Streamflow modelling is a very important process in the management and planning of water resources. However, com-plex processes associated with the hydro-meteorological variables, such as non-stationarity, non-linearity, and randomness, make the streamflow prediction chaotic. The study developed multi linear regression (MLR) and back propagation neural network (BPNN) models to predict the streamflow of Wadi Hounet sub-basin in north-western Algeria using monthly hy-drometric data recorded between July 1983 and May 2016. The climatological inputs data are rainfall (P) and reference evapotranspiration (ETo) on a monthly scale. The outcomes for both BPNN and MLR models were evaluated using three statistical measurements: Nash–Sutcliffe efficiency coefficient (NSE), the coefficient of correlation (R) and root mean square error (RMSE). Predictive results revealed that the BPNN model exhibited good performance and accuracy in the prediction of streamflow over the MLR model during both training and validation phases. The outcomes demonstrated that BPNN-4 is the best performing model with the values of 0.885, 0.941 and 0.05 for NSE, R and RMSE, respectively. The highest NSE and R values and the lowest RMSE for both training and validation are an indication of the best network. Therefore, the BPNN model provides better prediction of the Hounet streamflow due to its capability to deal with complex nonlinearity procedures.

The Kelani River is the second largest watershed in Sri Lanka and the main water-supply intake point for the Greater Colombo. The present study focuses to identify the sources of pollutants of the meandering zone of the Kelani River, par-ticularly due to the absence of more recent information. Accordingly, a survey was conducted to obtain information on in-dustrial discharges, anthropological, and social activities within the area of 15 m from left and right banks of the river. The high contaminations (total and faecal coliform – 1100 MPN∙(100 cm3)–1; COD – 10 mg∙dm–3; BOD – 4 mg∙dm–3) of surface and groundwater are corroborated with the results obtained via the demographic and land usage statistics. Industrial pollu-tant sources and harmful anthropological practices were identified as major threats to the river basin. In this survey, agricul-ture and land degradation were identified as issues due to improper land use management. As policy recommendations based on the results of the study, it was identified that the awareness for Kelani River protection should be increased; moni-toring and evaluation of the Kelani River basin under a management plan should be implemented; and stakeholder and pri-vate partnerships contribution to the sustainability of the Kelani River basin should be established.

Our scientific research is based on oxidation reactions and monitoring of chemical reaction kinetics in the Velekinca groundwaters plant in Gjilan municipality, Kosovo. The GW of this plant contains high concentration of manganese so we need to use potassium permanganate (KMnO4) as one of the most power oxidants in the water treatment plant. In our re-search the high concentration of Mn in groundwaters is 0.22–0.28 mg∙dm–3 and this concentration is not in accordance with the WHO. Chlorine is one of the most common disinfectants used in the water treatment industry because it has a low cost and immediate effect on the destruction of microorganisms, the concentration of chlorine (Cl2) in our research is 0.1–0.32 mg∙dm–3. The speed of chemical reactions in the technology of GW is extremely important because sometimes in the elimi-nation of chemical pollutants using oxidizing agents often form intermediate species. The speed of reactions indicates how fast chemical bonds are formed in the creation of a product, and this depends on the rate of reaction (XA). The focus for the research is to study the potassium permanganate and chlorine gas reactions in water if it forms intermediate products (in-termediate species) due to the high speed of reactions. Scientific research conclusion, intermediate species in the oxidation reactions of Mn and water disinfection with Cl2(g) it is impossible to cause a high rate of chemical reactions from the reac-tion rate (XA = 1%) to the reaction rate (XA = 99%). The maximum speed at the highest XA Cl2 is from 4.405∙10–11 to 8.87∙10–10 mol∙dm–3∙s–1, while at Mn is (2.030–4.034)∙10–7 mol∙dm–3∙s–1.

