FLOOD INUNDATION IN THE SOUTHEASTERN UNITED STATES FROM AIRCRAFT AND SATELLITE IMAGERY1

ABSTRACT: Panchromatic black and white, color, and color infrared photographs and thermal infrared imagery are compared for a capability to show flood boundaries. In open agricultural and urban areas, these boundaries are easily delineated on all types of am. Boundaries are more difficult to see in wooded areas. In March, hardwood trees are dormant, but black and white photographs and color photographs show only the tops of these trees. Color infrared photographs in January and March have a distinctive color or tone in inundated woods; the limit of this tone is the flood boundary. Daytime thermal infrared imagery in March shows that inundated woods are cooler than dry land but warmer than open water. After about April 1, both color infrared photography and thermal infrared imagery show only the top of the tree canopy and do not reflect underlying flood water. Inundated areas can be delineated easily on ERTS satellite imagery from December through March. On imagery from May 4–5, 1973, however, most inundation boundaries had to be drawn as dashed lines; the tree canopy obscures flood waters in wooded areas. Despite this problem, the results of mapping flood boundaries on May imagery are believed to be reasonable for the scale of the imagery.     

PICTURE OR PLACE? A MULTIPLE SORTING STUDY OF LANDSCAPE

Previous research has often used photographs as a tool for examining preference for landscape and in clarifying an understanding of what is aesthetically pleasing. Implicit in their use is the assumption that they will be regarded by the participants asrepresentingthe places shown. The present study demonstrates that there is a theoretical and empirical distinction between evaluations of pictures and evaluations of the places they represent, and thus future research needs to distinguish between evaluating thecontentof the photograph and theplacesrepresented in them. Using a sorting task, 41 participants sorted 20 photographs of local places, which they knew, in a free sort and a directed sort. The directed short instructed the participants to think about the places in the photographs, and to sort the items according to their knowledge of those place. Analysis of the first sort showed that items were grouped according to the content of the photograph, focusing on land form and the presence of water. The second sort showed that the items were grouped according to memories and sense experiences other than just the visual information presented in the photographs. The results showed that the participants conceptualise photographs differently according to whether they are asked to evaluate the photograph or the place represented by the photograph. Landscape evaluation research therefore needs to be clear aboutwhatis being evaluated, picture or place.     

MATHEMATICAL MODELS: PLANNING TOOLS FOR THE GREAT LAKES1

The Great Lakes Basin Commission has initiated a Framework Study to assess the present and projected water- and related land-resource problems and demands in the Great Lakes Basin. Poorly defined objectives; incomplete and inconsistent data arrays; unknown air, biota, water, and sediment interactions; and multiple planning considerations for interconnected, large lake systems hinder objective planning. To incorporate mathematical modeling as a planning tool for the Great Lakes, a two-phase program, comprising a feasibility and design study followed by contracted and in-house modeling, data assembly, and plan development, has been initiated. The models will be used to identify sensitivities of the lakes to planning and management alternatives, insufficiencies in the data base, and inadequately understood ecosystem interactions. For the first time objective testing of resource-utilization plans to identify potential conflicts will provide a rational and cost-effective approach to Great Lakes management. Because disciplines will be interrelated, the long-term effects of planning alternatives and their impacts on neighboring lakes and states can be evaluated. Testing of the consequences of environmental accidents and increased pollution levels can be evaluated, and risks to the resource determined. Examples are cited to demonstrate the use of such planning tools.     

A PLANNING METHOD FOR EVALUATING DOWNSTREAM EFFECTS OF DETENTION BASINS1

While storm water detention basins are widely used for controlling increases in peak discharges that result from urbanization, recent research has indicated that under certain circumstances detention storage can actually cause increases in peak discharge rates. Because of the potential for detrimental downstream effects, storm water management policies often require downstream effects to be evaluated. Such evaluation requires the design engineer to collect additional topographic and land use data and make costly hydrologic analyses. Thus, a method, which is easy to apply and which would indicate whether or not a detailed hydrologic analysis of downstream impacts is necessary, should decrease the average cost of storm water management designs. A planning method that does not require either a large data base or a computer is presented. The time co-ordinates of runoff hydrographs are estimated using the time-of-concentration and the SCS runoff curve number; the discharge coordinates are estimated using a simple peak discharge equation. While the planning method does not require a detailed design of the detention basin, it does provide a reasonably accurate procedure for evaluating whether or not the installation of a detention basin will cause adverse downstream flooding.     

