Implicit and Explicit Biases for Recycled Water and Tap Water

American Geophysical Union (AGU) | May 31st, 2022

Increasing use of recycled water to irrigate agricultural products and decreasing consumption of bottled water are important components of sustainable water management pr

Increasing use of recycled water to irrigate agricultural products and decreasing consumption of bottled water are important components of sustainable water management practices and consumer-driven efforts to improve water security and quality. However, consumers frequently discount agricultural products irrigated with recycled water relative to products irrigated with conventional water and place a premium on bottled water relative to tap water. This study measures consumer attitudes regarding recycled water and bottled water to understand more fully the reasons behind these preferences. We conduct two studies involving 2,616 adult consumers in the United States designed to measure consumer attitudes and preferences: the use of recycled water versus conventional water to irrigate food products and tap water versus bottled water for drinking. In each study, implicit attitudes are measured using an Implicit Association Test as well as explicit attitudes. We find that respondents have negative implicit attitudes regarding recycled water compared to conventional water and tap water compared to bottled water, and a negative explicit attitude toward recycled water. Tap water and food grown with recycled water were believed to be less healthy to consume and less tasty, although these are believed to be more sustainable options. Beliefs about water attributes (i.e., healthfulness, taste, and sustainability) are associated with attitudes, and both beliefs about attributes and attitudes are associated with preferences for products. Further, we find that respondents' stated preferences are consistent with their implicit and explicit attitudes.

Importance of subsurface water for hydrological response during storms in a post-wildfire bedrock landscape

Nature Portfolio (Springer Nature) | June 29th, 2023

Improved Bias Correction Techniques for Hydrological Simulations of Climate Change

American Meteorological Society (AMS) | December 13th, 2015

Global climate model (GCM) output typically needs to be bias corrected before it can be used for climate change impact studies. Three existing bias correction met

Global climate model (GCM) output typically needs to be bias corrected before it can be used for climate change impact studies. Three existing bias correction methods, and a new one developed here, are applied to daily maximum temperature and precipitation from 21 GCMs to investigate how different methods alter the climate change signal of the GCM. The quantile mapping (QM) and cumulative distribution function transform (CDF-t) bias correction methods can significantly alter the GCM’s mean climate change signal, with differences of up to 28C and 30% points for monthly mean temperature and precipitation, respectively. Equidistant quantile matching (EDCDFm) bias correction preserves GCM changes in mean daily maximum temperature but not precipitation. An extension to EDCDFm termed PresRat is introduced, which generally preserves the GCM changes in mean precipitation. Another problem is that GCMs can have difficulty simulating variance as a function of frequency. To address this, a frequency-dependent bias correction method is introduced that is twice as effective as standard bias correction in reducing errors in the models’ simulation of variance as a function of frequency, and it does so without making any locations worse, unlike standard bias correction. Last, a preconditioning technique is introduced that improves the simulation of the annual cycle while still allowing the bias correction to take account of an entire season’s values at once.

Improved Imaging of the Large-Scale Structure of a Groundwater System with Airborne Electromagnetic Data

American Geophysical Union (AGU) | March 17th, 2022

A groundwater model is a representation of a groundwater system used to both understand the properties and processes of the subsurface, and to manage the groundwater reso

A groundwater model is a representation of a groundwater system used to both understand the properties and processes of the subsurface, and to manage the groundwater resource. An important step in developing a groundwater model is describing the large-scale structure, the "plumbing system" that controls the groundwater flow. Given the size of many groundwater models, obtaining an accurate description of the large-scale structure can be a challenging task. The traditional approach has involved the drilling of wells. While wells can provide accurate information at the location of the wells, the spatial sampling of the subsurface that can be accomplished through the drilling of wells is limited. An airborne electromagnetic (AEM) method provides an alternative by using a geophysical measurement to map out the electrical resistivity to depths of hundreds of meters. Working with AEM data acquired in the Kaweah Subbasin in the Central Valley of California, we were able to image the large-scale structure - the bedrock surface and a thick clay layer. The key improvement was made by incorporating prior knowledge into the inversion of the data. Once we had obtained the large-scale structure, we found that this could be used to improve the imaging of the smaller-scale structure.

