Development Of Water Management Strategies Research Articles

Effects of Drought Stress on the Morphological Structure and Flower Organ Physiological Characteristics of Camellia oleifera Flower Buds

Investigations on the impact of drought stress on the reproductive growth of C. oleifera have been relatively limited compared to the extensive research conducted on its nutritional growth. To study the effects of drought stress on the growth and development of C. oleifera flower buds, we investigated the effects of drought stress on the bud anatomical structure, relative water content, relative electrical conductivity, antioxidant enzyme activity, osmoregulation substance content, and hormone contents of C. oleifera using 4-year-old potted plants (‘Huaxin’ cultivar) as experimental materials. We observed C. oleifera flower bud shrinkage, faded pollen colour, shortened style length, decreased relative water content, increased relative electrical conductivity, and decreased pollen germination rate under drought stress. As the stress treatment duration increased, the malondialdehyde (MDA), soluble sugar (SS), soluble protein (SP), and proline (Pro) contents, as well as peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) activities increased. Moreover, the levels of the plant hormones indole acetic acid (IAA) and cytokinin (CTK) increased, whereas those of salicylic acid (SA) and jasmonic acid (JA) decreased, and those of abscisic acid (ABA) and gibberellin a3 (GA3) first increased and then decreased. Compared to the control group, the drought treatment group exhibited stronger antioxidant capacity, water regulation ability, and drought stress protection. These results indicate that C. oleifera is adaptable to drought-prone environments. The results of this study provide a theoretical basis for the evaluation of drought resistance in C. oleifera, as well as the development of water management strategies for cultivation.

Responses of Terrestrial Evapotranspiration to Extreme Drought: A Review

Terrestrial evapotranspiration (ET) is crucial to the exchange of global carbon, water, and energy cycles and links the hydrological and ecological processes. The frequency and intensity of extreme droughts are expected to increase due to ongoing climate change, strongly impacting terrestrial ET with implications for ecosystems, societies, and climate systems. However, the response of terrestrial ET to extreme drought and the underlying mechanism of terrestrial ET change during droughts are still unclear. Here, we review previous studies on terrestrial ET’s responses to extreme drought and investigate the control factors of ET change in response to extreme drought under different situations. The response of terrestrial ET to extreme drought is affected by various factors including the duration and intensity of the drought, the original climate conditions, as well as the plant species. Terrestrial ET change during droughts is controlled by complex biological and physical processes that can be divided into four parts including supply, energy, demand, and vegetation activities. The response of terrestrial ET to elevate CO2 may offset the effects of drought because CO2 fertilization tends to increase water use efficiency through stomatal regulation. We found that large uncertainties remain in the terrestrial ET response to drought due to the discrepancies among different ET products and simulations. This work highlights the requirement for accurate estimates of ET changes in ET products and models. This review provides a systematic investigation of the terrestrial ET response to extreme drought and the underlying mechanism of terrestrial ET changes during droughts and will significantly improve the development of water management strategies under climate change.

Development and Management of Base Flow of a Sand-dominated Alluvial Aquifer of a Large Ephemeral River for Drinking Water Supply in Semi-arid and Fluoride Affected Areas: Example of the River Mayurakshi, Birbhum District, West Bengal, India

Semi-arid tropical regions in India and elsewhere face major challenges in the management of public water supply for drinking purpose. In such regions knowledge on base flow availability in major rivers is important in development of water management strategies and estimation of small to medium water supplies especially for semi-arid conditions where groundwater is contaminated with fluoride at variable depths.

Modeling and assessing the function and sustainability of natural patches in salt-affected agro-ecosystems: Application to tamarisk (Tamarix chinensis Lour.) in Hetao, upper Yellow River basin

Relatively low-lying zones of natural vegetation within irrigated areas are not only carriers of biodiversity but also dry drainage areas of excess water and salts applied to nearby croplands. It is thus useful to have a correct understanding of the soil water-salt dynamics and plant water use for keeping the sustainability of those natural areas. The HYDRUS-dualKc model that couples the HYDRUS-1D model with the FAO-56 dualKc approach was extended to simulate the eco-hydrological processes in natural patches of Hetao Irrigation District (Hetao), upper Yellow River basin. Field experiments were conducted in a tamarisk (Tamarix chinensis Lour.) dominated area during the growing seasons of 2012 and 2013. The model was calibrated and validated using the two-year experimental data, and applied to analyze the water and salt dynamics and the tamarisk water consumption for the present situation. Then, various groundwater depth (i.e. the depth from groundwater surface to water table, GWD) scenarios were simulated while considering the fluctuating and constant regimes of GWD changes, as well as variations of the rooting depth. Results indicated that this natural land functioned efficiently as a drainage area for subsurface flow and excess salt from surrounding croplands. However, the present GWDs were too shallow leading to high soil evaporation and severe salt stress. The soil evaporation accounted for 50% of the total evapotranspiration (ETa) while root zone salt storage increased about 50% during growing seasons. On the basis of scenario analysis, an optimum groundwater depth of 140–200 cm with smaller fluctuation was suggested for the growing seasons of natural patches. In addition, tamarisk growth could be largely improved if the roots can grow deeper with water table decline in the future. We demonstrated that monitoring and modeling could be used to support the development of water management strategies in Hetao aimed at conserving water while sustaining local ecosystems.

