Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Oceanography and Atmospheric Sciences and Meteorology (171)
- Natural Resources Management and Policy (155)
- Fresh Water Studies (132)
- Earth Sciences (128)
- Life Sciences (123)
-
- Natural Resources and Conservation (120)
- Social and Behavioral Sciences (120)
- Hydrology (114)
- Law (109)
- Environmental Health and Protection (102)
- Water Law (98)
- Public Affairs, Public Policy and Public Administration (97)
- Environmental Policy (83)
- Natural Resources Law (82)
- State and Local Government Law (81)
- Environmental Monitoring (80)
- Engineering (75)
- Environmental Law (70)
- Civil and Environmental Engineering (63)
- Administrative Law (59)
- Environmental Indicators and Impact Assessment (55)
- Sustainability (49)
- Energy and Utilities Law (47)
- Animal Sciences (46)
- Natural Resource Economics (46)
- Public Policy (46)
- Energy Policy (40)
- Institution
-
- University of Arkansas, Fayetteville (107)
- University of Colorado Law School (104)
- University of Kentucky (26)
- Department of Primary Industries and Regional Development, Western Australia (24)
- University of Nevada, Las Vegas (24)
-
- City University of New York (CUNY) (14)
- Utah State University (14)
- University of Nebraska - Lincoln (11)
- Old Dominion University (8)
- Arkansas State University (6)
- Bemidji State University (5)
- California State University, San Bernardino (4)
- Missouri State University (4)
- Portland State University (4)
- SIT Graduate Institute/SIT Study Abroad (4)
- Stephen F. Austin State University (4)
- University of New Hampshire (4)
- University of New Mexico (4)
- West Virginia University (4)
- William & Mary Law School (4)
- Colby College (3)
- Extension Journal Inc (3)
- Mississippi State University (3)
- University of Montana (3)
- Air Force Institute of Technology (2)
- Cal Poly Humboldt (2)
- Duquesne University (2)
- Gettysburg College (2)
- Linfield University (2)
- Longwood University (2)
- Publication Year
- Publication
-
- Arkansas Water Resources Center Technical Reports (83)
- KWRRI Research Reports (19)
- Publications (WR) (15)
- International Conference on Hydroinformatics (13)
- Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences (8)
-
- Resource management technical reports (8)
- Graduate Theses and Dissertations (7)
- Shifting Baselines and New Meridians: Water, Resources, Landscapes, and the Transformation of the American West (Summer Conference, June 4-6) (7)
- Western Water Law, Policy and Management: Ripples, Currents, and New Channels for Inquiry (Martz Summer Conference, June 3-5) (7)
- Arkansas Water Resource Center Fact Sheets (6)
- Books, Reports, and Studies (6)
- Groundwater in the West (Summer Conference, June 16-18) (6)
- Journal of the Department of Agriculture, Western Australia, Series 4 (6)
- Student Theses and Dissertations (6)
- Electronic Theses and Dissertations (5)
- Civil & Environmental Engineering Theses & Dissertations (4)
- Conference papers and presentations (4)
- Daugherty Water for Food Global Institute: Faculty Publications (4)
- Electronic Theses, Projects, and Dissertations (4)
- Faculty Publications (4)
- Graduate Theses/Dissertations (4)
- Honors Capstones (4)
- Independent Study Project (ISP) Collection (4)
- Monitoring and Protecting Groundwater During Oil and Gas Development (November 26) (4)
- Reports (4)
- School of Natural Resources: Dissertations, Theses, and Student Research (4)
- The Future of Natural Resources Law and Policy (Summer Conference, June 6-8) (4)
- UNLV Theses, Dissertations, Professional Papers, and Capstones (4)
- Water as a Public Resource: Emerging Rights and Obligations (Summer Conference, June 1-3) (4)
- Water, Climate and Uncertainty: Implications for Western Water Law, Policy, and Management (Summer Conference, June 11-13) (4)
- Publication Type
Articles 391 - 420 of 446
Full-Text Articles in Water Resource Management
Projections Of Agricultural And Fish And Wildlife Water Demand In The Ouachita River Basin: A Linear Programming Approach, Mark J. Cochran, Mike Tessaro, J. Martin Redfern, Larry Childress, E. Moye Rutledge, Rob Raskin, Robert N. Shulstad
Projections Of Agricultural And Fish And Wildlife Water Demand In The Ouachita River Basin: A Linear Programming Approach, Mark J. Cochran, Mike Tessaro, J. Martin Redfern, Larry Childress, E. Moye Rutledge, Rob Raskin, Robert N. Shulstad
Arkansas Water Resources Center Technical Reports
The availability of an abundant water supply has been a major resource of the Ouachita River Basin. In recent years, water requirements for a number of uses have increased, raising the concern that future water shortages could occur in the basin. The purpose of the study reported here was to estimate future water demand for irrigation, commercial fisheries, and fish and wildlife uses.
