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• 41. [Image] Draft resource management plan/environmental impact statement for the Upper Klamath Basin

  	"March 1994."
  	Citation × Citation Citation Abstract Copy Title: Draft resource management plan/environmental impact statement for the Upper Klamath Basin Author: United States. Bureau of Land Management. Klamath Falls Resource Area Office Year: 1994, 2005 "March 1994." Title: Draft resource management plan/environmental impact statement for the Upper Klamath Basin Author: United States. Bureau of Land Management. Klamath Falls Resource Area Office Year: 1994, 2005 "March 1994." Close

• 42. [Image] The geology and petrography of Crater lake national park

  	167, iii p.; xix pl. (incl. 2 maps); Geology by J.S. Diller; Petrography by H.B. Patton; 35.00S
  	Citation × Citation Citation Abstract Copy Title: The geology and petrography of Crater lake national park Author: Diller, Joseph Silas; Patton, Horace Bushnell Year: 1902, 2006 167, iii p.; xix pl. (incl. 2 maps); Geology by J.S. Diller; Petrography by H.B. Patton; 35.00S Title: The geology and petrography of Crater lake national park Author: Diller, Joseph Silas; Patton, Horace Bushnell Year: 1902, 2006 167, iii p.; xix pl. (incl. 2 maps); Geology by J.S. Diller; Petrography by H.B. Patton; 35.00S Close

• 43. [Image] Range maps of terrestrial species in the interior Columbia River basin and Northern portions of the Klamath and Great Basins

  	Abstract Marcot, Bruce G.; Wales, Barbara C; Demmer, Rick. 2003. Range maps of terrestrial species in the interior Columbia River basin and northern portions of the Klamath and Great Basins. Gen. Tech. ...
  	Citation × Citation Citation Abstract Copy Title: Range maps of terrestrial species in the interior Columbia River basin and Northern portions of the Klamath and Great Basins Author: Marcot, Bruce G. Year: 2003, 2005, 2004 Abstract Marcot, Bruce G.; Wales, Barbara C; Demmer, Rick. 2003. Range maps of terrestrial species in the interior Columbia River basin and northern portions of the Klamath and Great Basins. Gen. Tech. Rep. PNW-GTR-583. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 304 p. Current range distribution maps are presented for 14 invertebrate, 26 amphibian, 26 reptile, 339 bird, and 125 mammal species and selected subspecies (530 total taxa) of the interior Columbia River basin and northern portions of the Klamath and Great Basins in the United States. Also presented are maps of historical ranges of 3 bird and 10 mammal species, and 6 maps of natural areas designated by federal agencies and other organizations. The species range maps were derived from a variety of publications and from expert review and unpublished data, and thus differ in degree of accuracy and resolution. The species maps are available in computer versions and are indexed herein by common and scientific names. Keywords: Maps, species range, species distribution, wildlife, invertebrates, arthropods, amphibians, reptiles, birds, mammals, bats, biodiversity, endemism, natural areas, interior Columbia River basin, Klamath Basin, Great Basin. Title: Range maps of terrestrial species in the interior Columbia River basin and Northern portions of the Klamath and Great Basins Author: Marcot, Bruce G. Year: 2003, 2005, 2004 Abstract Marcot, Bruce G.; Wales, Barbara C; Demmer, Rick. 2003. Range maps of terrestrial species in the interior Columbia River basin and northern portions of the Klamath and Great Basins. Gen. Tech. Rep. PNW-GTR-583. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 304 p. Current range distribution maps are presented for 14 invertebrate, 26 amphibian, 26 reptile, 339 bird, and 125 mammal species and selected subspecies (530 total taxa) of the interior Columbia River basin and northern portions of the Klamath and Great Basins in the United States. Also presented are maps of historical ranges of 3 bird and 10 mammal species, and 6 maps of natural areas designated by federal agencies and other organizations. The species range maps were derived from a variety of publications and from expert review and unpublished data, and thus differ in degree of accuracy and resolution. The species maps are available in computer versions and are indexed herein by common and scientific names. Keywords: Maps, species range, species distribution, wildlife, invertebrates, arthropods, amphibians, reptiles, birds, mammals, bats, biodiversity, endemism, natural areas, interior Columbia River basin, Klamath Basin, Great Basin. Close

