This study aims to assess the quality of lagoon water used as a dumping ground for shrimp farming waste. The research uses the descriptive method. The research was conducted at the Shrimp Cultivation Site in the Banaran Kulon Progo Village, Special Region of Yogyakarta, Indonesia. The research focuses on physicochemical parameters, including temperature, pH, total suspended solid ( TSS), dissolved oxygen ( DO), ammonium (NH ₄-N), nitrate (NO ₃-N), and phosphate. The sampling technique is based on SNI 6989.57:2008. Sampling was carried out 48 times in 3 lagoons during rainy and dry seasons. Dialysis data was descriptively classified with the help of Storage and Retrieval of Water Quality Data System (STORET) and water quality was generally classified as C (moderately polluted) and D (heavily polluted) categories in dry and rainy seasons. The results showed that in the rainy season the highest pH, nitrate and phosphate levels of 8.3, and 6.1 and 20.8 mg∙dm ^–3, were up to 15% less than in the dry season in the same point. Thus, it can be concluded that these values from the STORET in the dry season are larger than those in the rainy season. The study results are expected to become a basis for the evaluation of the quality of shrimp farming wastewater so that environmental health can be controlled and the risk of waste pollution reduced.

The development of cities and peri-urban areas is exerting an increasingly strong impact on the natural environment and, at the same time, on the living conditions and health of people. Problems and challenges that need to be addressed include increasing air pollution in these areas, formation of a surface urban heat island (SUHI), water management disruptions (water scarcity or excess), and the destruction of natural habitats. One of the solutions that contributes to climate change mitigation is the introduction of blue-green infrastructure into the city space and urbanised areas. The research objective was to identify spatial features (geodata) that determine the optimum location of selected blue-green infrastructure (BGI) components, acquire them, and then use the Geographical Information System (GIS) to determine their optimum locations. As the first step, cartographic models were developed which indicated areas that enable the development of selected blue-green infrastructure components in the Olsztyn city area, Warmińsko-Mazurskie Province, Poland. The models were juxtaposed with other two models developed by the authors, i.e. a surface urban heat island model and a demographic model that showed the age structure of the city’s population. Consequently, maps with potential locations for the blue-green infrastructure were developed, while taking into account reference data from the National Land Surveying and Cartographic Resource and Landsat 8 images.

Climate change and its consequences, including rising ocean temperature and sea level rise are well scientifically documented. The changes are especially severe for coastal communities, which are estimated to have reached c. 50% of the world’s population. Using an example of the Gulf of Gdansk region, which is of European importance, due to the presence of two major Baltic ports and global tourism, we explore, how sea related threats may affect the region and we analyse how the three major cities are prepared to these threats. The four city developmental strategies and an additional document, an “umbrella strategy” focusing on climate change threats do not consider sea level rise and more frequent storm surges as threats. The sea level rise is briefly discussed in the fourth document. The adaptation plan, an appendix to the document, mentions sea level rise, but the discussion of the problem is indirect and involves some examples of adaptation actions in loosely similar environmental conditions. The adaptation plan, in fact includes a list of possible threats, rather than a detailed discussion of the suggestions of the measures to be undertaken. For comparison, we present a multilevel approach, which is effectively run in the Port of Rotterdam and argue that such approach should be undertaken in the studied region. We conclude that despite years of education on climate change, the problem is still not recognised and is underrepresented in practical measures of the studied region. We also provide hints on how to overcome this situation.

The paper concentrates on seasonal and spatial variations of sub-daily water temperature dynamics in lowland agricultural streams. Temperature monitoring was carried out in 24 sampling sites distributed along the tributaries of the Wkra River during the hydrological year 2021. Statistical analysis of the obtained data documented the highest water temperature dynamics in the morning, from 5:00 to 9:00 CEST, while the lowest – from 14:00 to 18:00 CEST. Seasonally, greater water dynamics were noted in the winter, expressed by a coefficient of variation reaching up to 100%. Spatially, the highest dynamics occurred in sites with the lowest proportion of riparian vegetation, while the lowest dynamics was related to higher catchment area. In the winter, the minimum daily values were recorded most frequently in the morning hours, while maximum values in the afternoon. A similar pattern was observed in the summer, but with much lower dispersion of the relative frequencies. It was found that in the winter, the dominant influence on temperature dynamics was exerted in the upstream catchment area, while in the summer, a negative relationship with riparian shade was marked. The findings suggest that the presence of riparian vegetation reduces diurnal dynamics of water temperature and is simultaneously extremely important in prolonging the duration of optimum fluctuation, responsible for the proper development of poikilothermic organisms.

