Search results for "streamflow"
showing 10 items of 25 documents
Chapter 3 patterns and thresholds of runoff generation and sediment transport on some Mediterranean hillslopes
2005
Abstract Runoff and sediment transport data obtained from hillslopes in two limestone areas in southeast Spain are analysed in order to define spatial and temporal thresholds for sediment movement at the patch scale under Mediterranean semiarid and subhumid climatological conditions. The data discussed in this paper include a 7-year series of runoff and sediment collection in open Gerlach plots. The 136 events are analysed in relation to characteristics of rainfall, soil and soil surface components. In both cases slopes behave as a patchwork of runoff and runon areas and the size of the runoff or runon patches being dependent on the climatological conditions. These control the hydrological …
Climate change impact on SWAT simulated streamflow in western Kenya
2009
12 pages (3/4 p.); International audience; Weather and climate extremes such as droughts and floods have far reaching impacts in Kenya. They have had implications in a variety of sectors including agriculture, water resources, health, energy, and disaster management among others. Lake Victoria and its catchment support millions of people and any impact on its ability to support the livelihoods of the communities in this region is of major concern. Thus, the main objective of this study was to assess the potential future climatic changes on the Nzoia catchment in the Lake Victoria basin, and how they might affect streamflow. The Soil and Water Assessment Tool was used to investigate the impa…
Introduction to Hydrology
2013
Hydrology deals with the occurrence, movement, and storage of water in the earth system. Hydrologic science comprises understanding the underlying physical and stochastic processes involved and estimating the quantity and quality of water in the various phases and stores. The study of hydrology also includes quantifying the effects of such human interventions on the natural system at watershed, river basin, regional, country, continental, and global scales. The process of water circulating from precipitation in the atmosphere falling to the ground, traveling through a river basin (or through the entire earth system), and then evaporating back to the atmosphere is known as the hydrologic cyc…
Economic Aspects of the Conjunctive Use of Ground and Surface Water
1989
Abstract The different structure of the costs of ground and surface water and the different and complementary characteristics of both kinds of resources make it possible to solve the specific needs of water quantity and quality more adequately and economically if both resources are used conjunctively. Higher discount rates favour the inclusion of elements involving lower initial investment and generally with higher groundwater components. Lower discount rates favour a higher participation of surface water. The external factors produced by groundwater pumping must be taken into consideration in any economic analysis. Examples of external factors are water level descents, surface water flow r…
Screening of currently used pesticides in water, sediments and biota of the Guadalquivir River Basin (Spain)
2013
The occurrence of 50 currently used pesticides and their transformation products in surface and waste waters, sediment and fish in the Guadalquivir River Basin was determined in 2010 and 2011. After selective sample extraction, pesticides were identified and quantified by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The contamination profile in water and sediments is marked by the presence of organophosphorus and triazines. Transformation products were even at higher concentrations than parent pesticides. A wider range of pesticides was present in water than in sediments but none of them were detected in fish. The mean concentrations ranged from 0.2 to 13.0 ng/L in …
Climate change impacts on river runoff in Latvia
2011
In order to assess climate change impacts on river runoff patterns at the end of this cen- tury, the hydrological model METQ2007BDOPT was applied to 8 river basins and sub-basins in Latvia, which is a part of the southeast Baltic Sea basin. The climate data we used originate from the PRUDENCE project and were prepared in a separate study. Changes in hydro-climate were analysed using one control run (1961-1990) and 2 IPCC scenario runs (A2 and B2; 2071-2100). For the A2 sce- nario, both annual and seasonal analysis predicted the major significant changes in most cases. For both scenarios, an increase of the mean annual climate data (air temperature, precipitation and evapo - transpiration) i…
Modeling the Effects of Climate Change on Catchment Hydrology with the GWLF Model
2009
The influence of catchment hydrology on the volume and timing of water inputs to waterbodies, and on the material loads of nutrients, sediment, and pollutants is central to any assessment of the impact of climate change on lakes. Changes in the timing and amount of precipitation, particularly when coupled with a change in air temperature, influence all the major components of the hydrological cycle, including evapotranspiration, snow dynamics, soil moisture, groundwater storage, baseflow, surface runoff, and streamflow.
Impact of climate variability, drainage and land-cover changes on hemiboreal streamflow
2017
ABSTRACTThe aim of the study was to determine the effects of climate variability, agricultural land drainage and afforestation of agricultural land on river discharge. The study was conducted in the Vienziemīte stream basin (6 km2), where discharge was monitored on a daily basis during the time period of 1946–2010. In the stream basin, natural afforestation of agricultural land began in the 1950s, and in the mid-1970s artificial drainage systems were installed in all agricultural land (70% of the total basin area). Climate variability and artificial drainage were the main factors observed to be affecting stream discharge. The changes were most evident in annual and seasonal mean, minimum an…
Basin-Scale Water Resources Assessment in Oklahoma under Synthetic Climate Change Scenarios Using a Fully Distributed Hydrologic Model
2010
Climate change resulting from the enhanced greenhouse effect is expected to have significant implications for the hydrological cycle. Several studies have pointed out the importance of basin-scale investigations for determining regional impacts on water resources, including the effects of floods and droughts. In this study, a fully distributed hydrologic model is used to assess the potential impacts of climate change on water availability in a basin in Oklahoma United States . With this aim, the hydrologic model was applied for current conditions as well as under the hypotheses of climate variations represented by scenarios consistent with a climatic trend analysis generated using a stochas…
Runoff generation, sediment movement and soil water behaviour on calcareous (limestone) slopes of some Mediterranean environments in southeast Spain
2003
Abstract An interpretation of soil hydrology and erosion data obtained from limestone areas in southeast Spain is presented in the framework of recent hypotheses on runoff generation mechanisms in Mediterranean environments. The main objective is to synthesise and harmonise the data in theoretical concepts or behavioural models of hydrological functioning of Mediterranean limestone slopes. For this purpose, data were collected in a typical limestone area, with climatic characteristics ranging from subhumid to semiarid. Several sites were chosen with comparable slopes, vegetation and soils along a transect of 20 km to carry out several research projects. The data discussed in this paper cons…