• 44. [Image] Status of Oregon's bull trout : distribution, life history, limiting factors, management considerations, and status

  	EXECUTIVE SUMMARY Limited historical references indicate that bull trout Salvelinus confluentus in Oregon were once widely spread throughout at least 12 basins in the Klamath River and Columbia River ...
  	Citation × Citation Citation Abstract Copy Title: Status of Oregon's bull trout : distribution, life history, limiting factors, management considerations, and status Author: Buchanan, David V; Hanson, Mary L; Hooton, Robert M Year: 1997, 2007, 2005 EXECUTIVE SUMMARY Limited historical references indicate that bull trout Salvelinus confluentus in Oregon were once widely spread throughout at least 12 basins in the Klamath River and Columbia River systems. No bull trout have been observed in Oregon's coastal systems. A total of 69 bull trout populations in 12 basins are currently identified in Oregon. A comparison of the 1991 bull trout status (Ratliff and Ho well 1992) to the revised 1996 status found that 7 populations were newly discovered and 1 population showed a positive or upgraded status while 22 populations showed a negative or downgraded status. The general downgrading of 32% of Oregon's bull trout populations appears largely due to increased survey efforts and increased survey accuracy rather than reduced numbers or distribution. However, three populations in the upper Klamath Basin, two in the Walla Walla Basin, and one in the Willamette Basin showed decreases in estimated population abundance or distribution. Some Oregon river basins have bull trout populations at extreme risk of extinction. This statewide status review listed only 19% of the bull trout populations in Oregon with a ulow risk of extinction" or "of special concern." Therefore, 81% of Oregon's bull trout populations are considered to be at a "moderate risk of extinction," "high risk of extinction," or "probably extinct." Populations in the Hood, Klamath, and Powder basins, as well as the Odell Lake population in the Deschutes basin, which contain only a few remaining bull trout, are examples of populations having a "moderate" or "high risk" of extinction. Approximately 55% of current bull trout distribution occurs on lands managed by the U.S. Forest Service. A much smaller proportion occurs on Bureau of Land Management managed lands (2%). Only 16% of current bull trout distribution occurs within a protected area defined as Wilderness, Wild and Scenic River, or within a National Park. The Northwest Forest Plan, Inland Native Fish Strategy, and Interim Strategies for Managing Anadromous Fish-producing Watersheds in Eastern Oregon and Washington, Idaho, and Portions of California have provided increased protection for bull trout habitat depending on their scope and geographic areas affected, and the extent to which they are being effectively implemented in watersheds containing bull trout. Recent reduction in timber production on National Forests (up to 50% in western Oregon National Forests and over 30% in eastern Oregon National Forests) should help improve riparian and stream habitat conditions for bull trout. The remaining bull trout distribution occurs on private, state, or tribal owned lands. A comparison of approximately 39 locations throughout the state with protective angling regulations on bull trout (in some areas more than one bull trout population is protected by one regulation) shows that all state managed areas were upgraded in a protective angling status or at least maintained in 1996 compared to 1989. Restrictive angling regulations prohibit angler harvest of all bull trout populations in Oregon except for one in the Deschutes Basin. Restrictive bull trout angling regulation changes (including the elimination of bull Vll trout harvest in all spawning areas) may be the major reasons why the Metolius River/Lake Billy Chinook and mainstem McKenzie River populations have shown significant increases in abundance. Statewide stocking of non-native brook trout, including the high lakes stocking program, has been discontinued in locations where managers believe brook trout could migrate downstream and potentially interact with native bull trout. Hatchery stocking of legal rainbow trout to promote recreational fisheries has been discontinued in most locations near bull trout populations to avoid incidental catch of bull trout. The spatial and temporal distributions of bull trout reported for each river basin in this status report should be used as an accurate baseline for fisheries managers. Current distribution and relative change of distribution should be useful indicators of population health and status. The GIS maps in this report provide a template to add new layers of data such as critical spawning and juvenile rearing areas, or as a method to compare distribution changes through time. Length frequency