carbonate weathering products are the main source of water ions in Hongyashan Reservoir, and evaporation also affects the ion characteristics of water. 相似文献
11.
Concern for natural hazard-triggered technological disasters (Natech disasters) in densely populated and industrialized areas
is growing. Residents living in urban areas subject to high natural hazard risk are often unaware of the potential for secondary
disasters such as hazardous materials releases from neighboring industrial facilities, chemical storage warehouses or other
establishments housing hazardous materials. Lessons from previous disasters, such as the Natech disaster during the Kocaeli
earthquake in Turkey in 1999 call for the need to manage low frequency/high consequence events, particularly in today’s densely
populated areas. However, there is little guidance available on how local governments and communities can assess Natech risk.
To add to the problem, local governments often do not have the human or economic resources or expertise to carry out detailed
risk assessments. In this article, we propose a methodology for preliminary assessment of Natech risk in urban areas. The
proposed methodology is intended for use by local government officials in consultation with the public. The methodology considers
possible interactions between the various systems in the urban environment: the physical infrastructure (e.g., industrial
plants, lifeline systems, critical facilities), the community (e.g., population exposed), the natural environment (e.g., delicate
ecosystems, river basins), and the risk and emergency management systems (e.g., structural and nonstructural measures). Factors
related to vulnerability and hazard are analyzed and qualitative measures are recommended. Data from hazardous materials releases
during the Kocaeli, Turkey earthquake of August 17, 1999 are used as a case study to demonstrate the applicability of the
methodology. Limitations of the proposed methodology are discussed as well as future research needs.
相似文献
Norio OkadaEmail: |
12.
Livelihood diversification can be crucial for poor rural households in the African Sahel. Migration is a common diversification
strategy during the dry season, but there are also areas with significant strategies on the farm, such as incomes from gum
and resins. Sudan is a country where the income from gum arabic, the gum from the Acacia senegal tree, has played a large economic role for smallholders for generations, but there are signs of a declining production which
is detrimental if people have no alternative incomes. The results showed that in parts of the country, the 1984 drought caused
an event-driven change resulting in a discontinuation of production. However, in other parts of the country, the agricultural
system providing gum arabic proved to be more resilient to the drought and the incomes from gum arabic still play a large
role. The results illustrated a complexity of driving forces, regional differences and a large variability in incomes between
households. Some causes were indirect such as prices, drought, precipitation and locust, whereas the others were direct and
hence more controllable by households. This study underlined the direct causes, such as how labour input is prioritised between
livelihood activities, which have not been given as much attention in previous literature. Secondly, the need for a holistic
view of livelihoods is underlined in order to understand the future of gum arabic production. Empirical data were collected
from extensive fieldwork.
相似文献
Bodil ElmqvistEmail: |
13.
Gutenberg and Richter developed an empirical relation, \(\log_{10} N(M) = a - bM\), to quantify the seismicity rate of various magnitudes in a given region and time period. They found the equation fit observed data well both globally and for particular regions. In conventional G–R relation, N(M) represents an arithmetic mean. As a result, the arithmetic standard deviation cannot be explicitly incorporated in the log-linear G–R relation. Moreover, this representation is susceptible to influence of spuriously large numbers of aftershocks of major earthquake sequences. To overcome these shortcomings, we propose an alternative representation of the G–R relation in terms of the logarithmic mean annual seismicity rate and its standard deviation. We select the crustal earthquake data from 1973 to 2011, as listed in the National Earthquake Information Center (NEIC) global catalog and the Central Weather Bureau (CWB) Taiwan regional catalog, to illustrate our methodology. We first show that by using the logarithmic annual seismicity rates we can significantly suppress the influences of spuriously large numbers of aftershocks following major earthquake sequences contained in the Taiwan regional catalog. More significantly, both the logarithmic mean annual seismicity rate and its standard deviation can be explicitly represented in the Gutenberg–Richter relation as follows: where log10 N represents the logarithmic annual seismicity rate. Above analytical equations are very well constrained by observed global seismicity data with \(5.0 \le M \le 7.0\) and by Taiwan seismicity data with \(3.0 \le M \le 5.0\). Both equations can be extrapolated with confidence to simultaneously estimate not only the median annual seismicity rates but also their uncertainties for large earthquakes for the first time since inception of the G–R relation. These equations can be used to improve the conventional probabilistic seismic hazard assessment by including the dispersion of the annual seismicity rate. Finally, the corresponding numerical median annual seismicity rate with its upper and lower bounds obtained from above equations for \(5.0 \le M \le 9.0\) is listed in Table 1.