Improving Adaptive Management in the Sacramento-San Joaquin Delta

Delta Stewardship Council (Delta Council) | January 1st, 2016

Adaptive management is a science-based, structured approach to environmental management. It aids decision-making in the face of uncertainty about outcomes by emphasizing

Adaptive management is a science-based, structured approach to environmental management. It aids decision-making in the face of uncertainty about outcomes by emphasizing the acquisition and use of new knowledge, experience, and stakeholder input in management of natural resources under changing conditions. The Delta Reform Act of 2009 calls for adaptive management of efforts to make water supplies more reliable and ecosystems healthier. It is often talked about, but as a comprehensive, science-based process, adaptive management is little used in the Delta. This is not a unique situation; many environmental management programs around the world have encountered difficulties in managing natural resources adaptively. The Delta Independent Science Board (Delta ISB) reviewed how adaptive management is perceived and used in the Delta and how it might be applied more efficiently and effectively. This report identifies impediments to adaptive management in the Delta and makes recommendations for incorporating adaptive approaches to improve management of the Delta and its resources.

Improving and Sustaining BLM-Tribal Relations (Handbook 1780-1)

Bureau of Land Management (BLM) | December 15th, 2016

Manual Section 1780 (MS-1780) and Handbook 1780-1 (H-1780-1) are being released simultaneously . H-1780-1 , I mproving and Sustaining BLM- Tribal Relations, rep

Manual Section 1780 (MS-1780) and Handbook 1780-1 (H-1780-1) are being released simultaneously . H-1780-1 , I mproving and Sustaining BLM- Tribal Relations, replaces H-8120-1 (Rel. 8-75, 12/03/04) . M S - 1780 , Tribal Relations, replaces MS-8120 (Rel. 8-74, 12/03/04). MS-8 120 and H-8120 - 1 were specific to implementation of historic preservation authorities only . Therefore, this new guidance is appropriately placed within the Bureau of Land Management (BLM) 1700 series, which addresses relations with other governments, including State, local, and international relations . Developed in response to the finalization of 512 Departmental M anual (DM) Chapters 4 and 5, H-1780-1 with MS-1780 provides direction for all BLM programs for improving and sustaining tribal relations , including government-to-government consultation. We attempted to be inclusive; however, this handbook does not contain sections for every program area or discipline who should be involved in tribal relations. Updates and additional chapters will be added when they are available.

Improving Groundwater Model Calibration with Repeat Microgravity Measurements

National Groundwater Association (NGWA) | December 23rd, 2021

Groundwater-flow models depend on hydraulic head and flux observations for evaluation and calibration. A different type of observation—change in storage measured using

Groundwater-flow models depend on hydraulic head and flux observations for evaluation and calibration. A different type of observation—change in storage measured using repeat microgravity—can also be used for parameter estimation by simulating the expected change in gravity from a groundwater model and including the observation misfit in the objective function. The method is demonstrated using new software linked to MODFLOW input and output files and field data from the vicinity of the All American Canal in southeast California, USA. Over a 10-year period following lining of the previously highly permeable canal with concrete, gravity decreased by over 100 μGal (equivalent to about 2.5 m of free-standing water) at some locations as seepage decreased and the remnant groundwater mound dissipated into the aquifer or was removed by groundwater pumping. Simulated gravity from a MODFLOW model closely matched observations, and repeat microgravity data proved useful for constraining both hydraulic conductivity and specific yield estimates. Specific yield estimated using the infinite-horizontal slab approximation agreed well with model-derived values, and the departure from the linear, flat-water-table approximation was small, less than 2%, despite relatively large and dynamic water-table slope. First-order second-moment parameter uncertainty analysis shows reduction in uncertainty for all hydraulic conductivity and specific yield parameter estimates with the addition of repeat microgravity data, as compared to drawdown data alone.