data are presented for most Oregon bull trout populations. This should provide estimates for the presence of multiple age classes and the percent of fluvial size life history component. Vlll Title: Status of Oregon's bull trout : distribution, life history, limiting factors, management considerations, and status Author: Buchanan, David V; Hanson, Mary L; Hooton, Robert M Year: 1997, 2007, 2005 EXECUTIVE SUMMARY Limited historical references indicate that bull trout Salvelinus confluentus in Oregon were once widely spread throughout at least 12 basins in the Klamath River and Columbia River systems. No bull trout have been observed in Oregon's coastal systems. A total of 69 bull trout populations in 12 basins are currently identified in Oregon. A comparison of the 1991 bull trout status (Ratliff and Ho well 1992) to the revised 1996 status found that 7 populations were newly discovered and 1 population showed a positive or upgraded status while 22 populations showed a negative or downgraded status. The general downgrading of 32% of Oregon's bull trout populations appears largely due to increased survey efforts and increased survey accuracy rather than reduced numbers or distribution. However, three populations in the upper Klamath Basin, two in the Walla Walla Basin, and one in the Willamette Basin showed decreases in estimated population abundance or distribution. Some Oregon river basins have bull trout populations at extreme risk of extinction. This statewide status review listed only 19% of the bull trout populations in Oregon with a ulow risk of extinction" or "of special concern." Therefore, 81% of Oregon's bull trout populations are considered to be at a "moderate risk of extinction," "high risk of extinction," or "probably extinct." Populations in the Hood, Klamath, and Powder basins, as well as the Odell Lake population in the Deschutes basin, which contain only a few remaining bull trout, are examples of populations having a "moderate" or "high risk" of extinction. Approximately 55% of current bull trout distribution occurs on lands managed by the U.S. Forest Service. A much smaller proportion occurs on Bureau of Land Management managed lands (2%). Only 16% of current bull trout distribution occurs within a protected area defined as Wilderness, Wild and Scenic River, or within a National Park. The Northwest Forest Plan, Inland Native Fish Strategy, and Interim Strategies for Managing Anadromous Fish-producing Watersheds in Eastern Oregon and Washington, Idaho, and Portions of California have provided increased protection for bull trout habitat depending on their scope and geographic areas affected, and the extent to which they are being effectively implemented in watersheds containing bull trout. Recent reduction in timber production on National Forests (up to 50% in western Oregon National Forests and over 30% in eastern Oregon National Forests) should help improve riparian and stream habitat conditions for bull trout. The remaining bull trout distribution occurs on private, state, or tribal owned lands. A comparison of approximately 39 locations throughout the state with protective angling regulations on bull trout (in some areas more than one bull trout population is protected by one regulation) shows that all state managed areas were upgraded in a protective angling status or at least maintained in 1996 compared to 1989. Restrictive angling regulations prohibit angler harvest of all bull trout populations in Oregon except for one in the Deschutes Basin. Restrictive bull trout angling regulation changes (including the elimination of bull Vll trout harvest in all spawning areas) may be the major reasons why the Metolius River/Lake Billy Chinook and mainstem McKenzie River populations have shown significant increases in abundance. Statewide stocking of non-native brook trout, including the high lakes stocking program, has been discontinued in locations where managers believe brook trout could migrate downstream and potentially interact with native bull trout. Hatchery stocking of legal rainbow trout to promote recreational fisheries has been discontinued in most locations near bull trout populations to avoid incidental catch of bull trout. The spatial and temporal distributions of bull trout reported for each river basin in this status report should be used as an accurate baseline for fisheries managers. Current distribution and relative change of distribution should be useful indicators of population health and status. The GIS maps in this report provide a template to add new layers of data such as critical spawning and juvenile rearing areas, or as a method to compare distribution changes through time. Length frequency data are presented for most Oregon bull trout populations. This should provide estimates for the presence of multiple age classes and the percent of fluvial size life history component. Vlll Close

