Ground water and climate change

Nature Portfolio (Springer Nature) | November 25th, 2012

As the world's largest distributed store of fresh water, ground water plays a central part in sustaining ecosystems and enabling human adaptation to climate variability a

As the world's largest distributed store of fresh water, ground water plays a central part in sustaining ecosystems and enabling human adaptation to climate variability and change. The strategic importance of ground water for global water and food security will probably intensify under climate change as more frequent and intense climate extremes (droughts and floods) increase variability in precipitation, soil moisture and surface water. Here we critically review recent research assessing the impacts of climate on ground water through natural and human-induced processes as well as through groundwater-driven feedbacks on the climate system. Furthermore, we examine the possible opportunities and challenges of using and sustaining groundwater resources in climate adaptation strategies, and highlight the lack of groundwater observations, which, at present, limits our understanding of the dynamic relationship between ground water and climate.

Ground Water Flow in a Desert Basin: Challenges of Simulating Transport of Dissolved Chromium

National Groundwater Association (NGWA) | December 13th, 2005

A large chromium plume that evolved from chromium releases in a valley near the Mojave River was studied to understand the processes controlling fate and migration of chr

A large chromium plume that evolved from chromium releases in a valley near the Mojave River was studied to understand the processes controlling fate and migration of chromium in ground water and used as a tracer to study the dynamics of a basin and range ground water system. The valley that was studied is naturally arid with high evapotranspiration such that essentially no precipitation infiltrates to the water table. The dominant natural hydrogeologic processes are recharge to the ground water system from the Mojave River during the infrequent episodes when there is flow in the river, and ground water flow toward a playa lake where the ground water evaporates. Agricultural pumping in the valley from the mid‐1930s to the 1970s significantly altered ground water flow conditions by decreasing water levels in the valley by more than 20 m. This pumping declined significantly as a result of dewatering of the aquifer, and water levels have since recovered modestly. The ground water system was modeled using MODFLOW, and chromium transport was simulated using MT3D. Several innovative modifications were made to these modeling programs to simulate important processes in this ground water system. Modifications to MODFLOW include developing a new well package that estimates pumping rates from irrigation wells at each time step based on available drawdown. MT3D was modified to account for mass trapped above the water table when the water table declines beneath nonirrigated areas and to redistribute mass to the system when water levels rise.

Ground water in Pahrump, Mesquite, and Ivanpah Valleys, Nevada and California

U.S. Geological Survey (USGS) | July 1st, 1921

Ground Water in the Central Valley, California - A Summary Report

U.S. Geological Survey (USGS) | June 1st, 1991

The agricultural productivity of the Central Valley depends on irrigation. Half of the 22 million acre-feet of irrigation water applied annually is ground water. The va

The agricultural productivity of the Central Valley depends on irrigation. Half of the 22 million acre-feet of irrigation water applied annually is ground water. The valley is a long, narrow structural trough filled with about 32,000 feet of sediment in the south and as much as 50,000 feet in the north. Nearly all the fresh ground water is contained in the continental rocks and deposits younger than Eocene age. Streamflow, an important factor in recharging the aquifer system, is influenced by precipitation in the mountains surrounding the valley. The majority of recharge from infiltration of streamflow occurs on the east side of the valley. Ground-water pumpage, which greatly exceeds the natural recharge rate, has dramatically altered the ground-water flow in the Central Valley. During the 1960's and 1970's, the recharge rate was more than five times that of the predevelopment period and was largely derived from percolation of imported surface water or recirculated pumped ground water rather than precipitation and recharge from streams. Prior to development, most ground water was discharged as evapotranspiration; however, in recent years, most discharge has been well pumpage. Computer simulation of the Central Valley aquifer system suggests that the total flow through the system has increased from about 2 million acre-feet per year to nearly 12 million acre-feet per year. The vertical movement of ground water has been artificially enhanced by many of the 100,000 irrigation wells that contain long intervals of perforated casing. When unpumped, these wells permit vertical flow between permeable layers within the aquifer system. The total fresh ground water presently (1986) in storage in the upper 1,000 feet of the aquifer system is about 800 million acre-feet. During the 1960's and 1970's, ground water in storage was depleted at an average rate of 800,000 acre-feet annually. In the San Joaquin Valley from the 1940's to the late 1960's, substantial withdrawals of ground water were accompanied by hundreds of feet of head decline. This head decline caused inelastic compaction of fine-grained beds, resulting in land subsidence that is unequaled anywhere else in the world. More than one-half of the San Joaquin Valley (or about 5,200 square miles) underwent subsidence of more than 1 foot. In one location, subsidence exceeded 29 feet. Within the areas of heavy withdrawals, subsidence is greatest where the aquifer system contains thick sections of montmorillonite clay. Land subsidence created engineering and economic problems, including damage to canals and drainage systems, and loss of irrigation wells caused by casing failure. More recently (since the drought of 1976-77), surface-water imports have increased, ground-water pumpage has decreased, and in places, ground-water levels have recovered. Land subsidence has virtually ceased; however, it could resume with increased pumpage, if water levels decline below previous lows. Ground-water quality in the Central Valley is generally influenced by the water from streams that are a major source of recharge. In general, water on the east side of the valley and from east-side streams contains low concentrations of dissolved solids compared to water on the west side and from west-side streams. Concentrations of dissolved solids in ground water generally are lower in the northern part of the valley than in the southern part. There are, however, localized exceptions in many places through the valley. Local concentrations of boron, chloride, and nitrate in the ground water of the Central Valley are large enough to be a problem either to crops or humans. Human activities have some influence on the concentration and location of water-quality problems in the valley. Significant increases in concentrations of dissolved solids and, specifically, dissolved nitrate indicate that ground-water quality is degrading as a result of increasing application of fertilizer in agricultural areas and the growth of urban population. Pesticides such as dibromochloropropane (DBCP) as well as selenium and other trace elements in agricultural drainage water cause ecological and health problems in the San Joaquin Valley.

