scholarly journals Czasowa zmienność i przestrzenne zróżnicowanie ewapotranspiracji w zlewni nizinnej rzeki Łasicy

2021 ◽  
Vol 66 (3) ◽  
pp. 35-46
Author(s):  
Urszula Somorowska
Keyword(s):  
Surface Energy Balance ◽  
Water Cycle ◽  
Spatial Differentiation ◽  
Remote Sensing Data ◽  
Growing Season ◽  
Catchment Scale ◽  
Water Demands ◽  
Agricultural Areas ◽  
Accurate Quantification

Accurate quantification of evapotranspiration is necessary for understanding the water cycle at a local scale. At catchment scale, evapotranspiration might be approximated using remote sensing data useful in spatialtemporal analyses. In this study, the long-term and seasonal variability of evapotranspiration in the Łasica River catchment in the years 2003–2020 was assessed on the basis of data acquired from the SSEBop project (Operational Simplified Surface Energy Balance). Additionally, using the index of precipitation utilization (WWO), the degree of precipitation consumption for the water demands of plants was determined. The highest evapotranspiration occurs in forest areas, slightly lower in marshy belts covered with meadow vegetation, and the lowest in agricultural areas and anthropogenically transformed areas. The spatial differentiation of evapotranspiration is particularly marked during the growing season, from April to October. Mean annual evapotranspiration sum is 403 mm, of which 96% falls on the growing season. Extremely low annual ET sums occurred in 2015 (329 mm), 2019 (342 mm) and 2003 (384 mm), while particularly high – in 2010 (455 mm) and 2013 (447 mm). In dry years, WWO is even 71–77%, while in particularly wet years, WWO is much lower and amounts to 54–58%.

scholarly journals Observed and simulated hydroclimatology using distributed hydrologic model from in-situ and multi-satellite remote sensing datasets in Lake Victoria region in East Africa

2010 ◽  
Vol 7 (4) ◽  
pp. 4785-4816 ◽  
Author(s):  
S. I. Khan ◽  
P. Adhikari ◽  
Y. Hong ◽  
H. Vergara ◽  
T. Grout ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Satellite Remote Sensing ◽  
Water Cycle ◽  
Lake Victoria ◽  
Remote Sensing Data ◽  
Hydrologic Model ◽  
East African ◽  
Catchment Scale ◽  
Distributed Hydrologic Model

Abstract. Floods and droughts are common, recurring natural hazards in East African nations. Studies of hydro-climatology at daily, seasonal, and annual time scale is an important in understanding and ultimately minimizing the impacts of such hazards. Using daily in-situ data over the last two decades combined with the recently available multiple-years satellite remote sensing data, we analyzed and simulated, with a distributed hydrologic model, the hydro-climatology in Nzoia, one of the major contributing sub-basins of Lake Victoria in the East African highlands. The basin, with a semi arid climate, has no sustained base flow contribution to Lake Victoria. The short spell of high discharge showed that rain is the prime cause of floods in the basin. There is only a marginal increase in annual mean discharge over the last 21 years. The 2-, 5- and 10-year peak discharges, for the entire study period showed that more years since the mid 1990's have had high peak discharges despite having relatively less annual rain. The study also presents the hydrologic model calibration and validation results over the Nzoia Basin. The spatiotemporal variability of the water cycle components were quantified using a physically-based, distributed hydrologic model, with in-situ and multi-satellite remote sensing datasets. Moreover, the hydrologic capability of remote sensing data such as TRMM-3B42V6 was tested in terms of reconstruction of the water cycle components. The spatial distribution and time series of modeling results for precipitation (P), evapotranspiration (ET), and change in storage (dS/dt) showed considerable agreement with the monthly model runoff estimates and gauge observations. Runoff values responded to precipitation events that occurred across the catchment during the wet season from March to early June. The hydrologic model captured the spatial variability of the soil moisture storage. The spatially distributed model inputs, states, and outputs, were found to be useful for understanding the hydrologic behavior at the catchment scale. Relatively high flows were experienced near the basin outlet from previous rainfall, with a new flood peak responding to the rainfall in the upper part of the basin. The monthly peak runoff was observed in the months of April, May and November. The analysis revealed a linear relationship between rainfall and runoff for both wet and dry seasons. The model was found to be useful in poorly gauged catchments using satellite forcing data and showed the potential to be used not only for the investigation of the catchment scale water balance but also for addressing issues pertaining to sustainability of the resources within the catchment.