Federal/State Relations In Theory And Practice: A Sovereignty Mismatch, Charles T. Dumars
Federal/State Relations In Theory And Practice: A Sovereignty Mismatch, Charles T. Dumars
Western Water Law in Transition (Summer Conference, June 3-5)
12 pages.
Contains footnotes.
Western Ground Water Law: Overview And Recent Developments, J. David Aiken
Western Ground Water Law: Overview And Recent Developments, J. David Aiken
Western Water Law in Transition (Summer Conference, June 3-5)
27 pages.
Agenda: Western Water Law In Transition, University Of Colorado Boulder. Natural Resources Law Center
Agenda: Western Water Law In Transition, University Of Colorado Boulder. Natural Resources Law Center
Western Water Law in Transition (Summer Conference, June 3-5)
Conference organizers and/or faculty included University of Colorado School of Law professors James N. Corbridge, Jr., Lawrence J. MacDonnell, Richard B. Collins, David H. Getches and Charles F. Wilkinson.
The prior appropriation doctrine has governed the allocation and use of water in the western United States since the 1850s. The shifting nature of water demand is bringing about changes in the traditional legal system. This conference will consider the fundamental principles of the prior appropriation doctrine together with the important new developments in the law now underway throughout the West.
Administering Water Rights: The Permit System, Lawrence J. Wolfe
Administering Water Rights: The Permit System, Lawrence J. Wolfe
Western Water Law in Transition (Summer Conference, June 3-5)
69 pages.
Contains references.
Selecting Non-Point Source Pollution Treatment Practices Using Linear Optimization, John Gardy Garland Iii
Selecting Non-Point Source Pollution Treatment Practices Using Linear Optimization, John Gardy Garland Iii
Civil & Environmental Engineering Theses & Dissertations
This paper provides a case study application of a linear optimization program as a water quality management tool. The optimization program seeks to minimize the cost of nonpoint source pollution control by selecting the best combination of pollution control management practices for Hampton, Virginia. The management practice options are grass swale roadways, porous pavers, ponds, detention basins and fertilizer management education. Management practice selection is limited by constraints on land-use and water quality. Pollutants evaluated are total nitrogen, total phosphorus, suspended solids, fecal coliforms and biochemical oxygen demand (five-day). The value in the water quality constraints for pollution loading on …
Water Quality For Irrigation, P R. George
Water Quality For Irrigation, P R. George
Journal of the Department of Agriculture, Western Australia, Series 4
Although irrigation and salinity problems are frequently inseperable, there is a range of management methods that can be used to handle marginal quality water. Freuently these methods are simple, but require careful planning.
The wide range in tolerance of crops to salinity can be exploiter to ensure that appropriate crops are selected for the water available.
Because crops vary in their sensitivity to salt uptake in the leaves or the roots, watering methods can be changed to avoid problems. For profitable production enough water should be applied to ensure adequate water is available for plant growth as well as to …
Groundwater Quality And Mineral Deposits Relationships In The Ozark Mountains, Kenneth F. Steele
Groundwater Quality And Mineral Deposits Relationships In The Ozark Mountains, Kenneth F. Steele
Arkansas Water Resources Center Technical Reports
Ninety-nine groundwater sites were sampled in northern Arkansas in order to determine the effect of local manganese, phosphate, pyrite, lead-zinc and uranium mineralization on the groundwater chemistry. Most of this study (75 springs) was concentrated in the Batesville manganese district. Hydrogeochemical exploration for these types of manganese deposits appears possible with 44 percent of the springs within 2000 feet of mineralization having anomalous metal concentrations (especially manganese). Because only a few springs were sampled in the remaining areas, the results are not conclusive; however, only the pyrite and small lead-zinc deposit would appear worthy of additional investigation. None of the …
A Statistical Comparison Of A Direct Filtration And A Conventional Water Treatment Facility In The Intermountain Region, Susan K. Burns, V. Dean Adams
A Statistical Comparison Of A Direct Filtration And A Conventional Water Treatment Facility In The Intermountain Region, Susan K. Burns, V. Dean Adams
Reports
Interest in low-cost direct filtration facilities and their effectiveness in treating the potable water sources of the Intermountain Region is increasing as the need for treated water supplies increase. Direct filtration is a water treatment scheme which does not include sedimentation and in some cases flocculation. Compared to conventional treatment, direct filtration has lowered capital costs, reduced space requirement, and decreased sludge quantities. Moreover, the direct filtration process may offer large reductions in coagulant dosages and costs.