In this research different methods for measuring water quality indices were conducted to investigate the performance of the newly designed, constructed and operated 9-Nissan water treatment plant, Iraq. Data gathering and implementation took place throughout winter and summer. Water samples were taken periodically, according to the standard method, the re-search was carried out by collecting different random samples for eight months (Jun. 2015–Jan. 2016) and measuring (tur-bidity, total hardness, pH, total dissolved solids, suspended solids, Cl–, Mg2+, Fe2+,NO3–, NH3+) for each sample. Five dif-ferent approaches and methodologies of calculating the water index were applied. The results revealed that the Water Qual-ity Indices varied from 70.55 to 88.24, when applying Canadian Council of Ministers of the Environment Water Quality Index (CCMEWQI) and British Columbia water quality index (BCWQI) geometric weighted mean respectively. All the results, from the five approaches indicated good water quality, multiple regression analyses were conducted for turbidity, total hardness and suspended solids, they found that these parameters are strongly related to each other and to other pa-rameters.

River training structures; such as submerged groynes are low profile linear structures that are generally located on the outside bank to form groynes fields and prevent the erosion of stream banks by keeping a flow away from it. In the present research, the maximum scour depth was measured based on laboratory experiments where different shapes of submerged groynes (I-shape, L-shape, T-shape) were used as sort of countermeasures to investigate about most shapes that reduce the scour around them. The result of submerged groynes showed a clear decrease in scour depth ratio due to increasing sub-merged ratio and increase the scour hole geometry with increasing of flow intensity, and also Froude number. The maxi-mum scour hole in this research was observed at T-shape groyne and then followed by I-shape groyne and L-shape groyne. The maximum scour depth that cased by I-shape was more than L-shape by a percentage about 8.2%, and it was less than T-shape by a percentage about 16.4%.

The use of non-centralised water supply in remote settlements is currently the only possible option. Monitoring the wa-ter quality of such supply sources is a complicated task in such areas, especially when there are active karst processes and difficult groundwater conditions. The application of deterministic analytical models of water supply under the risk of dis-turbance to groundwater dynamics is not efficient. Significant quantitative and even qualitative changes in groundwater conditions may take place between the calculated points, and the underestimation of these changes in expectation-driven computation models may result in serious geoecological issues. This research studied and justifies the use of adaptive dy-namic hydrogeological control in an area of non-centralised water supply based on the identification of key zones of geo-dynamic karst monitoring and the electrical express-monitoring of water resources. The identification of key zones is based on an integrated analysis of available groundwater information that describes changes in groundwater hydrodynamic condi-tions at the time of the karst forecast. The development of karst-suffusion processes is accompanied by more intense dy-namic changes in local areas of geologic environment compared to the general variation in intensity. Information about the occurrence of destructive groundwater processes by means of selective geodynamic monitoring may thus be obtained much earlier than with environmental geodynamics monitoring as a whole. The experimental hydrogeological control of an area of non-centralised water supply was conducted on the right bank of the Oka River in Nizhny Novgorod region, a locality with an active manifestation of karst processes. Structure and algorithms of space-time processing of hydrogeological con-trol data developed by authors have been used. The approach based on multifrequency vertical electrical sounding (MFVES) method has shown good correspondence with direct borehole observation when measuring depth of the first aq-uifer. Zones of unsafe water use have been revealed. The results demonstrated the effectiveness of the proposed method and the need for further regular observations of destructive groundwater processes by means of selective hydrogeodynamic monitoring.

Round goby (Neogobius melanostomus (Pallas, 1814)) is an invasive species in the Oder River. In this study, age of 147 fish was determined using scales and otoliths, and the Fraser-Lee back-calculation method was used for population structure and theoretical length growth rates with 3 mathematical models of growth: von Bertalanffy, Ford–Walford and 2nd degree polynomial. Fish condition was determined using Fulton, Le Cren and Clark equations. Average total length and weight of fish was 162.00 mm and 83.00 g, respectively. Males were more abundant than females, representing 70% of the fish caught, and achieved greater total lengths and weights. Age 2+ dominated females and 3+ males age groups. Of the three mathematical models used to estimate fish growth, the 2nd degree polynomial model had the best fit to back-calculated lengths. Males had slightly higher growth rates than females in the first two years of life but comparable in subsequent years. The diet consisted of various benthic organisms that varied with fish age. The most frequently occurring food com-ponent was Dreissena polymorpha, which accounted for approximately 70% in the diet of fish with a body length greater than 191 mm.

