Showing papers on "Water cycle published in 1977"

Climate, water, and agriculture in the tropics

Abstract: Part 1 Water in the tropics: evaporation and rainfall the hydrological cycle. Part 2 Origins of precipitation: the tropical circulation sub-tropical highs trade winds the equatorial trough the south-east Asian monsoon El Nino and the southern oscillation. Part 3 Rainfall seasonality and variability: seasonal rainfall regimes drought fluctuations and trends. Part 4 Other rainfall characteristics: intensity-duration-frequency spatial and diurnal variations runoff. Part 5 Evaporation: relation to rainfall climatic classification. Part 6 Water and plants - a general review: the significance of water to plants the atmosphere-soil-plant water system. Part 7 Water and plants - the tropical situation: the implications of the nature of tropical rainfall and of the high evaporative demand water-yield relationships. Part 8 Water and agriculture in the tropics: water-balance studies the role of agricultural techniques in crop-water relations rainfall regimes and crops. Part 9 Human impact on the hydrological cycle: modification of climactic factors land use and the hydrological cycle forest cover and the effects of change grazing modifications to surface water and ground water. Part 10 Problems and priorities: scientific and technical aspects the human element. References. Index.

Water at the surface of the earth : an introduction to ecosystem hydrodynamics

Abstract: Preface Chapter I Introduction Just What is the Earth's Surface? The Budget Idea Water in Systems Water Supplied by the Atmosphere to the Earth's Surface Chapter II Atmospheric Vapor Flows and Atmospheric Storms Water Vapor and Its Movement over the Earth's Surface Atmospheric Storms Sizes and Movement of Atmospheric Storms Atmospheric Storms: Causes of Variability in Rainfall References Chapter III Point Rainfall-The Delivery of Water to an Ecosystem Measuring Rain and Snow The Dimensions of Point Rainfall The Frequency of Precipitation-Intensity Events Water Delivery to Ecosystems References Chapter IV Hydrologic Storms The Area of Hydrologic Storms Areal Syntheses The Episodic Occurrence of Hydrologic Storms Closing References Chapter V Large-Scale Organization of Rainfall Organization of Storms in Time Spatial Grouping of Rainfall Spatial Pattern of Annual Precipitation Areal Pattern of Long-Term Changes in Rainfall Associated Mass Fluxes Time and Space Organization of the Water Delivered to Ecosystems References Chapter VI Reception of Water by Ecosystems Ecosystem Hydrodynamics Delivery of Rain and Snow to Vegetation Interception of Water by Vegetation Storage of Rain and Snow on Foliage during Storms The Outflows from Interception Storage of Rain and Snow Evaporation as a Mode of Outflow from Interception Storage Water Intercepted by Litter Areal Redistribution of Water by Vegetation above the Soil References Chapter VII Water Detained on the Soil Surface Snow Cover Liquid Water on the Ground Outflows from Detention Storage References Chapter VIII Infiltration of Water into the Soil of an Ecosystem The Soil as Environment of Water Infiltration of Water into the Soil Influences of Vegetation on Infiltration Time Differences in Infiltration Infiltrated Water in Ecosystems References Chapter IX Soil Moisture Soil-Moisture Bookkeeping Soil-Moisture Distributions in Space Time Variations of Soil Moisture Freezing and Melting of Soil Water Outflows of Water from the Soil References Chapter X Evaporation from Wet Surfaces Determining Evaporation Rates Evaporation from Deep Water Bodies Evaporation from Shallow Water Bodies Evaporation from a Wet Soil Surface Evaporation References Chapter XI Evaporation from Well-Watered Ecosystems Transpiration of Water from Leaves Evapotranspiration from Plant Communities Empirical Patterns of Potential Evapotranspiration Evaporation Differs with Ecosystems References Chapter XII Evaporation from Drying Ecosystems Bare Soil Surfaces Evapotranspiration from a Drying Soil-Vegetation System Variations in Evapotranspiration over Time Large-Scale Patterns The Era of Evaporation References Chapter XIII Water in the Local Air Water Vapor in the Local Air Visible Forms of Water in the Local Air Condensation of Vapor on the Underlying Surface References Chapter XIV Percolation from Ecosystems Shallow Percolation Deeper Percolation Mass Transports by Percolating Water Significance of Percolation Percolation and Recharge References Chapter XV Groundwater and Its Outflows into Local Ecosystems The Environments of Groundwater Groundwater Recharge The Volume of Stored Underground Water Mass Budgets Associated with Groundwater Local Outflows of Water from Underground Storage Artificial Outflows from Underground Storage Groundwater Budgets References Chapter XVI Surface Transports from Ecosystems Movement of Snow Gravity-Powered Movement of Liquid Water Other Forms of Mass Transport Associated with the Flow of Water at and near the Surface Time Variations in Off-Site Flow Off-Site Flows from Ecosystems References Chapter XVII Off-Site Yield of Ecosystems Outflows from Groundwater Storage Water Yield as Associated with Biological Yield Total Off-Site Movement of Water Total Yield References Chapter XVIII Water in Ecosystems Environments of Water in Ecosystems Unknowns and Uncertainties in Water Budgets Patterns of Distribution Water is Everywhere References Index

