Silná bouře na Pelhřimovsku dne 23. května 2005

11311

Surface water and sediment contamination by heavy metals in the Střela River Basin

The analysis is based on analysis of surface water and sediment chemistry data from the longterm regular monitoring network completed by the own samples taken on the network of profiles set up within the research project. The standard methods were used to analyze the sediment chemistry - water quality classification using the ČSN 757221 standard, sediment contamination classification using the geoaccumulation index and comparison of observed concentrations of heavy metals in sediments. Unlike numerous water basins where the contaminated sediments were washed out and the pollution load levels dropped, the Střela River Basin did not record significant changes in pollution level related to the flood1139215

Contamination of surface water and sediment by heavy metals in Střela river basin

13915

Teplota drenážní vody jako indikátor formování odtoku

36937

Pesticides in Small Agricultural Catchments in the Czech Republic

Generally, pesticides are the products containing at least one chemical substance which should protect plant or plant products against pests/diseases. Among them, the most important ones are herbicides, followed by insecticides and fungicides. As a result of intensive agriculture techniques, large amounts of pesticides are applied on agricultural soil. They remain and degrade in soil, but they can enter water bodies and negatively affect water quality and the aquatic ecosystem. The article deals with the level of pesticide load in soil, bottom sediment and surface water in chosen agriculture catchments in the Czech Republic. Results revealed that the main general problem is glyphosate and its metabolite AMPA, although their application has been constrained for several years. Furthermore, the difference in contents of chosen parent pesticide substances and their metabolites in soils and waters was pointed out

Drainage Runoff Separation of New and Old Water Based on Precipitation, Air, Water, and Soil Temperature Compared to Stable Isotopes ¹⁸O and ²H

In order to evaluate the proportion of old and new water in drainage runoff, we recorded air temperature, drainage discharge, drainage runoff temperature, soil temperature, precipitation totals, and temperature. The results of separation by temperature were compared with the results of chemical separation using the stable isotopes δ 18O and δ 2H measured in causal precipitation and monitored in drainage runoff. Separation was determined based on precipitation temperature in 18 rainfall–runoff events and on soil temperature in 20 rainfall–runoff events, with no significant difference between results of separation of drainage runoff based on temperature and that based on isotopes. Separation of runoff based on temperature is feasible only for simple isolated rainfall–runoff events as opposed to those involving multiple rainfalls. Time to peak discharge was identified as a viable factor to determine whether to employ separation based on soil temperature or on precipitation temperature. Time to peak discharge showed a strong correlation with the intensity of precipitation. The results suggest that, conditional on analysis of a larger dataset, isotope separation of drainage runoff and, possibly, runoff in watercourses may potentially be replaced with more economical and technically simple measurement of soil and precipitation/air temperature

Pesticides in Small Agricultural Catchments in the Czech Republic

Generally, pesticides are the products containing at least one chemical substance which should protect plant or plant products against pests/diseases. Among them, the most important ones are herbicides, followed by insecticides and fungicides. As a result of intensive agriculture techniques, large amounts of pesticides are applied on agricultural soil. They remain and degrade in soil, but they can enter water bodies and negatively affect water quality and the aquatic ecosystem. The article deals with the level of pesticide load in soil, bottom sediment and surface water in chosen agriculture catchments in the Czech Republic. Results revealed that the main general problem is glyphosate and its metabolite AMPA, although their application has been constrained for several years. Furthermore, the difference in contents of chosen parent pesticide substances and their metabolites in soils and waters were pointed out

Incorporating Rainfall-Runoff Events into Nitrate-Nitrogen and Phosphorus Load Assessments for Small Tile-Drained Catchments

Rainfall-runoff events significantly influence water runoff and the loss of pollutants from tile-drained agricultural land. We monitored ten small (4 to 38 ha) tile-drained catchments in Czechia for three to five years (2012 to 2016). The discharge was measured continuously; a regular 14-day scheme of water quality monitoring was accompanied with event sampling provided by automatic samplers in 20 to 120 min intervals. A new semi-automated algorithm was developed for the identification of runoff events (RE) based on discharge and water temperature changes. We then quantified the share of RE on the total runoff and the N and P losses, and we compared six methods for nutrient load estimation on an annual and monthly basis. The results showed considerable differences among the monitored sites, seasons, and applied methods. The share of RE on N loads was on average 5% to 30% of the total annual load, whereas for P (dissolved and total), the share of RE was on average 10% to 80% on the total annual load. The most precise method for nutrient load estimation included the RE. The methods based on point monitoring of the discharge and water quality underestimated the loads of N by 10% to 20% and of P by 30% to 80%. The acquired findings are crucial for the improvement of nutrient load assessment in tile-drained catchments, as well as for the design of various mitigation measures on tile-drained agricultural land