scholarly journals Trends of runoff processes in the Otava River basin

Geografie ◽  
2005 ◽  
Vol 110 (1) ◽  
pp. 32-45
Author(s):  
Zdeněk Kliment ◽  
Milada Matoušková

Recent floods in the Czech Republic raised many questions about a possible man-made impact on the outflow process. The contribution evaluates runoff changes in the Otava River basin. Attention is paid to the methodology, which is based mainly on the use of mass curves of rainfall and runoff characteristics. Results of analysis are discussed and compared with climatic factors and human activities.

2019 ◽  
Vol 11 (13) ◽  
pp. 1628 ◽  
Author(s):  
Jing Zhao ◽  
Shengzhi Huang ◽  
Qiang Huang ◽  
Hao Wang ◽  
Guoyong Leng ◽  
...  

Understanding the changing relationships between vegetation coverage and precipitation/temperature (P/T) and then exploring their potential drivers are highly necessary for ecosystem management under the backdrop of a changing environment. The Jing River Basin (JRB), a typical eco-environmentally vulnerable region of the Loess Plateau, was chosen to identify abrupt variations of the relationships between seasonal Normalized Difference Vegetation Index (NDVI) and P/T through a copula-based method. By considering the climatic/large-scale atmospheric circulation patterns and human activities, the potential causes of the non-stationarity of the relationship between NDVI and P/T were revealed. Results indicated that (1) the copula-based framework introduced in this study is more reasonable and reliable than the traditional double-mass curves method in detecting change points of vegetation and climate relationships; (2) generally, no significant change points were identified during 1982–2010 at the 95% confidence level, implying the overall stationary relationship still exists, while the relationships between spring NDVI and P/T, autumn NDVI and P have slightly changed; (3) teleconnection factors (including Arctic Oscillation (AO), Pacific Decadal Oscillation (PDO), Niño 3.4, and sunspots) have a more significant influence on the relationship between seasonal NDVI and P/T than local climatic factors (including potential evapotranspiration and soil moisture); (4) negative human activities (expansion of farmland and urban areas) and positive human activities (“Grain For Green” program) were also potential factors affecting the relationship between NDVI and P/T. This study provides a new and reliable insight into detecting the non-stationarity of the relationship between NDVI and P/T, which will be beneficial for further revealing the connection between the atmosphere and ecosystems.


2015 ◽  
Vol 46 (6) ◽  
pp. 1019-1036 ◽  
Author(s):  
Ye Zhu ◽  
Wen Wang ◽  
Yi Liu ◽  
Hongjie Wang

The impacts of climate variability and anthropogenic activities on hydrological processes have been of wide concern in the hydrology community during recent decades. In this study, specific investigations of individual impacts of climate variability and anthropogenic activities on runoff during 1964–2010 are conducted for the upper Huaihe River Basin at Huaibin (HB) and its five sub-catchments. The non-stationary relationship between precipitation and runoff was firstly analyzed, and according to change point detection results, long-term series for each catchment was divided into pre-change period and post-change period, respectively. Then, the climate variability and human activities that occurred in the whole HB catchment were analyzed. Finally, using two quantitative evaluation methods, the individual impacts of climate variability and human activities for each catchment were assessed. The results showed that for the whole HB catchment, runoff changes during the whole post-change period are mainly attributed to climate variability, as for its sub-catchments except the Xinxian catchment. As for decadal behaviors, runoff generally suffered more human-induced impacts in dry decades (1990s) than wet decades (1980s and 2000s). These results reflected the complex role of climate variability and human activities in influencing the runoff regime, which could be considered in local water resources management.


2006 ◽  
Vol 5 ◽  
pp. 14-17
Author(s):  
Luboš Beran

Vertigo moulinsiana (Dupuy, 1849) was found in 2003–2005 in Northern Bohemia (Czech Republic) at 11 sites. All these sites are situated on floodplains of smaller streams in a sandstone area. The known occurrence of this endangered relict in the Czech Republic is concentrated in three areas – a large area of Bohemian Cretaceous Basin, a floodplain near villages Břežany and Božice (Dyje River Basin) in Southern Moravia and small, isolated, treeless fens in the White Carpathians (Bílé Karpaty Mts.). The principal habitats where V. moulinsiana lives in the Czech Republic are sedge marshes, Typha swamps, reed swamps (with Carex spp.), alder carrs (also with Carex spp.) and tufa-forming spring fens.


2021 ◽  
Vol 13 (1) ◽  
pp. 675-689
Author(s):  
Yunjun Zhan ◽  
Jiemeng Fan ◽  
Tingting Meng ◽  
Zhongwu Li ◽  
Yan Yan ◽  
...  