The integration of geodetic and photogrammetric data has become a new tool that has expanded the existing measurement capabilities, as well as it found its application outside the geodetic sector. As a result, over the past decades, the process of topographic data acquisition has caused cartographic industry to move from classical surveying methods to passive and active detection methods. The introduction of remote sensing technology has not only improved the speed of data acquisition but has also provided elevation data for areas that are difficult to access and survey. The aim of the work is to analyse consistency of elevation data from the Georeference Database of Topographic Objects (Pol. Baza danych obiektów topograficznych – BDOT500) with data from airborne laser scanning (ALS) for selected 15 research areas located in the City of Kraków. The main findings reveal discrepancies between elevation data sources, potentially affecting the accuracy of various applications, such as flood risk assessment, urban planning, and environmental management. The research gap identified in the study might stem from the lack of comprehensive investigations into the consistency and accuracy of elevation data across different databases and technologies in urban areas. This gap highlights the need for a thorough examination of the reliability of various data sources and methods of urban planning, disaster management, and environmental analysis. The integration of diverse databases and technologies, like ALS and geodetic measurements, in various applications introduces potential discrepancies that can significantly impact decision-making and outcomes.

The paper presents the results of studies on local resistance coefficients (ζ). The study used pipe aerators with filling made according to the Polish patent PL235924. The hydraulic investigations were performed in real working conditions of a water treatment plant in a testing rig built in the Scientific and Research Water Station of the Warsaw University of Life Sciences (SGGW). The investigation encompassed two plastic pipe aerators of an internal diameter 101.6 and 147.6 mm with steel Białecki rings of 12 and 25 mm in diameter. Measurements of pressure difference (Δp) in the investigated aerators were performed at volumetric water flows ( Q) selected from the range 2–20 m ³∙h ^–1 with the interval 2 m ³∙s ^–1. The values of ζ were determined according to the PN-EN 1267:2012 standard. The investigation showed that the ζ depends both on an internal diameter of the plastic pipe aerator and the diameter of Białecki steel rings. The values of ζ increase with a decrease of the internal diameter of the pipe aerator and a decrease of the ring diameter.

The objective of this study is to examine the implementation of a combined scheme involving payment environment services (PES) and non-payment environment services (non-PES) in the management of the Cidanau River Basin. This study used exploratory research to analyse the structure and mechanism of PES and non-PES schemes for the governance system. The Cidanau Watershed governance is a pioneer in sustainable integrated water resources management in Indonesia and has persisted until the present time. The governance of the Cidanau Watershed is dynamic, resilient, and evolving in response to various changes in social and ecological systems. A bridging organisation like the Cidanau Watershed Communication Forum (Ind.: Forum Komunikasi DAS Cidanau – FKDC) requires legal standing to be visible and gain the trust of the public, especially when implementing a PES approach like the Cidanau River Basin, where service buyers utilise non-direct payment mechanisms. The challenging aspect of developing a PES scheme is empowering knowledge regarding the importance of soil and water preservation among upstream communities, particularly in developing countries like Indonesia, where upstream communities are predominantly composed of low-income farmers whose livelihoods depend on nature. The non-PES scheme represents the government’s mandatory responsibility, whereas the PES scheme presents public participation in active collaboration through the FKDC as an ad hoc institution. A combination of the non-PES and PES scheme approach can serve as a model and reference for similar river basin governance frameworks. Further research is needed regarding social networks and institutional development of sustainable watershed governance in the Cidanau River Basin.

