The Water Balance of the World's Continents and a Balance Estimate of the World's Freshwater Resources

The results of several years of investigation of the water balance of continents and the world's freshwater resources are presented. Through the use of interpolation relationships to make up for data gaps, maps are compiled for the basic elements of the water balance of the world: total runoff, including its surface and subsurface components, evaporation, gross wetness (soil moisture) and the coefficient of subsurface alimentation of streams, which reflects much of the stable component of streamflow. Revised estimates for the water-balance elements are offered for continents on the basis of revised data. The per capita water supply of continents is calculated, with separate listing of the stable component of runoff, consisting not only of the subsurface flow to streams but also the portion of surface streamflow that is regulated through lakes and reservoirs.     

Principles of Construction of Long-Term Water-Management Balances

Total runoff (R) is broken down into two components: stable underground runoff (U) and unstable surface runoff (S). The surface component may be reduced by agricultural amelioration measures that would retain a greater share on cultivated fields. The total supply available from runoff may be increased by long-term stream regulation. Water uses must be based on the stable underground component of runoff because the surface component is not dependable. The underground component is then distributed among users: industry and thermal power, which is largely provided by a recirculation system; urban and rural household uses, and regular irrigation. Rural and urban sewage may be used for sewage irrigation. The total elimination of discharge of industrial wastes and sewage is desirable so that all these uses represent withdrawal depletions.     

Causes and Factors of Ground-Ice Formation

The concept of ground ice is expanded to cover all forms of ice formed at the interface between two environments—the solid state and the gaseous. Ground ice is thus defined as the product of the layer-by-layer freezing of liquid water or droplets of any origin as it passes from a zone of positive temperatures into a zone below the freezing point. Ground ice may be produced by subsurface waters (springs and groundwater), surface waters (river, lake, sea, glacier and snow meltwater) and atmospheric moisture (glaze, rime, hail). [The definition excludes ice formed within the solid-state environment of the lithosphere (segregated ice, cement ice, injection ice).] Ground ice produced by subsurface waters may be formed at the surface or in large subterranean cavities, and it may be associated with the natural discharge of water or with the freezing of aquifers. Ground ice produced by surface waters may be associated with an increase of water volume in a waterbody as the level of the ice cover remains stable; with a constriction of the discharge cross section, and with changes in heat and moisture exchange. Ground ice derived from atmospheric moisture is formed either on terrestrial objects (glaze, rime) or in the free atmosphere (hail, ice formed on aircraft).     

Scientific Principles of the Complex Utilization and Conservation of Water Resources

A leading water-resource geographer outlines a series of measures that, in his view, would assure mankind with an unpolluted water supply for many more generations. He opposes the view that inland waters are virtually lost to man as a source of water and that other sources such as desalting of seawater or melting of icebergs must be sought. The proposed measures envisage the gradual reduction and ultimately halting of the discharge of wastes and sewage into streams and lakes by the use of municipal sewage for irrigation of forage crops near urban centers and the provision of closed water systems within industrial plants, including treatment and reuse of wastes.     

The Water-Balance Components of the Aral Sea and their Impact on Long-Term Level Fluctuations

An analysis of water-balance components over the 45-year period 1926–1970 seeks to establish their relative significance in the marked decline of the Aral Sea level since 1961. Long-term fluctuations in the sea level are found to reflect both natural fluctuations in the water resources available to the drainage basin and the steady growth of human activity in the watershed area. An increase in water withdrawals for irrigation in the 1950s did not appreciably affect the Aral Sea level because of generally large water resources during those years. The intensive decline of the water level since 1961 is attributed mainly to a growth of consumptive withdrawals from the Syrdarya and Amudarya, the two main tributaries of the Aral Sea. The position of the sea level also depends on the annual fluctuations of evaporation from the sea surface, which tends to be more variable than the annual streamflow to the sea. The subsurface component of Aral Sea inflow, contrary to previous studies, is found to be a negligible factor.     

GEOGRAPHICAL ASPECTS OF A TERRITORIAL REDISTRIBUTION OF WATER RESOURCES IN THE USSR

A set of principles for a geographical research program relating to the future impact of major interbasin water transfers is outlined. Such a program, evaluating the impact of proposed tranfers both in the European USSR and in the Midland Region of Western Siberia, Kazakhstan and Central Asia, should be based on the following considerations. Noneconomic criteria, such as the environmental impact of water transfers, must be given as much attention as economic and engineering criteria. Experience suggests that any measures designed to protect or ameliorate the environment, for example, inland fisheries, should precede actual water-project construction by at least 15 to 20 years. North-south transfers should be so designed as to benefit both the northern region, from which water is to be withdrawn, and the southern region, where water resources are to be enhanced. The problem of interbasin transfers should be accompanied by a program of intensification of water use, measured by a reduction of water input into the economy per unit of output. Water use can be intensified by such measures as shifting grain production from south to north and building irrigation reservoirs in Central Asian mountains to regulate runoff.     