Hydrology and Water Quality in the Central Kentucky Karst: Phase 1

Abstract: Study of springs and cave streams has shown that heavy metal-rich effluent from a wastewater treatment plant can be traced to Hidden River Cave (beneath the city of Horse Cave) and thence 4 to 5 miles north to a group of 39 springs at 14 locations along a 5-mile reach of Green River. Nickel, chromium, copper and zinc in these effluent-bearing springs are in concentrations of as much as 30 times greater than other springs upstream and downstream from this reach, 20 times greater than the Green River, and 60 times greater than in shallow domestic wells between Horse Cave and the river. Mean concentration ratios, based on samples taken during moderate to flood flow, are considerably lower. Although the heavy metal content of the effluent-bearing stream in Hidden River Cave greatly exceeds various maximum concentrations set by current standards, the concentrations in the effluent-bearing springs do not exceed current maximums allowed for public water supplies. None of the domestic shallow wells between the cave and the river intercept this effluent-rich water. The distributary system that was postulated to feed the 39 springs was entered by digging in June 1975; 14.6 miles of this floodwater maze has been mapped. Water tracing over distances of as much as 15 miles has made it possible to delineate thirteen groundwater basins, eleven of them characterized by distributary flow. Study of the water quality· of five adjacent groundwater basins showed that they could be geochemically differentiated. One of these, the Three-Springs Groundwater Basin, has a distributary complex that is 2.4 miles wide and its discharge is believed to be affected by brines released by drilling. Dendritic flow paths, identified by dye-traces to and from caves (and mapping of these caves), have been recognized in the Turnhole Spring Groundwater Basin (Quinlan, 1976) and the Graham Springs Groundwater Basin. Flow converges to trunk streams as much as 40 ft wide that may rise and fall as much as 100 ft in response to heavy rains. Groundwater velocities in the upper part of the principal aquifer range from 30 ft per hour to 1300 ft per hour, depending upon the duration and intensity of rains. Recorrmendations are made for: l) the use of drainage basin maps for regional planning and protection of water supplies, 2) protection of other water supplies, and 3) development of specific springs as potential public water supplies. DESCRIPTORS: Water Cycle, Water Quantity Management and Control, Water Quality Management and Protection IDENTIFIERS: *Karst, *Kentucky, *Caves, *Limestone, *Tracers, *Dyes, Optical Brighteners, Springs, Heavy Metals, Water Pollution, *Groundwater

Reducing transpiration to conserve water in soil and plants

Abstract: Not Available – First paragraph follows: A major pathway of water loss from plants is by transpiration, which accounts for 99 percent of the water taken up by plant roots. This water is lost from the immediate area where the plant is growing, since it passes via the atmosphere to some other point in the hydrologic cycle. Because the water that is transpired is essentially pure, salts in the soil water system become more concentrated.

A general description of estuarine behaviour

Abstract: The hydrological cycle begins and ends in the sea. The first stage in the cycle is evaporation of water from the surface of the sea and the last stage is the return of water to the sea through rivers. Most rivers enter the sea where there is enough tidal rise and fall to modify flow near their mouths. The part of the river system in which the river widens under the influence of tidal action is the estuary, but the behaviour of the estuary is influenced by the circulation of water and solids in the sea as well as by the whole tidal part of the river system. The estuary cannot be considered in isolation; the whole system has many inter-dependent parts, extending from the landward limit of the tidal rivers forming it to a point offshore beyond which the effect of an individual estuary on water circulation and sediment movement can no longer be discerned.

Some observations concerning the change in the hydrological cycle caused by irrigation

Abstract: Irrigation causes the most drastic change in the short stretch of the hydrological cycle which crosses the unsaturated zone and influences evapotranspiration. On the basis of theoretical studies and observed data a characteristic curve of the groundwater balance was established to describe hydrological phenomena above the water table. Examples of this curve in semi-arid and humid regions illustrate how the unsaturated zone is modified under irrigated conditions. Seasonal fluctuation of water table and moisture content and evapotranspiration on the basis of hydrological and meteorological observations are demonstrated, and conclusions are reached concerning the summer deficit of evapotranspiration and surface evaporation under irrigated condition.