Green walls, along with green roofs, parks, and vertical gardens, belong to the green infrastructure of cities, which will encompass the majority of humanity in the coming decades. Green infrastructure benefits both urban residents and nature in the urban landscape, although there is no scientific consensus on the extent to which green walls, especially green facades, impact biodiversity in cities. This study examined the influence of green facades on the richness of mammals, birds, and invertebrates, considering the species and age of the plants comprising the green facade in a medium-sized city located in southwestern Poland. It was found that the implementation of green facades significantly enhances species’ biodiversity compared to non-vegetated walls. Four synanthropic bird species were nesting on green facades: Eurasian collared dove ( Streptopelia decaocto), blackbird ( Turdus merula), house sparrow ( Passer domesticus) and woodpigeon ( Columba palumbus). For the beech marten (Martes foina), the green facades are a hunting ground for birds and their eggs. This simple and effective method of creating green walls provides benefits to local wildlife by creating habitats, shelter, and foraging opportunities for selected species. However, it is difficult to determine whether green facades contribute to the formation of ecological corridors in urban environments. The study also examined the social aspect related to the establishment and maintenance of green facades on the surveyed buildings.

Nutrient deficiency (ND) stands as a prominent environmental factor that significantly impacts global plant growth and productivity. While numerous methods have been employed for detecting nutrient deficiencies in plants, many of them are invasive, time-consuming, and costly. In contrast, chlorophyll fluorescence (ChlF) signals have emerged as a non-destructive tool for the identification of specific nutrient deficiencies, such as nitrogen (N), phosphorus (P), and potassium (K), across various plant species. In this pioneering study, ChlF measurements were employed for the first time to detect a combination of nutrient deficiencies, including deficiencies in nitrogen and phosphorus (–NP), nitrogen and potassium (–NK), potassium and phosphorus (–KP), and a complete NPK deficiency (–NPK). The experiment was conducted using wheat (Triticum aestivum) and maize ( Zea mays) plants, which were grown under controlled laboratory conditions. An optimal hydroponic system was established to facilitate eight experimental conditions, namely: control, –N, –P, –K, –NP, –NK, –KP, and –NPK. Measurements were systematically collected at two-day intervals over a span of 24 days. Our findings demonstrate that chlorophyll fluorescence signals can enable the differentiation of various nutrient deficiencies even prior to the onset of observable symptoms. Furthermore, the examination of chlorophyll fluorescence parameters enables us not only to identify a singular macronutrient deficiency but also to detect multiple macronutrient deficiencies concurrently in a plant.

A study was conducted on changes in the abundance and diversity of floristic composition in baulks and cultivated agrocenoses in the area of the village of Nowokornino, located on the outskirts of the Białowieża Forest. Within the geodesic area of the village, which covers approximately 1,100 ha, agricultural crops are grown under three farming systems: conventional farming, integrated farming and organic farming. In the study area, there are unique marginal ecosystems in the form of mid-field baulks on which various weed species of ecological importance occur. Three study plots were designated on the baulks, and three plots on field crops Floristic surveys were carried out in 2016, 2020 and 2022. The cover of individual species was estimated according to the 7-level Braun-Blanquette scale. A total of 91 plant species belonging to 6 phytosociological groups were found, with the Stellarietea mediae group having the highest species richness. The significance of differences in floristic richness between study and control plots was tested by one-way analysis of variance (ANOVA). Statistical analysis showed that the factors differentiating the floristic composition on the baulks were their location within the cultivated agrocenoses, natural soil abundance and interaction with fertiliser factors. The highest species abundance of plants defined as weeds, occurred in fields under the integrated farming system (58 species), the lowest in fields under the conventional system (39 species). The vegetation of the baulks and adjacent arable fields was dominated by plants representing mainly three types of ecological strategies: C, R and C-R.