This study aims to assess the water quality and determine the pollution index of the Bedadung River in the urban-area segment of Jember Regency, East Java. The sampling in the urban segment of Jember was conducted in May 2019 at five different locations, namely Slamet Riyadi Street, Mastrip Street, Bengawan Solo Street, Sumatra Street, and Imam Bonjol Street. The pollution index assessment refers to the Decree of the State Minister for the Environment of Indonesia Republic number 115 of 2003. The analysis showed that the parameters of TDS, TSS, pH, COD, BOD, NH3-N, Co, Cd, Cu, Zn, H2S, Cl–, SO4, oil and fats, MBAS, NO2-N, Fe, Pb, F, Cl2, NO3-N, phenol, and As did not exceed the quality standards. The parameters PO4, CN, total coliform, and faecal coliform were found to breach the quality standards at the 5 water sam-pling points. Total coliform and faecal coliform were the dominant pollutants in this segment. Therefore, the parameters of PO4, total coliform, and faecal coliform were considered as indicators of pollution arising from domestic and agricultural activities. The pollution index values for the five sampling locations ranged from 7.21 to 8.23. These scores indicate that the Bedadung River section that passes through the urban segment in Jember is classified as being in the moderately pollut-ed category. This preliminary rapid assessment is therefore one of the considerations for the management of water quality in the Bedadung River section that passes through the urban area of Jember.

Dry marginal agricultural land (DryMAL) potentially use as an alternative resource for crop production. DryMAL de-fined as land having low natural fertility due to its intrinsic properties and forming environmental factors. This study uses Sentinel-2A imagery to map the spatial extent, compare the result of the classification, and identify the change in DryMAL occupation. The area of study (461.9 km2) is part of Situbondo Regency and is located at the eastern part of East Java, In-donesia. Sentinel-2A image captured in dry-season of 2018 use for this study. Then, supervised image classification using a maximum likelihood algorithm use for image treatment and processing. Furthermore, 450 ground control points for train-ing areas collected during the field surveys. Five bands use in the classification process. The maps produced from the clas-sification process were then compared to the land-use map from the year 2000. The change in DryMAL occupation from 2000 to 2018 was calculated by comparing the classified and land-use map. Supervised classification yielded an overall accuracy of 95.8% and a kappa accuracy of 93.2%. The classification produced six (6) classes of land use: (1) forest, (2) pavement or built-up area, (3) irrigated paddy field, (4) non-irrigated rural area, (5) dry marginal land and (6) water body. Globally, during the last two decades, regional development led by the Regency occupied more DryMAL area for develop-ing plantation. The effort reduces the amount of non-irrigated and converting to the plantation, pavement areas, and irrigat-ed paddy-field.

Infiltration process plays important role in water balance concept particularly in runoff analysis, groundwater re-charged, and water conservation. Hence, increasing knowledge concerning infiltration process becomes essential for water manager to gain an effective solution to water resources problems. This study employed multiple linear regression for esti-mating infiltration rate where the soil properties used as the predictor variable and measured infiltration rate as the response variable. Field measurement was conducted at sixteen points to obtain infiltration rate using double ring infiltrometer and soil properties namely soil porosity, silt, clay, sand content, degree of saturation, and water content. The result showed that measured infiltration rate had an average initial infiltration rate (f0) of 6.92 mm∙min–1 and final infiltration rate (fc) of 1.49 mm∙min–1. Soil porosity and sand content showed a positive correlation with infiltration rate by 0.842, 0.639, respectively, while silt, clay, water content, and degree of saturation exhibited a negative correlation by –0.631, –0.743, –0.66 and –0.49, respectively. Three types of regression equations were established based on type of soil properties used as predictor varia-bles. The model performance analysis was conducted for each equation and the result shows that the equation with five predictor variables fMLR_3 = – 62.014 + 1.142 soil porosity – 0.205 clay, – 0.063 sand – 0.301, silt + 0.07 soil water content with R2 (0.87) and Nash–Sutcliffe (0.998) gave the best result for estimating infiltration rate. The study found that soil po-rosity contributes mostly to the regression equation that indicates great influence in controlling soil infiltration behavior.

