Geology topics

D.P. Mau

Publications and source records attributed to D.P. Mau.

5 recordsLinked to original sources

USGS2005

Estimating ground-water recharge from streamflow hydrographs for a small mountain watershed in a temperate humid climate, New Hampshire, USA

Hydrographs of stream discharge were analyzed to determine ground-water recharge for two small basins draining into Mirror Lake, New Hampshire. Two methods of hydrograph analysis developed for determining ground-water recharge were evaluated, the instantaneous recharge method and the constant recharge method. For the instantaneous recharge method, recharge is assumed to be instantaneous and uniform over the basin. For the constant recharge method, recharge is assumed to be constant and uniform over the basin for a period of weeks to months. Both methods require that a ground-water recession slope be determined. The recession slope is used directly in the calculation for the instantaneous recharge method, and it is used as a base of reference for fitting a type curve in the constant recharge method. Results of the study indicated that the estimates of ground-water recharge for both methods agree to within about 10 percent. Two approaches to the instantaneous recharge method, manual and automated, were also evaluated, and the results were statistically similar. The baseflow component of streamflow commonly is assumed to be equivalent to ground-water recharge; therefore, two methods developed for determining the baseflow component of streamflow, graphical partitioning and digital filtering, were evaluated also. Baseflow values determined by graphical partitioning of hydrographs were about 25 percent less than the ground-water recharge values. Baseflow values determined by two different approaches to the mathematical digital filtering method were generally less than baseflow determined by graphical partitioning. However, one of the approaches to digital filtering agreed reasonably well with graphical partitioning if an appropriate filter constant was used. The other approach to digital filtering resulted in baseflow values that were much less than the other baseflow values and was therefore deemed inappropriate for use on these small mountain watersheds.

Groundwater↗

USGS2005

Effects of nonpoint and selected point contaminant sources on stream-water quality and relation to land use in Johnson County, northeastern Kansas, October 2002 through June 2004

Water and sediment samples were collected by the U.S. Geological Survey in 12 watersheds in Johnson County, northeastern Kansas, to determine the effects of nonpoint and selected point contaminant sources on stream-water quality and their relation to varying land use. The streams studied were located in urban areas of the county (Brush, Dykes Branch, Indian, Tomahawk, and Turkey Creeks), developing areas of the county (Blue River and Mill Creek), and in more rural areas of the county (Big Bull, Captain, Cedar, Kill, and Little Bull Creeks). Two base-flow synoptic surveys (73 total samples) were conducted in 11 watersheds, a minimum of three stormflow samples were collected in each of six watersheds, and 15 streambed-sediment sites were sampled in nine watersheds from October 2002 through June 2004. Discharge from seven wastewater treatment facilities (WWTFs) were sampled during base-flow synoptic surveys. Discharge from these facilities comprised greater than 50 percent of streamflow at the farthest downstream sampling site in six of the seven watersheds during base-flow conditions. Nutrients, organic wastewater-indicator compounds, and prescription and nonprescription pharmaceutical compounds generally were found in the largest concentrations during base-flow conditions at sites at, or immediately downstream from, point-source discharges from WWTFs. Downstream from WWTF discharges streamflow conditions were generally stable, whereas nutrient and wastewater-indicator compound concentrations decreased in samples from sites farther downstream. During base-flow conditions, sites upstream from WWTF discharges had significantly larger fecal coliform and Escherichia coli densities than downstream sites. Stormflow samples had the largest suspended-sediment concentrations and indicator bacteria densities. Other than in samples from sites in proximity to WWTF discharges, stormflow samples generally had the largest nutrient concentrations in Johnson County streams. Discharge from WWTFs with trickling-filter secondary treatment processes had the largest concentrations of many potential contaminants during base-flow conditions. Samples from two of three trickling-filter WWTFs exceeded Kansas Department of Health and Environment pH- and temperature-dependent chronic aquatic-life criteria for ammonia when early-life stages of fish are present. Discharge from trickling-filter facilities generally had the most detections and largest concentrations of many organic wastewater-indicator compounds in Johnson County stream-water samples. Caffeine (stimulant), nonylphenol-diethoxylate (detergent surfactant), and tris(2-butoxyethyl) phosphate (floor polish, flame retardant, and plasticizer) were found at concentrations larger than maximum concentrations in comparable studies. Land use and seasonality affected the occurrence and magnitude of many potential water-quality contaminants originating from nonpoint sources. Base-flow samples from urban sites located upstream from WWTF discharges had larger indicator bacteria densities and wastewater-indicator compound concentrations than did base-flow samples from sites in nonurban areas. Dissolved-solids concentrations were the largest in winter stormflow samples from urban sites and likely were due to runoff from road-salt application. One sample from an urban watershed had a chloride concentration of 1,000 milligrams per liter, which exceeded the Kansas Department of Health and Environment's acute aquatic-life use criterion (860 milligrams per liter) likely due to effects from road-salt application. Pesticide concentrations were the largest in spring stormflow samples collected in nonurban watersheds. Although most wastewater-indicator compounds were found at the largest concentrations in samples from WWTF discharges, the compounds 9-10, anthraquinone (bird repellent), caffeine (stimulant), carbazole (component of coal tar, petroleum products), nonylphenol-diethoxylate (detergent surfactant),

Scientific Investigations Report↗

USGS2003

Evaporation determined by the energy-budget method for Mirror Lake, New Hampshire

Evaporation was determined by the energy - budget method for Mirror Lake during the open water periods of 1982-1987. For all years, evaporation rates were low in spring and fall and highest during the summer. However, the times of highest evaporation rates varied during the 6 yr. Evaporation reached maximum rates in July for three of the years, in June for two of the years, and in August for one of the years. The highest evaporation rate during the 6-yr study was 0.46 cm d -1 during 27 May-4 June 1986 and 15-21 July 1987. Solar radiation and atmospheric radiation input to the lake and long-wave radiation emitted from the lake were by far the largest energy fluxes to and from the lake and had the greatest effect on evaporation rates. Energy advected to and from the lake by precipitation, surface water, and ground water had little effect on evaporation rates. In the energy - budget method , average evaporation rates are determined for energy - budget periods, which are bounded by the dates of thermal surveys of the lake . Our study compared evaporation rates calculated for short periods, usually ∼1 week, with evaporation rates calculated for longer periods, usually ∼2 weeks. The results indicated that the shorter periods showed more variability in evaporation rates, but seasonal patterns, with few exceptions, were similar.