Comparing global precipitation data sets in eastern Africa: a case study of Kilombero Valley, Tanzania

In the face of limited or no precipitation data, global precipitation data sets (GPDs) may provide a viable alternative to gauge or ground radar data. This study aims to provide guidance to the choice of GPDs targeting scales relevant to water resources management in data poor regions. Specifically, the 34 000 km2 Kilombero Valley in central Tanzania, where water resource management is seen as integral to poverty reduction and food security, is used as a case study for performance evaluation of seven GPDs and their ensemble mean against the Tropical Rainfall Measuring Mission (TRMM) multi-satellite precipitation analysis research-grade product v7 (TRMMv7). The GPDs include one satellite rainfall product [Climate Prediction Center morphing technique v1.0 CRT (CMORPH)], three reanalysis products [Climate Forecasting System Reanalysis (CFSR), European reanalysis interim (ERA-i) and Modern Era Retrospective-Analysis for Research and Applications (MERRA)] and three interpolated data sets [Climate Research Unit Time Series 3.21 (CRU), Global Precipitation and Climatology Center v6 data set (GPCC) and University of Delaware Air Temperature and Precipitation v3.01 data set (UDEL)]. Standard statistical performance measures and spatial patterns were evaluated for the common overlap time period 1998–2010. For this region, the principal seasonality of the climatology was well represented in all GPDs; however, the intraseasonal variability and the spatial precipitation patterns were less well represented. The ensemble mean and GPCC had the best performance with regard to the analysis of the time series while CMORPH and GPCC had the best performance with regard to the spatial pattern analysis. These results indicate that the spatial scale intended for application is a major factor impacting the suitability of a given GPD for hydrometrological studies that form a basis for development of water management strategies.

Connecting European snow cover variability with large scale atmospheric patterns

Abstract. Winter snowfall and its temporal variability are important factors in the development of water management strategies for snow-dominated regions. For example, mountain regions of Europe rely on snow for recreation, and on snowmelt for water supply and hydropower. It is still unclear whether in these regions the snow regime is undergoing any major significant change. Moreover, snow interannual variability depends on different climatic variables, such as precipitation and temperature, and their interplay with atmospheric and pressure conditions. This paper uses the EASE Grid weekly snow cover and Ice Extent database from the National Snow and Ice Data Center to assess the possible existence of trends in snow cover across Europe. This database provides a representation of snow cover fields in Europe for the period 1972–2006 and is used here to construct snow cover indices, both in time and space. These indices allow us to investigate the historical spatial and temporal variability of European snow cover fields, and to relate them to the modes of climate variability that are known to affect the European climate. We find that both the spatial and temporal variability of snow cover are strongly related to the Arctic Oscillation during wintertime. In the other seasons, weaker correlation appears between snow cover and the other patterns of climate variability, such as the East Atlantic, the East Atlantic West Russia, the North Atlantic Oscillation, the Polar Pattern and the Scandinavian Pattern.

DSS Application to the Development of Water Management Strategies in Ribeiras do Algarve River Basin

Within the Project – “Developing Strategies for Regulating and Managing Water Resources and Demand in Water Deficient Regions (WSM)” funded by the EU in fifth Research Framework Program, the Ribeiras do Algarve River Basin was chosen as a case study to develop a DSS for planning purposes. Located in the southern stretch of the Portuguese territory, crucial conflicts do exist between tourist and agricultural water uses within the river basin. Additionally, there are important deficiencies in urban secondary water supply. Also inadequate irrigation methods and poor quality of water existing in some areas urge the implementation of management measures. Different ways to improve the water management situation were analysed: (a) structural options, (b) demand management options and (c) socio-economic measures. These options were analysed using a range of combinations of extreme demand and availability scenarios and ranked based on indicators reflecting the perception of the local stakeholders towards economic development and social and environmental sustainability. On a second phase, the formulation of strategies using the available options was addressed and two different strategies, resulting from a tentative timeframe of water management options combination, were applied aiming to achieve goals defined with regional stakeholders, namely: (a) on a first stage, the optimization of the domestic and irrigation water demand coverage and aquifer’s groundwater exploitation use ratio; (b) on a second stage, the determination of the water pricing increase necessary to achieve economical sustainability, aiming at cost recovery goals in accordance with the Water Framework Directive compliance.