scholarly journals The MUSICA MetOp/IASI H<sub>2</sub>O and δD products: characterisation and long-term comparison to NDACC/FTIR data

2014 ◽  
Vol 7 (4) ◽  
pp. 3915-3952 ◽  
Author(s):  
A. Wiegele ◽  
M. Schneider ◽  
F. Hase ◽  
S. Barthlott ◽  
O. E. García ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Water Vapour ◽  
Water Cycle ◽  
Remote Sensing Data ◽  
Global Scale ◽  
Atmospheric Composition ◽  
Complex Nature ◽  
Quality Assessment Study ◽  
Complementary Value

Abstract. Within the project MUSICA (MUlti-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water) ground- and space-based remote sensing as well as in-situ datasets of tropospheric water vapour isotopologues are provided. The space-based remote-sensing dataset is produced from spectra measured by the IASI (Infrared Atmospheric Sounding Interferometer) sensor and is potentially available on a global scale. Here, we present the MUSICA IASI data for three different geophysical locations (subtropics, mid-latitudes, and arctic) and we provide a comprehensive characterisation of the complex nature of such space-based isotopologue remote sensing products. The quality assessment study is complemented by a comparison to MUSICA's ground-based FTIR (Fourier-Transform InfraRed) remote sensing data retrieved from the spectra recorded at three different locations within the framework of NDACC (Network for the Detection of Atmospheric Composition Change). We confirm that IASI is able to measure tropospheric H2O profiles with a vertical resolution of about 4 km and a random error of about 10%. In addition IASI can observe middle tropospheric δD that adds complementary value to IASI's middle tropospheric H2O observations. Our study is both, a theoretical and an empirical proof that IASI has the capability for a global observation of middle tropospheric water vapour isotopologues on a daily timescale and at a quality that is sufficiently high for water cycle research purposes.

scholarly journals Changes in growing season duration and productivity of northern vegetation inferred from long-term remote sensing data

2016 ◽  
Vol 11 (8) ◽  
pp. 084001 ◽  
Author(s):  
Taejin Park ◽  
Sangram Ganguly ◽  
Hans Tømmervik ◽  
Eugénie S Euskirchen ◽  
Kjell-Arild Høgda ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Remote Sensing Data ◽  
Growing Season ◽  
Sensing Data

scholarly journals Can we trust remote sensing ET products over Africa?

2019 ◽  
Author(s):  
Imeshi Weerasinghe ◽  
Ann van Griensven ◽  
Wim Bastiaanssen ◽  
Marloes Mul ◽  
Li Jia
Keyword(s):  
Remote Sensing ◽  
Water Cycle ◽  
Temporal Distribution ◽  
Remote Sensing Data ◽  
Global Scale ◽  
Data Availability ◽  
Systematic Evaluation ◽  
Basin Scale ◽  
Long Term Trends

Abstract. Evapotranspiration (ET) is one of the most important components in the water cycle. However, there are relatively few direct measurements of ET (using flux towers), whereas various disciplines ranging from hydrology to agricultural and climate sciences, require information on the spatial and temporal distribution of ET at regional and global scale. Due to limited data availability, attention has turned toward satellite based products to fill observational gaps. Various remote sensing data products have been developed, providing a large range of ET estimations. Across Africa only a limited number of flux towers are available which are insufficient for systematic evaluation of remotely sensed (RS) derived ET products. Thus we propose a methodology for evaluating RS derived ET data at the basin scale using a general water balance (WB) approach, where ET is equal to precipitation minus discharge for long-term annual averages. Firstly, RS ET products are compared with WB inferred ET for basins without long-term trends present. The RS products are then assessed according to spatial characteristics through analysing two land cover elements across Africa, irrigated areas and water bodies. A cluster analysis is also conducted to identify similarities between individual ET products. Finally, the RS products are evaluated against the Budyko equation. The results show that CMRSET, SSEBop and WaPOR rank highest in terms of estimation of long-term annual average mean ET across basins with low biases. Along with ETMonitor, the same three products rank highest in spatial distribution of ET patterns across Africa. GLEAM and MOD16 consistently rank the lowest in most criteria evaluation. Many of the products analysed in this study can be trusted depending on the study under question, keeping in mind some of these products have large biases in magnitude estimation. However our recommendation would be the three highest ranked products being CMRSET, SSEBop and WaPOR.

scholarly journals The relevance of glacier melt in the water cycle of the Alps: an example from Austria