New Hampshire↗

USGS2003

Metals, trace elements, and organochlorine compounds in bottom sediment of Tuttle Creek Lake, Kansas, U.S.A.

Bottom-sediment cores were used to investigate the occurrence of 44 metals and trace elements, and 15 organochlorine compounds in Tuttle Creek Lake, a reservoir with an agricultural basin in northeast Kansas, U.S.A. On the basis of U.S. Environmental Protection Agency sediment-quality guidelines, concentrations of Ag, As, Cr, Cu, Ni, and Zn frequently or typically exceeded the threshold-effects levels for toxic biological effects. Organochlorine compounds either were not detected or were detected at concentrations generally below the threshold-effects levels. Statistically significant positive depositional trends were determined for several elements. However, because the vertical profiles of element concentrations typically indicated a bimodal distribution and much of the variability could be attributable to analytical variance, the statistical trends may not represent actual trends. DDE concentrations reflected the history of DDT use. Substantial increases in grain corn and soybean production, irrigated land, and hog production in the basin have not had a discernible effect on sediment quality in the reservoir. Future research focused on small impoundments throughout the basin may enhance understanding of the effects of human activity on sediment quality within the Tuttle Creek Lake system and elsewhere.

Conference Paper↗

USGS2001

Sediment deposition and trends and transport of phosphorus and other chemical constituents, Cheney Reservoir watershed, south-central Kansas

Sediment deposition, water-quality trends, and mass transport of phosphorus, nitrogen, selected trace elements, and selected pesticides within the Cheney Reservoir watershed in south-central Kansas were investigated using bathymetric survey data and reservoir bottom-sediment cores. Sediment loads in the reservoir were investigated by comparing 1964 topographic data to 1998 bathymetric survey data. Approximately 7,100 acre-feet of sediment deposition occurred in Cheney Reservoir from 1965 through 1998. As of 1998, sediment had filled 27 percent of the reservoir's inactive conservation storage pool, which is less than the design estimate of 34 percent. Mean annual sediment deposition was 209 acre-feet per year, or 0.22 acre-feet per year per square mile, and the mean annual sediment load was 453 million pounds per year. During the 3-year period from 1997 through 1999, 23 sediment cores were collected from the reservoir, and subsamples were analyzed for nutrients (phosphorus and nitrogen species), selected trace elements, and selected organic pesticides. Mean concentrations of total phosphorus in reservoir bottom sediment ranged from 94 milligrams per kilogram at the upstream end of the reservoir to 710 milligrams per kilogram farther downstream near the reservoir dam. The mean concentration for all sites was 480 milligrams per kilogram. Total phosphorus concentrations were greatest when more silt- and clay-sized particles were present. The implications are that if anoxic conditions (inadequate oxygen) occur near the dam, phosphorus could be released from the sediment and affect the drinking-water supply. Analysis of selected cores also indicates that total phosphorus concentrations in the reservoir sediment increased over time and were probably the result of nonpoint-source activities in the watershed, such as increased fertilizer use and livestock production. Mean annual phosphorus loading to Cheney Reservoir was estimated to be 226,000 pounds per year on the basis of calculations from deposited sediment in the reservoir. Mean total phosphorus concentration in the surface-water inflow to Cheney Reservoir was 0.76 milligram per liter, mean annual phosphorus yield of the watershed was estimated to be 0.38 pound per year per acre, and both are based on sediment deposition in the reservoir. A comparison of the Cheney Reservoir watershed to the Webster Reservoir, Tuttle Creek Lake, and Hillsdale Lake watersheds showed that phosphorus yields were smallest in the Webster Reservoir watershed where precipitation was less than in the other watersheds. Mean concentrations of total ammonia plus organic nitrogen in bottom sediment from Cheney Reservoir ranged from 1,200 to 2,400 milligrams per kilogram as nitrogen. A regression analysis between total ammonia plus organic nitrogen as nitrogen and sediment particle size showed a strong relation between the two variables and suggests, as with phosphorus, that total ammonia plus organic nitrogen as nitrogen adsorbs to the silt- and clay-sized particles that are transported to the deeper parts of the reservoir. An analysis of trends with depth of total ammonia plus organic nitrogen as nitrogen did not indicate a strong relation between the two variables despite the increase in fertilizer use in the watershed during the past 40 years. Selected cores were analyzed for trace elements. Concentrations of arsenic, chromium, copper, and nickel at many sites exceeded levels where adverse effects on aquatic organisms sometimes occur. Larger concentrations of these elements also occurred in sediment closer to the reservoir dam where there is a larger percentage of silt and clay in the bottom sediment than farther upstream. However, the lack of industrial or commercial land use in the watershed suggests that these concentrations may be the result of natural conditions. Organochlorine insecticides were detected in the reservoir-bottom sediment in Cheney Reservoir. DDT and its degradation products DDD and DD

Water-Resources Investigations Report↗