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At least 397 records · Page 22Linked to original sources
USGS2026

Decadal trends in the quality of groundwater used for public drinking-water supply in California, 2004–23, California Groundwater Ambient Monitoring and Assessment Program, Priority Basin Project

This study provides a comprehensive assessment of decadal changes in the quality of groundwater used for public drinking-water supply at 444 monitoring sites across California during 2004–23. We assessed decadal step trends in groundwater quality for 145 water-quality constituents and geochemical indicators statewide and across geographic and land-use based network groups. We evaluated the statistical significance of directional changes (predominant increase or decrease of constituent concentrations) and the magnitude of those changes across all network groups. Uranium showed the most widespread directional and high-magnitude increases of all constituents with regulatory benchmarks statewide, particularly in the agriculture-dominated Central Valley as well as urban-and desert-dominated regions of Southern California. Fluoride and perchlorate showed the most widespread directional and high-magnitude decreases of all constituents with regulatory benchmarks statewide, which were also most pronounced in Southern California. Although arsenic and nitrate did not often register significant directional changes across network groups, they showed widespread, high-magnitude changes in both directions (increase and decrease) at levels often exceeding 10 percent of respective regulatory benchmarks statewide. Triazine herbicides (atrazine and simazine) and the gasoline oxygenate methyl tert -butyl ether showed significant directional decreases statewide, but not at levels considered to be of high magnitude compared to respective regulatory benchmarks. We observed significant directional and high-magnitude increases of total dissolved solids statewide, which were most pronounced in agricultural areas. Analysis of explanatory geochemical indicators indicated that prevalent statewide increases of alkalinity and calcium were the predominant components of the observed statewide increases in total dissolved solids by mass. Widespread increases in groundwater alkalinity and calcium across agricultural and urban areas may be related, in part, to warm-season irrigation and other anthropogenic factors that have shifted soil weathering dynamics over the long term. Increasing alkalinity concentrations were related to increasing uranium concentrations, particularly in areas with aquifer materials derived from granitic rocks. Conversely, increasing calcium concentrations were related to decreasing fluoride concentrations, particularly in areas where fluoride occurred naturally at elevated concentrations. Decrease of perchlorate, triazine herbicides, and methyl tert -butyl ether are likely related to decreased anthropogenic source inputs over time and natural attenuation in aquifers.

California↗
USGS2000

Pesticides and their metabolites in selected surface-water public supplies in New York State, 1999

Sixteen different pesticides or their metabolites (degradations products) where detected in water samples collected in 1999 from three networks of lakes and reservoirs in upstate New York that are sources of public water supply. The networks sampled included the New York City network (10 reservoirs); the Finger Lakes-Great Lakes network (three Finger Lakes and two Great Lakes that supply large and small cities) and the western New York reservoir network (three reservoirs that supply small cities or towns). The concentrations of the compounds detected in the samples generally were low. Only a few of the compounds detected had a concentration exceeding 1 mg/L (microgram per liter), and no compounds detected in the New York City reservoirs network had concentrations exceeding 0.05 mg/L. None of the compounds detected exceeded any Federal or State water-quality standard. Compounds that were most frequently detected, and whose concentrations were highest, were the three herbicides atrazine, metolachlor, and simazine, and two herbicide metabolites (the atrazine metabolite deethylatrazine, and the metolachlor metabolite metolachlor ESA). Most of these compounds, or their parent compounds, are used on corn or other row crops. Median total pesticide and metabolite concentration for each network ranged from less than 0.02 mg/L for the New York City reservoirs network to more than 2 mg/L for the western New York reservoir network; the median for the Finger Lakes.Great Lakes network was about 0.1 mg/L. These differences reflect the amount of agricultural land use within each of the three networks, although other factors can affect pesticide and metabolite concentrations. The watersheds of the New York City reservoirs have the lowest percentage of agricultural land, and those of the western New York reservoirs have the highest. The highest herbicide or herbicide-metabolite concentrations among the New York City reservoirs were in the Cannonsville reservoir, whose watershed has a high percentage of agricultural land. The highest pesticide concentrations of the Lake sites were in Cayuga Lake, and the highest pesticide concentrations of the western New York reservoir sites were at the LeRoy reservoir. The drought conditions in 1999 resulted in a general decrease in median total concentrations, and in the median number of detected compounds, in all networks, from January through September. Pesticide concentrations at the western New York reservoir sites were lower in 1999 than in 1998, as a result of the late-spring and early-summer drought conditions in 1999. Concentrations of pesticides in surface-water supplies are likely to be higher during years with normal or high streamflows than in years of drought, and the small reservoirs are likely to show a greater change in pesticide concentrations from drought year to nondrought years than the larger water bodies.