The intensive agricultural use of the land affects both quantity and quality of river water in the catchment area. Such impact is visible also in the Szreniawa River catchment in the Małopolskie Voivodeship. The combination of intensive plowing and soil susceptibility to water erosion are the main causes of soil and nutrients depletion during the heavy rainfall. The aim of the study is to determine changes in the water quality in the Szreniawa River catchment compared to the agri-culture use and precipitation level.

The quality of surface water has been analysed in the river catchment area in three sampling points. The concentration of the total suspended soils in the samples collected after heavy rainfall in August 2017 reached a value of 837 mg·dm–3. The average concentrations of N-NO3 in the years of 2016–2019 ranged from 0.16 to 13.46 mg·dm–3, with the highest val-ues in the summer (up to 13.46 mg·dm–3). The concentration of N-NH4 and P-PO4 in the Szreniawa water was affected by precipitation. The highest value of average concentration of N-NH4 3.00 mg·dm–3 was recorded in the autumn of 2019 in the middle section of the river. The highest value of P-PO4 0.90 mg·dm–3 was recorded in the autumn of 2019 mostly due to water erosion of the loess areas. Erosion has been caused by the short-term heavy rainfall. As a result, suspended solids, soluble and insoluble phosphorus compounds leaked to the river.

The paper deals with the digital architecture concept which is trying to introduce a new spatial language into the con-text of water urbanism, using nature as a model, measure and mentor. The first part analyses Biomimetics with its design strategies and methods. The Problem-Based Approach (designers look to nature for solutions) and the Solution-Based Ap-proach (biological knowledge influences human design) are defined here. In the second part of the research, the authors present selected examples to the topic. This case study has demonstrated that a new approach to architectural design is emerging. This approach redefines the process of architectural design, understood not as the traditional shaping of the ob-ject's form, but as a compilation of various factors resulting from changeable climate characteristics and ecology. The con-clusions emphasize that not only the contemporary understanding of ecology should be changed, but also the way architects approach the built environment, especially in the aquatic environment.

This paper investigated the problems and impacts of transient flow in pipeline systems due to pump power failure. The impact of different protection devices was presented to assure surge protection for the pipeline system. A model via Bent-ley HAMMER V8.0 Edition was employed to analyse and simulate hydraulic transients in the pipeline system, and protec-tion alternatives were studied.

Surge protection included using only an air vessel, using an air vessel and two surge tanks, and employing five air ves-sels and vacuum breaker. The obtained results for pressures, heads, and cavitation along the pipeline system were graph-ically presented for various operating conditions. Using five air vessels with vacuum breaker valve as surge protection proved to be more effective and economical against pump power failure.

Changing the flow density did not have a significant impact on the pressures.

For protection with an air vessel; it was concluded that the value 40% of the original diameter for inlet pipe diameter of air vessel, and the value of 2/3 of original pipe diameter were critical values for the transient pressures. Cast iron pipes proved to be the best pipe material for all studied volumes of the air vessel.

For protection with an air vessel and two surge tanks; as the inlet pipe diameters increased the maximum pressures in-creased and the minimum pressures decreased.

Regression analyses were performed obtaining equations to predict the pressures according to the inlet pipe diameter, the area of surge tank, and the pipe diameter.

