scholarly journals Trends in Global and Basin-Scale Runoff over the Late Twentieth Century: Methodological Issues and Sources of Uncertainty

2011 ◽  
Vol 24 (12) ◽  
pp. 3000-3014 ◽  
Author(s):  
R. Alkama ◽  
B. Decharme ◽  
H. Douville ◽  
A. Ribes

Abstract While human influence has been detected in global and regional surface air temperature, detection–attribution studies of direct (i.e., land use and water management) and indirect (i.e., climate related) effects of human activities on land surface hydrology remain a crucial and controversial issue. In the present study, a set of global offline hydrological simulations is performed during the 1960–94 period using the Interactions between Soil, Biosphere, and Atmosphere–Total Runoff Integrating Pathways (ISBA-TRIP) modeling system. In contrast to previous numerical sensitivity studies, the model captures the observed trend in river runoff over most continents without including land use changes and/or biophysical CO2 effects, at least when the comparison is made over 154 large rivers with a minimum amount of missing data. The main exception is northern Asia, where the simulated runoff trend is negative, in line with the prescribed precipitation forcing but in contrast with the observed runoff trend. The authors hypothesize that the observed surface warming and the associated decline of permafrost and glaciers, not yet included in most land surface models, could have contributed to the increased runoff at high latitudes. They also emphasize that the runoff trend is a regional-scale issue, if not basin dependent. In line with recent observational studies, their results suggest that CO2 stomatal conductance effects and land use changes are not the primary drivers of the multidecadal runoff variability at continental scales. However, the authors do not rule out a human influence on land runoff, at least through the high-latitude surface warming observed over recent decades.

10.5109/27370 ◽  
2013 ◽  
Vol 58 (2) ◽  
pp. 377-387
Author(s):  
Yanna Xiong ◽  
Guoqiang Wang ◽  
Yanguo Teng ◽  
Kyoichi Otsuki

2019 ◽  
Vol 20 (7) ◽  
pp. 1399-1416
Author(s):  
Simon Schick ◽  
Ole Rössler ◽  
Rolf Weingartner

AbstractSubseasonal and seasonal forecasts of the atmosphere, oceans, sea ice, or land surfaces often rely on Earth system model (ESM) simulations. While the most recent generation of ESMs simulates runoff per land surface grid cell operationally, it does not typically simulate river streamflow directly. Here, we apply the model output statistics (MOS) method to the hindcast archive of the European Centre for Medium-Range Weather Forecasts (ECMWF). Linear models are tested that regress observed river streamflow on surface runoff, subsurface runoff, total runoff, precipitation, and surface air temperature simulated by ECMWF’s forecast systems S4 and SEAS5. In addition, the pool of candidate predictors contains observed precipitation and surface air temperature preceding the date of prediction. The experiment is conducted for 16 European catchments in the period 1981–2006 and focuses on monthly average streamflow at lead times of 0 and 20 days. The results show that skill against the streamflow climatology is frequently absent and varies considerably between predictor combinations, catchments, and seasons. Using streamflow persistence as a benchmark model further deteriorates skill. This is most pronounced for a catchment that features lakes, which extend to about 14% of the catchment area. On average, however, the predictor combinations using the ESM runoff simulations tend to perform best.


2005 ◽  
Vol 22 (3) ◽  
pp. 343-348 ◽  
Author(s):  
Zhang Jingyong ◽  
Dong Wenjie ◽  
Wu Lingyun ◽  
Wei Jiangfeng ◽  
Chen Peiyan ◽  
...  

Solid Earth ◽  
2016 ◽  
Vol 7 (6) ◽  
pp. 1551-1564 ◽  
Author(s):  
Sajad Zareie ◽  
Hassan Khosravi ◽  
Abouzar Nasiri ◽  
Mostafa Dastorani

Abstract. Land surface temperature (LST) is one of the key parameters in the physics of land surface processes from local to global scales, and it is one of the indicators of environmental quality. Evaluation of the surface temperature distribution and its relation to existing land use types are very important to the investigation of the urban microclimate. In arid and semi-arid regions, understanding the role of land use changes in the formation of urban heat islands is necessary for urban planning to control or reduce surface temperature. The internal factors and environmental conditions of Yazd city have important roles in the formation of special thermal conditions in Iran. In this paper, we used the temperature–emissivity separation (TES) algorithm for LST retrieving from the TIRS (Thermal Infrared Sensor) data of the Landsat Thematic Mapper (TM). The root mean square error (RMSE) and coefficient of determination (R2) were used for validation of retrieved LST values. The RMSE of 0.9 and 0.87 °C and R2 of 0.98 and 0.99 were obtained for the 1998 and 2009 images, respectively. Land use types for the city of Yazd were identified and relationships between land use types, land surface temperature and normalized difference vegetation index (NDVI) were analyzed. The Kappa coefficient and overall accuracy were calculated for accuracy assessment of land use classification. The Kappa coefficient values are 0.96 and 0.95 and the overall accuracy values are 0.97 and 0.95 for the 1998 and 2009 classified images, respectively. The results showed an increase of 1.45 °C in the average surface temperature. The results of this study showed that optical and thermal remote sensing methodologies can be used to research urban environmental parameters. Finally, it was found that special thermal conditions in Yazd were formed by land use changes. Increasing the area of asphalt roads, residential, commercial and industrial land use types and decreasing the area of the parks, green spaces and fallow lands in Yazd caused a rise in surface temperature during the 11-year period.