New York↗
USGS2004

Characteristics of and Areas Contributing Recharge to Public-Supply Springs in Massachusetts

The geohydrologic and physical characteristics were determined for 28 public-supply springs, 27 of which are in western Massachusetts. Discharge ranged from zero at various small intermittent springs to more than 240 gallons per minute at Waubeeka Springs in Williamstown, Massachusetts. To determine the annual variability of spring discharge, discharge from 12 springs was measured during different seasonal conditions from June 2001 to November 2002, and the discharge from Red Mill Spring in Clarksburg, Massachusetts was recorded continuously from April 2002 to November 2002. The area contributing recharge to each spring was delineated on the basis of the geohydrologic conditions determined from reconnaissance investigations; these areas ranged from 0.010 to 0.682 square mile. Ground-water recharge, estimated on the basis of average discharge and the areas contributing recharge, ranged from 0.5 to 24.4 inches per year. High ground-water recharge rates for some of the high-discharge springs indicate that the areas contributing recharge for these springs may be too small. Detailed water-table mapping in the vicinity of two low-discharge springs indicates that the area contributing recharge to some of the smaller springs may be smaller than the area indicated by reconnaissance investigation. Monthly flow durations and low flow statistics were determined for the index streamflow-gaging stations for a 25-year period from 1976 to 2000. Annual hydrographs were prepared for each index station from median streamflows at the 50-percent monthly flow duration, normalized by drainage area. A median monthly flow of 1 ft3/s/mi2 was used to split hydrographs into a high-flow period (November?May), and a low-flow period (June?October). The hydrographs were used to classify index stations into groups with similar median monthly flow durations. Index stations were divided into four regional groups, roughly paralleling the coast, to characterize streamflows for November to May; and into two groups, on the basis of base-flow index and percentage of sand and gravel in the contributing area, for June to October.

Water-Resources Investigations Report↗
USGS2004

Delineation of Areas Contributing Water to the Dry Brook Public-Supply Well, South Hadley, Massachusetts