2010 ◽  
Vol 7 (3) ◽  
pp. 2897-2913 ◽  
Author(s):  
G. R. Koboltschnig ◽  
W. Schöner
Keyword(s):  
Hydrological Model ◽  
Water Cycle ◽  
Point Of View ◽  
Hydrological Models ◽  
Catchment Scale ◽  
Ice Melt ◽  
Glacier Melt ◽  
The Alps ◽  
The Mean

Abstract. This paper gives an overview on available methods how the contribution of glacier melt to runoff can be calculated with and without glaico-hydrological models. Further we applied an approach, which shows the potential of glacier melt contribution during the extreme hot and dry summer of 2003 by calculating the quotient qA03 of the mean monthly August runoff in 2003 and the long-term mean August runoff. The extreme summer 2003 was worth to be analysed as from the meteorological and glaciological point of view an extraordinary situation was observed. During June and July nearly the entire snow-cover melted and during the hot and dry August mainly ice melt of glaciers contributed to runoff. The mean runoff in August 2003 was calculated from observed mean daily runoff data of a selected period in August 2003 (3 to 27 August). This was done for 27 Austrian gauging stations in the glacierized basins of the rivers Inn, Salzach and Drau with a degree of glaciation between 2 and 76%. The quotient qA03 was calculated between 0.63 and 1.82, which means for the lower value that only 63% of the long-term mean August runoff and for the higher value 82% more than the long-term mean August runoff was observed in 2003. Additionally two stations at river Danube (0.4 and 1% glacierized) and further six gauging stations in catchments with no glacier cover were investigated to define qA03 quotients for non-glacierized basins. These qA03 quotients were calculated between 0.31 and 0.54. Hence, it was possible to qualitatively visualize the decreasing impact of glacier melt for a decreasing degree of glaciation. Nevertheless, for the accurate calculation of the glacier melt contribution for a certain catchment scale and time a glaio-hydrological model is needed.

scholarly journals Hydroclimatology of Lake Victoria region using hydrologic model and satellite remote sensing data

2011 ◽  
Vol 15 (1) ◽  
pp. 107-117 ◽  
Author(s):  
S. I. Khan ◽  
P. Adhikari ◽  
Y. Hong ◽  
H. Vergara ◽  
R. F Adler ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Satellite Remote Sensing ◽  
Water Cycle ◽  
Lake Victoria ◽  
Remote Sensing Data ◽  
Hydrologic Model ◽  
Catchment Scale ◽  
Hydro Climatology ◽  
Peak Discharges

Abstract. Study of hydro-climatology at a range of temporal scales is important in understanding and ultimately mitigating the potential severe impacts of hydrological extreme events such as floods and droughts. Using daily in-situ data over the last two decades combined with the recently available multiple-years satellite remote sensing data, we analyzed and simulated, with a distributed hydrologic model, the hydro-climatology in Nzoia, one of the major contributing sub-basins of Lake Victoria in the East African highlands. The basin, with a semi arid climate, has no sustained base flow contribution to Lake Victoria. The short spell of high discharge showed that rain is the prime cause of floods in the basin. There is only a marginal increase in annual mean discharge over the last 21 years. The 2-, 5- and 10- year peak discharges, for the entire study period showed that more years since the mid 1990's have had high peak discharges despite having relatively less annual rain. The study also presents the hydrologic model calibration and validation results over the Nzoia basin. The spatiotemporal variability of the water cycle components were quantified using a hydrologic model, with in-situ and multi-satellite remote sensing datasets. The model is calibrated using daily observed discharge data for the period between 1985 and 1999, for which model performance is estimated with a Nash Sutcliffe Efficiency (NSCE) of 0.87 and 0.23% bias. The model validation showed an error metrics with NSCE of 0.65 and 1.04% bias. Moreover, the hydrologic capability of satellite precipitation (TRMM-3B42 V6) is evaluated. In terms of reconstruction of the water cycle components the spatial distribution and time series of modeling results for precipitation and runoff showed considerable agreement with the monthly model runoff estimates and gauge observations. Runoff values responded to precipitation events that occurred across the catchment during the wet season from March to early June. The spatially distributed model inputs, states, and outputs, were found to be useful for understanding the hydrologic behavior at the catchment scale. The monthly peak runoff is observed in the months of April, May and November. The analysis revealed a linear relationship between rainfall and runoff for both wet and dry seasons. Satellite precipitation forcing data showed the potential to be used not only for the investigation of water balance but also for addressing issues pertaining to sustainability of the resources at the catchment scale.