The aim of the paper is to provide climatic data from the basic elements and characteristics of the energy balance in terms of the current state and in terms of trends and assumptions of their future changes in Slovakia. Climate change affect agriculture and its procedures. Changes in vegetation period in Slovakia of selected vegetables are presented in this study. We used for agro-climatic analysis one hundred climatological stations, which were selected to cover all agricultural re-gions up to 800 m a.s.l. Actual data and predictions were compared with time period 1961–2010. Due to homogeneity in data measurements, was chosen this period. We obtained climate trends and assumed map outputs of future climate chang-es by mathematical-statistical methods for horizons of years 2011–2020, 2041–2050, 2071–2080 and 2091–2100. We ana-lysed vegetation period changes of selected fruit vegetables, Brassica vegetables and root vegetable in field conditions with prediction to year 2100. In our results is shown the earlier beginning of vegetation period in a spring and later end in an autumn in last 30 years. The vegetation period is getting longer about 15–20 days for Capsicum annuum; 15–20 days for Brassica oleracea var. capitate; 10–15 days for Beta vulgaris subsp. vulgaris with comparation of nowadays situation and period 2091–2100.

Anaerobic digestion (AD) is an adequate alternative to treat wastewater generated from fruit and vegetable processing (FVWW); likewise, in recent years, artificial wetlands (AWs) have been applied as a post-treatment process for anaerobi-cally pre-treated wastewater. The objective of this work was to design a sustainable treatment system for FVWW composed of upflow anaerobic reactors (UASB) with phase separation and an AW system that receive the anaerobically pretreated effluent. Using the design methodologies for the UASB reactors and artificial wetlands with sub-surface flow (AW-SSF), the parameters of the combined AD-AW system that treat a wastewater flow of 300 m3∙d–1 were calculated. The UASB acidogenic system was adjusted to a hydraulic retention time (HRT) of 10 h and organic loading rate (OLR) of 13.84 kg COD m–3∙d–1; meanwhile, the methanogenic and cascade UASB reactors with OLRs of 10.0 and 3.0 kg COD m3∙d–1, and HRTs of 11 and 10 h, respectively, achieve a high COD removal efficiency (above 94%), and an overall biogas production rate of 1.53 m3 of biogas per m3 of reactor capacity per day. According to the results obtained with the theoretical design, anaerobic-wetland combined system achieves an overall efficiency greater than 98%. The wastewater treated by the pro-posed system will allow the reuse of 30% of the water used in the washing of fruits and vegetables.

The study took place between 2012 and 2014 in Falenty near Warsaw, Poland, as part of a long-term scientific experi-ment (first began in 1987) using the randomized block method. All blocks were irrigated until 2008. In 2009 each block was divided into two areas: irrigated and non-irrigated. The study involved four levels of inorganic nitrogen fertilizer and two levels of mixed inorganic and organic fertilizer in the form of fermented cattle urine. The soil in all experimental plots was characterized by low levels of zinc, ranging from 7.6 to 16.7 mg Zn∙kg–1 dry matter. Much lower Zn content in both soil layers of all irrigated plots was associated with increased yields on these plots, regardless of the level and form of ferti-lizer. The content of Zn in soil and sward in 2014 year was significantly lower compared in 2012. Inadequate levels of zinc for ruminant nutrition were observed in the sward from all plots (15.4–28.8 mg∙kg–1 dry matter). The higher content of zinc was found in sward harvested from the plot, which was not fertilized with phosphorus. The long-term inorganic and fer-mented urine fertilization resulted in very low zinc content in the soil and meadow sward.