The study area of the Nida valley was examined to investigate variations in groundwater and surface water levels, as well as the interaction between them. In the valley, there were three branches. The two actives were the Nida River itself and the Smuga Umianowicka branch while the Stara Nida branch was dry during the measurement session. Over a 12-month period from June 2021 to June 2022, 7 monitoring points were equipped with piezometers, comprising 5 groundwater points and 2 surface water points. The monitoring frequency was set to 30 minutes. The results of this research indicate that there are significant differences in the water level at the same observed point at different times. This study demonstrates seasonal changes in both surface water and groundwater levels with higher levels in autumn and winter and lower levels in spring and summer, which are closely tied to the changes in meteorological conditions during the research period, such as precipitation and air temperature. The study results also indicate that during summer and winter at the Nida River and its riparian area, losing stream is the primary process occurring in the studied reach. Conversely, during autumn and spring, the main process is gaining stream. At the human-maintained Smuga Umianowicka branch and in its riparian area, losing stream is the main process during summer and autumn, and gaining stream is the main process during spring. During winter, losing stream and gaining stream processes can occur simultaneously, and neither process takes place mainly.

The aggregate of various taxonomic groups of microorganisms colonising living organisms is known as the microbiome. The plant microbiome encompasses a wide network of biological, chemical and metabolic interactions between the plant and microorganisms (mainly algae, bacteria and protozoa). The relationships between microbes and peatland plants, particularly carnivorous plants, are a very interesting subject that is still little understood. Microbes colonising carnivorous peatland plants may be present in their traps or on the surface of the plant. Previous research on the relationships between the microbiome composition of carnivorous plants and the external factors influencing it directly and indirectly is still inadequate. There is a lack of review articles analysing the current state of knowledge regarding carnivorous plant–microbiome interactions. This review of the literature is a collection of data on the functioning of the microbiome of carnivorous plants growing in peatland ecosystems. In addition, it summarises the available information on host–microorganism relationships.

Drought is characterised as a recurring climatic phenomenon with prolonged duration, affecting land through below-average rainfall and often accompanied by high temperatures. When the available water falls below the optimum level, water deficit or water stress arises, disrupting normal plant processes. This condition poses challenges for plant growth and development as it hampers the internal water transport, induces stomatal closure, and limits access to photosynthetic resources.
The study employed the annual sunflower as the experimental plant. The plants were cultivated in a controlled environment with a temperature ranging from 20 to 25°C and a humidity level of 55 to 60%, supplemented by MARS HYDRO artificial LED lighting set to a 12-h photoperiod. Radial changes in the plant stems were monitored using a DD-S type dendrometric sensor to measure radial fluctuations. The collected data were recorded in a dendrometric data logger DL 18. Data collection occurred at hourly intervals from February 20 to March 9, 2023. The nine plants were divided into three groups, each comprising three plants. All plants from groups 1 and 2 received irrigation at one- day intervals (group 1 – 80 cm ³ per plant, group 2 – 40 cm ³ per plant) and group 3 was not irrigated.
Based on these findings, visible water stress was evident in the plants under experimental conditions. Consequently, continuous monitoring throughout the growing season will be essential to adjust the irrigation rate to meet the requirements of the plants.

Flame retardants (FRs) that have an adverse effect on human and the environment have been subject to regulation since 1972. However, FRs emerging as a replacement, are not proving to be fully environmentally safe. Water and sediment contamination by FRs, including organophosphorus (OPFRs) and novel brominated (NBFRs) ones, is a matter of major concern. Due to their common usage, many release sources, and relatively high mobility, they pose a threat to aquatic organisms and ecosystems. This review summarises studies on the OPFRs’, and NBFRs’ simultaneous occurrence in water and corresponding sediment. The main sources of occurrence and routes of entry of FRs into the environment are presented. The newest reports on the ecotoxicity of selected FRs had been summarised in order to bring the matter to attention. The research revealed that although great efforts had been made to study the occurrence of OPFRs and NBFRs in water and sediment separately, there is a lack of research on their occurrence in both media in the same area. Although major efforts have been made to study the ecotoxicity of OPFRs, there are some deficiencies for the NBFRs. Considering their relatively high ecotoxicity, further studies should be conducted on joint ecotoxicity, which may cause synergistic or antagonistic effects.