2011 ◽  
Vol 11 (9) ◽  
pp. 24857-24881 ◽  
Author(s):  
K. Ashworth ◽  
G. Folberth ◽  
C. N. Hewitt ◽  
O. Wild

Abstract. Large-scale production of feedstock crops for biofuels will lead to land-use changes. We quantify the effects of realistic land use change scenarios for biofuel feedstock production on isoprene emissions and hence atmospheric composition and chemistry using the HadGEM2 model. Two feedstocks are considered: oil palm for biodiesel in the tropics and short rotation coppice (SRC) in the mid-latitudes. In total, 69 Mha of oil palm and 92 Mha of SRC are planted, each sufficient to replace just over 1 % of projected global fossil fuel demand in 2020. Both planting scenarios result in increases in total global annual isoprene emissions of about 1 %. In each case, changes in surface concentrations of ozone and biogenic secondary organic aerosol (bSOA) are significant at the regional scale and are detectable even at a global scale with implications for air quality standards. However, the changes in tropospheric burden of ozone and the OH radical, and hence effects on global climate, are negligible. The oil palm plantations and processing plants result in global average annual mean increases in ozone and bSOA of 38 pptv and 2 ng m−3 respectively. Over SE Asia, one region of planting, increases reach over 2 ppbv and 300 ng m−3 for large parts of Borneo. Planting of SRC causes global annual mean changes of 46 pptv and 3 ng m−3. Europe experiences peak monthly mean changes of almost 0.6 ppbv and 90 ng m−3 in June and July. Large areas of Central and Eastern Europe see changes of over 1.5 ppbv and 200 ng m−3 in the summer. That such significant atmospheric impacts from low level planting scenarios are discernible globally clearly demonstrates the need to include changes in emissions of reactive trace gases such as isoprene in life cycle assessments performed on potential biofuel feedstocks.


Author(s):  
S. Youneszadeh ◽  
N. Amiri ◽  
P. Pilesjo

The Netherlands is a small country with a relatively large population which experienced a rapid rate of land use changes from 2000 to 2008 years due to the industrialization and population increase. Land use change is especially related to the urban expansion and open agriculture reduction due to the enhanced economic growth. This research reports an investigation into the application of remote sensing and geographical information system (GIS) in combination with statistical methods to provide a quantitative information on the effect of land use change on the land surface temperature. In this study, remote sensing techniques were used to retrieve the land surface temperature (LST) by using the MODIS Terra (MOD11A2) Satellite imagery product. As land use change alters the thermal environment, the land surface temperature (LST) could be a proper change indicator to show the thermal changes in relation with land use changes. The Geographical information system was further applied to extract the mean yearly land surface temperature (LST) for each land use type and each province in the 2003, 2006 and 2008 years, by using the zonal statistic techniques. The results show that, the inland water and offshore area has the highest night land surface temperature (LST). Furthermore, the Zued (South)-Holland province has the highest night LST value in the 2003, 2006 and 2008 years. The result of this research will be helpful tool for urban planners and environmental scientists by providing the critical information about the land surface temperature.


2015 ◽  
Vol 12 (6) ◽  
pp. 6305-6325 ◽  
Author(s):  
A. Ervinia ◽  
J. Huang ◽  
Z. Zhang

Abstract. Study on runoff dynamics across different physiographic regions is fundamentally important to formulate the sound strategies for water resource management especially in the coastal watershed where peoples heavily concentrated and relied on water resources. The L−R diagram, a conceptual model by which the land-changes evapotranspiration (ΔL) was estimated as the difference between actual and climate evapotranspiration to identify the specific impact of land-use changes on annual runoff changes (ΔR), was developed using the 53-year hydro-climatic data of Jiulong River Watershed, a typical medium-sized subtropical coastal watershed in China. This study found that land-use changes have reinforced the impact of climatic changes on runoff changes where nearly all points were scattered in II and IV quadrant. Deforestation and expansion of built up area has diminished the water retention capacity in a catchment as well as evapotranspiration thus produce extra runoff accounting for 12–183 % of total runoff increase. In contrast, reforestation makes the significant contribution to decreasing annual runoff for about 21–82 % of total runoff loss. This study revealed the river runoff has become more vulnerable to intensive anthropogenic disturbances under the context of climate changes in a coastal watershed.


Author(s):  
Risya Lailarahma ◽  
I Wayan Sandi Adnyana

Land use changes over Jakarta caused by urbanization affected the increasing of infrastructure and decreasing vegetation from 2003 to 2016. This condition reduced water infiltration and caused inundation when heavy rainfall coming. Then Aedes aegypti would breed.and increased which brought dengue fever desease. This study was about analyzing the land use change in Jakarta Province using Landsat image, and its relationship with land surface temperature and dengue fever distribution. The effects of land use change also analysed by this study which including the effects from temperature and dengue fever that analysed by indices of land use in Jakarta at 2003 and 2016. The temperature analysis could be obtained by TIR band in Landsat and using some algortitma which calculated in band math of ENVI software. Vegetation index value’s average decreased from 0.652 in 2003 to 0.647 2016 in 2016. Built up index value’s average increased from -0.03 in 2003 to -0.02 in 2016. While Bareland index value’s average decreased from 0.16 in 2003 to -0.46 in 2016. Land surface temperature increased 3?C from 2003 to 2016. Vegetation area decreased 27.929 ha, bare land area decreased 6.012 ha, while built up area increased 34.278 ha from 2003 to 2016. Increasing of land surface temperature proportional to increasing dengue fever patients 1.187 patients. Increasing of land surface temperature increasing dengue fever cases 1.187 patients. To review and monitor more about the relationship between landuse changes and temperature changes required image with high resolution so that the results obtained more accurate. Complete data of dengue fever per subdistricts also required to analyse further more about relationship between landuse changes, temperature changes, and dengue fever.


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