SCS URBAN CURVE NUMBERS FROM A LANDSAT DATA BASE1

Estimating the Curve Numbers used in the Soil Conservation Service hydrologic models is a tedious and costly task. Recent advances in remote sensing and data processing have led to the development of readily available land cover data bases for many areas of the United States. This study evaluated the potential of using a Landsat data base to make the Curve Number estimation process more cost-effective and less tedious. Ten watersheds in the Washington, D.C., area were evaluated using a Landsat land cover data base developed by the U.S. Geological Survey. Results showed that these data can be useful. Predictions can be improved if ancillary data on residential lot size are included. It was concluded that this type of data base must be examined carefully before implementation.     

THE USE OF A SIMPLE MODEL AND UNCERTAINTY ANALYSIS IN LAKE MANAGEMENT1

ABSTRACT: A simple, black-box lake model was developed for phosphorus, using nonlinear regression analysis on a data base of north temperate lakes. The uncertainty associated with the model was then combined with the parameter uncertainty and the independent variable uncertainty to provide an estimate of the confidence limits associated with a predicted value. The prediction uncertainty is often neglected, yet it is an important measure of the usefulness of a model. Prediction uncertainty reflects the modeler's confidence in the model, and it should be used by a decision maker as a weight indicating the value of the model prediction. A procedure is outlined that combined lake modeling and uncertainty analysis for use in lake quality assessment and lake management. An example is provided illustrating the use of this procedure in nutrient budget sampling design, data analysis, and the evaluation of lake management strategies for a 208 program in New Hampshire.     

METEOROLOGICAL EXPERIMENTS FOR AUTOMATED SATELLITES

Four satellites have been used in meteorology. They are TIROS, ESSA, Nimbus, and Applications Technology Satellite (ATS). The first three operate in the orbital altitudes of about 1000 to 1200 km while the fourth, ATS, is at geosynchronous altitude of 36,000 km. Cloud cover is being observed operationally from low orbit and experimentally from synchronous altitude. Wind velocity has been inferred from the frequent cloud cover pictures taken by ATS and satellite-balloon systems are being developed which will locate and track constant-density level balloons for determining wind flow. Spectrometers and radiometers operating in the electromagnetic spectral region from the ultraviolet to the microwave region are being developed to quantitatively measure temperature, water vapor, density, and wind profiles. These will furnish data for the development and testing of atmospheric models for numerical prediction. In addition, experiments are being developed to measure ozone and other constituents of the air, solar energy, surface conditions, heat balance and other atmospheric attributes which affect the structure and dynamics of the atmosphere.     

CONJUNCTIVE MANAGEMENT OF WATER RESOURCES IN THE CONTEXT OF TEXAS WATER LAW1

ABSTRACT: This paper examines the critical interaction between existing Texas water law and the state's water resources. Conjunctive use and management of interrelated water resources, though seldom practiced, is generally considered desirable. However, a significant barrier to the coordinated, efficient use and management of water resources is the legal division of water in the various phases of the hydrologic cycle into different classes and recognition of well-defined water rights in the separate phases. Several examples of the problems which relate to, or result from, present Texas water law and which prevent correlated water resource management are discussed. Any substantive revision of Texas law, particularly ground water law, will apparently be difficult to achieve in the immediate future, primarily because of the large number of recognized private water rights and the political power inherent in them. Data necessary for operation of conjunctive management systems are gradually being acquired, and perhaps someday other hydrologic phases can be integrated with surface and ground water. Nevertheless, Texas courts and the legislature have sufficient information on the interrelated hydrologic cycle so that prospective water conflicts should be anticipated and avoided. Great care must be exercised in the recognition of new types of private water rights or extension of existing rights, because this institutional structure, once established, presents a formidable obstacle to desirable revisions of the law.     

