The aims of this study are: i) to better understand the coupled interactions between land use changes, climate change and the aquatic ecosystem in a small agricultural catchment (<100 km
2
) with a ...long observation history (1963–2018) and a known land use history, and ii) to test available approaches to separate land use and climate change impacts on water resources in such a small catchment. The pre- and post-change periods have been separated based on change points and the known land use history. Next, conceptual and analytical approaches were applied to quantify and to distinguish between the impacts of climate and land use changes on annual runoff for these two periods. Over the observation period, both land use changes (increase in forest areas) as well as climate change (a temperature rise and a decrease in annual precipitation) occurred. These changes contributed to a decrease in the average annual runoff by 51.9 mm (49% of the long-term average) during the observation period. The quantified contributions of climate and land use changes to the decrease in the mean annual runoff amount to between 60% and 80% and between 40% and 20%, respectively. (i) The results obtained from different methods were consistent - a change in runoff was primarily caused by shifts in climatic variables. (ii) However, the quantified contributions varied depending on the method applied and the form of the Budyko curve. (iii) Thus, special care should be taken in relation to the selection of the Budyko curve for quantifying these changes. (iv) Knowledge of the water deficit sources can result in better planning of water resources management in such small catchments.
Predicting and estimating sediment yield from the catchment is crucial for the effective management of water resources and controlling soil erosion. Until now, Universal Soil Loss Equations (USLE) ...and their modifications are appreciated and commonly applied among many methods. The idea of this work is to use the ESDAC database (a web platform hosting a series of pan-European and global datasets on soil erosion) to build the modified form of the USLE for the Zagożdzonka catchment, a small agricultural area located in central Poland. The calculated sediment yield is compared with the one determined based on the reservoir survey. Conducted analyses show that the average annual suspended sediment yield from the study catchment estimated using the MUSLE equation accounts for 201 Mg and is close to that determined based on the reservoir survey, i.e., 248 Mg. However, MUSLE, with the initially proposed parameters, will overpredict sediment transport at the study site. The ESDAC database may support local studies concerning soil erosion and sediment transport. The research is helpful for policymakers, planners, and engineers.
River intermittence was studied based on data from hydrological monitoring in Poland. We screened the entire state database and two another data sources applying the criterion for zero-flow event: ...discharge less than 0.0005 m 3∙s –1, and found five intermittent rivers with catchment area from 9.2 to 303.7 km 2. We aimed at finding associations between intermittence and climatic driving forces (temperature and precipitation), and between intermittence and anthropogenic activity. We used the Spearman correlation coefficient, circular statistics, and statistical tests for trend. The concentration of zero-flow days, mostly in summer, and the decreasing trend in the standardised precipitation evapotranspiration index ( SPEI) in all catchments at various aggregation levels, and an increasing trend in the total number of zero-flow days and in the maximum length of zero flow events in two rivers, were detected. The strong negative correlation (–0.62 ≤ ρ < 0) between intermittence and the SPEI backward lagged in time showed that intermittence resulted from prolonged deficits in climatic water balance due to increasing evapotranspiration. The reaction of the Noteć catchment, amplified by the anthropogenic pressure (brown coal mines), was reflected in the atypical shape of the rose diagram and in inhomogeneities in river discharges. The results show that the rose diagram can serve as an indicator of the degree of anthropogenic impact on runoff conditions.
Changes of land use, population and climate cause spatial and temporal changes in renewable water resources. For better understanding of the changes and effective management of water resources, ...hydrological investigations in river catchments are carried out around the world. A special investigation involves a study of hydrological processes in small site-specific catchments. The aim of the study is to analyse three characteristic river flows of a small lowland river on the basis of field surveys over two multiannual periods and to evaluate the applicability of indirect methods for determining characteristic flows in the catchment. Hydrological studies in the small agricultural catchment of the Mławka River, located in the Mławka Hills mesoregion, a part of the North Mazovian Lowland macro-region, have continued since 1966. The recorded data were used to determine daily flows and selected characteristic flows for multiannual periods of 1966–1990 and 1991–2020. To determine characteristic flows with indirect methods, three regional formulae and isorea methods were used. The study showed a decrease in renewable water resources over the period. In the multiannual periods, the average flow at the gauge station of Mławka River decreased by 15.6%. The outflow coefficient decreased from 0.303 to 0.265. The minimum annual flows also decreased by 29.1% and annual maximum flows showed an average increase by 19.7%. The use of indirect methods to determine the mean flow yielded results that converged with those from the second multiannual period.
To identify location-scale trends, which environmental data often exhibit, location-scale tests have to be addressed. The aim of this article was to estimate size and power of the Cucconi rank-based ...test when applied to various skewed distributions, typical in hydrology. Results of the Monte Carlo simulation revealed great power for series with low coefficient of variation, time of change close to the middle, not very heavy tail, and with length of at least 60. Comparison to the Lepage test discovered larger usefulness of the Cucconi test for short series and change close to the middle. Several practical applications were presented.