The Aral Sea Problem and its Solution

A hydrogeologist suggests that nine-tenths of the present stream flow into the Aral Sea can be diverted for other purposes without causing the sea to dry up. The diversion would cause the sea level to drop by 12 meters, where it would stabilize because of a greater intake of subsurface runoff resulting from an increased artesian pressure differential, and because the draining of flooded shore areas and the drying up of reed growths will make more water available through savings in evaporation and transpiration.     

PRINCIPAL TRENDS AND PROSPECTS OF THE USE OF WATER RESOURCES IN THE USSR

The increasing demand on water in the Soviet Union and the problem of assuring water quality require the construction of long-term water-management balances by drainage basins. These balances, based on predicted demand and water availability, would suggest the need for water-management projects within basins and interbasin transfers. Water needs would be evaluated both in terms of water requirements by categories of users and in terms of water quality. The most crucial regional problems involve the increasing shortage of water in Central Asia (with the prospect of interbasin transfer from Siberia) and in southern regions of the European USSR (with the problem of diverting water southward from the northern runoff slope). The Caspian Sea is expected to require a supplementary inflow of 80 to 100 cubic kilometers a year by the end of the century if the decline of its waterlevel is to be arrested. But southward diversion of northern waters is not expected to add more than 50 to 70 km³ at best, with a possible saving of an additional 10 to 20 km³ through decline of evaporation from a reduced Caspian Sea surface. The preservation of conditions in the Sea of Azov, the Aral Sea and Lake Balkhash pose additional water problems. [The senior author died in October, 1974].     

The World's Water Resources and their Changes Over Space and Time

A moisture cycle of 1800 to 2000 years has been established for the earth as a whole, and the present period represents a transition from a wet to a dry phase in which the amount of water in oceans is gradually increasing at the expense of water from the land surface. Runoff fluctuations on the land surface also follow cycles of varying duration. It has been established that wet periods in some sections of the earth's surface are always matched by dry periods elsewhere. A definite geographic localization of zones of synchronous and asynchronous runoff fluctuations can be used in long-range runoff forecasts, which are needed for water-budget and waterpower-potential calculations. Prospects for future elimination of the disproportion between water needs and water resources are suggested. Steps to overcome the growing pollution problem are also proposed.     

The Water Resources of the Ob' River Basin

The original author of the great Siberian diversion scheme defends his views at a 1965 conference on multipurpose use of the water resources of the Ob' basin. Noting the development of West Siberia's oil and gas resources, which was just beginning to get under way, Davydov says it would be a mistake to base the local use of water resources solely on the interests of the oil and gas industry. He also rejects objections of the fishery industry to the construction of hydroelectric stations, and contends that the diversion of Siberian waters to the heavily populated and developed southern regions of the USSR will be essential to insure adequate water supply by the year 2000.     

Response of Alum Rock springs to the October 30, 2007 Alum Rock earthquake and implications for the origin of increased discharge after earthquakes

The origins of increased stream flow and spring discharge following earthquakes have been the subject of controversy, in large part because there are many models to explain observations and few measurements suitable for distinguishing between hypotheses. On October 30, 2007 a magnitude 5.5 earthquake occurred near the Alum Rock springs, California, USA. Within a day we documented a several‐fold increase in discharge. Over the following year, we have monitored a gradual return towards pre‐earthquake properties, but for the largest springs there appears to be a permanent increase in discharge. The Alum Rock springs discharge waters that are a mixture between modern (shallow) meteoric water and old (deep) connate waters expelled by regional transpression. After the earthquake, there was a small and temporary decrease in the fraction of connate water in the largest springs. Accompanying this geochemical change was a small (1–2°C) temperature decrease. Combined with the rapid response, this implies that the increased discharge has a shallow origin. Increased discharge at these springs occurs both for earthquakes that cause static volumetric expansion and for those that cause contraction, supporting models in which dynamic strains are responsible for the subsurface changes that cause flow to increase. We make a quantitative comparison between the observed changes and model predictions for three types of models: (i) a permanent increase in permeability; (ii) an increase in permeability followed by a gradual decrease to its pre‐earthquake value; and (iii) an increase of hydraulic head in the groundwater system discharging at the springs. We show that models in which the permeability of the fracture system feeding the springs increases after the earthquake are in general consistent with the changes in discharge. The postseismic decrease in discharge could either reflect the groundwater system adjusting to the new, higher permeability or a gradual return of permeability to pre‐earthquake values; the available data do not allow us to distinguish between these two scenarios. However, the response of these springs to another earthquake will provide critical constraints on the changes that occur in the subsurface and should permit a test of all three types of models.     

