Geology topics

Dina K. Saleh

Publications and source records attributed to Dina K. Saleh.

6 recordsLinked to original sources

USGS2010

Comparison of two parametric methods to estimate pesticide mass loads in California's Central Valley

Mass loadings were calculated for four pesticides in two watersheds with different land uses in the Central Valley, California, by using two parametric models: (1) the Seasonal Wave model (SeaWave), in which a pulse signal is used to describe the annual cycle of pesticide occurrence in a stream, and (2) the Sine Wave model, in which first-order Fourier series sine and cosine terms are used to simulate seasonal mass loading patterns. The models were applied to data collected during water years 1997 through 2005. The pesticides modeled were carbaryl, diazinon, metolachlor, and molinate. Results from the two models show that the ability to capture seasonal variations in pesticide concentrations was affected by pesticide use patterns and the methods by which pesticides are transported to streams. Estimated seasonal loads compared well with results from previous studies for both models. Loads estimated by the two models did not differ significantly from each other, with the exceptions of carbaryl and molinate during the precipitation season, where loads were affected by application patterns and rainfall. However, in watersheds with variable and intermittent pesticide applications, the SeaWave model is more suitable for use on the basis of its robust capability of describing seasonal variation of pesticide concentrations.

California↗

USGS2010

Stream gage descriptions and streamflow statistics for sites in the Tigris River and Euphrates River Basins, Iraq

Statistical summaries of streamflow data for all long-term streamflow-gaging stations in the Tigris River and Euphrates River Basins in Iraq are presented in this report. The summaries for each streamflow-gaging station include (1) a station description, (2) a graph showing annual mean discharge for the period of record, (3) a table of extremes and statistics for monthly and annual mean discharge, (4) a graph showing monthly maximum, minimum, and mean discharge, (5) a table of monthly and annual mean discharges for the period of record, (6) a graph showing annual flow duration, (7) a table of monthly and annual flow duration, (8) a table of high-flow frequency data (maximum mean discharge for 3-, 7-, 15-, and 30-day periods for selected exceedance probabilities), and (9) a table of low-flow frequency data (minimum mean discharge for 3-, 7-, 15-, 30-, 60-, 90-, and 183-day periods for selected non-exceedance probabilities).

Data Series↗

USGS2009

Using the Soil and Water Assessment Tool (SWAT) to Simulate Runoff in Mustang Creek Basin, California

This study is an evaluation of the calibration and validation of the Soil and Water Assessment Tool (SWAT) version 2005 watershed model for the Mustang Creek Basin, San Joaquin Valley, California. The study is part of a national study on the process of agricultural chemical movement through the hydrologic system, which is being done by the U.S. Geological Survey (USGS) National Water-Quality Assessment program. The SWAT model was used to simulate streamflow in the Mustang Creek Basin on the basis of a set of model inputs derived and modified from various data sources. The 2005 version of the model was calibrated for 29 days in February 2004, and validated for 58 days in January and February 2005. Measured streamflow for a USGS gaging station was used for model calibration and validation. Results of the simulated monthly streamflow had a Nash Sutcliffe efficiency value of 0.72 during the calibration period. The 2005 version of the model was unsuccessful in simulating streamflow during the validation period, as indicated by a Nash Sutcliffe efficiency value of 0.33. This lack of a successful simulation probably is due to the limited amount of measured streamflow data available for calibration, the ephemeral nature of flows in Mustang Creek, and the fact that the SWAT model was developed primarily for long time period (2 years and more) simulations and not for limited monthly simulations as used in Mustang Creek.

