During the last few years, the City of Bechar in Algeria has witnessed some extreme events, such as the great flood of the year 2008 in which an exceptional amount of rain was recorded with a flow rate of 830 m3∙s–1 (hwater = 4 m, b = 200 m); similar flooding also occurred in 2012 and 2014. The problem is that most of the City of Bechar has an urban sprawl that extends to the banks of Wadi Bechar, which represents a huge risk for the lives of the inhabitants of the region. The present work aims to assess the flood risk through flood hazard mapping. This method consists in determining the flow rates for the return periods of 25 years (Q25 = 388.6 m3∙s–1, hwater = 3.5 m, b = 200 m, Sspot = 55.35 ha), 50 years (Q50 = 478.3 m3∙s–1, hwater = 5 m, b = 200 m, Sspot = 66.48 ha) and 100 years (Q100 = 567.3 m3∙s–1, hwater = 7 m, b = 200 m, Sspot = 133 ha). For this, it is necessary to adjust the flow rates using Gumbel law along with some computer supports such as HEC-RAS, HEC- -GeoRAS and ArcGis for mapping the event. Finally, this work enables us to determine the zones exposed to risk of flooding and to classify them according to the flood water height.
Based on chemical analyses, the quality of ground waters for drinking, agricultural and industrial purposes was deter-mined in Rafsanjan Plain-Iran. Samples for analyses were taken from 22 wells in 2012. Because of high water hardness and total dissolved solids content, water was found to be unsuitable for drinking purposes. Water quality for agriculture was determined with the use of the Wilcox method. Among the analysed water, 10.33% were attributed to C3-S1 class (high electrolytic conductivity and low sodium adsorption ratio), 59.5% to class C4-S1 (very high EC and low SAR) and 30.17% to class C4-S2 (very high EC and medium SAR). 89.67% of studied wells were unsuitable for agriculture. Because of corro-sive water properties all but two wells on Rafsanjan Plain were undesirable for use in the industry. The results of qualitative analyses were presented in GIS and in databases to support making decision and management of groundwater on Rafsanjan Plain.
A strategic vision to ensure an adequate, safe and secure drinking water supply presents a challenge, particularly for such a small country as Jordan, faced with a critical supply-demand imbalance and a high risk of water quality deterioration. In order to provide sustainable and equitable long-term water management plans for the future, current and future demands, along with available adaptation options should be assessed through community engagement. An analysis of available water resources, existing demands and use per sector served to assess the nation’s historic water status. Taking into account the effect of both population growth and rainfall reduction, future per sector demands were predicted by linear temporal trend analysis. Water sector vulnerability and adaptation options were assessed by engaging thirty five stakeholders. A set of weighed-criterions were selected, adopted, modified, and then framed into comprehensive guidelines. A quantitative ratio-level approach was used to quantify the magnitude and likelihood of risks and opportunities associated with each proposed adaptation measure using the level of effectiveness and severity status. Prioritization indicated that public awareness and training programs were the most feasible and effective adaptation measures, while building new infrastructure was of low priority. Associated barriers were related to a lack of financial resources, institutional arrangements, and data collection, sharing, availability, consistency and transparency, as well as willingness to adapt. Independent community-based watershed-vulnerability analyses to address water integrity at watershed scale are recommended.
The paper presents the problem of the growing water deficit and the possibility of sustainable development of water resources in rural areas of Central and Eastern Europe (using the example of Poland). It is estimated that the amount of resources in this region is reduced by about 70% compared to the average for Europe. In drought periods it comes to limitation of economic activity, including agriculture. Particular attention was paid to the necessity to extend landscape, underground, and snow retention, as an alternative to dams, which are currently the most popular in lower-order catchments. It has been shown that the construction of small agricultural reservoirs is not always preceded by adequate consultations and pre-design studies, which may result in financial losses and legal problems. Simultaneous use of many alternative forms of retention should be more effective than the implementation of reservoirs. In addition, increasing the hydraulic roughness of the catchments slows down the outflow of products of erosion and contributes to the protection of surface retention structures (maintaining natural and economic usefulness of reservoirs).
Views on the objectives and role of water management have remarkably changed in the last years. The need of a complex water management that would consider all water users including agriculture and natural environment is often underlined. It is pointed out that agriculture and natural environment (including commercial forests) are basic consumers of precipitation water which is not considered in water and economic balances. More and more importance is attributed to the utilisation of waters from catchment basin and to application of non-technical measures of controlling water cycles. A large impact of agro-ecosystems and natural or semi-natural (forests, wetlands) ecosystems on water balance is underlined. This different approach to the problems of water management is expressed e.g. in Water Framework Directive of European Union devoted to surface and ground water protection. The directive attributes a great role to the protection of aquatic and water related ecosystems. More and more often it is realised that the total water resources are equal to the volume of atmospheric precipitation. Water management should involve not only the water in geological aquifers or river channels but also that which is retained in soil profile. Such elements of water balance as spatial distribution, interception, infiltration and recharge of ground water reservoirs, soil retention capacity, surface runoff and evapotranspiration depend largely on land use in a catchment. Through appropriate land use and catchment management, application of rational agro-technical methods, development of small retention, wetland restoration, and hampering water outflow from draining systems one may significantly affect water cycling in a catchment.