Areas contributing water to the Dry Brook public-supply well in South Hadley, Massachusetts, were delineated with a numerical ground-water-flow model that is based on geologic and hydrologic information for the confined sand and gravel aquifer pumped by the supply well. The study area is along the Connecticut River in central Massachusetts, about 12 miles north of Springfield, Massachusetts. Geologic units in the study area consist of Mesozoic-aged sedimentary and igneous bedrock, late-Pleistocene glaciolacustrine sediments, and recent alluvial deposits of the Connecticut River flood plain. Dry Brook Hill, immediately south of the supply well, is a large subaqueous lacustrine fan and delta formed during the last glacial retreat by sediment deposition into glacial Lake Hitchcock from a meltwater tunnel that was likely near where the Connecticut River cuts through the Holyoke Range. The sediments that compose the aquifer grade from very coarse sand and gravel along the northern flank of the hill, to medium sands in the body of the hill, and to finer-grained sediments along the southern flank of the hill. The interbedded and overlapping fine-grained lacustrine sediments associated with Dry Brook Hill include varved silt and clay deposits. These fine-grained sediments form a confining bed above the coarse-grained aquifer at the supply well and partially extend under the Connecticut River adjacent to the supply well. Ground-water flow in the aquifer supplying water to Dry Brook well was simulated with the U.S. Geological Survey ground-water-flow modeling code MODFLOW. The Dry Brook aquifer model was calibrated to drawdown data collected from 8 observation wells during an aquifer test conducted by pumping the supply well for 10 days at a rate of 122.2 cubic feet per minute (ft3/min; 914 gallons per minute) and to water levels collected from observation wells across the study area. Generally, the largest hydraulic conductivity values used in the model were in the sand and gravel aquifer near the Dry Brook well, which is consistent with the geologic information. Results of aquifer-test simulation indicated that spatially variable aquifer hydraulic properties and boundary conditions affected heads and ground-water flow near the well. A comparison and analysis of water-level fluctuations in study area wells to fluctuations in the Connecticut River indicated a hydraulic connection of the aquifer with the river, which is also consistent with geologic information. Simulated ground-water levels indicated that most ground water in the study area flowed toward and discharged to the Connecticut River and the Dry Brook well. Small amounts of ground water also discharged to smaller streams (Dry Brook and Bachelor Brook) in the study area. Areas contributing water to the well were delineated with the MODPATH particle-tracking routine. Results of the contributing-area analysis indicated that the greatest sources of water to the well were recharge in the Dry Brook Hill area and infiltration of Connecticut River water in an area beyond the extent of the confining bed where the aquifer is in hydraulic connection with the river. The amount of water entering the Dry Brook well from recharge dominated at a lower pumping rate (40.0 ft3/min); about 90 percent of the pumped water originated from recharge and boundary flow, and infiltration from the Connecticut River supplied the remaining 10 percent. At a high pumping rate (122.2 ft3/min), however, about half of the water pumped from the Dry Brook well originated from recharge and boundary flow (49 percent), and half originated from infiltration of water from the Connecticut River (51 percent). Results of a sensitivity analysis of the extent of areas contributing water to the Dry Brook well when pumped at 122.2 ft3/min indicated that the size of these areas did not substantially change when aquifer properties were varied. In contrast, however, the size of these areas changed most when the recharge

Water-Resources Investigations Report↗
USGS1977

Public water supplies of selected municipalities in Florida, 1975

In 1975, the 169 municipalities and 5 county water systems listed in this report supplied 1.037 million gallons of water each day, on the average to 77 percent of the population of the State of Florida. The quantity of water supplied represented 90 percent of the State's public water supply demand. Of the 169 municipalities and 5 county systems, 150 supplied 887 million gallons of ground water and 24 supplied 150 million gallons of surface water each day, on the average, representing 85 percent and 15 percent, respectively, of the total demand of the 174 water systems. Three of the 150 municipal ground-water suppliers are reported to have processed, that year, about 3.2 million gallons of water each day by desalination.

Florida↗
USGS1994

Agricultural pesticides in six drainage basins used for public water supply in New Jersey, 1990