• 45. [Image] Geology and ground-water resources of the Swan Lake-Yonna Valleys area, Klamath County, Oregon

  	Abstract The Swan Lake-Yonna Valleys area consists of two intermountain valleys with their subordinate side valleys adjoining slopes, and mountainous boundary ridges, In all the area covered is about 256 ...
  	Citation × Citation Citation Abstract Copy Title: Geology and ground-water resources of the Swan Lake-Yonna Valleys area, Klamath County, Oregon Author: Meyers, Joseph D. Year: 1952, 2007, 2005 Abstract The Swan Lake-Yonna Valleys area consists of two intermountain valleys with their subordinate side valleys adjoining slopes, and mountainous boundary ridges, In all the area covered is about 256 square miles but the essential agricultural sections are restricted to the floors of Swan Lake and Yonna valleys with their respective subsidiary extensions of Pine Flats and Alkali Lake flats, a valley-floor area totaling about 90 square miles The floors of Swan Lake Valley and Yonna Valley lie at an altitude of about U52OO feet but the mountainous boundary ridges rise generally to 6000 feeto Yonna Valley is largely drained to Lost River by Buck Creek but also in part to Alkali Lakeo Swan Lake Valley and Pine Flats have only internal drainage. The Swan Lake Valley floor is the top of a deep alluvial fill, while Yonna Valley floor is mainly an erosional surface sloping to lines of through drainage Precipitation is about lit inches annually on the valley floors 9 but must be much more, possibly 18 to 24 inches, on the higher parts of the drainage basins. The growing season is short and killing frosts do occur in late spring and early fall. The rock units forming the bedrock structure of the area are consolidated or semiconsolidated rocks of Tertiary age and are largely of volcanic-flow and volcanic-sedimentary originc They consist of three main elements, a lower lava-rock unit, a sedimentary and volcanic-sedimentary unit, and an upper lava-rock unito The unconsolidated deposits are the older alluvium of Quaternary (and in part of late-Tertiary) age and the younger alluvium of Quaternary age0 The bedrock is faulted and deformed particularly so along a northwest-southeast set of fault lines that have given a remarkable linearity to the topography. Unpublished records subject to revision Ground water occurs below a regional water table that slopes south-ward to the level of the Lost Rivero The upper lava rocks and the lower lava rocks contain the principal permeable zones that occur beneath the areao Breccia and other porous zones in those rocks in places yield water to wells at a rate as large as 35OOO gallons per minute with but 1 or 2 feet of drawdowno The economical construction of irrigation wells requires the determination of the best possible location at which those rocks may be tapped at shallow depth below the level of the water tableo The ground water in general relatively low in dissolved mineral matter and is but slightly to moderately hard and would be considered chemically satisfactory for most uaeso Irrigation is the principal use of the ground water in the area north of the Horsefly Irrigation Districto There 3? wells supplied about 6,000 acre-feet of water to about 3800 acres of land in 1950. Water-level records obtained since 19U8 and approximations of the probable annual recharge from precipitation indicate that the present withdrawals are considerably less than the annual increment of the ground-water recharge, Rough estimates indicate that an increase in withdrawals of as much as 100 percent or more can take place before ground-water levels, by a persistent lowering, will begin to indicate that the annual replenishment is being exceeded. Title: Geology and ground-water resources of the Swan Lake-Yonna Valleys area, Klamath County, Oregon Author: Meyers, Joseph D. Year: 1952, 2007, 2005 Abstract The Swan Lake-Yonna Valleys area consists of two intermountain valleys with their subordinate side valleys adjoining slopes, and mountainous boundary ridges, In all the area covered is about 256 square miles but the essential agricultural sections are restricted to the floors of Swan Lake and Yonna valleys with their respective subsidiary extensions of Pine Flats and Alkali Lake flats, a valley-floor area totaling about 90 square miles The floors of Swan Lake Valley and Yonna Valley lie at an altitude of about U52OO feet but the mountainous boundary ridges rise generally to 6000 feeto Yonna Valley is largely drained to Lost River by Buck Creek but also in part to Alkali Lakeo Swan Lake Valley and Pine Flats have only internal drainage. The Swan Lake Valley floor is the top of a deep alluvial fill, while Yonna Valley floor is mainly an erosional surface sloping to lines of through drainage Precipitation is about lit inches annually on the valley floors 9 but must be much more, possibly 18 to 24 inches, on the higher parts of the drainage basins. The growing season is short and killing frosts do occur in late spring and early fall. The rock units forming the bedrock structure of the area are consolidated or semiconsolidated rocks of Tertiary age and are largely of volcanic-flow and volcanic-sedimentary originc They consist of three main elements, a lower lava-rock unit, a sedimentary and volcanic-sedimentary unit, and an upper lava-rock unito The unconsolidated deposits are the older alluvium of Quaternary (and in part of late-Tertiary) age and the younger alluvium of Quaternary age0 The bedrock is faulted and deformed particularly so along a northwest-southeast set of fault lines that have given a remarkable linearity to the topography. Unpublished records subject to revision Ground water occurs below a regional water table that slopes south-ward to the level of the Lost Rivero The upper lava rocks and the lower lava rocks contain the principal permeable zones that occur beneath the areao Breccia and other porous zones in those rocks in places yield water to wells at a rate as large as 35OOO gallons per minute with but 1 or 2 feet of drawdowno The economical construction of irrigation wells requires the determination of the best possible location at which those rocks may be tapped at shallow depth below the level of the water tableo The ground water in general relatively low in dissolved mineral matter and is but slightly to moderately hard and would be considered chemically satisfactory for most uaeso Irrigation is the principal use of the ground water in the area north of the Horsefly Irrigation Districto There 3? wells supplied about 6,000 acre-feet of water to about 3800 acres of land in 1950. Water-level records obtained since 19U8 and approximations of the probable annual recharge from precipitation indicate that the present withdrawals are considerably less than the annual increment of the ground-water recharge, Rough estimates indicate that an increase in withdrawals of as much as 100 percent or more can take place before ground-water levels, by a persistent lowering, will begin to indicate that the annual replenishment is being exceeded. Close