Ground Water in the Redding Basin, Shasta and Tehama Counties, California

U.S. Geological Survey (USGS) | December 31st, 1983

The Redding Basin covers about 510 square miles in the northern part of the Central Valley of California and is surrounded by the Cascade Range, Klamath Mountains,and Coa

The Redding Basin covers about 510 square miles in the northern part of the Central Valley of California and is surrounded by the Cascade Range, Klamath Mountains,and CoastRanges. It is separated from the main part of the valley by the Red Bluff Arch, a subsurface geologic structure. Ground water in the Redding Basin is obtained principally from wells tapping continental deposits of Tertiary and (or) Quaternary age. These deposits are arranged in a synclinal structure that trends and plunges south- ward. They are deposited on the Chico Formation, a marine sedimentary unit, and a basement complex composed of older igneous, metamorphic, and sedimentary rocks. Recharge to the Redding ground-water basin is from subsurface inflow; infiltration of precipitation and applied irrigation water; and percolation from stream san dcreeks.

Ground Water in White River Valley, White Pine, Nye, and Lincoln Counties, Nevada

State of Nevada | July 1st, 1949

Ground-water and surface-water relations along the Mojave River, Southern California

U.S. Geological Survey (USGS) | July 1st, 1996

The Mojave River and the associated floodplain aquifer are important water supplies in the Mojave Desert of Southern California. The river and aquifer, in many areas,

The Mojave River and the associated floodplain aquifer are important water supplies in the Mojave Desert of Southern California. The river and aquifer, in many areas, are in excellent hydraulic connection, and when flow conditions change in one, the other almost always is affected. To better understand these relations, records of gaging stations were analyzed to determine the frequency and duration of historical streamflow. Annual ground-water recharge from the river during water years 1931-94 was estimated from an accounting of all streamflow accretions and losses. Annual recharge ranged from about 24,000 to 460,000 acre-feet and averaged about 96,000 acre-feet. Channel-geometry regression techniques were used to estimate runoff of ungaged ephemeral streams that are tributary to the river. Water-table and gravity changes were used to estimate specific yield of the aquifer and changes in ground-water storage following storm runoff during the winters of 1992-94. In addition, streamflow hydrographs were analyzed to estimate both ground-water discharge to the river (base flow) and historical streamflow depletion caused by ground-water pumping and evapotranspiration. Ground-water pumpage from the flood-plain aquifer was about 120,000 acre-feet during water year 1994. Annual evapotranspiration along the river probably ranges from about 10,000 to 30,000 acre-feet. Factors controlling the exchange of water are identified in this report on the basis of the historical response of the river-aquifer system to stress (stormflows and pumping). Also identified are reaches of the river that are hydraulically suitable for artificial recharge.

Ground-water conditions and potential for artificial recharge in Lucerne Valley, San Bernardino County, California

U.S. Geological Survey (USGS) | January 2nd, 1979

Ground-Water Conditions in Amargosa Desert, Nevada-California, 1952-87

U.S. Geological Survey (USGS) | July 1st, 1991

Ground-Water Conditions in Las Vegas Valley, Clark County, Nevada, Part 1, Hydrogeologic Framework

U.S. Geological Survey (USGS) | July 1st, 1989

Click here for Part 2

Click here for Part 2