Soybean ( Glycine max (L.) Merrill.) yielding potential depends on environmental conditions (precipitation, temperature, soil). The aim of the work was to evaluate stability of yielding (and other traits) of three soybean cultivars (Abelina, SG Anser, Merlin) grown under the climatic conditions of central-eastern Poland. The studied material was obtain in a field experiment conducted at Łączka (52°15' N, 21°95' E) during the growing seasons of 2017–2019. Trait stability was determined based on Shukla’s genotype stability variance and Wricke’s ecovalence describing the genotype-by-environment interaction. For all the examined parameters, there were found significant differences between successive growing seasons, cultivars, and cultivars within study years. The greatest influence of environmental conditions (years) was determined for plant height (64%) and first pod height (54.2%). Stability parameters indicated that cv. Abelina was the most stable in terms of yielding, 1000 seed weight, seed number per pod and average seed number per pod, cv. SG Anser being the least stable in this respect

The paper presents in form of a case study the results of 10-year long hydro-chemical studies on the Korzeń stream on which the “Skrzyszów” small storage reservoir was built. Studies aimed at evaluating the impact of the reservoir on the surface water quality in a Flysch stream. The basis for the analysis was results of 21 hydro-chemical water quality parameters, from the following groups of indicators: physical and acidity, oxygen and organic pollution, biogenic, salinity, metals. Indicators were determined in one-month intervals in two periods: 2005–2009 (before the reservoir was built) and 2015–2019 (after the reservoir was built). Obtained results were subjected to a statistical analysis. The trend analysis of changes was performed using the Mann–Kendall test or the seasonal Kendall test; significance of differences between indicator values from two periods was evaluated using the nonparametric Mann– Whitney U test. Results of analysis showed significant change trends of water quality parameters, in case of total iron concentration the trend was downward in both periods. Statistically significant differences between the values of definite majority of indicators were found in two analysed periods, indicating both favourable and unfavourable impact of the reservoir on water quality in the stream. Construction of the storage reservoir resulted in a significant change of physical and chemical indicators of water flowing in the stream. Random variation dynamics as well as tendencies and trends of changes over time have changed. In addition to modifying the stream hydro-chemical regime, the reservoir also affected the social and natural conditions.

In this paper, the regression analysis technique is applied to a large water quality dataset for the Sitnica River in Kosovo. It has been done to assess the correlation between water quality parameters. The data are generated by a wireless sensors network deployed in Sitnica. A regression analysis is applied to four water quality parameters: temperature, dissolved oxygen, pH, and electrical conductivity. The correlation between each pair of parameters has been assessed by using the WEKA software package, which is a popular time-saving tool for data analysis in distinct domains. The data are pre-processed to exclude out-of-range values and then the assessment of correlation for the pairs of parameters is applied. In comparison to other pairs of water quality parameters, the results show that dissolved oxygen and electrical conductivity correlate particularly closely with temperature. Regression equations of these two pairs of parameters may provide inferred information on dissolved oxygen and electrical conductivity about the Sitnica River. Such information may otherwise not be available to resource managers in Kosovo. Moreover, due to its easy to use and availability as an open-source software, WEKA may aid decision-makers on the management providing almost real-time information about surface water quality within the basin. This can be particularly useful especially in the case of continuous observation of water quality and a huge dataset gathered by using wireless sensors.

The study of changes in grassland was conducted on the territory of individual counties of the West Pomeranian Voivodship. Based on data collected in the Valorisation of the Agricultural Production Space of Poland and spatial data (an electronic 1:5000 soil and agricultural map) the basic information on the use of agricultural land in the 70s of the 20th century. Changes in use over time were analysed based on data the Statistics Poland (Pol.: Główny Urząd Statystyczny – GUS), General Geographic Database and The Agency for Restructuring and Modernisation of Agriculture Crop Register (Pol.: Agencja Restrukturyzacji i Modernizacji Rolnictwa – ARiMR).
The studies showed that in the West Pomeranian Voivodship, a successive decrease in the share of permanent grasslands (0.9%) and arable lands (1.4%) is observed. There is a spatial variation in the share of permanent grassland in the province’s counties, with a distinction between northern and southern counties. The main direction of change in grassland area is arable land, which applies to counties with the highest share of permanent grassland (PG) and counties with a high share of the best soils and forest direction. Land quality was the main factor determining the direction of grassland changes, with the best PG converted to arable land or for investment purposes. In contrast, the weakest were converted to forestry or spontaneously wooded through abandonment. The main reasons for changes in grassland areas in the West Pomeranian Voivodship were: conversion of use to arable land, afforestation of grasslands, land use for urban planning purposes, leaving land fallow and conversion for constructing fishponds.

