Water Resources: Agricultural and Environmental Issues

Pimentel, David; Berger, Bonnie; Filiberto, David; Newton, Michelle; Wolfe, Benjamin; Karabinakis, Elizabeth; Clark, Steven; Poon, Elaine; Abbett, Elizabeth; Nandagopal, Sudha

doi:10.1641/0006-3568(2004)054[0909:wraaei]2.0.co;2

Cited by 611 publications

(298 citation statements)

References 11 publications

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“…Despite this small areal extent, there are substantial gaps in our knowledge of the distribution and variability of terrestrial surface water resources over time (Alsdorf et al, 2007;Turpie et al, 2015). Freshwater is poorly monitored and managed across the globe, especially with regard to wetlands and water applied to agricultural lands (Alsdorf et al, 2007;Pimentel et al, 2004). Even in California, which has one of the most highly engineered and intensively managed water systems in the U.S., water rights in some areas represent 1000% of the surface water supply (Grantham and Viers, 2014;Jenkins et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

Three decades of Landsat-derived spring surface water dynamics in an agricultural wetland mosaic; Implications for migratory shorebirds

Schaffer‐Smith

Swenson

Barbaree

et al. 2017

Remote Sensing of Environment

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Satellite measurements of surface water offer promise for understanding wetland habitat availability at broad spatial and temporal scales; reliable habitat is crucial for the persistence of migratory shorebirds that depend on wetland networks. We analyzed water extent dynamics within wetland habitats at a globally important shorebird stopover site for a 1983-2015 Landsat time series, and evaluated the effect of climate on water extent. A range of methods can detect open water from imagery, including supervised classification approaches and thresholds for spectral bands and indices. Thresholds provide a time advantage; however, there is no universally superior index, nor single best threshold for all instances. We used random forest to model the presence or absence of water from >6200 reference pixels, and derived an optimal water probability threshold for our study area using receiver operating characteristic curves. An optimized mid-infrared (1.5-1.7 μm) threshold identified open water in the Sacramento Valley of California at 30-m resolution with an average of 90% producer's accuracy, comparable to approaches that require more intensive user input. SLC-off Landsat 7 imagery was integrated by applying a customized interpolation that mapped water in missing data gaps with 99% user's accuracy. On average we detected open water on ~26000 ha (~3% of the study area) in early April at the peak of shorebird migration, while water extent increased five-fold after the migration rush. Over the last three decades, late March water extent declined by ~1300 ha per year, primarily due to changes in the extent and timing of agricultural flood-irrigation. Water within shorebird habitats was significantly associated with an index of water availability at the peak of migration. Our approach can be used to optimize thresholds for time series analysis and near-real-time mapping in other regions, and requires only marginally more time than generating a confusion matrix.

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Section: Introductionmentioning

confidence: 99%

Three decades of Landsat-derived spring surface water dynamics in an agricultural wetland mosaic; Implications for migratory shorebirds

Schaffer‐Smith

Swenson

Barbaree

et al. 2017

Remote Sensing of Environment

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“…Less saline or brackish waters are actually attributed to animal Table 3: Vertical profile of macro ions in water samples collected from 14 saline lakes. impact in the Gobi region, due to limits of available freshwater supply for wild animals and livestock [3,5,20].…”

Section: Analysis Of Physical and Chemical Parametersmentioning

confidence: 99%

Physico-Chemical Composition of Saline Lakes of the Gobi Desert Region, Western Mongolia

Bayanmunkh¹,

Sen-lin²,

Narangarvuu³

et al. 2017

J Earth Sci Clim Change

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Mongolian saline lakes have been rarely studied. In particular, physicochemical composition of small shallow lakes of the Gobi Desertregion in western Mongolia is simply unknown. Objectives were to characterize chemical composition and describe biogeochemical characteristics of saline lakes in the Gobi Desertregions and steppe mountains, with an emphasis on environmental parameters associated with heavy metal ions. Major physicochemical parameters were determined in 14 lakes (with varying degrees of salinity) located in western Mongolia and associations with geographic variation and distance were determined. Vertical profiles for temperature, specific conductance, and dissolved oxygen were characterized. Salinity and pH were measured with multiparameter submersible profilers. Heavy metal ions (i.e., As, Pb, and Cd) and microelements (i.e., K, Na, Zn, Cu, Ni, Cr, and Co) were analyzed with Inductively Coupled Plasma-Mass Spectrometry. Hydrogen sulfide, ammonia, nitrite, and nitrate were also determined by commercial kits for elemental analysis. Overall, 43 environmental parameters were determined from 31 water samples from various locations, representing distinct geographic features, including Gobi Desert, mountain range and steppe area. Several of these lakes had harmful concentrations of arsenate (< 0.34 mg/L). Heavy metal concentrations were correlated with selected physico-chemical variables of lake salinity and geographic specificity. We inferred that various environmental features, in addition to environmental pollution and mining activity, may be responsible for increased heavy metal concentrations in the Gobi Desert of the western Mongolia. The outcome of this study not only provided insights into lake chemistry, but should also be valuable for water resource management to mitigate potential poisoning and improve public health.

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“…Water scarcity already hits the many parts of the world and it was estimated that by the 2025 about 1.8 billion people will going to face absolute water scarcity and two third of total population under water stress (FAO, 2012b). About 70 percent of fresh water used for Agriculture (Pimentel et al, 2004).…”

Section: Water Use Efficiencymentioning

confidence: 99%