Small water resources of Poland, increasing water consumption, climate changes and requirements of environmental protection enforce the implementation of complex methods of water management and search for environmental-friendly methods of limiting economic losses caused by water deficit or excess. Saving water used for economic purposes and agriculture would permit better fulfilment of the needs of natural environment.
The Water Framework Directive (WFD), whose basic aim was to create a legal back-ground for water bodies’ protection, undoubtedly affects all economic sectors. Being a specific and distinctly different water user, agriculture will have the greatest share in the implementation of WFD out of all sectors of national economy. This results from its special character (60% of the country area used by agriculture), large volume of water consumed by evapotranspiration, diffuse pollution etc. Implementation of WFD will call for undertaking of many activities to restrict an unfavourable im-pact of agriculture on water resources and water related ecosystems. It is assumed that agriculture should also protect water resources. Accomplishment of this task imposes significant changes in the land use of river basins. Water management can be an essential factor deciding about the sustainable development of rural areas and biological diversity of agricultural landscape. Actions undertaken so far to implement the WFD are mainly limited to the protection of water quality from agricultural pol-lution. It is also necessary to undertake implementation of other aims of WFD. This refers especially to the provision of good hydromorphological status of water bodies, protection of water related eco-systems and effective water use.
Polish water resources depend on precipitations, which are variable in time and space. In dry years the water balance is negative in central parts of Poland but sudden thaws and downfalls may result in periodical water excess and dangerous floods almost in the entire country. The retention capacity of artificial reservoirs in Poland permits to store only 6% of the average annual runoff, which is commonly considered insufficient. Another method to increase retention is soil water con-trol. About fifty percent of soils in Poland consist of light and very light sandy soils with low water capacity. Loams and organogenic soils cover approximately 25% and 8.5% area of the country, re-spectively. Almost half of agricultural lands (48%) have relatively good water conditions, but the rest requires soil water control measures. An increase of the soil water content could be achieved by changes of soil properties, water table control and soil water management. Modernization and recon-struction of drainage and irrigation systems, which were built mainly in the period 1960–1980, is needed.
Irrigation in Croatia was until recently a neglected measure in food production, especially in continental part of the country. Development of drainage system in the last fifty years was more important due to the problems caused by floods and excess water in the fields. In the last decade the hydrological regime has been changed and drought events became as frequent as flood events, causing even more damage. Future development of agriculture in the northern counties of Croatia depends on the introduction of new, profitable crops which imply irrigation as an essential factor of future social and economic growth.
The first step in the implementation of irrigation was the development of National Irrigation Master
Plan as a framework for future activities.
According to the recommendations of the National Master Plan all counties have created County Irrigation Plans considering local natural conditions, social and economic background.
This paper is going to present how is that process of integrated water resources management developing in the continental part of Croatia on the example of Osijek County Irrigation Plan located in the Danube river basin.
The purpose of the paper is to analyze the spatial variability of precipitation in Poland in the years 1981–2010. The av-erage annual rainfall was 607 mm. Precipitation in Poland is characterized by high spatial and temporal variability. The lowest annual precipitation was recorded in the central part of the country, where they equaled 500 mm. The highest annual precipitation totals were determined in the south, equaling 970 mm. The average precipitation in the summer half-year is 382 mm (63% of the annual total). On the basis of data from 53 climate stations, maps were made of the spatial distribution of precipitation for the period of the year and winter and summer half-year. The kriging method was used to map rainfall distribution in Poland. In the case study, cross-validation was used to compare the prediction performances of three periods. Kriging, with exponential type of semivariogram, gave the best performance in the statistical sense. Their application is justices especially in areas where landform is very complex. In accordance with the assumptions, the mean prediction error (ME), mean standardized prediction error (MSE), and root mean-square standardized prediction error (RMSSE) values are approximately zero, and root-mean-square prediction error (RMSE) and average standard error (ASE) reach values well below 100.
Forecasts suggest that the freshwater resources available to our civilization will shrink by 30% in the coming two decades. How can we reverse the degradation of water resources and create a balance between the society’s demand for water and the capacity of the hydrosphere?