The aim of the study was to use regenerated activated carbon to adsorb phenol from a river. Coconut shell activated carbon was derived from used tap water filter cartridges. The activated carbon was carbonised and then activated with KOH at 200°C, under a nitrogen atmosphere. The resulting adsorbent was characterised on the basis of nitrogen adsorption by Brunauer–Emmett–Teller (BET), scanning electron microscopy (SEM) analysis and point of zero charge (pH PZC). The study of periodic adsorption included kinetic and equilibrium modelling, determined the effect of solution pH on efficiency and the possibility of regeneration and reuse of the adsorbent. The efficiency of phenol removal from model water was evaluated, followed by the possibility of their adsorption from a polluted river in Silesia Province. Phenol adsorption followed pseudo-second-order kinetics. The adsorbents showed high adsorption abilities, as determined by the Langmuir isotherm model. The model fits the experimental data well. The concentration of phenol in the river was in the range of 0.45–0.77 mg∙dm– ³, which means that its value was at least five times higher than the standard values. The use of regenerated activated carbon from waste filter cartridges removed phenol from the river by 78% using optimal test parameters.

Radial gates are more common than vertical sluice gates for a number of reasons. They are simpler to use, cause less flow disturbance, require less lifting force, and deliver better discharge. Radial gates are commonly used in new barrages, such as the New Assuit Barrage. Prior researchers used physical investigations to study the efficiency of stilling basin downstream radial gates, but physical studies cost a lot of money and time, so numerical solutions should be investigated. The current study aimed to explore numerically the influence of stilling basin shape and baffle block arrangement on the stability of bed protection, near-bed velocity, energy dissipation, and hydraulic jump characteristics downstream of radial gates. Different 12 discharges were investigated, and their results were compared with previous physical results to verify the performance of the numerical results. The results obtained from the numerical model from all trials are almost identical to the physical model results. Five different alternative designs were carried out numerically to enhance the design of the New Assuit Barrage (NAB) spillway stilling basin. Results showed that alternatives 4 (changing the geometry of the basin by removing the end step and concrete slab) and 5 (as alternative 4 in addition to adding rounded baffle blocks presented in two rows arranged in a staggered way) gave good velocity distribution with low turbulence, low values of near-bed velocities, and stability of bed protection. Also, it is more economical because of the lower cost of concrete and excavation.

Over the last two decades, geodetic surveying has seen significant advancements with terrestrial and unmanned aerial vehicle (UAV) laser scanning, alongside automatic observations being increasingly utilised throughout the construction process.
In the context of dam structures, periodic geodetic displacement measurements are a compulsory component of control measurements and safety assessments. In Poland, however, control measurements have largely remained rooted in traditional techniques such as classic linear and angular measurements and precise levelling. These methods are typically carried out within distinct control networks, i.e. without dual-function observation points and targets. Furthermore, network points (pillars, targets) have often not been renewed since their installation several decades ago, and glass discs, used for crown measurements in the baseline method, frequently face damage.
Changes in property ownership and modifications in environmental regulations are compounded by these issues, which often impede the proper upkeep of the sight line.
The article proposes the adaptation and reconstruction of control networks to incorporate automatic observation techniques, including linear and angular measurements. This approach includes activities aimed at reconstructing and supplementing damaged network structures, modernising the geodetic process of determining structure displacements, and enhancing the accuracy, credibility, and reliability of geodetic displacement measurement results.
The article presents the findings of an inventory assessment conducted on the existing control network infrastructure, focusing on the analysis of displacements for structures with diverse constructions and functions – a concrete dam (class I) and a water damming weir with a water intake. Furthermore, it presents practical conclusions regarding the efficient organisation of geodetic control measurements.