• 46. [Image] The Water Report. Klamath Fishery Science: Controversy in the Klamath River Basin

  	Only portions of issues of The Water Report are available in the Klamath Waters Digital Library. Includes bibliographic references. See the full report at http://www.thewaterreport.com/.
  	Citation × Citation Citation Abstract Copy Title: The Water Report. Klamath Fishery Science: Controversy in the Klamath River Basin Author: Envirotech Publications Year: 2005, 2008, 2006 Only portions of issues of The Water Report are available in the Klamath Waters Digital Library. Includes bibliographic references. See the full report at http://www.thewaterreport.com/. Title: The Water Report. Klamath Fishery Science: Controversy in the Klamath River Basin Author: Envirotech Publications Year: 2005, 2008, 2006 Only portions of issues of The Water Report are available in the Klamath Waters Digital Library. Includes bibliographic references. See the full report at http://www.thewaterreport.com/. Close

• 47. [Image] Surface water-supply of the United States. pt. 11. Pacific slope basins in California

  	Includes Klamath River Basin; Chiefly tables; Includes indexes; Prepared in cooperation with the states and other agencies
  	Citation × Citation Citation Abstract Copy Title: Surface water-supply of the United States. pt. 11. Pacific slope basins in California Author: U.S. Dept. of the Interior, Geological Survey Year: 1910, 2008, 2005 Includes Klamath River Basin; Chiefly tables; Includes indexes; Prepared in cooperation with the states and other agencies Title: Surface water-supply of the United States. pt. 11. Pacific slope basins in California Author: U.S. Dept. of the Interior, Geological Survey Year: 1910, 2008, 2005 Includes Klamath River Basin; Chiefly tables; Includes indexes; Prepared in cooperation with the states and other agencies Close

• 48. [Article] A stratigraphic and geochemical investigation of ferruginous bauxite deposits in the Salem Hills, Marion County, Oregon

  Pacific Northwest ferruginous bauxite deposits have formed in four main areas of northwestern Oregon and southwestern Washington by laterization of flows of the Columbia River Basalt Group (CRBG). The ...

  Citation × Citation Citation Abstract Copy Title: A stratigraphic and geochemical investigation of ferruginous bauxite deposits in the Salem Hills, Marion County, Oregon Author: Hoffman, Charles William Year: 1981 Pacific Northwest ferruginous bauxite deposits have formed in four main areas of northwestern Oregon and southwestern Washington by laterization of flows of the Columbia River Basalt Group (CRBG). The deposits, averaging 36.3% Al2O3 , 31.8% Fe2O3 , and 5.9% Sio2, generally occur near the surface of hilltops in gently rolling areas. Two very different views have been advanced regarding the setting in which the deposits have formed. The first hypothesis calls for a blanket-type laterization by erosion of much of the original deposit upon uplift and dissection of the area. Title: A stratigraphic and geochemical investigation of ferruginous bauxite deposits in the Salem Hills, Marion County, Oregon Author: Hoffman, Charles William Year: 1981 Pacific Northwest ferruginous bauxite deposits have formed in four main areas of northwestern Oregon and southwestern Washington by laterization of flows of the Columbia River Basalt Group (CRBG). The deposits, averaging 36.3% Al2O3 , 31.8% Fe2O3 , and 5.9% Sio2, generally occur near the surface of hilltops in gently rolling areas. Two very different views have been advanced regarding the setting in which the deposits have formed. The first hypothesis calls for a blanket-type laterization by erosion of much of the original deposit upon uplift and dissection of the area. Close