A reconnaissance study of six drainage basins in New Jersey was conducted to evaluate the presence of pesticides from agricultural runoff in surface water. In the first phase of the study, surface-water public-supply drainage basins throughout New Jersey that could be affected by pesticide applications were identified by use of a Geographic Information System. Six basins--Lower Mine Hill Reservoir, South Branch of the Raritan River, Main Branch of the Raritan River, Millstone River, Manasquan River, and Matchaponix Brook--were selected as those most likely to be affected by pesticides on the basis of calculated pesticide-application rates and percentage of agricultural land. The second phase of the project was a short-term water-quality reconnaissance of the six drainage basins to determine whether pesticides were present in the surface waters. Twenty-eight surface-water samples (22 water-quality samples, 3 sequentially collected samples, and 3 trip blanks), and 6 samples from water-treatment facilities were collected. Excluding trip blanks, samples from water-treatment facilities, and sequentially collected samples, the pesticides detected in the samples and the percentage of samples in which they were detected, were as follows: atrazine and metolachlor, 86 percent; alachlor, 55 percent; simazine, 45 percent; diazinon, 27 percent; cyanazine and carbaryl, 23 percent; linuron and isophenfos, 9 percent; and chlorpyrifos, 5 percent.Diazinon, detected in one stormflow sample collected from Matchaponix Brook on August 6, 1990, was the only compound to exceed the U.S. Environmental Protection Agency's recommended Lifetime Health Advisory Limit. Correlation between ranked metolachlor concentrations and ranked flow rates was high, and 25 percent of the variance in metolachlor concentrations can be attributed to variations in flow rate. Pesticide residues were detected in samples of pretreated and treated water from water-treatment facilities. Concentrations of all pesticides detected in the treated water were lessthan the U.S. Environmental Protection Agency's recommended Lifetime Health Advisory Limits.

Water-Resources Investigations Report↗
USGS1998

Factors affecting Escherichia coli concentrations at Lake Erie public bathing beaches

The environmental and water-quality factors that affect concentrations of Escherichia coli (E. coli) in water and sediment were investigated at three public bathing beachesEdgewater Park, Villa Angela, and Sims Parkin the Cleveland, Ohio metropolitan area. This study was done to aid in the determination of safe recreational use and to help water- resource managers assess more quickly and accurately the degradation of recreational water quality. Water and lake-bottom sediments were collected and ancillary environmental data were compiled for 41 days from May through September 1997. Water samples were analyzed for E. coli concentrations, suspended sediment concentrations, and turbidity. Lake- bottom sediment samples from the beach area were analyzed for E. coli concentrations and percent dry weight. Concentrations of E. coli were higher and more variable at Sims Park than at Villa Angela or Edgewater Park; concentrations were lowest at Edgewater Park. Time-series plots showed that short-term storage (less than one week) of E. coli in lake-bottom sediments may have occurred, although no evidence for long-term storage was found during the sampling period. E. coli concentrations in water were found to increase with increasing wave height, but the resuspension of E. coli from lake-bottom sediments by wave action could not be adequately assessed; higherwave heights were often associated with the discharge of sewage containing E. coli during or after a rainfall and wastewater-treatment plant overflow. Multiple linear regression (MLR) was used to develop models to predict recreational water quality at the in water. The related variables included turbidity, antecedent rainfall, antecedent weighted rainfall, volumes of wastewater-treatment plant overflows and metered outfalls (composed of storm-water runoff and combined-sewer overflows), a resuspension index, and wave heights. For the beaches in this study, wind speed, wind direction, water temperature, and the prswimmers were not included in the model because they were shown to be statistically unrelated to E. coli concentrations. From the several models developed, one model was chosen that accounted for 58 percent of the variability in E. coli concentrations. The chosen MLR model contained weighted categorical rainfall, beach-specific turbidity, wave height, and terms to correct for the different magnitudes of E. coli concentrations among the three beaches. For 1997, the MLR model predicted the recreational water quality as well as, and in some cases better than, antecedent E. coli concentrations (the current method). The MLR model improved the sensitivity of the prediction and the percentage of correct predictions over the current method; however, the MLR model predictions still erred to a similar degree as the current method with regard to false negatives. A false negative would allow swimming when, in fact, the bathing water standard was exceeded. More work needs to be done to validate the MLR model with data collected during other recreational seasons, especially during a season with a greater frequency and intensity of summer rains. Studies could focus on adding to the MLR model other environmental and water-quality variables that improve the predictive ability of the model. These variables might include concentrations of E. coli in deeper sediments outside the bathing area, the direction of lake currents, site-specific-rainfall amounts, time-of-day information on overflows and metered outfalls, concentrations of E. coli in treated wastewater-treatment plant effluents, and occurrences of sewage-line breaks. Rapid biological or chemical methods for determination of recreational water quality could also be used as variables in model refinements. Possible methods include the use of experimental rapid assay methods for determination of E. coli concentrations or other fecal indicators and the use of chemical tracers for fecal contamination, such as coprostanol (a degradation