Currently information comparing a direct filtration system to a conventional water treatment system in the Intermountain area is not readily available. The specific …
Precedings Of Arkansas Lakes Symposium Limnological Studies Of Lake Chicot, Arkansas, Joe F. Nix, Frank R. Schiebe
Precedings Of Arkansas Lakes Symposium Limnological Studies Of Lake Chicot, Arkansas, Joe F. Nix, Frank R. Schiebe
Arkansas Water Resources Center Technical Reports
Lake Chicot is an oxbow lake that was created more than 600 years ago by the meandering of the Mississippi River. It is located in Chicot county in southeastern Arkansas adjacent to the present Mississippi River. As the largest natural lake in Arkansas it earned an early reputation for its good fishing and recreational value. Development of a levee system forced the enlargement of the lakes watershed to its present 350 square miles. Initially this alteration affected only the volume flow through the lake, drastically reducing the water residence time. Because the watershed was located in one of the most …
Water Quality Evaluation Yatesville Lake Project: Volume 1, Stephen B. Sullivan, Edward G. Foree, John S. Tapp
Water Quality Evaluation Yatesville Lake Project: Volume 1, Stephen B. Sullivan, Edward G. Foree, John S. Tapp
KWRRI Research Reports
Point sources of pollution identified in the Blaine Creek watershed area consisted of oil and gas facility sources and mine related sources. A total of 493 point sources of pollution were inventoried which included 167 oil and gas related sources, 321 mine sediment structures, and 5 hollow fill groundwater seeps. The highest concentration of these point sources of pollution occurred in the south to southwest portion of the watershed in the area proximate to the Martha Field.
Adverse impacts to surface and groundwaters resulting from the 326 mine and groundwater point sources of pollution identified did not appear significant as …
Las Vegas Wash Advanced Water Quality Study: Final Report, Richard A. Roline, James J. Sartoris, U.S. Bureau Of Reclamation
Las Vegas Wash Advanced Water Quality Study: Final Report, Richard A. Roline, James J. Sartoris, U.S. Bureau Of Reclamation
Publications (WR)
The purpose of the Las Vegas Wash Advanced Water Quality Study is to determine the existence, extent, and mechanisms of nutrient and toxin stripping in Las Vegas Wash under present conditions and under future conditions, both with and without construction of the proposed salinity control unit as described by the Bureau of Reclamation (USBR, 1982b). This study was performed for the Lower Colorado Region Division of Planning by personnel of the Environmental Sciences Section of the Division of Research and Laboratory Services, E&R Center, Denver, Colorado. Work on the study began in February 1983. The general approach adopted for this …
Chemistry Of The Springs Of The Ozark Mountains, Northwestern Arkansas, Kenneth F. Steele
Chemistry Of The Springs Of The Ozark Mountains, Northwestern Arkansas, Kenneth F. Steele
Arkansas Water Resources Center Technical Reports
Three lead-zinc mineralized areas of northern Arkansas were selected to study the effect of mineralization on ground water chemistry. The Ponca area has the largest amount of lead sulfide mineralization, the Zinc area has a significant amount of zinc silicate and zinc sulfide; whereas, the Rush area has zinc carbonate and zinc sulfide. A total of 143 samples were collected from these areas and analyzed for general water chemistry parameters including heavy metal The water quality of the area is generally good; however, a few springs exceed the drinking water standards for ammonia, nitrate, iron, manganese and lead. The surface …
Causes Of Localized Copper Corrosion In Drinking Water Supplies, R. A. Sims, R. W. Raible
Causes Of Localized Copper Corrosion In Drinking Water Supplies, R. A. Sims, R. W. Raible
Arkansas Water Resources Center Technical Reports
Excessive amounts of copper have been observed in drinking water at certain installations on Lake DeGray and at isolated locations in the Arkadelphia area of Arkansas. A study of these installations was conducted to determine the source of the copper contamination. The supply water was very low in copper and therefore dissolution of the copper plumbing caused by low water pH and long residence times was determined to be the most probable source.