Sensitivity of Thermal Habitat of a Trout Stream to Potential Climate Change,Wisconsin, United States1

Abstract: Airborne thermal remote sensing from four flights on a single day from a single‐engine airplane was used to collect thermal infrared data of a 10.47‐km reach of the upper East Branch Pecatonica River in southwest Wisconsin. The study uses a one‐dimensional stream temperature model calibrated with the longitudinal profiles of stream temperature created from the four thermal imaging flights and validated with three days of continuous stream temperature data from instream data loggers on the days surrounding the thermal remote‐sensing campaign. Model simulations were used to quantify the sensitivity of stream thermal habitat to increases in air and groundwater temperature and changes in base flow. The simulations indicate that stream temperatures may reach critical maximum thresholds for brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta) mortality, particularly if both air temperature increases and base flow declines. The approach demonstrates that thermal infrared data can greatly assist stream temperature model validation due to its high spatial resolution, and that this spatially continuous stream temperature data can be used to pinpoint spatial heterogeneity in groundwater inflow to streams. With this spatially distributed data on thermal heterogeneity and base‐flow accretion, stream temperature models considering various climate change scenarios are able to identify thermal refugia that will be critical for fisheries management under a changing climate.     

SELECTING RECONNAISSANCE STRATEGIES FOR FLOODPLAIN SURVEYS1

ABSTRACT: Multispectral aircraft and satellite data over the West Branch of the Susquehanna River were analyzed to evaluate potential contributions of remote sensing to floodplain surveys. Multispectral digital classifications of land cover features indicative of floodplain areas were used by interpreters to locate various floodprone area boundaries. The boundaries thus obtained were found to be more striking and continuous in the Landsat data than in the low altitude aircraft data. The digital approach permitted satellite results to be displayed at 1:24,000 scale and aircraft results at even larger scales. Results indicate that remote sensing techniques can delineate floodprone areas more easily in agricultural and limited development areas than in areas covered by a heavy forest canopy. At this time it appears that the remote sensing data would be best used as a form of preliminary planning information or as an internal check on previous or ongoing floodplain studies. In addition, the remote sensing techniques can assist in effectively monitoring floodplain activities after a community enters into the National Flood Insurance Program.     

USING LANDSAT DATA TO CLASSIFY LAND USE FOR ASSESSING THE BASINWIDE RUNOFF INDEX1

Remote sensing data in the form of Landsat computer compatible tapes (CCT) was used to determine land use and land cover as an aid in hydrologic studies that were used to estimated a basinwide runoff index. With the use of the General Electric Image 100 multispectral image processing system in conjunction with the Earth Resources Laboratory Application Software (ELAS), CCT's on February 9, 1976, were analyzed by spectral differences to determine unique land use conditions within the Econlockhatchee (Econ) River Basin, Florida. The result showed that the Landsat data can be successfully used to monitor the USGS land use Level 1. An advantage of using the Landsat data for land use classification is that new data are periodically available for updating the land use information. The Soil Conservation Service curve number was used to establish a basinwide runoff index which includes a prime variable of land use changes with the time. The basinwide runoff index in 1972 (with USGS 1972 Land Use maps) was similar to the one in 1976 (with Landsat data dated February 9, 1976). This implies that the runoff from the entire Econ Basin was not noticeably changed during the period of 1972 and 1976.     

THE USE OF LANDSAT IMAGERY IN GROUND WATER EXPLORATION1

ABSTRACT: Water supplies in Arizona are becoming increasingly limited because municipal, industrial, and agricultural consumption depletes ground water reserves by three million acre-feet annually. Additional demands are being created by electric power generation, particularly in northeastern Arizona where ground water pumpage is expected to escalate by sixfold during the next 10 years. The results of a study to determine the ease and feasibility of using satellite imagery as a tool in exploring for new sources of ground water are reported. Lineaments detected on Landsat images of two sites were mapped and correlated with well data in the two study areas by means of well centered grid model. The correlations developed between lineament density and water well data in the two study sites support the hypothesis that a relationship exists between regional geologic structure and the presence of ground water.     