Water-Resources Investigations Report↗
USGS1948

Public water supplies in eastern Texas

This report gives a summarized description of the public water supplies in 77 counties of eastern Texas, extending from the Louisiana boundary to a northsouth line approximately along the ninety-seventh meridian. It gives the available data as follows for each of 323 communities: The population of the community; the name of the official from whom the information was obtained; the ownership of the waterworks, whether private or municipal; the source of supply, whether ground or surface water; the amount of water consumed; the facilities for storage; the number of customers served; the character of the chemical and sanitary treatment of the water, if any; and the chemical analyses of the water. Where ground water is used the following is also given: Records of wells, including drillers' logs; character of the pumping equipment; yield of the wells and water level records where they are available.

Water Supply Paper↗
USGS1949

Public water supplies in central and north-central Texas

This report gives a summarized description of the public water supplies in 35 counties of central and north-central Texas, extending from the southern boundaries of Travis, Blanco, Gillespie, and Kerr Counties northward to the TexasOklahoma State line. It gives the available data as follows for each of the 145 communities: Population of the community; name of the official from whom the information was obtained; ownership of water works, whether private or municipal source of supply, whether ground water or surface water; the amount of water consumed; the facilities for storage; the number of customers served; the character of the chemical and sanitary treatment, if any; and chemical analyses of the water. Where ground water is used, the following is also given: Records of wells, including drillers' logs; character of the pumping equipment; yields of the wells, and records of water levels, if available.

Water Supply Paper↗
USGS1954

The industrial utility of public water supplies in the United States, 1952; Part 2: States west of the Mississippi River

Public water supplies are utilized extensively by industries for processing, cooling, and steam generation. The requirements as to quality of water for each industry are specific, therefore information on the quality or chemical character of the water supply is essential not only in the location of industrial plants but also is an aid in the manufacture and distribution of products. Data are given in this report on the water supplies for 1,315 of the larger cities (or places) throughout the United States. The population of these cities represents 58.3 percent of the total population (1950 census), and more than 90 percent of the total urban population, of the United States. Part 1 of the report contains data for 819 cities east of the Mississippi River, and part 2 includes data for 416 cities west of the river. All cities of 15,000 or more population and many cities of smaller population are included. The information given for each place includes, in most instances, population of the place; ownership, source, and treatment of supply; storage facilities for both raw and finished water; and chemical analyses of the supplies.

Water Supply Paper↗
USGS1963

Ground water for public supply in St. Croix, Virgin Islands

The ground-water resources of St. Croix, V.I., if properly developed should be adequate to supply the present and near-future demand for water for public supply. Ground water is obtained from weathered volcanic and intrusive rocks (bedrocks), from limestone, and from alluvium. The water obtained from weathered bedrocks and from alluvium in the valleys of the North Side Range is generally of better quality than that obtained elsewhere on the island. The greatest yields are obtained from the limestone and alluvium of the south-central coastal plain, but the water there is generally of poor to only fair quality. In the East End area no water, or salty water, is obtained from wells.

Water Supply Paper↗
USGS1996

Descriptions of anisotropy and heterogeneity and their effect on ground-water flow and areas of contribution to public supply wells in a karst carbonate aquifer system