A Survey Of Soils Irrigated With Arkansas River Water, John T. Gilmour, H. D. Scott, R. E. Baser
A Survey Of Soils Irrigated With Arkansas River Water, John T. Gilmour, H. D. Scott, R. E. Baser
Arkansas Water Resources Center Technical Reports
Interest in the use of Arkansas River water for irrigation has increased recently as land adjacent to the river is converted to crop production and river water is considered as an alternative to depleted underground supplies. Since the Arkansas River can contain elevated concentrations of sodium chloride, this study was designed to determine if soil conditions adverse to crop growth were developing where river water has been used. The impact of river water on sites where river water was used as either the sole source for up to 3 years or as a supplement to another surface source for up …
The Effects Of Forest Harvest On Water Quality And Aquatic Life (Phase I), Edmond J. Bacon
The Effects Of Forest Harvest On Water Quality And Aquatic Life (Phase I), Edmond J. Bacon
Arkansas Water Resources Center Technical Reports
A long term study on the effects of clearcut forest harvest and regeneration was conducted in a representative watershed of the Ouachita National Forest. Fourteen water quality parameters were analyzed to characterize baseline water quality. Water quality was classified as excellent. A total of 350 quantitative benthic samples and 15 ultraviolet light trap samples yielded 173 species of macroinvertebrates. Mean densities of macroinvertebrates ranged from 4,800/m2 to 23,040/m2 and averaged 12,499/m2 in the upper Little Missouri River. Twenty-two quantitative collections of fishes were made at representative riffles and pools. The average biomass estimates for riffles and pools were 5.69 kg/ha …
Agricultural Water Quality Criteria : Irrigation Aspects., P R. George
Agricultural Water Quality Criteria : Irrigation Aspects., P R. George
Resource management technical reports
Water quality criteria for irrigation are imprecise. The final result of quality evaluation depends on plant, soil and climatic variables all of which can be inter-dependent. A range of management strategies of varying complexity are available to mitigate the effects of poor quality water. The heavy winter rainfall in the south-west of Western Australia affects the applicability of published salinity criteria most of which have been developed in arid and semi-arid environments with little effective rainfall.
The Effects Of Limited Food Availability On The Striped Bass Fishery In Lake Mead, John R. Baker, Larry J. Paulson
The Effects Of Limited Food Availability On The Striped Bass Fishery In Lake Mead, John R. Baker, Larry J. Paulson
Publications (WR)
The original range of striped bass (Morone saxatilis) was along the Atlantic Coast. They were introduced into the lower Sacramento River in 1879 and are now also found along the Pacific Coast. A landlocked striped bass fishery was established in Santee-Cooper Reservoir, South Carolina, in 1954, and they have since been introduced into numerous other reservoirs, including Lake Havasu, Lake Mead and Lake Powell on the Colorado River. Striped bass were introduced into Lake Mead in 1969 in response to declines in the largemouth bass (Micropterus salmoides) fishery that occurred during the 1960s and in order to further utilize the …
Scientific Perspectives On Integrated Aquatic Resources Management Of The Colorado River, Larry J. Paulson
Scientific Perspectives On Integrated Aquatic Resources Management Of The Colorado River, Larry J. Paulson
Publications (WR)
When management requires water quality standards, we should establish standards in a scientific and logical manner to serve the long-term needs of the users. It was this very process that led to enactment of the Reclamation Act of 1902 and the Boulder Canyon Project Act of 1928 - legislation that still serves the needs of users in the Colorado River Basin. This process can work again if we can make the "tradeoffs" that are so vital in management of a multi-purpose river. In order to do this, however, we must first be able to identify "tradeoffs." This requires good scientific …
Effects Of Wastewater Discharges On Periphyton Growth In Lake Mead, Nevada-Arizona, Marsha Korb Morris
Effects Of Wastewater Discharges On Periphyton Growth In Lake Mead, Nevada-Arizona, Marsha Korb Morris
Publications (WR)
A study of the effects of secondary-treated wastewater on periphyton growth in Lake Mead, Nevada-Arizona was conducted from September 1979 to December 1980. Periphyton ash-free dry weight, chlorophyll-a, dominant species composition, and alkaline phosphatase activity were measured on fiberglass substrates. Substrates were incubated for two to four weeks in littoral and limnetic habitats. Physical and chemical variables and phytoplankton chlorophyll-a were measured concurrently.
