The Uneven Nature of Daily Precipitation and Its Change

American Geophysical Union (AGU) | October 19th, 2018

Rain falls unevenly in time, which can lead to floods and droughts. It is widely known that precipitation is uneven, but it is difficult to quantify. Here we develop a me

Rain falls unevenly in time, which can lead to floods and droughts. It is widely known that precipitation is uneven, but it is difficult to quantify. Here we develop a measure for the unevenness of precipitation: the number of the wettest days each year in which half of the annual rain falls. We apply this to rain observed by gauges around the world. At all gauges combined, it takes only 12 days each year for half of the rain to fall. We also apply the measure to climate model simulations, with projections for the rest of the century. In the climate model simulations, the change in future rainfall is even more uneven than rainfall today: In a scenario with high greenhouse‐gas emissions, half of the increase in rainfall happens in the wettest 6 days each year. Rather than assuming more rain in general, society needs to take measures to deal with little change most of the time and a handful of events with much more rain.

The uneven response of different snow measures to human-induced climate warming

American Meteorological Society (AMS) | June 25th, 2013

The effect of human-induced climate warming on different snow measures in the western United States is compared by calculating the time required to achieve a stat

The effect of human-induced climate warming on different snow measures in the western United States is compared by calculating the time required to achieve a statistically significant linear trend in the different measures, using time series derived from regionally downscaled global climate models. The measures examined include the water content of the spring snowpack, total cold-season snowfall, fraction of winter precipitation that falls as snow, length of the snow season, and fraction of cold-season precipitation retained in the spring snowpack, as well as temperature and precipitation. Various stakeholders may be interested in different sets of these variables. It is found that temperature and the fraction of winter precipitation that falls as snow exhibit significant trends first, followed in 5–10 years by the fraction of cold-season precipitation retained in the spring snowpack, and later still by the water content of the spring snowpack. Change in total cold-season snowfall is least detectable of all the measures, since it is strongly linked to precipitation, which has large natural variability and only a weak anthropogenic trend in the western United States. Averaging over increasingly wider areas monotonically increases the signal-to-noise ratio of the 1950–2025 linear trend from 0.15 to 0.37, depending on the snow measure.

The Untapped Potential of California’s Urban Water Supply: Water Efficiency, Water Reuse, and Stormwater Capture

Pacific Institute | April 12th, 2022

In this assessment, we quantify the potential for a range of water strategies in urbanized parts of California to both reduce inefficient and wasteful water uses and expa

In this assessment, we quantify the potential for a range of water strategies in urbanized parts of California to both reduce inefficient and wasteful water uses and expand local water supplies. This assessment finds that urban water-use efficiency improvements could reduce statewide urban water use by 2.0 million to 3.1 million acre-feet per year (AFY). The reuse potential of municipal wastewater is 1.8 million to 2.1 million AFY, and the stormwater capture potential is 580,000 AFY in a dry year to as much as 3.0 million AFY in a wet year. Previous assessments have shown that these efficiency and supply options are more cost effective than traditional – and increasingly hard to implement – options to expand supply. Programs to tap this potential would tremendously help solve California’s long-standing water problems.

The Untapped Potential of California’s Water Supply

Pacific Institute | June 10th, 2014

California could be saving up to 14 million acre-feet of untapped water – providing more than the amount of water used in all of California’s cities in one year – w

California could be saving up to 14 million acre-feet of untapped water – providing more than the amount of water used in all of California’s cities in one year – with an aggressive statewide effort to use water-saving practices, reuse water, and capture lost stormwater, according to a new analysis released by the Pacific Institute and the Natural Resources Defense Council. “Our current approach to water use is unsustainable, but that doesn’t mean there isn’t enough water to meet our needs,” said Kate Poole, NRDC senior attorney with the water program. “At a time when every drop counts, we need to employ sensible and cost-effective 21st century solutions that will help us reduce uses today while promising new, resilient supplies for cities and farms tomorrow.” “As climate change brings more extreme weather, including droughts, ramping up forward-thinking solutions now will help us be more resilient,” said Peter Gleick, president of the Pacific Institute. “With widespread adoption of available water conservation and efficiency improvements, demand can be met more readily, less expensively, and with less pressure on our tapped-out rivers and groundwater basins. Moreover, water reuse and stormwater capture can help boost local supplies.”