The main objective of the paper was to propose and evaluate the performance of a regional approach to estimate
values and to test the impact of different initial abstraction ratios. The curve number ...(
) was analyzed for five Slovak and five Polish catchments situated in the Carpathian Mountains. The L-moment based method of Hosking and Wallis and the ANOVA test were combined to delineate the area in two homogenous regions of catchments with similar
values. The optimization condition enabled the choice of the initial abstraction ratio, which provided the smallest discrepancy between the tabulated and estimated
s and the antecedent runoff conditions. The homogeneity in the
within the regions of four Slovak and four Polish catchments was revealed. Finally, the regional
was proposed to be at the 50% quantile of the regional theoretical distribution function estimated from all the
s in the region.
The approach is applied in a group of Slovak and Polish catchments with physiographic conditions representative for the Carpathian region. The main benefit of introducing a common regional
is the opportunity to apply this procedure in catchments of similar soil-physiographic characteristics and to verify the existing tabulated
The paper could give rise to an alternative way of estimating the
values in forested catchments and catchments with a lack of data or without observations.
Climate-induced changes in small watersheds are still not well researched because long-term datasets are usually missing for these watersheds. Such studies can, however, improve our understanding of ...the watershed response to climatic changes at such a small scale being transparent. In this study, we investigate trends in temperature, precipitation and river-flow characteristics in a small watershed, typical for Central Poland, with 53 years of observations (1963–2015) using the Mann-Kendall test. Particularly, we examine whether any trends in hydro-meteorological variables can be identified, and if any associated changes in water resources in this region can already be observed. We found that this short period already allows for detecting some changes in hydro-meteorological variables. These changes could be characterized by a significant increase in the mean annual air temperature on a daily basis, and a significant decrease in the mean annual discharge on a daily basis and in the minimum annual discharge on a daily basis. Yet, no significant trend could be detected for the total annual precipitation, the maximum summer rainfall, and the maximum annual discharge on a daily basis. These findings indicate that water resources are decreasing in this region, which affects natural habitats, agriculture and local communities.
Runoff estimation is a key component in various hydrological considerations. Estimation of storm runoff is especially important for the effective design of hydraulic and road structures, for the ...ï¬ood ï¬ow management, as well as for the analysis of land use changes, i.e. urbanization or low impact development of urban areas. The curve number (CN) method, developed by Soil Conservation Service (SCS) of the U.S. Department of Agriculture for predicting the ï¬ood runoff depth from ungauged catchments, has been in continuous use for ca. 60 years. This method has not been extensively tested in Poland, especially in small urban catchments, because of lack of data. In this study, 39 rainfall-runoff events, collected during four years (2009â2012) in a small (A=28.7 km²), urban catchment of SÅużew Creek in southwest part of Warsaw were used, with the aim of determining the CNs and to check its applicability to ungauged urban areas. The parameters CN, estimated empirically, vary from 65.1 to 95.0, decreasing with rainfall size and, when sorted rainfall and runoff separately, reaching the value from 67 to 74 for large rainfall events.
As a follow up and an advancement of the recently published Rainfall Erosivity Database at European Scale (REDES) and the respective mean annual R-factor map, the monthly aspect of rainfall erosivity ...has been added to REDES. Rainfall erosivity is crucial to be considered at a monthly resolution, for the optimization of land management (seasonal variation of vegetation cover and agricultural support practices) as well as natural hazard protection (landslides and flood prediction). We expanded REDES by 140 rainfall stations, thus covering areas where monthly R-factor values were missing (Slovakia, Poland) or former data density was not satisfactory (Austria, France, and Spain). The different time resolutions (from 5 to 60 min) of high temporal data require a conversion of monthly R-factor based on a pool of stations with available data at all time resolutions. Because the conversion factors show smaller monthly variability in winter (January: 1.54) than in summer (August: 2.13), applying conversion factors on a monthly basis is suggested. The estimated monthly conversion factors allow transferring the R-factor to the desired time resolution at a European scale. The June to September period contributes to 53% of the annual rainfall erosivity in Europe, with different spatial and temporal patterns depending on the region. The study also investigated the heterogeneous seasonal patterns in different regions of Europe: on average, the Northern and Central European countries exhibit the largest R-factor values in summer, while the Southern European countries do so from October to January. In almost all countries (excluding Ireland, United Kingdom and North France), the seasonal variability of rainfall erosivity is high. Very few areas (mainly located in Spain and France) show the largest from February to April. The average monthly erosivity density is very large in August (1.67) and July (1.63), while very small in January and February (0.37). This study addresses the need to develop monthly calibration factors for seasonal estimation of rainfall erosivity and presents the spatial patterns of monthly rainfall erosivity in European Union and Switzerland. Moreover, the study presents the regions and seasons under threat of rainfall erosivity.
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