Hydrologic response of a small forested swamp complex,Seymour Valley,British Columbia

Wetlands are common in Coastal Western Hemlock forests yet the hydrologic processes that generate runoff from small swamps are not completely understood. Direct field observations, hydrologic, and electrical conductivity data were collected from a gently sloping forested swamp complex from July to November 2009. Swamps occupied depressions between raised mounds (0.1 to 3 m high) and were connected by an ephemeral creek. Runoff was controlled by antecedent moisture conditions and influenced by basin microtopography. Two hydrologic regimes occurred during the study period and different runoff processes dominated each regime. Runoff was generated by subsurface flow during dry antecedent conditions as swamps remained hydrologically disconnected from each other. Runoff was generated by surface outflow from hydrologically connected swamps during wet antecedent conditions as ponded water spilled out of the depressions. The forested swamp complex produced a faster but limited hydrologic response during dry antecedent conditions compared to a slower but greater hydrologic response during wet antecedent conditions. Stormwater runoff and runoff ratios were up to two orders of magnitude higher in wet conditions than during similarly sized events in dry conditions. These factors should be considered when designing monitoring programs or runoff models in forested swamps with significant microtopography. Field surveys and estimates of hydrologic inputs and outputs may be useful in predicting the potential hydrologic connectivity of isolated forested swamps.     

城镇可持续生活供水价格研究--以陕西省关中地区为例

本分析了关中地区城镇生活水价现状和问题,得出了城镇生活水价是不可持续的结论,即水价低于供水生产成本,水价结构不合理。在探讨可持续水价的调整原则的基础上,提出了价格杠杆调节关中生活水价的措施,包括：逐步把水价调整到成本水价以上的水平,并调整水价结构,使之能反映供水成本和水资源价值;实行累进加价制度,对超定额用水征收高水价;实施季节性水价等。     

ON THE PROBLEM OF REGULATING THE REGIME OF THE CASPIAN SEA

In an effort to stabilize the declining level of the Caspian Sea, it has been proposed that evaporation from the water surface be reduced by decreasing the size of the sea through construction of a dam in the northern portion. Data on the geology and hydrology of the Caspian Sea bed suggest that the construction of a dam might have undesirable consequences not only for the northern fisheries basin but for the sea as a whole. The findings are based on the presence of salt domes on the bottom of the northern Caspian Sea. An influx of highly mineralized subsurface waters along faults associated with the salt domes as well as leaching of salt from the structures themselves may threaten to raise the salinity of the northern fisheries basin to intolerable magnitudes. The presence of a man-made dam, in the author's view, would also interfere with the natural circulation of water, threatening contamination of deeper layers of the Caspian Sea with hydrogen sulfide, as has happened in the case of the Black Sea. [For a discussion of the Caspian Sea problem, see Soviet Geography, November 1972.]     

河谷型城市兰州中心城区人口规模初步研究

人口容量规模是城市发展的战略性议题,尤其河谷型城市。基于用地空间、水资源及生态环境三个主要影响因素,对河谷型城市人口容量规模的测算途径和方法进行了探讨和总结。以典型河谷型城市兰州中心城区为例,估算了其在该三个因素下的各自适宜人口规模和最大人口规模,进而反映出河谷用地空间对中心城区人口规模的限制作用较水资源及生态环境更为强烈,并根据木桶原理最短边,得出现有条件下适宜人口规模为230.56万、最大人口规模为342.17万的基本结论。     

Screening Climatic and Non‐Climatic Risks to Australian Catchments

Emerging and future climatic change across the Australian continent has been identified as a significant threat to the successful sustainable management of the nation's water resources. However, the impacts of climate change must be viewed within the context of past, present and future climatic variability and human agency. A qualitative screening‐level risk assessment was undertaken for Australia's 325 surface water management areas by aggregating a suite of six relevant risk indicators. Four indicators addressed the antecedent conditions upon which future climate change will act. These included 50‐year trends in rainfall, the status of surface and groundwater development, and catchment condition. Two indicators addressed future drivers of supply and demand; specifically, projected changes in runoff and population. The results indicate that the management challenges currently experienced in Australia's population centres and key agricultural areas such as the Murray‐Darling Basin are likely to increase in future decades. Furthermore, the geographic distribution of net risk, inclusive of multiple biophysical and socioeconomic drivers, is more extensive than is suggested by consideration of surface water development and availability alone. Comparison of at‐risk catchments with the spatial distribution of various social and environmental assets identified a high degree of overlap among catchment risk and human populations, water storages, irrigated agricultural land, and wetlands of international significance. This suggests that the catchments of the greatest value are also those judged to be at greatest risk. Though considerable work remains in evaluating the security of Australia's water resources to climatic and other stressors, this study provides a first‐order scheme for prioritising the risks to which catchments are exposed and an assessment of how some key drivers are likely to interact to drive risk.     