The Use of Smolt Survival Estimates to Quantify the Effects of Habitat Changes on Salmonid Stocks in the Sacramento-San Joaquin Rivers, California

Canada Department of Fisheries and Oceans (DFO) | July 1st, 1989

The value of ecosystem services in global marine kelp forests

Nature Portfolio (Springer Nature) | April 18th, 2023

While marine kelp forests have provided valuable ecosystem services for millennia, the global ecological and economic value of those services is largely unresolved. Kelp

While marine kelp forests have provided valuable ecosystem services for millennia, the global ecological and economic value of those services is largely unresolved. Kelp forests are diminishing in many regions worldwide, and efforts to manage these ecosystems are hindered without accurate estimates of the value of the services that kelp forests provide to human societies. Here, we present a global estimate of the ecological and economic potential of three key ecosystem services - fisheries production, nutrient cycling, and carbon removal provided by six major forest forming kelp genera (Ecklonia, Laminaria, Lessonia, Macrocystis, Nereocystis, and Saccharina). Each of these genera creates a potential value of between $64,400 and $147,100/hectare each year. Collectively, they generate between $465 and $562 billion/year worldwide, with an average of $500 billion. These values are primarily driven by fisheries production (mean $29,900, 904 Kg/Ha/year) and nitrogen removal ($73,800, 657 Kg N/Ha/year), though kelp forests are also estimated to sequester 4.91 megatons of carbon from the atmosphere/year highlighting their potential as blue carbon systems for climate change mitigation. These findings highlight the ecological and economic value of kelp forests to society and will facilitate better informed marine management and conservation decisions.

The value of marsh restoration for flood risk reduction in an urban estuary

Nature Portfolio (Springer Nature) | March 21st, 2024

The Value of Water Supply Reliability in Urban Water Systems

Journal of Environmental Economics and Management (Elsevier) | January 4th, 1994

Reliability is an important dimension of urban water supply. While out-of-pocket losses appear small, water customers place high values on reliability. This demand for re

Reliability is an important dimension of urban water supply. While out-of-pocket losses appear small, water customers place high values on reliability. This demand for reliability can be measured by contingent valuation methods, while the costs of providing various levels of reliability can be estimated through hydrologic simulation. A framework for optimizing reliability is presented and the contingent valuation survey is described. Results from three Colorado towns are presented.

The Vernalis Adaptive Management Program (VAMP): Report of the 2010 Review Panel

California State Water Resources Control Board (SWRCB) | May 11th, 2010

Panel members were asked by the Delta Science Program to carry out an independent review of a 12-year VAMP (Vernalis Adaptive Management Plan) experimental program design

Panel members were asked by the Delta Science Program to carry out an independent review of a 12-year VAMP (Vernalis Adaptive Management Plan) experimental program designed to develop water management measures that would provide protection to juvenile Chinook salmon migrating through the San Joaquin River system and associated Sacramento-San Joaquin River Delta (Delta) waterways. The Charge to the Panel was expressed as a series of three questions that the Panel was obligated to address: 1) Do the results to date from the VAMP study provide useful scientific information about the relationship between salmon survival and each of the following factors: Flows, Exports, and Barrier installation at the head of Old River? 2) How can the results from the VAMP to date be used to inform the State Water Resources Control Board's (SWRCB) current efforts to review and potentially revise the San Joaquin River flow objectives and their implementation? 3) How can the experiences to date from the VAMP study be used in a scientific manner to inform future monitoring and study efforts related to determining appropriate flow, operational, and water quality requirements to protect San Joaquin River fisheries (specifically Chinook salmon and steelhead)?

The vertical distribution and biological transport of marine microplastics across the epipelagic and mesopelagic water column

Nature Portfolio (Springer Nature) | July 6th, 2019

Plastic waste has been documented in nearly all types of marine environments and has been found in species spanning all levels of marine food webs. Within these marine en

Plastic waste has been documented in nearly all types of marine environments and has been found in species spanning all levels of marine food webs. Within these marine environments, deep pelagic waters encompass the largest ecosystems on Earth. We lack a comprehensive understanding of the concentrations, cycling, and fate of plastic waste in sub-surface waters, constraining our ability to implement effective, large-scale policy and conservation strategies. We used remotely operated vehicles and engineered purpose-built samplers to collect and examine the distribution of microplastics in the Monterey Bay pelagic ecosystem at water column depths ranging from 5 to 1000 m. Laser Raman spectroscopy was used to identify microplastic particles collected from throughout the deep pelagic water column, with the highest concentrations present at depths between 200 and 600 m. Examination of two abundant particle feeders in this ecosystem, pelagic red crabs (Pleuroncodes planipes) and giant larvaceans (Bathochordaeus stygius), showed that microplastic particles readily flow from the environment into coupled water column and seafloor food webs. Our findings suggest that one of the largest and currently underappreciated reservoirs of marine microplastics may be contained within the water column and animal communities of the deep sea.