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Central Asia is among the most heavily affected regions worldwide by climate change and water shortages. Impacts include changes in precipitation patterns, more frequent temperature extremes and increased aridity causing a negative impact on agricultural production, food availability, and environmental security. To combat this threat, it is important to enhance information literacy among all water users. This can be done through awareness campaigns, blended learning by providing the proper Technical and Vocational Education and Training (TVET) programs and utilizing all available facilities. This will address relevant issues, such as miscommunication, complexities of transboundary water sharing issues, overexploitation of water resources, and poor flood-drought mitigation techniques. Proper and user-friendly lifelong blended learning for scientific information dissemination focusing water issues can provide stronger support to increase awareness among water users and decision policy makers. Worldwide, especially in North America and Australia, information literacy campaigns have proven successful. This strategy can be replicated in the Mountainous Kyrgyz-Kazakh Chu-Talas transboundary river basin. The issues concerning the Mountainous KyrgyzKazakh Chu-Talas transboundary river basin is elaborated and compared with Australian, Canadian, and US river basin management programs. The foresight analysis is presented, as to what would be a rationale to improve water resources more sustainably in Central Asia. Methodologies, programs, technologies, communities-based river basin committees, snow-water collection with agroforestry, and basin-based water market opportunities were analyzed to assess potential applications in Central Asia region. [ABSTRACT FROM AUTHOR]

Water quality in the Delaware River, USA, has improved significantly since the Federal Water Pollution Control Act (1948), Clean Water Act of 1972, and authorization of the Delaware River Basin Commission Compact in 1961. Initial economic analysis by the Federal Water Pollution Administration in 1966 concluded the multimillion dollar pollution abatement programme would generate $350 million in annual benefits by improving dissolved oxygen levels to fishable standards in the Delaware River. Although water quality in the Delaware has improved substantially, scientists have called for raising the 1960s dissolved oxygen criteria from 3.5 mg/L to 5.0 mg/L to ensure year‐round propagation of anadromous American shad and Atlantic sturgeon. This higher level would also mitigate atmospheric warming resulting in increased water temperatures and sea water incursion, both of which would lead to reductions in dissolved oxygen saturation in the river. Additional economic valuation of this water quality improvement shows direct use benefits in the Delaware River to range from $371 million to $1.1 billion per year. Other economic sectors benefiting from improved water quality include recreational boating ($46–$334 million), recreational fishing ($129–$202 million), agriculture ($8–$188 million), nonuse value ($76–$115 million), viewing/boating/fishing ($55–$68 million), bird watching ($15–$33 million), property value ($13–27 million), water supply ($12–$24 million), commercial fishing (up to $17 million), and navigation ($7–$16 million). Future economic research is needed in the Delaware River watershed to more precisely measure nonuse benefits by public willingness to pay for improved water quality. [ABSTRACT FROM AUTHOR]

Abstract Within river basins, water resources competition often exists between agricultural, municipal and industrial sectors, particularly in semi-arid regions where surface water and groundwater are managed conjunctively to sustain urban areas and food production. There is a need for physically-based modeling tools to assist with identifying successful water management strategies in these basins. This paper presents an updated version of SWAT-MODFLOW that allows application to large agro-urban river basins in semi-arid regions. Code changes include linkage between MODFLOW pumping cells and SWAT HRUs for groundwater irrigation, joint groundwater and surface water irrigation routines, and the use of MODFLOW-PSB to handle the large array of groundwater sources/sinks that exist in a highly managed river basin. Model performance is demonstrated for the 72,000 km2 South Platte River Basin, Colorado, USA. The model can be used in agro-urban river basins worldwide to assess water resources supply under a variety of scenarios. Highlights • Updated SWAT-MODFLOW code can be used for large agro-urban river basins. • The model includes all major water transfer pathways for managed river basins. • The model links MODFLOW pumping to SWAT groundwater irrigation. • The model is tested in a 72,000 km2 river basin in Colorado, USA. [ABSTRACT FROM AUTHOR]

Previous studies of correlation coefficients between paired observations using census, hydrologic, and remote sensing data abound. It is well established that bivariate relationships at coarser spatial resolutions are often stronger than at finer resolutions. No assessment as yet, however, corroborates this tendency with water resources variables. In this study, multiscale correlations between water use or water availability and population are presented in three river basins—the Missouri (United States), Danube (Europe), and Ganges (South Asia). High-resolution gridded data sets were obtained at 0.5° and resampled to fourteen different geographic scales to examine the effects of scale on the strength and trends of correlations. Correlation coefficients between most variable pairs increased at coarser scales. Smoothing fine-scale spatial patterns in the data at coarser scales is posited as a possible explanation. The increase was not often linear, however, nor was there always an increase. The Missouri Basin did not show a significant increase in correlations between water use and population with grid-cell size and nonlinear increases are evident in the Ganges Basin. [ABSTRACT FROM AUTHOR]