The article comprises synthesis of magnetically susceptible carbon sorbents based on bio raw materials – beet pulp. The synthesis was performed by one- and two-step methodology using FeCl3 as an activating agent. X-ray diffraction methods showed an increase in the distance between graphene layers to 3.7 Å in biocarbon synthesized by a two-step tech-nique and a slight decrease in inter-graphene distance to 3.55 Å for biocarbon synthesized by an one-step technique. In both magnetically susceptible samples, the Fe3O4 magnetite phase was identified. Biocarbon synthesized by a two-step technique is characterized by a microporous structure in which a significant volume fraction (about 35%) is made by pores of 2.2 and 5 nm radius. In the sample after a one-step synthesis, a significant increase in the fraction of pores with radii from 5 to 30 nm and a decrease in the proportion of pores with radii greater than 30 nm can be detected. Based on the analysis of low-angle X-ray scattering data, it is established that carbon without magnetic activation has the smallest specific area of 212 m2∙сm–3, carbon after one-stage synthesis has a slightly larger area of 280 m2∙сm–3, and after two-stage synthesis has the largest specific surface area in 480 m2∙сm–3. The adsorption isotherms of blue methylene have been studied. Biocarbon ob-tained by two-step synthesis has been shown to have significantly better adsorption properties than other synthesized bio-carbons. Isotherms have been analysed based on the Langmuir model.

The conservation of rainwater and augmentation of groundwater reserve is necessary to meet the increased water de-mands. Precipitation occurring in the smart cities need to be understood for a better water management action plan. There-fore, monotonic precipitation trend analysis was performed for eight smart cities drawn from six monsoon homogeneous regions across India. The precipitation data were investigated for trends using the modified Mann–Kendall (MMK) test and Sen’s slope estimator at annual, seasonal and monthly scales. The trend analysis was carried out over 118 years (from 1901 to 2018) at 95% significance level. The Dehradun city (Northern Himalayan region) showed a significant increasing annual precipitation trend (Z = +3.22). Indore and Bhopal cities from West Central region showed significant increasing annual trend (Z = +2.01) and non-significant decreasing annual trend respectively. Although, Vadodara and Jaipur are lying in the same Northwest region, the trends are opposite in nature. Jaipur city showed a significant increasing annual pre-monsoon trend (Z = +2.44). The winter rainfall in the city of Vadodara is showing a significant decreasing trend (Z = –2.16). The pre-monsoon rainfall in Bhubaneswar (Central Northeast region) and monsoon precipitation in Trivandrum (Peninsular region) are showing significant increasing (Z = +2.56) and decreasing (Z = –2.71) trends, respectively. A non-significant decreasing trend was seen in Guwahati city (Northeast region). The eight smart cities selected for investigation are not truly representing the entire country. However, the study is clearly pointing towards the regional disparity existing in the coun-try. These findings will be helpful for water managers and policymakers in these regions for better water management.

Contemporary challenges related to rapid urbanization, migration, deepening inequalities and climate change inspire to contemplate the future of dwelling. The article aims to present particular solutions in housing that use advantages created by the relation to the water. The aquatic neighbourhoods become a field of experience for residential architecture, where traditional systems are enriched with new elements and solutions. Some of these solutions can be brought back to the sys-tem and improve the overall catalogue of answers for the development of traditional dwelling.

The analysis discusses contemporary housing projects 1998–2005 and includes: the program overview, basic numerical parameters, accessibility details and relation to the context. Current water-related examples are accompanied by a reference to standard solutions developed in the modern era. All presented designs use traditional components of dwelling program, grouping day zone elements and separate them from private spaces. In basic parameters development is visible in bigger areas of living space. In terms of accessibility housing on or close to water gives new opportunities, as well as in relation to the context.

The paper presents research on different types of dwelling located by the water, with particular emphasis on functional and architectural advantages, which may be used to improve contemporary housing models. The proposed guidelines can be used in further studies on housing typologies in aim to develop more open and flexible spatial layouts.

The results of a long-term water level monitoring in three forest ponds are presented in the paper. The ponds are locat-ed in the Wielisławice and Laski forest districts in South Wielkopolska, Poland. Two of the analysed ponds are natural ones supplied by precipitation and the third now is disused artificial fishpond of throughflow water management. Systematic water level measurements, as well as measurement of basic meteorological conditions – precipitation and air temperature – were carried out in the 2000–2016 hydrological period. The basic statistics as well as the trends in long-time changes in water levels, were determined using the nonparametric Mann–Kendall test were calculated. The results obtained were sta-tistically inconclusive, but they indicated downward trends in water levels in the natural ponds and upward trends in water levels in the artificial pond. Although a statistically significant downward trend was observed in only one natural pond, it may suggest some negative changes occurring in the catchment of ponds in general.

