Geology topics

J. G. Peters

Publications and source records attributed to J. G. Peters.

4 recordsLinked to original sources

USGS1988

Effects of agricultural irrigation on water resources in the St. Joseph River basin, Indiana, and implications for aquifer yield

During the past decade, the acreage of irrigated agricultural land in Indiana has tripled, causing public concern about competition for water and resulting in several State laws for regulating water withdrawals. The St. Joseph River basin represents less than one-tenth of the area of the State, but it contains one-third of the State 's irrigated land. Irrigated land in the basin is composed of permeable soils that are underlain by productive glacial aquifers. A computer model was used to analyze the effects of maximum irrigation withdrawals on aquifer drawdown and streamflow in a 16.5 sq mi area of intensive irrigation. Simulation of maximum pumping resulted in predicted aquifer drawdowns of one-fourth of the total available drawdown. Flow in a nearby stream was decreased by 40%. Areas of most intensive irrigation in the basin also are areas that have productive aquifers and well-sustained streamflows. Aquifer yield is based on the concept of capture - the volume of increased recharge to the aquifer or decreased discharge from the aquifer that results from pumping. The high rates of capture for aquifers in the basin supply ample water for present (1982) irrigation and for substantial future development. (USGS)

Indiana↗

USGS1987

Description and comparison of selected models for hydrologic analysis of ground-water flow, St. Joseph River basin, Indiana

The Indiana Department of Natural Resources (IDNR) is developing water-management policies designed to assess the effects of irrigation and other water uses on water supply in the basin. In support of this effort, the USGS, in cooperation with IDNR, began a study to evaluate appropriate methods for analyzing the effects of pumping on ground-water levels and streamflow in the basin 's glacial aquifer systems. Four analytical models describe drawdown for a nonleaky, confined aquifer and fully penetrating well; a leaky, confined aquifer and fully penetrating well; a leaky, confined aquifer and partially penetrating well; and an unconfined aquifer and partially penetrating well. Analytical equations, simplifying assumptions, and methods of application are described for each model. In addition to these four models, several other analytical models were used to predict the effects of ground-water pumping on water levels in the aquifer and on streamflow in local areas with up to two pumping wells. Analytical models for a variety of other hydrogeologic conditions are cited. A digital ground-water flow model was used to describe how a numerical model can be applied to a glacial aquifer system. The numerical model was used to predict the effects of six pumping plans in 46.5 sq mi area with as many as 150 wells. Water budgets for the six pumping plans were used to estimate the effect of pumping on streamflow reduction. Results of the analytical and numerical models indicate that, in general, the glacial aquifers in the basin are highly permeable. Radial hydraulic conductivity calculated by the analytical models ranged from 280 to 600 ft/day, compared to 210 and 360 ft/day used in the numerical model. Maximum seasonal pumping for irrigation produced maximum calculated drawdown of only one-fourth of available drawdown and reduced streamflow by as much as 21%. Analytical models are useful in estimating aquifer properties and predicting local effects of pumping in areas with simple lithology and boundary conditions and with few pumping wells. Numerical models are useful in regional areas with complex hydrogeology with many pumping wells and provide detailed water budgets useful for estimating the sources of water in pumping simulations. Numerical models are useful in constructing flow nets. The choice of which type of model to use is also based on the nature and scope of questions to be answered and on the degree of accuracy required.

Indiana, Michigan↗

USGS1986

Review of the hydrologic data-collection network in the St. Joseph River basin, Indiana

The St. Joseph River Basin data-collection network in the St. Joseph River for streamflow, lake, ground water, and climatic stations was reviewed. The network review included only the 1700 sq mi part of the basin in Indiana. The streamflow network includes 11 continuous-record gaging stations and one partial-record station. Based on areal distribution, lake effect , contributing drainage area, and flow-record ratio, six of these stations can be used to describe regional hydrology. Gaging stations on lakes are used to collect long-term lake-level data on which to base legal lake levels, and to monitor lake-level fluctuations after legal levels are established. More hydrogeologic data are needed for determining the degree to which grouhd water affects lake levels. The current groundwater network comprises 15 observation wells and has four purposes: (1) to determine the interaction between groundwater and lakes; (2) to measure changes in groundwater levels near irrigation wells; (3) to measure water levels in wells at special purpose sites; and (4) to measure long-term changes in water levels in areas not affected by pumping. Seven wells near three lakes have provided sufficient information for correlating water levels in wells and lakes but are not adequate to quantify the effect of groundwater on lake levels. Water levels in five observation wells located in the vicinity of intensive irrigation are not noticeably affected by seasonal withdrawals. The National Weather Sevice operates eight climatic stations in the basin primarily to characterize regional climatic conditions and to aid in flood forecasting. The network meets network-density guidelines established by the World Meterological Organization for collection of precipitation and evaporation data but not guidelines suggested by the National Weather Service for density of precipitation gages in areas of significant convective rainfalls. (Author 's abstract)

Indiana↗

USGS1985

Hydrologic effects of ground- and surface-water withdrawals in the Milford area, Elkhart and Kosciusko counties, Indiana

Agricultural irrigation in northern Indiana has increased rapidly since 1975 and might double by the year 2000. A 16.5 square-mile area in north-central Indiana was studied to determine possible effects of increased irrigation on local water supply. In 1982, an average of 2 inches of water was used to irrigate 975 acres of sandy soil overlying highly transmissive outwash deposits. Irrigational pumpage was 75 percent of the summer water use but was less than potential irrigational pumpage because (1) only one-third of the suitable land was irrigated, and (2) precipitation was near normal for the year. A three-dimensional digital flow model, calibrated with data collected in 1982, was used to simulate four hypothetical pumping plans representing various irrigational schemes and possible rainfall conditions: (1) 1982 acreage irrigated and 1982 (above normal) precipitation; (2) 1982 acreage irrigated and below-normal precipitation; (3) maximum acreage irrigated and normal precipitation; and (4) maximum acreage irrigated and below-normal precipitation. A fifth pumping plan was used to simulate maximum year-round water use. Plan 5 was not designed to simulate irrigational development but rather a maximum rate of withdrawal sustainable year-round until steady-state is reached. Of the four pumping plans that simulated irrigational pumpage, plan 4 had the greatest effect on ground- and surface-water supply. Compared with 1982 pumpage, this plan represented a thirteenfold increase in the volume of water pumped for irrigation from wells and from Turkey Creek, a stream bordering the area of study. The model predicted a potentiometric decline of as much as 20.7 feet over an 8-acre area of the aquifer. This decline was one-fourth of the available drawdown and would not dewater the source aquifer. Streamflow in Turkey Creek would be reduced 39 percent by simulated ground-water and surface-water pumpage but remaining flow would still be twice the 7-day, 10-year low flow. However, the model predicted that flow in two smaller streams would be reduced to zero. The rate of pumping used in plan 5 was nearly 4 times the pumping rate in 1982. Potentiometric decline for plan 5 was as much as 40 percent of available drawdown, and predicted streamflow reduction would cause flow in Turkey Creek to decrease below the 7-day, 10-year low flow. Results of plans 1, 2, 3, and 4 indicate that the outwash system provides adequate water for current (1982) needs and substantial growth for irrigation. However, maximum irrigational development might cause temporary, local competition for water in several parts of the area. Plan 5 indicates .that water use could increase substantially before effects of pumping would prevail year-round.

Indiana↗