The use of Landsat multispectral scanner data for the analysis and management of flooding on the river Severn,England

Remote sensing has emerged as one of the major techniques for the analysis and delineation of large floods. This analysis can provide data invaluable for the hydrological management of large river systems. A need for information on the extent of floodplain inundation for the lower reaches of the largest river in the UK was met by a search through Landsat images of floods and the analysis of the best example recorded. Automated classification of the Landsat imagery of this flood on the river Severn in 1977 was used to provide estimates of the extent and spatial distribution of inundation. Flood images were generated using the Plessey IDP 3000 image processor, and the maps derived accorded well with aerial photography and qualitative flood information. Three distinct floodplain environments were delineated and flood images produced by different spectral bands compared. Specific questions prompted by flood hazard management and concerning the processes and extent of flooding were answered by the Landsat data analysis. Management of the flood risk of large rivers is expensive and remote sensing data is a relatively cheap and effective way of monitoring control works and providing data for the prediction of the effects of future hydrological works. Remote sensing is a practical way in which spatial information concerning the behavior of large dynamic systems can be obtained both quickly and relatively cheaply.     

THE IMPACT OF PRESSURE SEWERS ON THE NATION'S WATER RESOURCES1

ABSTRACT. Over the last few years, several studies sponsored by both government and interested national engineering associations have evaluated the relative merits of pressure sewer systems. Surprisingly little data has been forthcoming, however, with regard to the effects of pressure sewers on both the economics of land development and the country's water resources. The intention of our paper is to detail the salutary effects of pressure sewers on water supply resources, the indirect effect on other resources by decreasing the contribution of sanitary sewage to their pollution, and to illustrate where, in some locations of the country, pressure sewers would benefit the economics of land development. As engineers from a large industrial firm that has built hardware that will allow the concepts stated above to become realities, we will present data to enforce our convictions. Some effects on municipal treatment plants, and emplacement costs of the system are described. Since the main thrust of our paper is to treat the effect of pressure sanitary sewers on the water resources of the country, specific peripheral data is not presented at length. The pressure sewer effects on lowering water usage in homes and the decrease in groundwater contamination by replacing septic tanks with pressure sewers in selected locations is presented. Advanced technology concepts such as energy assisted sewer systems should be considered as a favorable economic manner in which to preserve selected water resources. During the 1965 drought that affected the Northeastern section of the U.S., a federal government document reported that there was really no shortage of water, but that present water resources lacked management. Pressure sewers may be a water resources management tool and an effective one if not promulgated as a cure-all for the water pollution problems facing this nation.     

THE RELATIONSHIP BETWEEN THE TIME BASES OF SIMULATION MODELS AND THEIR STRUCTURE1

ABSTRACT: The time base of a simulation model can be defined as a combination of two time intervals. One is the interval used for input and internal computations. The second is the interval used for the output and calibration of the model. The time base of a model is related on the one hand to the type of applications for which the simulated data are used, and on the other hand to the structure and complexity of the model. The latter may be represented by the number of parameters employed to specify the operation of the model. Using data typical to relatively small watersheds in a semiarid climate, the interaction between the complexity of a series of models and the time bases used by them was studied. This included the effects of the two factors, time base and complexity, on the values of the optimal parameters, prediction of mean annual flow, and general performance of the models. The main conclusion is that if the acceptable time base is longer, the model can be less complex needing fewer parameters. There is also an advantage in using a time base comprising a shorter input time interval and a longer output time interval.     

ASSESSMENT OF REMOTE SENSING INPUT TO HYDROLOGIC MODELS1

Remotely sensed variables such as land cover type and snow-cover extent can currently be used directly and effectively in a few specific hydrologic models. Regression models can also be developed using physiographic and snow-cover data to permit estimation of discharge characteristics over extended periods such as a season or year. Most models, however, are not of an appropriate design to readily accept as input the various types of remote sensing parameters that can be obtained now or in the future. Because this new technology has the potential for producing hydrologic data that has significant information content on an areal basis, both inexpensively and repetitively, effort should be devoted now to either modifying existing models or developing new models that can use these data. Minor modifications would at least allow the remote sensing data to be used in an ancillary way to update the model state variables, whereas major structural modifications or new models would permit direct input of the data through remote sensing compatible algorithms. Although current remote sensing inputs to hydrologic models employ only visible and near infrared data, model modification or development should accommodate microwave and thermal infrared data that will be more widely available in the future.     