相似文献
$${\text{For}}\,{\text{global}}\,{\text{crustal}}\,{\text{seismicity}}{:}\;\log_{10} N = 8.14 - 1.03M \pm (0.04M - 0.13);$$
$${\text{For}}\,{\text{Taiwan}}\;{\text{crustal}}\,{\text{seismicity}}{:}\;\log_{10} N = 5.62 - 0.90M \pm (0.02M + 0.17)$$
Table 1 Observed and estimated median annual seismicity rate and return period with their dispersions for Taiwan and global crustal earthquakes
Magnitude | Catalog | |||
---|---|---|---|---|
Taiwan catalog (CWB) | Taiwan catalog (CWB) | Global catalog (NEIC) | Global catalog (NEIC) | |
Annual rate (event/year) | Return period (year) | Annual rate (event/year) | Return period (year) | |
M ≥ 5.0 | 24.55 13.18 7.08 | 0.041 0.076 0.14 | 1148.16 977.24 831.76 | 0.0009 0.001 0.0012 |
M ≥ 5.5 | 8.91 4.68 2.45 | 0.11 0.21 0.41 | 367.28 298.54 242.66 | 0.0027 0.0033 0.0041 |
M ≥ 6.0 | 3.24 1.66 0.85 | 0.31 0.60 1.18 | 117.49 91.20 70.79 | 0.0085 0.011 0.014 |
M ≥ 6.5 | 1.17 0.59 0.30 | 0.85 1.69 3.33 | 37.58 27.86 20.65 | 0.027 0.036 0.048 |
M ≥ 7.0 | 0.43 0.21 0.10 | 2.33 4.76 10.0 | 12.02 8.51 6.03 | 0.083 0.12 0.17 |
M ≥ 7.5 | 0.15 0.074 0.036 | 6.67 13.51 27.78 | 3.85 2.60 1.76 | 0.26 0.38 0.57 |
M ≥ 8.0 | 0.056 0.026 0.012 | 17.86 38.46 83.33 | 1.23 0.79 0.51 | 0.81 1.27 1.96 |
M ≥ 8.5 | 0.020 0.009 0.004 | 50.00 111.11 250.0 | 0.39 0.24 0.15 | 2.56 4.17 6.67 |
M ≥ 9.0 | 0.0074 0.0033 0.0015 | 135.14 303.03 666.67 | 0.13 0.074 0.04 | 7.69 13.51 25.00 |
14.
A method of combining hydrochemical data logging and in situ titrating with measurement of stable carbon and oxygen isotopes was used to reveal the hydrochemical and isotopic characteristics in the Baishuitai travertine scenic area of SW China. It was found that the travertine-forming springs have a very high concentration of calcium and bicarbonate, and accordingly very high CO2 partial pressures, which are not likely to be produced by biological activity in soil alone. Further analysis of the stable carbon isotopes of the springs shows that the high pressure of CO2 is mainly related to an endogenic CO2 source. That means the Baishuitai travertine is endogenic in origin. This is contrast to the commonly accepted saying that the travertine deposition in this study simply is a product of warm and humid conditions in a karst ecological environment. Rapid CO2 degassing from the water is triggered by the much higher partial pressures in water than that of the surrounding air. Consequently, as the waters flow downstream of the spring the pH increases, the waters become supersaturated with respect to calcite, and travertine is deposited. The preferential release of 12CO2 to the atmosphere results in a progressive increase of travertine 13C downstream. This is concluded with a preliminary discussion of variation in travertine-forming water temperatures, according to differences in stable oxygen isotopic compositions of the travertine formed in different epochs at Baishuitai. It was found that the change in water temperature is as high as 13 °C, i.e., from 23 °C at about 2500 years b.p., to 10 °C at present. This may mainly reflect that the effect of geothermal source on water temperature is decreasing. The problems involved in paleoenvironmental reconstruction with endogene travertine are also discussed. They are the impacts of "dead carbon" in radiocarbon dating and the enrichment in 13C of travertine by endogenic CO2 and degassing of CO2 from water, which has to be considered in paleovegetation reconstruction when using 13C data of the endogene carbonate deposits. 相似文献
15.
Henry Darcy in his own words 总被引:1,自引:1,他引:0
Patricia Bobeck 《Hydrogeology Journal》2006,14(6):998-1004
A recently published English translation of the Les Fontaines publiques de la ville de Dijon
1 provides access to Henry Darcy's own words on the importance of water for public sanitation and on questions engineers face in building water supply systems. Written near the end of Darcy's life, the book is a compendium of the water knowledge he had gained over decades and his opinions on these topics reveal his personality. In the 1840s, Darcy built a water supply system to provide water to 120 street fountains for domestic purposes, street washing and firefighting. Surrounded by poverty, Darcy insisted on free water for the poor and on sharing the spring water with towns located along the aqueduct that brought it to Dijon. In the preface to the book, Darcy introduces his experiment on water flow through sand with the modest words “to my knowledge, no one has experimentally demonstrated the laws of water flow through sand.” This article provides a sampling of the book's insights into the personality of this remarkable man.
相似文献
Patricia BobeckEmail: |
16.