Delineation of areas of contribution to wells tapping a karst carbonate aquifer system can be extremely difficult using conventional approaches designed for isotropic and homogeneous aquifers, because ground-water flow tends to be through solution-enhanced conduits. Nonradial flow along preferential zones can result in inaccurate estimates of flow paths and traveltimes. Because of the large variability in factors affecting contributing areas and an imperfect understanding of how these factors can vary, the estimation of contributing areas is an approximation at best. To better understand the effects of aquifer anisotropy and heterogeneity on areas of contribution, an exploratory modeling approach was used. MODFLOW, a numerical flow model, and MODPATH, a particle tracking program, were used to generate time-related areas of contribution for six hypothetical carbonate aquifer system types. The six types were conceptualized to approximate different types of aquifer anisotropy and heterogeneity. These include: (1) an isotropic and homogeneous single-layer system; (2) an anisotropic in a horizontal plane single layer system; (3) a discrete vertically fractured single-layer system; (4) a multilayered system; (5) a doubly porous single-layer system; and (6) a vertically and horizontally interconnected heterogeneous system. The simulated aquifer anisotropy was 5:1 (Kxx/Kyy) determined from TENSOR2D results. The simulated discrete vertical fracture network represents locations inferred from mapped photolineaments. The simulated enhanced flow zones were determined from borehole video and geophysical logs. Areas of contribution were simulated for two prototype regions. The two prototypes were selected to be representative of the hydrologic diversity within the study area and were designated the Central Swamp and Lake Terrace regions. Localized conditions in pumping, production well distribution, and aquifer transmissivity affect the size, shape, and orientation of areas of contribution to public supply wells. The simulated areas of contribution are 60 percent larger in the Central Swamp region where pumpage is more than double and transmissivity is about half that of the Lake Terrace region. Although these factors are important, this study focused on the effects from hydrogeologic factors common to karst carbonate aquifer systems. This study indicates that the distribution and type of aquifer anisotropy and heterogeneity will affect the size, shape, and orientation of areas of contribution in a karst carbonate aquifer system. The size of the 50-year time-related areas of contribution ranged from 8.2 to 39.1 square miles in the Central Swamp region and from 4.0 to 18.3 square miles in the Lake Terrace region. Simulations showed that the size of areas of contribution is primarily affected by simulated withdrawal rates, effective porosity of the carbonate rock, and transmissivity. The shape and orientation of the simulated areas of contribution primarily result from aquifer anisotropy, well distribution, flow along solution-enhanced zones, and short-circuiting of flow through fracture networks. Comparisons also were made between protection zones delineated using analytical models and areas of contribution delineated using numerical models. The size of the 5-year time-related protection zone in the Central Swamp region using an analytical model was almost twice as large as the numerically simulated area of contribution, and more than eight times larger than the numerically simulated area of contribution in the Lake Terrace region. The differences in size are primarily the result of how the flow field is approximated. The analytical method assumes only lateral flow to wells but numerical methods allow particles to move laterally and vertically. Additionally, multiple-well-interference effects resulting from the close proximity of several pumping wells cause individual capture zones to converge or diverge, depending on the difference in pumping rates and orientation among the wells. Such an interpretation is not available from analytical methods. The simulated distributions of aquifer anisotropy and heterogeneity, in this study, were highly conceptualized, but were based on plausible occurrences of anisotropy and heterogeneity inherent in carbonate aquifer systems.

Florida↗
USGS2013

Towards a publicly available, map-based regional software tool to estimate unregulated daily streamflow at ungauged rivers

Streamflow information is critical for addressing any number of hydrologic problems. Often, streamflow information is needed at locations that are ungauged and, therefore, have no observations on which to base water management decisions. Furthermore, there has been increasing need for daily streamflow time series to manage rivers for both human and ecological functions. To facilitate negotiation between human and ecological demands for water, this paper presents the first publicly available, map-based, regional software tool to estimate historical, unregulated, daily streamflow time series (streamflow not affected by human alteration such as dams or water withdrawals) at any user-selected ungauged river location. The map interface allows users to locate and click on a river location, which then links to a spreadsheet-based program that computes estimates of daily streamflow for the river location selected. For a demonstration region in the northeast United States, daily streamflow was, in general, shown to be reliably estimated by the software tool. Estimating the highest and lowest streamflows that occurred in the demonstration region over the period from 1960 through 2004 also was accomplished but with more difficulty and limitations. The software tool provides a general framework that can be applied to other regions for which daily streamflow estimates are needed.