The flux of nitrogen in large rivers in North America and Europe is well explained as a function of the net anthropogenic inputs of nitrogen to the landscape, with on average 20 to 25% of these inputs exported in rivers and 75 to 80% of the nitrogen retained or denitrified in the landscape. Here, we use data for average riverine nitrogen fluxes and anthropogenic inputs of nitrogen over a 6-year period (1988–1993) for 16 major watersheds in the northeastern United States to examine if there is also a climatic influence on nitrogen fluxes in rivers. Previous studies have shown that for any given river, nitrogen fluxes are greater in years with higher discharge, but this can be interpreted as storage of nitrogen in the landscape during dry years and flushing of this stored nitrogen during wet years. Our analyses demonstrate that there is also a longer-term steady-state influence of climate on riverine nitrogen fluxes. Those watersheds that have higher precipitation and higher discharge export a greater fraction of the net anthropogenic inputs of nitrogen. This fractional export ranges from 10 to 15% of the nitrogen inputs in drier watersheds in the northeastern United States to over 35% in the wetter watersheds. We believe this is driven by lower rates of denitrification in the wetter watersheds, perhaps because shorter water residence times do not allow for as much denitrification in riparian wetlands and low-order streams. Using mean projections for the consequences of future climate change on precipitation and discharge, we estimate that nitrogen fluxes in the Susquehanna River to Chesapeake Bay may increase by 3 to 17% by 2030 and by 16 to 65% by 2095 due to greater fractional delivery of net anthropogenic nitrogen inputs as precipitation and discharge increase. Although these projections are highly uncertain, they suggest a need to better consider the influence of climate on riverine nitrogen fluxes as part of management efforts to control coastal nitrogen pollution. [ABSTRACT FROM AUTHOR]

Our increasingly affluent and growing population, and our expanding economy are multiplying the demands on the nation's water resources. Water quality control is a key element of plans to assure that water resources can be used and reused effectively. Water management requires quantitative knowledge of the resource, but such knowledge is seriously lacking. Congress has established a Water Resources Council to define the data needs and to spearhead water resources planning. Regional commissions and committees have been established to co-ordinate the studies and development planning in the nation's 16 major river basins. [ABSTRACT FROM AUTHOR]

The herbicide acetochlor [2-chloro-N-(ethoxymethyl)-N-(2-ethyl-6-methylphen yl) acetamide] was first used on corn (Zea mays L.) in the USA during the growing season of 1994. By 1996, it was the third most heavily used corn herbicide in the midwestern USA. During the growing season of 1997, 78% of 375 samples collected at 32 stream sites in the Mississippi River Basin contained detectable concentrations of acetochlor. However, concentrations in only 2% of the samples exceeded 2 mug/L, the maximum annual average concentration allowable in public water supplies derived primarily from surface water. The largest acetochlor concentrations were detected in streams draining basins in parts of Illinois, Indiana, and Iowa. The median concentration of acetochlor in streams was about 10%a that of atrazine (6-chi N-ethyl-N-isopropyl-1,3,5-triazine-2,4-dianline), about 25% that of metolachlor [2-chloro-N-(2-ethyl-6-methyiphenyl)-N-(2-methoxy- l methylethy1) acetamide] about 50 deg. / that of cyanazine [2-[[4-chloro-6-(ethylandino)-1,3,5-triazin-2-yl]a mino]-2-methylpropionitrile],and on about threefold that of alachlor [2-chloro-2',6'-diethyl-N-(meth-Ogyoxymethyi) acetanilide]. Load estimates indicate that, during the season of 1997 agricultural subbasins draining areas of Illinois, Indiana, and Iowa contributed about 37000 kg, or 74%, of the 50 000 kg of acetochlor measured in streams of the Mississippi River Basin. [ABSTRACT FROM AUTHOR]

Periphyton accumulation variables and diatom assemblage structure were examined on nutrient diffusing pots placed in three rivers in the Minnesota River basin. The Minnesota River, which had the highest accrual of inorganic and organic matter, appeared to have phosphate and light limited algal accumulation. No nutrient effects were observed in the Blue Earth River although phosphate limitation was predicted bythe N:P ratio. Cyclotella meneghiniana responded negatively and Gomnhonema parvulum responded positively to ammonia diffusing pots in theYellow Medicine River. Otherwise no release from nutrient limitationwas observed in this stream. Diatom species composition varied independently of algal accumulation rates. [ABSTRACT FROM AUTHOR]