Scientific Investigations Report↗

USGS2006

Assessment of hydrologic and water quality data collected in Abbotts Lagoon watershed, Point Reyes National Seashore, California, during water years 1999 and 2000

Abbotts Lagoon is part of Point Reyes National Seashore, located about 40 miles northwest of San Francisco and about 20 miles south of Bodega Bay. Water-quality samples were collected quarterly during water year 1999 at a site in each of three connected lagoons that make up Abbotts Lagoon and at a site in its most significant tributary. The quarterly samples were analyzed for major ions, nutrients, and chlorophyll-a. A bed-sediment sample was collected in each lagoon during August 1999 and was analyzed for organic carbon, iron, and total phosphorus. Seven tributaries were sampled during a February 1999 storm and four during an April 1999 storm. These samples were analyzed only for nutrients. One storm sample collected in April 1999 from a tributary downstream of the I Ranch dairy was analyzed for a suite of 47 compounds indicative of wastewater. Continuous water-level recorders were installed in the most significant tributary and the two largest lagoons for portions of the study. A water budget analysis for an April 2000 storm indicated that the main tributary accounted for 85 percent of surface inflows to Abbotts Lagoon. The portion of the surface inflow from the main tributary was lower in the February 1999 storms and is a function of upstream storage and vegetative growth in the tributary basins. Another water budget analysis for a period of no surface inflow (June and July 2000) indicated that the net ground-water contribution was an outflow (seepage) from Abbotts Lagoon of about 0.3 ft3/s. Salinity increased and nutrient concentrations decreased from upstream to downstream in the chain of lagoons. The lower lagoon, nearest the ocean, had less organic carbon and total phosphorus in the bed sediment than the upper lagoons. The two tributaries originating in the I Ranch dairy had the highest concentrations of nutrients in storm runoff, and the highest loading rates and yields of ammonia and phosphorus. These tributaries account for only 10.3 percent of the area drained by the sampled tributaries, but contributed 83 percent of the ammonia load and 79 percent of the orthophosphate load. The basins with the highest nutrient loading rates and yields had the highest percentage of dairy and (or) ranching impacted land use and, to a lesser extent, grazing land use. The ratios of inorganic nitrogen to phosphorus in the lagoons ranged from 0.1 to 9.5 in the upper lagoon, 0.10 to 0.15 in the middle lagoon, and 0.05 to 0.10 in the lower lagoon. Thus, there is an abundance of phosphorus in the lagoons, and nitrogen appears to be limiting the growth of phytoplankton. Two sterols indicative of fecal material were among 11 compounds detected in the sample collected for analysis of wastewater indicators from a tributary downstream of the I Ranch dairy.

California↗

USGS2003

Selenium and sediment loads in storm runoff in Panoche Creek, California, February 1998

Five to nine samples were collected per storm throughout the hydrograph of four storms in February 1998 from Panoche Creek at Interstate 5, California. The rainfall total of 10.40 inches for the month was greater than any other month during 1957 to 2000, and peak streamflows on February 3 and 7 exceeded the previous peak streamflow of record. Concentrations of suspended sediment, which were highly variable during the storms, ranged from 32,900 to 251,000 mg/L (milligram per liter) with a median of 126,000 mg/L. Dissolved selenium concentrations in the storm samples ranged from 16 to 60 μg/L (microgram per liter), with a median of 30 μg/L. These concentrations were considerably higher during the first storm than during subsequent storms. Total selenium concentrations in the storm samples ranged from 57 to 320 μg/L, with a median of 115 μg/L. Total selenium in four replicate and four rerun samples was highly variable (relative percent differences ranged from 0 to 57 percent), probably due to the extremely high concentrations of suspended sediment in the samples and possible interferences from other compounds. The calculated concentration of selenium attached to suspended sediment was less variable than suspended sediment or total selenium concentrations during storm runoff; concentrations ranged from 0.50 to 2.1 μg/g (microgram per gram) with a median of 0.89 μg/g. The logarithms of suspended sediment and total selenium concentrations were closely correlated to the logarithm of streamflow (R2 = 0.82, R2 = 0.71, respectively for all storm data). These relations for the first storm were significantly different from the later three storms. Because of these correlations, the logarithm of suspended sediment loading rate and the logarithm of total selenium loading rate were closely correlated to the logarithm of streamflow (R2 = 0.982 for both for all storm data). Loads of suspended sediment and total selenium were calculated for each of the four storms in three ways, including simple linear regression with streamflow for all storms, simple linear regressions for the first storm and the combined later three storms, and integration under the instantaneous load curves. The resulting suspended sediment loads for all four storms ranged from 1,793,000 to 2,555,000 tons; total selenium ranged from 4,909 to 5,830 lb (pound). Dissolved selenium concentrations correlated significantly with both the logarithm of streamflow and specific conductance. Simple linear regression with the logarithm of streamflow had an R2 of 0.45, and a multiple linear regression with the logarithm of streamflow and specific conductance had an adjusted R2 of 0.48 for all storm data. The relation between streamflow and specific conductance for the first storm and for the later three storms were significantly different. As for suspended sediment and total selenium, dissolved selenium loads were calculated three ways. The resulting loads for all four storms ranged from 773 to 1,007 lb. No significant storm occurred during the remainder of the study period (water years 1998 to 2000), and thus, no additional storm sampling took place. Assuming that future sediment and selenium transport is similar to that of 1998, a reasonable estimate of loading rates can be calculated from the streamflow record at the Interstate 5 gage. Additional storm sampling would improve the estimates and possibly allow for separate equations for the rising and falling limbs of storm hydrographs.