Post-Bam earthquake: recovery and reconstruction 总被引:3,自引:1,他引:2
This paper gives a brief explanation of the earthquake in Bam. It also reports on the rescue and relief operations, including
the construction of emergency shelters and temporary housing, and on the country’s plan for the reconstruction of the city,
which includes debris removal, the rebuilding of rural and urban residential and commercial units, the reconstruction of state
and public buildings and public facilities such as schools, rural and urban water aqueducts and grids, the construction of
a sewage system, power network and telecommunication system, the provision of water to orchards and farmlands, the renovation
of industries and the revival of the cultural heritage, particularly the historical Bam citadel, among others. We also report
briefly on the effect of the Bam earthquake on the Iran Earthquake Risk Reduction Strategy and actions.
相似文献
Mohsen Ghafory-AshtianyEmail: |
17.
Managing for sustainability in an arid climate: lessons learned from 20 years of groundwater management in Arizona,USA 总被引:7,自引:1,他引:6
Substantial progress has been made within central Arizona in moving towards a more sustainable water future, particularly in transitioning the urban demand from a primarily nonrenewable groundwater-based supply to increasing dependence on the Colorado River, Salt River and effluent. Management efforts include a wide range of regulatory and voluntary programs which have had mixed success. The Department of Water Resources has learned a number of key lessons throughout the years, and this paper attempts to establish the water management context and identify those lessons for the benefit of others who may want to evaluate alternative approaches to groundwater management. Themes to be discussed include evaluating water management approaches in a public policy context, the effectiveness of alternative management approaches and the relative merits of regulatory vs. nonregulatory efforts, and the importance of high-quality data in making management decisions.
相似文献
James M. HolwayEmail: |
18.
Over the past several decades, consumers in the global North have increasingly looked to fair or alternative trading systems
as a means to promote ecologically and socially sustainable agricultural production. While fair trade has historically been
limited to international commodity networks, US-based agro-food activists have recently turned their attentions towards building
a domestic movement, to bring fair trade principles and standards ‘home.’ Through an exploration of this growing movement,
we consider the potential for third party certification and labeling to incorporate social justice into US-based agricultural
production, with a particular focus on the implications for farm workers. We view current efforts to bring the principles
of fair trade to the domestic arena as a reflection of several interrelated developments: a growing need on the part of small
and mid-sized farmers to garner price premiums due to the erosion of the organic price premium; a recognition of the failure
of organic certification to advance a holistic vision of sustainability; and the strategic embrace of voluntary regulatory
mechanisms as an alternative to public regulation and collective bargaining. Initial research suggests that this has led to
particular framings of the domestic fair trade concept, which may undermine the movement’s ability to address the social relations
of agro-food production. Specifically, prioritization of the ‘family-scale’ farm and an undercurrent of food localism may
obscure farm workers’ role in valorizing the US agricultural landscape.
相似文献
Christy GetzEmail: |
19.
A hydrometric, hydrochemical and environmental isotopic study was conducted to identify the source and origin of observed springs on the foot of the hillock abutting the left flank of the Gollaleru earthen dam, Nandyal, Andhra Pradesh, India. Water samples (springs, reservoir water and groundwater) in and around the dam area were collected and analyzed for environmental isotopes (\(\updelta ^{18}\!\hbox {O}\), \(\updelta ^{2}\hbox {H}\) and \(^{3}\hbox {H}\)) and hydrochemistry. Reservoir level, spring discharges and physico-chemical parameters (temperature, electrical conductivity, pH, etc.) were monitored in-situ. Isotopic results indicated that the source of springs is from the Owk reservoir and groundwater contribution to the springs is insignificant. Based on hydrometric observations, it is inferred that the springs might be originated from the reservoir level of 209 m amsl. It is found that the lower spring discharges were derived from diffuse sources (seepage) which could be a mixture of reservoir water and the groundwater, while the relatively higher spring discharges were resulted from concentrated sources (leakage) from the reservoir. Thus, the study portraits the usefulness of isotope techniques in understanding the dam seepage/leakage related problems. 相似文献
20.
Edella Schlager 《Hydrogeology Journal》2006,14(3):350-360
Over the last several decades, water users in the western United States have increasingly turned to groundwater resources to support economic development, but few institutional arrangements were in place to govern groundwater use. Over time, numerous groundwater problems have emerged. Two closely related explanations for this are explored. Surface water sources were the first to be developed, and institutional arrangements to allocate surface water were the first to be devised. These arrangements are not particularly well suited for governing groundwater. Furthermore, the physical differences between rivers and aquifers lead to differences in the development of each type of water, and in production and organization costs. Groundwater development involves low upfront production costs, which individual water users can cover. Once groundwater users have individually invested in productive activities problems emerge, such as declining water tables. Thus, unlike surface water users, groundwater users are faced with devising institutional arrangements to coordinate their water uses after they have invested in and developed productive economic activities. Most western states regulate pumping, although groundwater users, in general, resist pumping limits. The discussion concludes with proposals for modifying the prior appropriation doctrine to better accommodate the active management of groundwater basins for long-term sustainability.
相似文献
Edella SchlagerEmail: Phone: 520-621-5840 |