• 49. [Article] Geophysical and geochemical analyses of selected Miocene coastal basalt features, Clatsop County, Oregon

  The proximity of Miocene Columbia River basalts to the "locally-erupted" coastal Miocene basalts in northwestern Oregon, and the compelling similarities between the two groups, suggest that the coastal ...

  Citation × Citation Citation Abstract Copy Title: Geophysical and geochemical analyses of selected Miocene coastal basalt features, Clatsop County, Oregon Author: Pfaff, Virginia Josette Year: 1980 The proximity of Miocene Columbia River basalts to the "locally-erupted" coastal Miocene basalts in northwestern Oregon, and the compelling similarities between the two groups, suggest that the coastal basalts, rather than being locally erupted, may be the westward extension of plateau basalts derived from eastern Oregon and Washington. The local-origin hypothesis is based largely on the interpretation of coastal dikes and sills as representing vent areas; however, a complex mechanism, as yet unsatisfactorily defined, would be required to cause the eruption of virtually identical magmas simultaneously from source areas 500 km apart. This study, therefore, has investigated the coastal basalt intrusions both laterally and vertically. Geochemical and paleomagnetic analysis was used to determine the occurrence and distribution of basalt units; gravity surveys enabled an examination of the subsurface extensions of basalt intrusions in sedimentary rocks. Title: Geophysical and geochemical analyses of selected Miocene coastal basalt features, Clatsop County, Oregon Author: Pfaff, Virginia Josette Year: 1980 The proximity of Miocene Columbia River basalts to the "locally-erupted" coastal Miocene basalts in northwestern Oregon, and the compelling similarities between the two groups, suggest that the coastal basalts, rather than being locally erupted, may be the westward extension of plateau basalts derived from eastern Oregon and Washington. The local-origin hypothesis is based largely on the interpretation of coastal dikes and sills as representing vent areas; however, a complex mechanism, as yet unsatisfactorily defined, would be required to cause the eruption of virtually identical magmas simultaneously from source areas 500 km apart. This study, therefore, has investigated the coastal basalt intrusions both laterally and vertically. Geochemical and paleomagnetic analysis was used to determine the occurrence and distribution of basalt units; gravity surveys enabled an examination of the subsurface extensions of basalt intrusions in sedimentary rocks. Close

• 50. [Article] CHANCE: a probabilistic model for electrical energy planning

  The energy resource planning process for electric utilities in the Northwestern United States is unique because the region relies upon a mix of hydro and thermal resources. Consequently, methods used to ...