The issues discussed in the paper concern the assessment of changes in quantitative and qualitative indicators of water resources in the climatic conditions of the southern part of Kazakhstan. For this purpose, many years of systematic field observations and other continuous data obtained from the functioning measurement and observation stations operating within the Aral-Syrdarya Basin Inspection were used. On the basis of the obtained data, indicators were determined that characterize the quantity and quality of water supplied to the soil in the irrigation process, as well as the quantity and quali-ty of water flowing out of the drainage systems, together with an evaluation of the effectiveness of irrigation and drainage systems. Soil salinity was assessed in five irrigated massifs with a total area of 332.55 thous. ha. For the same irrigated massifs, the annual amounts of water taken for irrigation, the amount of outflowing water and the assessment of the miner-alization level were determined. Based on the developed results of field observations characterizing the hydrological and environmental situation of the lower section of the Syr Darya River in 1960–2015, the negative reaction coefficients were calculated for the local population, soil and vegetation for five of the irrigated massifs of the Kyzylorda region. The ecolog-ical situation of the habitat of soil and plants in the lower reaches of the Syr Darya River in all irrigation areas deteriorates on a time scale, since as a result of the reclamation of agricultural lands, intensive secondary soil salinization occurs and the formation of infiltration runoff with high mineralization, contributing to the violation of the harmonization of the relation-ship between nature and man.

Scarcity of freshwater is one of the major issues which hinders nourishment in large portion of the countries like Ethio-pia. The communities in the Dawe River watershed are facing acute water shortage where water harvesting is vital means of survival. The purpose of this study was to identify optimal water harvesting areas by considering socioeconomic and biophysical factors. This was performed through the integration of soil and water assessment tool (SWAT) model, remote sensing (RS) and Geographic Information System (GIS) technique based on multi-criteria evaluation (MCE). The parame-ters used for the selection of optimal sites for rainwater harvesting were surface runoff, soil texture, land use land cover, slope gradient and stakeholders’ priority. Rainfall data was acquired from the neighbouring weather stations while infor-mation about the soil was attained from laboratory analysis using pipette method. Runoff depth was estimated using SWAT model. The statistical performance of the model in estimating the runoff was revealed with coefficient of determination (R2) of 0.81 and Nash–Sutcliffe Efficiency (NSE) of 0.76 for monthly calibration and R2 of 0.79 and NSE of 0.72 for monthly validation periods. The result implied that there's adequate runoff water to be conserved. Combination of hydrological model with GIS and RS was found to be a vital tool in estimating rainfall runoff and mapping suitable water harvest home sites.

The awareness of the growing importance of the complexity in creating a new type of a modern enterprise strategy and in introducing changes within planning, control and organizational structures contributed to undertaking studies on relationships occurring between the complexity of a modern enterprise and its flexibility in the sector of industrial automation, as well as filling the gap relating to the cognitive impact of poor complexity management on the flexibility of the company. The main objective of the research work is to check whether there is an important relationship between the complexity of the business and its flexibility in the industrial automation sector. Quantification of the relationship between these two quantities – the complexity and flexibility – happened by the use of the Multidimensional Correspondence Analysis (MCA) and Perceptual Maps. The study which has been carried out indicated that the flexibility and complexity functions in the enterprise management rise, however, the knowledge of these issues is highly insufficient. The research discovered that the obstacles which hamper striking a balance between the flexibility and complexity in their advanced stages exert a devastating impact on the quality of the process management. Reducing the flexibility at its higher levels generates a context in which the market risk is enhanced. Companies characterised by improper flexibility management bear higher workforce costs and their processes of decision-making last longer. Methodical and systematized study of flexibility and complexity will decrease the destructive influence of the interaction between these two categories.