Journal of The American Water Resources Association最新文献

Water regulation, extraction, and application have major effects on water availability. We investigated the impact of anthropogenic water use on the water balance in two intensively irrigated headwater watersheds in Wyoming using geospatially comprehensive water right data in a watershed hydrologic-allocation modeling framework. Water balance variables were compared under natural flow conditions and scenarios representing water right appropriative demands. Across both watersheds, the full appropriative demand scenario resulted in a 54% decrease in streamflow, an 18% increase in evapotranspiration, and a 6% decrease in watershed storage during the growing season. The study watersheds exhibited distinct responses to the scenarios with incremental changes in potential return flow and appropriative demand, reflecting differences in water right network structure, spatial density, use, and appropriative demand. Testing the effects of spatial and non-spatial water right characteristics revealed significant relationships between changes in streamflow and factors such as trans-watershed transfers and water right spatial density. Resource distribution among water balance components varied by sub-watershed, with reduced variability at larger watershed scales. The differences in water balance changes between scenarios within the study watersheds highlight the importance of geospatially comprehensive water right data in incorporating abstractions in hydrologic models.

A two-stage constructed floating wetland with a 0.7% ratio of wetland to drainage area was studied for removing phosphorus from subsurface agricultural drainage. This system consisted of two stages, the first being a floating wetland containing Scirpus atrovirens, Carex vulpinoidea, Juncus effusus, Ranunculus hispidus, and Acorus americanus, and the second containing a filter media of pea stone. It was found that total phosphorus (TP) in plant tissues was not statistically different across macrophyte species; however, total biomass did differ. Therefore, to obtain maximum TP removal, plant shoots should be removed when they reach their maximum biomass. Scirpus had the highest average dry mass (17.1 g) and average TP shoot mass and was significantly greater than the other species examined. Total P removal by plant shoots ranged between 0.89% and 19.3% of the soluble reactive phosphorus (SRP) entering the wetland, depending on the year. The average annual SRP and total phosphorus reductions from discharge entering and exiting the system equated to 65 and 36%, respectively. Additionally, the average SRP concentration across all 3 years during the growing season was reduced from 0.087 mg/L to 0.029 mg/L, and TP was reduced from 0.168 mg/L to 0.068 mg/L, keeping both SRP and TP effluent concentrations below maximum concentrations recommended for flowing waters to minimize eutrophication and harmful algal blooms.

There is an increasing need for safe drinking water. Yet, public perceptions of drinking water providers are not always positive. Incidents like those in Flint, Michigan, and Jackson, Mississippi, contribute to mistrust and poor perceptions of public water providers. To better understand public perceptions, we conducted an exploratory survey with 1100 respondents using online Qualtrics panels, guided by five research questions. First, we explored public perceptions of drinking water safety. Most respondents used municipal water and generally trusted their source although many reported problems such as odd smells, tastes, or hardness. Second, we examined trust in entities involved in drinking water management. Water utilities were the most trusted, followed by local and state governments. Respondents also believed these groups were responsible for ensuring water safety. Third, we analyzed water problems respondents had experienced, which included odd tastes, smells, and hardness. Fourth, we identified concerns about contamination sources with pesticides, industrial chemicals, pathogens, and heavy metals ranking highest. Fifth, we explored sources of information, finding respondents relied primarily on water providers, social media, and word-of-mouth. Our findings emphasize the need for educational programs and transparent communication about drinking water safety, particularly targeting groups with higher distrust (e.g., women, non-whites, renters).

Changes in snowmelt and stream runoff timing due to warming temperatures are a concern for water managers. This study analyzed runoff estimates from 10 Sierra Nevada watersheds upstream of California's San Francisco Estuary (1872–2022) to examine trends and temperature sensitivities. Monthly runoff time series, reconstructed using a multivariate regression model with temperature and precipitation data, revealed high variability with multi-year wet and dry periods. While no statistically significant annual runoff trends were detected over the entire period, nine of 10 watersheds showed significant decreases in April–July runoff fractions. Breakpoints in the mid-20th century indicated stationary fractions of April–July runoff followed by declining fractions in six watersheds, with the sharpest reductions occurring in the last decade. Sensitivity analysis linked warming to earlier runoff timing and modest reductions in annual runoff volumes, though interannual precipitation variability masked the impacts. We estimate a 3.7% decrease in total annual flow per ^oC of warming in the historical record, the effects of which may become more consequential under future warmer periods and during drought conditions. This work confirms previous findings of earlier runoff from snow-fed watersheds in western North America in recent decades; importantly, it highlights the stationarity in this quantity from the late 19th century to mid-20th century before significant warming trends emerged.

To relieve droughts and supply demand imbalances in Henan Yellow River water supply area and improve water security, this study focuses on the drought evolution characteristics at different times and spaces. Standardized runoff index (SRI) and standardized soil moisture index (SSMI) were selected to characterize hydrological and agricultural drought. Based on Arc GIS and Mann–Kendall trend test method, this study revealed the temporal and spatial variation characteristics of drought trend at the hydrological and agricultural levels. The Gray Relational Analysis method is used to analyze the correlation degree between SRI and SSMI at different scales. The Pearson correlation coefficient and sliding window method are used to assess the correlation between multi scale SRI and monthly scale SSMI sequences and the seasonal changes in drought propagation time. The results of the study demonstrate that: (1) Hydrological drought in Henan Yellow River water supply area is generally moderate or severe in spring and winter, it is mainly mild or nonexistent in summer and autumn; (2) Agricultural drought of mild severity or above is primarily concentrated in the central-eastern regions; (3) The overall drought propagation time from hydrological to agricultural drought is 6 months. The optimal drought propagation times for the four seasons are 2, 1, 2, and 4 months. This study enabling early implementation of drought emergency prevention and control measures.