Transparency increased with increasing distance from the discharge. Secchi depth ranged from 0.75 m at the discharge confluence (station 2) in August, to greater than 20 m at the most distant stations (stations 9 and 10) in …
A Benefit Cost Analysis Of A Soil Erosion Control Program For The Northern Watershed Of Lake Chicot, Arkansas, C. Tim Osborn, Alan D. Mcqueen, Robert N. Shulstad
A Benefit Cost Analysis Of A Soil Erosion Control Program For The Northern Watershed Of Lake Chicot, Arkansas, C. Tim Osborn, Alan D. Mcqueen, Robert N. Shulstad
Arkansas Water Resources Center Technical Reports
Lake Chicot, a 5,025-acre oxbow lake created by the ancient meandering of the Mississippi River, is located near the town of Lake Village in Chicot County of southeastern Arkansas (Fig. 1). Today the lake is separated into a northern basin of 1,154 acres and a southern basin of 3,871 acres by a levee maintained by the Arkansas Game and Fish Commission (Fig. 2). The entire lake once offered excellent fishing and recreational benefits. But with channelization in the drainage basin and final closure of the Cypress Creek gap along the Mississippi River levee in 1920, drainage and flood waters from …
Classification And Ranking Of Selectd Arkansas Lakes, Robert E. Babcock, Eugene H. Schmitz, Thomas Buchanan, Richard L. Meyer, James I. Meinecke, David B. Czarnecki
Classification And Ranking Of Selectd Arkansas Lakes, Robert E. Babcock, Eugene H. Schmitz, Thomas Buchanan, Richard L. Meyer, James I. Meinecke, David B. Czarnecki
Arkansas Water Resources Center Technical Reports
Trophic-state related problems associated with waters in the United States have generated tremendous public interest and concern, particularly during the past decade. These interests and concerns led to Public Law 92-500, the mandate by Congress known as the Federal Water Pollution Control Act. Various sections of PL 92-500 directly address the need for trophic-state analyses, particularly Section 314 referred to as the Clean Lakes Program which assigns states the responsibility for classifying their lakes according to water quality, identifying methods of pollution control and restoring those lakes which have become degraded.
Comparing Three Water Quality Sampling Techniques For Measuring Non-Point Source Pollution In Forest Streams, R. Scott Beasley
Comparing Three Water Quality Sampling Techniques For Measuring Non-Point Source Pollution In Forest Streams, R. Scott Beasley
Arkansas Water Resources Center Technical Reports
Coshocton wheel samplers, ISCO pumping samplers, and single stage samplers were compared on each of three small (5-6 ha), forested watersheds in the Ouachita Mountains of central Arkansas. The objective of the comparisons was to evaluate the performance of each sampling method in providing reliable samples for measuring concentrations of total suspended solids (TSS). H-flumes and water level recorders provided stream discharge data; a network of recording and non-recording raingages provided preciptation measurements. Rainfall and storm discharges during the study period were unusually low. No samples were collected by the single stage samplers. They appear unsuited for use on small …
An Analysis Of Residential Water Demand Schedules In Arkansas, Richard K. Ford, Joseph A. Zieger
An Analysis Of Residential Water Demand Schedules In Arkansas, Richard K. Ford, Joseph A. Zieger
Arkansas Water Resources Center Technical Reports
Water has held man's interest for centuries, and a considerable body of knowledqe has been developed about this subject, but it has only been considered only recently by decision makers in an economic sense. Because water is required to sustain life, the thought of its being an economic good to individuals has not been considered applicable or "fair" by those individuals who are concerned with its acquisition and distribution. Moreover, water has been in fairly abundant supply relative to demand for most of the country. However, as this situation is upset by increases in population and water use, a realization …
Distribution Of Trace Elements In A Warm Water Release Impoundment, J. Nix
Distribution Of Trace Elements In A Warm Water Release Impoundment, J. Nix
Arkansas Water Resources Center Technical Reports