California↗

USGS2003

Organic carbon trends, loads, and yields to the Sacramento-San Joaquin Delta, California, water years 1980 to 2000

Organic carbon, nutrient, and suspended sediment concentration data were analyzed for the Sacramento and San Joaquin River Basins for the period 1980-2000. The data were retrieved from three sources: the U.S. Geological Survey's National Water Information System, the U.S. Environmental Protection Agency's Storage and Retrieval System, and the California Interagency Ecological Program's relational database. Twenty sites were selected, all of which had complete records of daily streamflow data. These data met the minimal requirements of the statistical programs used to estimate trends, loads, and yields. The seasonal Kendall program was used to estimate trends in organic carbon, nutrient, and suspended sediment. At all 20 sites, analyses showed that in the 145 analyses for the seven constituents, 95 percent of the analyses had no significant trend. Dissolved organic carbon (DOC) concentrations were significant only for four sites: the American River at Sacramento, the Sacramento River sites near Freeport, Orestimba Creek at River Roads near Crows Landing, and the San Joaquin River near Vernalis. Loads were calculated using two programs, ESTIMATOR and LOADEST2. The 1998 water year was selected to describe loads in the Sacramento River Basin. Organic carbon, nutrient, and suspended sediment loads at the Sacramento River sites near Freeport included transported loads from two main upstream sites: the Sacramento River at Verona and the American River at Sacramento. Loads in the Sacramento River Basin were affected by the amount of water diverted to the Yolo Bypass (the amount varies annually, depending on the precipitation and streamflow). Loads at the Sacramento River sites near Freeport were analyzed for two hydrologic seasons: the irrigation season (April to September) and the nonirrigation season (October to March). DOC loads are lower during the irrigation season then they are during the nonirrigation season. During the irrigation season, water with low concentrations of DOC is released from reservoirs and used for irrigation. On the other hand, during the nonirrigation season, streamflow results from surface water runoff and has higher concentrations of organic carbon, nutrients, and suspended sediment. The 1986 and 1987 water years were selected to describe loads in the San Joaquin River Basin. Organic carbon, nutrient, and suspended sediment loads in the San Joaquin River near Vernalis included transported loads from upstream sites, such as the Mud and Salt Sloughs, the Merced River at River Roads Bridge near Newman, the Tuolumne River at Modesto, and the Stanislaus River at Ripon. Loads at the San Joaquin River near Vernalis also were analyzed for the two seasons. The DOC load for the San Joaquin River at Vernalis is slightly higher during the irrigation season. Yields were calculated in an attempt to rank the subbasins in the Sacramento and San Joaquin River Basins. Five sites delivered streamflow from agricultural and urban sources that had relatively high yields of organic carbon: Sacramento Slough near Knights Landing, Arcade Creek near Del Paso Heights, Salt Slough, Mud Slough, and Colusa Basin Drain at Road 99E near Knights Landing.

California↗