Improving Groundwater Security in the United States

The White House | December 14th, 2024

The U.S. is facing a serious and unprecedented groundwater challenge. In many aquifers, groundwater withdrawal has outpaced natural recharge, which is exacerbated by the

The U.S. is facing a serious and unprecedented groundwater challenge. In many aquifers, groundwater withdrawal has outpaced natural recharge, which is exacerbated by the changing climate and precipitation variability. Much of the water in the major aquifers in the U.S. is fossil water, recharged over 10,000 years ago, and will not be replaced naturally on human timescales. In the western U.S., groundwater resources are being depleted at alarming rates, mostly from agricultural withdrawal. The depletion has caused land subsidence and earth fissures as well as permanent reduction of storage capacity. The depletion has national and global consequences as non-renewable groundwater in the west is embedded in agricultural products transported to the rest of the U. S. and in agricultural commodities exported globally. Many federal agencies have programs to measure the quality and quantity of groundwater, as well as conservation programs for sustainable use of groundwater. PCAST applauds and endorses their efforts as well as those by state governments, non-governmental organizations, professional organizations, local communities, private citizens, and others, to manage their groundwater resources. To ensure the sustainability of this indispensable resource and mitigate risks from its depletion, it is imperative that we enhance our understanding and management of groundwater resources.

Improving Habitats Along Delta Levees: A Review of Past Projects and Recommended Next Steps

Delta Stewardship Council (Delta Council) | January 15th, 2016

This review of habitat improvements along Delta levees was conducted to support the development of the Delta Stewardship Council’s (Council) Delta Levee Investment Stra

This review of habitat improvements along Delta levees was conducted to support the development of the Delta Stewardship Council’s (Council) Delta Levee Investment Strategy (DLIS), which focuses on flood risk reduction as the primary purpose of State levee investments. The report is intended to provide guidance to the Council to ensure that those investments also contribute to long-term improvement of river corridors, with net benefits for fish and wildlife. The Council must ensure that the DLIS helps to implement the Delta Reform Act and the Delta Plan. The Delta Reform Act of 2009 established the Council and defined its mission: to achieve the coequal goals of water supply reliability for California and ecosystem restoration in the Delta, in a manner that protects and enhances the values of the Delta as an evolving place (Water Code section 85054). The Delta Plan includes 14 regulatory policies, including one that calls for levee projects to incorporate habitat benefits, where feasible, and another requiring the use of the best available science and adaptive management. This report is intended to support the application of best available science and adaptive management to habitat improvements along Delta levees. It should be noted that levee-related habitat improvements alone are not expected to provide all the ecosystem benefits needed by native species. These projects take place within the larger context of ecosystem restoration in the Delta and Suisun Marsh, which will require more natural functional flows, restoration and conservation of a wide range of habitat types1, improved water quality, and the management of nonnative invasive species. Nevertheless, given its significant role in Delta levee investments, the State must ensure that these habitat projects are part of a program that provides a net benefit for aquatic species in the Delta.

Improving Infrastructure for Wildlife

Social Science Research Network (SSRN) | February 25th, 2021

In Washington v. United States, 584 U.S. ___ (2018), the Supreme Court required Washington State to improve fish passage through almost 1,000 culverts originally built to

In Washington v. United States, 584 U.S. ___ (2018), the Supreme Court required Washington State to improve fish passage through almost 1,000 culverts originally built to allow streamflow under roads and highways. The case highlighted conflicts between wildlife needs and infrastructure development. Fish passage through outdated or ill-designed culverts is only a small facet of the larger problem of outdated wildlife infrastructure. Impinged migration corridors for ungulates, turtles, and other mobile taxa; levees disconnecting floodplains from rivers; poor water temperature controls on dams; and eroding ecological productivity accompanying aging of reservoirs exemplify the types of challenges to wildlife created by contemporary infrastructure.