A detailed water quality survey (including trace metals) was conducted on DeGray Reservoir in south west Arkansas from 1969 through 1975. The results of this investigation are used to describe physical and chemical processes which affect the concentration of many of the constituents found in the reservoir and river system. Detailed dissolved oxygen profiles as well as turbidity (% transmittance) profiles were useful in delineating the movement of water through the reservoir. Underflows, innerflows, and overflows were observed during different seasons. The development of a metalimnetic dissolved oxygen minima appears to be related to advective transport within the metalimnion. Metalimnetic …
Water, Waste And Quality Management During Preparation And Processing Of Vegetables, W. A. Sistrunk
Water, Waste And Quality Management During Preparation And Processing Of Vegetables, W. A. Sistrunk
Arkansas Water Resources Center Technical Reports
The research was designed to test and/or develop new systems of washing, peeling and blanching, develop methods of utilization of solid wastes, and find ways to reduce wastestrength of effluent without affecting quality of vegetables for processing. The highest wastestrength of effluent from vegetable processing in the region was found in plants that were canning Irish potatoes, dry beans and hominy. The high volumes of water used for washing spinach and leafy greens and the physical damage to the washed product is one of the major problems. Repetitive washing of spinach in the same water did not affect quality as …
Study Of Cumulative Growth-Inhibiting Factors In Recycled Water For Catfish Cultivation, R. W. Raible
Study Of Cumulative Growth-Inhibiting Factors In Recycled Water For Catfish Cultivation, R. W. Raible
Arkansas Water Resources Center Technical Reports
Channel catfish were grown in tanks with integral biological filters and complete recirculation of water. After the fish had resided in the tanks for 120 days, solvent extraction was performed on a portion of the tank water. Fresh pond-raised specimen channel catfish showed decreases in their heartbeat rates of about 20 percent when exposed to the extract. This metabolic disturbance is thought to be a factor in reducing the growth rate of fish held in close confinement in recirculating systems.
Influence Of Nitrogen Fertilization On The Quality And Quantity Of Streamflow From A Forested Watershed, George B. Coltharp, Michael T. Shearer, Everett P. Springer, Robert F. Wittwer
Influence Of Nitrogen Fertilization On The Quality And Quantity Of Streamflow From A Forested Watershed, George B. Coltharp, Michael T. Shearer, Everett P. Springer, Robert F. Wittwer
KWRRI Research Reports
This project was designed to determine the effects of nitrogen fertilization on the quality and quantity of streamflow eminating from an eastern hardwood forest watershed. A 40.67 ha watershed, located in mountainous eastern Kentucky, was aerially fertilized in late April 1975. The forest stand was principally oak, hickory, and yellow poplar, 50 - 55 years of age and in a relatively undisturbed condition. A helicopter applied anunonium nitrate at a rate of 504 kg/ha. Because a large part of applied nitrogen fertilizer ends up in the highly mobile nitrate nitrogen.form, this is the principal ion monitored in this study. No …
Apis: Arkansas Planning Information System, William R. Draper, David B. Beasley, Theo A. Dillaha Iii, Ronald W. Skeith
Apis: Arkansas Planning Information System, William R. Draper, David B. Beasley, Theo A. Dillaha Iii, Ronald W. Skeith
Arkansas Water Resources Center Technical Reports
The Federal Water Pollution Control Act Amendments of 1972 call for the restoration and maintenance of the chemical, physical and biological integrity of the Nation's waters. The Act sets forth two primary goals; 1) the elimination of the discharge of all pollutants into the navigable waters of the United States by 1985 and 2) an interim level of water quality that provides for the protection of fish, shellfish, wildlife and recreation by July 1, 1983. Section 208 of the Act mandated the development and implementation of area wide water quality management plans to achieve the goals previously mentioned.
"Ecosystems", William E. Cooper
"Ecosystems", William E. Cooper
Special Collections: Oregon Public Speakers
From a lecture series with M.A. Arbib, "Environmental simulation and long-term planning."