Selective statistical estimates of multi-year monthly concentrations of biogenous pollution of small rivers of the Northwest zone of the Russian Federation

2020 ◽  
pp. 9-13
Author(s):  
Sergey Kovalenko
Keyword(s):  
Statistical Processing ◽  
Point Of View ◽  
Small Rivers ◽  
Statistical Parameters ◽  
Monthly Data ◽  
Statistical Estimates ◽  
Scientific Task ◽  
The Russian Federation ◽  
Agricultural Areas

The management of surface watercourses is an urgent scientific task. The article presents the results of statistical processing of long-term monthly data of field observations of hydrological and hydrochemical parameters along the Upper Yerga small river in the Vologda region. Sampling estimates of statistical parameters are obtained, autocorrelation and correlation analyzes are performed. The limiting periods from the point of view of pollution for water receivers receiving wastewater from drained agricultural areas are identified.

River Quality Models for Consent Setting in England and Wales

1989 ◽  
Vol 21 (8-9) ◽  
pp. 1015-1024 ◽  
Author(s):  
C. P. Crockett ◽  
R. W. Crabtree ◽  
I. D. Cluckie
Keyword(s):  
River System ◽  
Quality Model ◽  
Catchment Scale ◽  
Quality Models ◽  
England And Wales ◽  
Future Developments ◽  
Statistical Framework ◽  
River Quality ◽  
National Approach

In England and Wales the placing of effluent discharge consents within a statistical framework has led to the development of a new hybrid type of river quality model. Such catchment scale consent models have a stochastic component for the generation of model inputs and a deterministic component to route them through the river system. This paper reviews and compares the existing approaches for consent modelling used by various Water Authorities. A number of possible future developments are suggested including the potential need for a national approach to the review and setting of long term consents.

scholarly journals Topoclimate Mapping Using Landsat ETM+ Thermal Data: Wolin Island, Poland

2021 ◽  
Vol 13 (14) ◽  
pp. 2712
Author(s):  
Marta Ciazela ◽  
Jakub Ciazela
Keyword(s):  
Land Surface ◽  
Meteorological Data ◽  
Remote Sensing Data ◽  
Animal Husbandry ◽  
Boundary Layer Processes ◽  
Lowland Area ◽  
Agricultural Areas ◽  
Glacial Landforms ◽  
Climatic Pattern

Variations in climatic pattern due to boundary layer processes at the topoclimatic scale are critical for ecosystems and human activity, including agriculture, fruit harvesting, and animal husbandry. Here, a new method for topoclimate mapping based on land surface temperature (LST) computed from the brightness temperature of Landsat ETM+ thermal bands (band6) is presented. The study was conducted in a coastal lowland area with glacial landforms (Wolin Island). The method presented is universal for various areas, and is based on freely available remote sensing data. The topoclimatic typology obtained was compared to the classical one based on meteorological data. It was proven to show a good sensitivity to changes in topoclimatic conditions (demonstrated by changes in LST distribution) even in flat, agricultural areas with only small variations in topography. The technique will hopefully prove to be a convenient and relatively fast tool that can improve the topoclimatic classification of other regions. It could be applied by local authorities and farmer associations for optimizing agricultural production.

scholarly journals Special Issue on Climate Migration

2021 ◽  
pp. 1-3
Author(s):  
Anda David ◽  
Frédéric Docquier
Keyword(s):  
Climate Change ◽  
Human Mobility ◽  
Economic Research ◽  
Special Issue ◽  
Low Latitude ◽  
Weather Shocks ◽  
Temperature Trends ◽  
Agricultural Areas ◽  
Slow Onset

How do weather shocks influence human mobility and poverty, and how will long-term climate change affect future migration over the course of the 21st century? These questions have gained unprecedented attention in public debates as global warming is already having severe impacts around the world, and prospects for the coming decades get worse. Low-latitude countries in general, and their agricultural areas in particular, have contributed the least to climate change but are the most adversely affected. The effect on people's voluntary and forced displacements is of major concern for both developed and developing countries. On 18 October 2019, Agence Française de Développement (AFD) and Luxembourg Institute of Socio-Economic Research (LISER) organized a workshop on Climate Migration with the aim of uncovering the mechanisms through which fast-onset variables (such as weather anomalies, storms, hurricanes, torrential rains, floods, landslides, etc.) and slow-onset variables (such as temperature trends, desertification, rising sea level, coastal erosion, etc.) influence both people's incentives to move and mobility constraints. This special issue gathers five papers prepared for this workshop, which shed light on (or predict) the effect of extreme weather shocks and long-term climate change on human mobility, and stress the implications for the development community.

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