Fish passes are essential elements for maintaining continuity for migrating fish. Without them, fish would be unable to undertake migration to satisfy their basic life needs. These devices must meet a range of requirements related to the size of individual fish pass elements and the hydrodynamic parameters of the flowing water. Despite efforts, it is not always possible to meet these requirements. There are many causes of errors in the design and construction of fish passes, and each case should be assessed individually. The most severe consequence of these errors is the obstruction of fish migrating upstream.
In this study, an analysis of the permeability of a semi-natural fish pass was conducted for fish. This assessment was carried out using two methods. In the first approach, the required geometric dimensions of the fish pass elements were determined based on the dimensions of individuals living in the river channel. In the second approach, the dimensions were extracted from publications dedicated to slot fish passes, as the studied object resembles such a design.
The analysis revealed that the fish pass does not fulfil its intended role. All fish species living in the Nidzica River channel face difficulties in passing through the fish pass, including the brook trout, for which the object is specifically designed. The main errors stem from the design and construction, resulting in exceeded values, primarily in the hydrodynamic parameters, rendering the fish pass impassable. The study also aimed to develop corrective recommendations considering the latest scientific developments.

Groundwater exploitation that exceeds its recharge capacity can have a negative impact on the hydrogeological environment. Optimal exploitation means maximising pumping discharge with the least reduction in the hydraulic head. In groundwater exploitation, the position of wells, number of wells, and the discharge of groundwater pumping greatly determine changes in hydraulic head and groundwater flow patterns in a given hydrological area. This article proposes an optimisation model which is expected to be useful for finding the optimal pumping discharge value from production wells in a hydrological area. This model is a combination of solving the Laplace equation for two-dimensional groundwater flow in unconfined aquifers and the optimum variable search method based on the Shuffled Complex Evolution (SCE- UA) algorithm. Laplace equation uses the finite difference method for the central difference rule of the Crank Nicolson scheme. The system of equations has been solved using the M-FILE code from MATLAB. This article is a preliminary study which aims to examine the stability level of the optimisation equation system. Testing using a hypothetical data set shows that the model can work effectively, accurately, and consistently in solving the case of maximising pumping discharge from production wells in a hydrological area with a certain hydraulic head limitation. Consequently, the system of equations can also be applied to the case of confined aquifers.

The purpose of the work is to characterise pluvial conditions in central-eastern Poland from the beginning of the 21 ^st century (2001–2020). The analysis involved seven meteorological stations of the Institute of Meteorology and Water Management – National Research Institute (IMGW-PIB): Białowieża, Legionowo, Pułtusk, Siedlce, Szepietowo, Terespol and Warsaw. The work contains the analysis of the annual and seasonal atmospheric precipitation pattern (summer, winter, spring and autumn) and its temporal and spatial variation throughout a 20-year period. Moreover, the percentage share of precipitation in each season in the annual sum was calculated. In order to analyse precipitation patterns in the study period, the Innovative Trend Analysis (ITA) was applied. The average long-term annual atmospheric precipitation sum ranged from 557 mm at Terespol to 653 mm at Białowieża. The highest seasonal precipitation sum in the studied region was recorded for the summer (218 mm) whereas in spring and autumn, precipitation stayed at a similar level and amounted to 130 and 131 mm, respectively. The lowest precipitation was recorded in winter (109 mm). The highest percentage share of the atmospheric precipitation sum was associated with summer rainfall (from 35 to 38%), whereas the lowest in winter (from 18 to 20%). Comparisons of 2001–2010 and 2011–2020 decades revealed a decline in the share of summer precipitation in the annual sum at most of the stations, and an increase in the share of winter precipitation. The ITA demonstrated that the most significant trends in precipitation change occurred in summer and winter and the directions of the trends were different for each station.