Abstract The mid-lower reaches of the Hanjiang River Basin, located in the core of economic development in Hubei Province, is an integral part of the Yangtze River Economic Belt. In recent years, the watershed ecosystem has become more sensitive to climate changes and human activities, thus affecting the regional vegetation cover. To maintain a stable watershed ecosystem, it is critical to analyze and evaluate the vegetation change and its response to temperature, precipitation, and human activities in this region. This study, based on the trend analysis, partial correlation analysis, and residual analysis, evaluated the change characteristics of vegetation cover as well as the corresponding driving factors in the basin from 2001 to 2015. The results showed that (1) the overall spatial pattern of vegetation cover in the study area was “high in the west and north, lower on both sides of Hanjiang River, and lowest in the center and southeast,” and the pattern changed parabolically with the increasing elevation. (2) Over the 15 years, vegetation cover in the basin showed an increasing trend, and the increased and decreased areas were 90.72 and 9.23%, respectively. (3) The response of vegetation cover to climatic factors varies greatly depending on the increasing elevation. That is, the lag effect under the impact of temperature disappeared gradually, while it became more evident under the impact of precipitation. (4) On the whole, human activities had a positive effect on the regional vegetation cover. The negative effect in the areas around the Nanyang Basin and the positive effect in most parts of the Jianghan Plain were gradually decreased.


Water ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 3473
Author(s):  
Shanjun Zhang ◽  
Jia Liu ◽  
Chuanzhe Li ◽  
Fuliang Yu ◽  
Lanshu Jing ◽  
...  

Climate change and human activities are two important factors affecting surface runoff. In water resource management and planning, it is generally important to separate the contribution of these factors when assessing runoff changes. The Changbai Mountain area is rich in water resources and is an important hydropower energy base for Northeast China. This study used Sen’s slope estimator to explore trends in runoff precipitation and evapotranspiration from 1960 to 2016, and the results showed a downward trend in runoff and an upward trend in precipitation and evaporation in most areas. The mutation point of the annual time series for the observed runoff was estimated, and the time series was divided into the base period (1960–1975) and impact period (1976–2016). Based on the Budyko framework, we performed attribution analysis of the runoff changes, and analyzed the difference between the mountainous region and the whole basin. We determined that the impacts of climate change and human activities, on average, accounted for decreases in the runoff by 60.15% and 39.85%, respectively, for the Second Songhua River Basin; 73.74% and 26.26%, respectively, for the Tumen River Basin; 84.76% and 15.24%, respectively, for the Yalu River Basin; human activities were the main causes of runoff changes in the Changbai Mountain area; climate change was the main cause of runoff changes in mountainous regions. The results of this study show that the reasons for the change in runoff in mountainous regions and the whole basin in the same area are different, which has some illuminating significance for water resources management of different elevation areas.


2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Sidong Zeng ◽  
Chesheng Zhan ◽  
Fubao Sun ◽  
Hong Du ◽  
Feiyu Wang

Quantifying the effects of climate change and human activities on runoff changes is the focus of climate change and hydrological research. This paper presents an integrated method employing the Budyko-based Fu model, hydrological modeling, and climate elasticity approaches to separate the effects of the two driving factors on surface runoff in the Luan River basin, China. The Budyko-based Fu model and the double mass curve method are used to analyze runoff changes during the period 1958~2009. Then two types of hydrological models (the distributed Soil and Water Assessment Tool model and the lumped SIMHYD model) and seven climate elasticity methods (including a nonparametric method and six Budyko-based methods) are applied to estimate the contributions of climate change and human activities to runoff change. The results show that all quantification methods are effective, and the results obtained by the nine methods are generally consistent. During the study period, the effects of climate change on runoff change accounted for 28.3~46.8% while those of human activities contributed with 53.2~71.7%, indicating that both factors have significant effects on the runoff decline in the basin, and that the effects of human activities are relatively stronger than those of climate change.


2011 ◽  
Vol 6 ◽  
pp. 97-102
Author(s):  
Petr Dušánek

During three years (2010 – 12) The Czech Office for Surveying, Mapping and Cadastre in cooperation with The Ministry of Defense of the Czech Republic and The Ministry of Agriculture of the Czech Republic are providing mapping of the entire area of the Czech Republic by Airborne laser scanning (ALS) technology. The goal of this project is to derive a highly accurate Digital Terrain Model (DTM) for purposes of administration like detection of flooded areas, orthorectification of areal images etc. Such data set also seems to be an interesting da ta source for mapping of human activities in countryside. Human settlements, agriculture or mining activities left significant scars on natural landscape. These significant man-made structures are a part of so called cultural landscape. Man-made structures include ancient settlements, remains of medieval mining activities or remains of settlements abandoned during 20th century. This article generally presents how to derive information about the man-made structures from raw LiDAR. Examples of significant findings of man-made imprints in countryside are also presented. Goal of this article is not to describe a certain archeological site but to inform about strengths of ALS data to map human activities in countryside, mainly in forested areas.


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