The Driver-Pressure-State-Impact-Response (DPSIR) approach for integrated catchment-coastal zone management: preliminary application to the Po catchment-Adriatic Sea coastal zone system

The European Water Policy and, in particular, the Water Framework Directive (WFD) 2000/60/EC introduced the necessity to evaluate new methodological approaches for the development of Water Management Strategies oriented to support Sustainable Development. In the context of the EUROCAT Project, the Driver-Pressure-State-Impact-Response (DPSIR) framework was identified as a possible analysis framework for the development of management strategies according to the European Water Policy. An ad-hoc DPSIR framework was developed for the Po River Catchment and the North Adriatic coastal zone in order to elaborate possible strategies for controlling and/or reducing eutrophication. This approach combines socio-economic analysis with spatial analysis of pollutant transport and impact on the catchment-coastal zone system. The preliminary evaluation of the DPSIR approach highlighted the fact that the major Driving forces are agriculture and livestock activities and the civil and industrial sectors. Before establishing possible management strategies, it is necessary to assess the relevance of each Driving force on eutrophication in terms of Pressure factors. Combining socio-economic analysis with the evaluation of major nutrient pathways, it is possible to understand the relationship between the socio-economic development of the Po basin and eutrophication in coastal zone. The nutrient loads, i.e. the Pressures deriving from each Driver were evaluated in terms of potential and effective loads. Fifty-one percent of the Nitrogen load (carried in superficial waters) derives from agriculture and livestock (fertilizer use and manure spreading), while 40% from civil and industrial sectors. Concerning phosphorus loads the major contribution is provided by civil and industrial sectors (62% of total phosphorus load). The DPSIR development permits the identification of the impact of socio-economic development on the qualitative state of both marine and superficial waters in terms of interaction between the trophic system and ecological conditions. The qualitative state of the Po River and the main tributaries ranges between the sufficient and good levels evaluated using the Macro-descriptor Pollution Level Index (LIM). The bulk of nutrients discharged into the North Adriatic coastal zone generate the change of environmental conditions in terms of loss of water qualitative state. The assessment of the water qualitative state for marine waters was performed using an appropriate indicator the Trophic Index (TRIX) according to the Italian legislative framework (Dlgs. 152/1999). Knowledge of the main biogeochemical processes of nutrients and the assessments of DPSIR components is the starting point for the scenario analysis.

Evapotranspiration Research Priorities for the Next Decade—Irrigation

ABSTRACT IRRIGATION uses ET data for design, management and establishing water rights. The process of irrigation is to apply water to meet the evapotranspiration demands of vegetation. The objective of this paper is to explore areas or topics for research that would enhance the design and operation of irrigation systems. Eight research priorities are identified as topics needing further study to develop the technology for improving the use of ET data in irrigation. Irrigation is one of the major users of our water resources. According to the Irrigation Journal's 1985* survey, approximately 24 million ha are irrigated in in the U.S. Irrigation is confined primarily to the western states, but irrigation is expanding quite rapidly in the humid regions of the eastern U.S. as well. In the west, the municipal, industrial and hydropower demands on water supplies are requiring improved irrigation management as the available water for irrigation becomes limited. Even in the east the water available for irrigation can be in short supply, particularly during times of drought. Evapotranspiration is an essential factor in the design of management of irrigation systems. Irrigation is the application of water to meet part of the evapotranspiration demands of vegetation. A significant amount of water is used for the irrigation of lawns, gardens, and ornamentals. However, in this paper the needs for ET research as used in irrigation will emphasize agricultural crop production. The proceedings of the ASAE 1985 National Conference on Advances in Evapotranspiration provide an insight to the emphasis of recent research. Many of the papers in this proceedings were directed towards the uses of ET for irrigation. The primary use of ET information in irrigation is for design, irrigation scheduling and development of water management strategies with and without water constraints. The adjudication of water rights and the transfer or sale of these rights often require past, present and future estimates of ET. The actual ET minus effective precipitation (beneficial use) is the amount of existing water rights that many states allow to be transferred to other uses such as municipal, industrial and other new agricultural development. The objective of this paper is to identify ET research needs for irrigation in the next decade. The following discussion will identify and discuss the uses of ET data for irrigation, but is not intended to be an exhaustive literature review of the subject. This will be followed by a brief discussion on how ET is measured or calculated. The last section proposes potential research needs to obtain adequate ET information for the design and management of irrigation systems..