Strontium isotopic characterization of the Palmottu hydrosystem (Finland): water–rock interaction and geochemistry of groundwaters

The Palmottu hydrosystem is located in a granitic host rock in southern Finland. Along well‐defined pathways in the fractured crystalline rock, strontium isotopes are used to trace the degree of water–rock interaction (WRI) and mixing processes in groundwaters. The ⁸⁷Sr/⁸⁶Sr ratios range between 0.716910 and 0.735606 in the surface waters and between 0.719991 and 0.750787 in the groundwaters, but are between 0.720 and 0.735 in most of the samples. Moreover, the results show a lack of correlation between the water chemistries determining the classification into different water‐types (Na–Cl, Na–SO₄, etc.) and the results of the strontium (Sr) contents and Sr isotopic ratios. From a WRI standpoint, this implies that the Sr behaviour is independent of the water chemistry; the occurrence of large ⁸⁷Sr/⁸⁶Sr variations is site specific and mainly dependent on the lithology. A model to determine the ⁸⁷Sr/⁸⁶Sr ratio of water after interaction with granite was developed. This model is based on the assumption that Sr was derived from three minerals: plagioclase, K‐feldspar and biotite. The results of the calculation indicate that around half of the water analysed within the Palmottu hydrosystem can be explained by the weathering of the granites. However, clearly lower ⁸⁷Sr/⁸⁶Sr are observed in waters when compared to the calculated ⁸⁷Sr/⁸⁶Sr and other sources of Sr, with low ⁸⁷Sr/⁸⁶Sr, rather than the calculated granite–water interaction, which may be suspected. When comparing the ⁸⁷Sr/⁸⁶Sr and ion ratios (Ca/Na, Mg/Na, Sr/Na, Cl/Na), the scattering of the data can be explained by the presence of four end‐members: a brine component (low ⁸⁷Sr/⁸⁶Sr and Ca/Na ratios…), a deep granitic component (high ⁸⁷Sr/⁸⁶Sr ratios and low Ca/Na ratios…), a subsurface component (intermediate ⁸⁷Sr/⁸⁶Sr ratios associated with high Ca/Na ratios…) and a surface end‐member:snow and river drainage (low ⁸⁷Sr/⁸⁶Sr and low Ca/Na ratios…). These extreme end‐members define a series of WRI‐mixing line within a rather complex hydrosystem.     

The risk of harm to archaeological artefacts in soil from dynamic subsurface pressures generated by agricultural operations: experimental studies

An investigation was made of the fracture risk to buried ceramic pots and bones from the subsurface pressures generated by agricultural operations. A method for generating subsurface pressures at 0.25 m depth in a soil bin was developed and used to explore fracture failure of modern replicates of ceramic pots corresponding to different archaeological periods and aged medieval human bone. Application of conductive traces to the objects’ surfaces allowed detection of fracturing in real‐time without excavation. Predictive models relating fracture of objects to subsurface pressure application were developed by relating the probability of fracture to observed survival statistics at increasing subsurface pressures. Subsurface pressures of above 100 kPa were sufficient to fracture the more fragile pots at a probability level of 90%. The lowest subsurface pressure causing bone fracture was 280 kPa; however, no relationship was observed between subsurface pressure and bone fracture, probably due to variation in bone material. The subsurface pressures generated and applied are within the range reported from field measurements during typical agricultural operations. They indicate that measures to control the generation of subsurface pressures would be necessary to mitigate risk of harm from agriculture to buried archaeology; for example, via low‐pressure tyres, tracks and appropriate tillage.     

INTERACTION BETWEEN THE COAL-ENERGY-CHEMICALS AND IRON-STEEL CYCLES IN THE DONETS BASIN

An economic-geographic model of two technologically related industry groups in the Donets Basin (coal-energy-chemicals and iron-steel) reveals bottlenecks that reduce the cost-effectiveness of industrial performance. They include cross hauls of coal, amounting to about 5 million tons a year within the Donets Basin; in-shipments of up to 3 million tons of coal from outside the Donbas, and the waste of 3 billion m³ of blast-furnace gas. Remedies that would insure more rational utilization of fuel and energy resources are proposed.     

Private Profits – Public Drought: The Creation of a Crisis in Water Management for West Yorkshire

This paper examines the political and corporate constructions of the 1995–96 drought crisis in West Yorkshire, when an unprecedented public furore was provoked by the threat of water-supply cut-offs. A key outcome of this process was a profound crisis of confidence over the governance of water resources, which can be linked to the privatization of the industry and, more broadly, to the processes of redrawing the boundaries of the state. The water industry illustrates the contestability of neoliberal reforms seeking to inspire market-led growth with minimal government intervention. In particular, political dogma about the anticipated benefits of market competitiveness failed adequately to take into account public concern for the 'common good'.