USE OF MICROCOMPUTERS FOR THE MANAGEMENT OF WATER QUALITY DATA1

ABSTRACT: Information on raw water quality, treatment process removal efficiency, and distribution system monitoring is essential to the proper management and operation of a water utility system. Microcomputer hardware and software systems using commercially available data base management systems (DBMS) have emerged within the last few years as an effective means of managing, analyzing, and displaying water quality data. Understanding hardware, software, and training requirements is essential to the proper use of these systems. Three types of data base design are common: relational, hierarchical, and network. Only the relational type of data base architecture is widely implemented on microcomputer DBMS. In this paper two examples of the application of DBMS to water utility problems are presented. One example deals with collection and analysis of data concerning the water quality of the Mississippi River. The second example deals with the DBMS as a means of analyzing water quality data in the North Penn Water Authority (NPWA) distribution system.     

Remote Sensing of Landscape-Level Coastal Environmental Indicators

Advances in technology and decreases in cost are making remote sensing (RS) and geographic information systems (GIS) practical and attractive for use in coastal resource management. They are also allowing researchers and managers to take a broader view of ecological patterns and processes. Landscape-level environmental indicators that can be detected by Landsat Thematic Mapper (TM) and other remote sensors are available to provide quantitative estimates of coastal and estuarine habitat conditions and trends. Such indicators include watershed land cover, riparian buffers, shoreline and wetland changes, among others. With the launch of Landsat 7, the cost of TM imagery has dropped by nearly a factor of 10, decreasing the cost of monitoring large coastal areas and estuaries. New satellites, carrying sensors with much finer spatial (1-5 m) and spectral (200 narrow bands) resolutions are being launched, providing a capability to more accurately detect changes in coastal habitat and wetland health. Advances in the application of GIS help incorporate ancillary data layers to improve the accuracy of satellite land-cover classification. When these techniques for generating, organizing, storing, and analyzing spatial information are combined with mathematical models, coastal planners and managers have a means for assessing the impacts of alternative management practices.     

DEVELOPMENT OF EARTH SATELLITE TECHNOLOGY FOR THE TELEMETRY OF HYDROLOGIC DATA1

ABSTRACT The use of satellite telemetry is playing a major role in the collection of hydrologic data. Advancing technology and availability of government satellites have permitted many agencies to take advantage of new procedures for acquiring data from automated remote data collection stations. Experiments with Earth satellite technology started in the 1960's and 1970's, with the polar-orbiting National Aeronautics and Space Administration Nimbus and Landsat satellites. Subsequent advancements took place through the development phase to operational systems using the Geostationary Operational Environmental Satellite (GOES) of the National Oceanic and Atmospheric Administration. This satellite system supports more than 2,500 active telemetry sites, of which approximately 1,200 are Geological Survey stream-gaging stations for the collection of hydrologic data. A satellite data collection system is made up of three primary components; a small battery-operated radio, and Earth-orbiting satellite, and an Earth receive and data processing station. The data relay satellites' vast aerial view of the Earth's surface gives satellite telemetry a large advantage over ground-based systems for the collection of real-time hydrologic data for flood warning, reservoir management, irrigation water control, hydropower generation, and the operation of hydrologic stations.     

EFFECTIVE USE OF LANDSAT DATA IN HYDROLOGIC MODELS1

ABSTRACT: In a cooperative demonstration project, NASA and the U.S. Army Corps of Engineers (Corps) compared conventional and Landsat-derived land-use data for use in hydrologic models, and the resulting discharge frequency curves were analyzed. When a grid-based data-management system was used on a cell-by-cell basis (size about 1.1 acres or 0.45 hectare), Landsat classification accuracy was only 64 percent, but, when the grid cells were aggregated into watersheds, the classification accuracy increased to about 95 percent. When both conventional and Landsat land-use data were input to the HEC-1 model for generating discharge frequency curves, the differences in calculated discharge were judged insignificant for subbasins as small as 1.0mi² (2.59 km²). For basins larger than 10mi² (25.9km²), use of the Landsat approach is more cost-effective than use of conventional methods. Digital Landsat data can also be used effectively by local and regional agencies for hydrologic analysis by incorporating the data into grid-based data-management systems. The transfer of this new technology is well under way through inclusion in some Corps training courses and through use by both county government personnel and private consultants.