Geoscientific Model Development↗
USGS1989

Duck harvest on public hunting areas in California

We summarized hunter visits and success, and the magnitude and species composition of the duck harvest recorded on California public hunting areas (PHAs) during 1950-87. Hunter visits and harvest increased during 1950-74 as new PHAs were added, then declined concurrently with duck populations. Of six geographic regions, the Sacramento Valley, with numerous PHAs and the largest duck concentrations, accounted for the largest portion of PHA hunter visits (28%) and harvest (35%). Duck population levels, regulations, and hunter numbers affected PHA hunter success. Success was highest during 1955-59 but declined with no consistent trend after 1960. Species vulnerability, abundance, distribution, and hunter preference affected harvest composition. Northern pintails, Anas acuta, averaged 27% of the PHA harvest but declined in importance after 1974. Green-winged teal, A. crecca, the most important species in southern regions, averaged 21% of the PHA harvest. Mallards, A. platyrhynchos, averaged 16% of the PHA harvest but increased in importance after 1974 to become the most common duck bagged after 1983. PHA harvest comprised a small (4-16%) portion of the total state harvest. However, this portion increased from 1950-70 because of increased hunter visits to new PHAs and after 1970 because hunter success on PHAs did not decline as on other areas. PHA hunters tended to harvest fewer preferred species and more vulnerable species, as proportions of total bag, than did other hunters. The continued decline in numbers of waterfowl hunters presents important challenges for management of waterfowl areas in California.

California Fish and Game↗
USGS1964

Microprint as a medium for primary publication

Microprint has been demonstrated an acceptable medium for publication in an experiment conducted by the Wildlife Disease Association. With author composition costs slightly over seven cents per 3x5 inch card, up to 47 pages. Need is recognized for development of standards and improvement of accessory retrieval apparatus.

Book chapter↗
USGS1991

Publication aspects of ethics in photogrammetry

According to the Code of Ethics of the American Society for Photogrammetry and Remote Sensing (ASPRS), the principles on which ethics are founded consist of honesty, justice, and courtesy, forming a moral philosophy associated with mutual interest among men. We will cover in particular the ethical problems of publication of photogrammetric material in the various media. There are many such problems, and we often face a dilemma in selecting a course which is the right thing to do.

Photogrammetric Engineering and Remote Sensing↗
USGS2002

North Carolina's natural heritage program: A case for public-private cooperation

Voluntary conservation programs are an effective tool for recognizing and preserving the value of special places on private forestlands. We evaluate private landowner participation in the Natural Heritage Program of North Carolina, finding that landowners are more likely to enroll land with high ecological significance in this voluntary program. Voluntary conservation is less likely on lands that are remote from threats such as roads, that have higher value in other uses, and that are near lands already conserved by the public.

Journal of Forestry↗
USGS2003

Volcanic debris flows in developing countries - The extreme need for public education and awareness of debris-flow hazards

In many developing countries, volcanic debris flows pose a significant societal risk owing to the distribution of dense populations that commonly live on or near a volcano. At many volcanoes, modest volume (up to 500,000 m 3) debris flows are relatively common (multiple times per century) and typically flow at least 5 km along established drainages. Owing to typical debris-flow velocities there is little time for authorities to provide effective warning of the occurrence of a debris flow to populations within 10 km of a source area. Therefore, people living, working, or recreating along channels that drain volcanoes must learn to recognize potentially hazardous conditions, be aware of the extent of debris-flow hazard zones, and be prepared to evacuate to safer ground when hazardous conditions develop rather than await official warnings or intervention. Debris-flow-modeling and hazard-assessment studies must be augmented with public education programs that emphasize recognizing conditions favorable for triggering landslides and debris flows if effective hazard mitigation is to succeed. ?? 2003 Millpress,.

Conference Paper↗