  Citation × Citation Citation Abstract Copy Title: CHANCE: a probabilistic model for electrical energy planning Author: Wakeland, Wayne William Year: 1977 The energy resource planning process for electric utilities in the Northwestern United States is unique because the region relies upon a mix of hydro and thermal resources. Consequently, methods used to study predominantly thermal or predominantly hydro systems are not applicable. Methods are needed to determine if a particular configuration of resources will be adequate to meet future energy load, taking into account various sources of uncertainty. A literature survey of presently available methods is described, and one method is studied in some detail. A new method for analyzing systems that rely upon a mix of hydro and thermal resources is then described. The primary contributors to uncertainty in a hydro/thermal electricity supply system are: (1) uncertain rainfall and snowfall, which results in uncertain availability of hydro energy; (2) the uncertain arrival times of planned nuclear and coal plants; (3) uncertain capacity factors for thermal plants; and (4) the uncertain amount of energy that customers will require in future years. The new model, called CHANCE, characterizes each of these uncertain phenomena with a probability density function. Mathematical convolution and an algorithm developed by the author are then used to determine the probability density function for the energy margin--the difference between supply and demand. Measures of the "energy adequacy" of the supply system are then computed from the energy margin probability density function. A computer program was designed so that the conceptual model can be easily applied to any desired electrical supply system. Once an appropriate set of input assumptions h2ve been determined, they are easily entered into the computer via a question and answer sequence and stored for future use. The computer program then computes the energy adequacy of the system. The user can then change assumptions and/or resource schedules via a question and answer sequence, and recompute the energy adequacy. The computer then prepares a report showing how the alternative assumptions and/or schedules compare. CHANCE has been applied to Pacific Power and Light Company, Portland, Oregon. At the present time, about half of their energy is generated by hydro plants and the other half is generated by coal plants. Only a small fraction is generated by nuclear plants. All planned additional generation is either coal-fired or nuclear-fired. The results of applying CHANCE indicate that planned resources are not likely to be adequate to meet the needs in the early 1980's. Several evaluation exercises have also been carried out. First, CHANCE was calibrated against other electrical energy planning models used by Pacific Power and Light. Next, the sensitivity of the CHANCE model to changes in input assumptions was measured. As was anticipated, the model is highly sensitive to the assumed energy load forecast, to the assumed potential delays in the arrival of resources, and to the assumed thermal plant capacity factors. Thus, more research in these areas is warranted. Research that might lead to improvements in the CHANCE model is then outlined, and final conclusions are drawn. The final conclusions are that the CHANCE model: (1) is valid relative to the outlined scope, (2) is quite versatile and flexible, and (3) fulfills an important need in electrical energy planning. Title: CHANCE: a probabilistic model for electrical energy planning Author: Wakeland, Wayne William Year: 1977 The energy resource planning process for electric utilities in the Northwestern United States is unique because the region relies upon a mix of hydro and thermal resources. Consequently, methods used to study predominantly thermal or predominantly hydro systems are not applicable. Methods are needed to determine if a particular configuration of resources will be adequate to meet future energy load, taking into account various sources of uncertainty. A literature survey of presently available methods is described, and one method is studied in some detail. A new method for analyzing systems that rely upon a mix of hydro and thermal resources is then described. The primary contributors to uncertainty in a hydro/thermal electricity supply system are: (1) uncertain rainfall and snowfall, which results in uncertain availability of hydro energy; (2) the uncertain arrival times of planned nuclear and coal plants; (3) uncertain capacity factors for thermal plants; and (4) the uncertain amount of energy that customers will require in future years. The new model, called CHANCE, characterizes each of these uncertain phenomena with a probability density function. Mathematical convolution and an algorithm developed by the author are then used to determine the probability density function for the energy margin--the difference between supply and demand. Measures of the "energy adequacy" of the supply system are then computed from the energy margin probability density function. A computer program was designed so that the conceptual model can be easily applied to any desired electrical supply system. Once an appropriate set of input assumptions h2ve been determined, they are easily entered into the computer via a question and answer sequence and stored for future use. The computer program then computes the energy adequacy of the system. The user can then change assumptions and/or resource schedules via a question and answer sequence, and recompute the energy adequacy. The computer then prepares a report showing how the alternative assumptions and/or schedules compare. CHANCE has been applied to Pacific Power and Light Company, Portland, Oregon. At the present time, about half of their energy is generated by hydro plants and the other half is generated by coal plants. Only a small fraction is generated by nuclear plants. All planned additional generation is either coal-fired or nuclear-fired. The results of applying CHANCE indicate that planned resources are not likely to be adequate to meet the needs in the early 1980's. Several evaluation exercises have also been carried out. First, CHANCE was calibrated against other electrical energy planning models used by Pacific Power and Light. Next, the sensitivity of the CHANCE model to changes in input assumptions was measured. As was anticipated, the model is highly sensitive to the assumed energy load forecast, to the assumed potential delays in the arrival of resources, and to the assumed thermal plant capacity factors. Thus, more research in these areas is warranted. Research that might lead to improvements in the CHANCE model is then outlined, and final conclusions are drawn. The final conclusions are that the CHANCE model: (1) is valid relative to the outlined scope, (2) is quite versatile and flexible, and (3) fulfills an important need in electrical energy planning. Close