Water Management Capacity Research Articles

Why Do Farmers Disadopt Successful Innovations? Socio-Ecological Niches and Rice Intensification

The adoption of innovations in rice cultivation is presumed to operate in a rational manner, wherein new technologies or practices that successfully increase productivity or resource efficiency are adopted by target farmers based on cost-benefit calculations. In contrast, this paper examines a case of a public initiative to promote the system of rice intensification (SRI), wherein farmers widely disadopted the technique despite reporting increasing yields and reduced water consumption. To explain this paradox, we use the concept of the socio-ecological niche to examine a range of social and institutional factors that shape farmers’ decision-making. These included (1) access to land and labour; (2) water management capacity; (3) the quality of networks for knowledge sharing. The research suggests that small variations in these categories among otherwise similar smallholder households can markedly shape farmers’ risk perceptions and tangible outcomes with SRI. The implication is that agricultural innovations should be judged within their wider social context rather than on narrow evaluations of agronomic efficiency. Importantly, this must involve greater feedback mechanisms from smallholders with a variety of socio-economic profiles to help shape the character of agricultural innovations and extension strategies.

Influence of rainfall changes from 4.6 to 3.0 ka BP on ceramic pipes

The impact of climate change on human social development has been a topic of research for a long time. Ceramic pipes, which are vital components of urban drainage engineering, are crucial means of managing rain hazards and floods. Exploring the historical evolution of ceramic pipes can help in better understanding the interplay between climate change and human behavior. This study examined the diameters of 86 ceramic pipes unearthed from six cultural sites in central China, including Pingliangtai, Taosi, and Erlitou, dated to 4600–3040 a BP. By combining speleothem records from the excavation sites with precipitation and temperature composite curves for China using Pearson correlation analysis, and verifying with pollen records. The results show that changes in rainfall were the main factor influencing the diameters of the ceramic pipes. This indicates that during this period, ancient people in the Central Plains of China were able to adjust the size of the ceramic pipes to regulate the water management capacity of urban water systems, thereby adapting urban development to climate change.

Liquid Water Characteristics in the Compressed Gradient Porosity Gas Diffusion Layer of Proton Exchange Membrane Fuel Cells Using the Lattice Boltzmann Method

The mitigation of water flooding in the gas diffusion layer (GDL) at relatively high current densities is indispensable for enhancing the performance of proton exchange membrane fuel cells (PEMFCs). In this paper, a 2D multicomponent LBM model is developed to investigate the effects of porosity distribution and compression on the liquid water dynamic behaviors and distribution. The results suggest that adopting the gradient GDL structure with increasing porosity along the thickness direction significantly reduces the breakthrough time and steady–state total water saturation inside the GDL. Moreover, the positive gradient structure reaches the highest breakthrough time and water saturation at 10% compression ratio (CR) when the GDL is compressed, and the corresponding values decrease with further increase of the CR. Considering the breakthrough time, total water saturation and water distribution at the entrance of the GDL at the same time, the gradient structure with continuously increasing porosity can perform better water management capacity at 30% CR. This paper is useful for understanding the two–phase process in a gradient GDL structure and provides guidance for future design and manufacturing.

Evaluation of the willingness and behavior of family farm water resource financing based on the Internet of Things SEM model

Abstract At present, China's rural water resources are in short supply and the water pollution situation is severe. Family farms are an important part of China's agricultural modernization, and their development level is an important indicator to measure the degree of modernization of a country and a region. The application of agricultural Internet of Things technology in the field of agriculture is helpful for solving the problem of water shortage in family farms in water shortage areas. Based on questionnaire data, this paper used structural equation modeling (SEM) to study the relationship between family farm water financing willingness and behavior. The results showed that the standardization coefficients of Assumption 1, Assumption 2 and Assumption 3 were 0.332, 0.267 and 0.311, respectively. It can be seen that the water resource financing willingness of family farms was greatly affected by their water-saving technology ability, water management ability and government policy support. However, the standardization coefficient of Assumption 5 was 0.087. It can be seen that the water management capacity had no significant impact on the water resource financing behavior, and the water resource financing behavior of family farms was mainly affected by their water-saving technical capacity and government policy support.

Water Management Capacity of Metal Foam Flow Field for PEMFC under Flooding Situation.

Porous metal foam with complex opening geometry has been used as a flow field to enhance the distribution of reactant gas and the removal of water in polymer electrolyte membrane fuel cells. In this study, the water management capacity of a metal foam flow field is experimentally investigated by polarization curve tests and electrochemical impedance spectroscopy measurements. Additionally, the dynamic behavior of water at the cathode and anode under various flooding situations is examined. It is found that obvious flooding phenomena are observed after water addition both into the anode and cathode, which are alleviated during a constant-potential test at 0.6 V. Greater abilities of anti-flooding and mass transfer and higher current densities are found as the same amount of water is added at the anode. No diffusion loop is depicted in the impedance plots although a 58.3% flow volume is occupied by water. The maximum current density of 1.0 A cm-2 and the lowest Rct around 17 mΩ cm2 are obtained at the optimum state after 40 and 50 min of operation as 2.0 and 2.5 g of water are added, respectively. The porous metal pores store a certain amount of water to humidify the membrane and achieve an internal "self-humidification" function.

Collective enhancement in hydrophobicity and electrical conductivity of gas diffusion layer and the electrochemical performance of PEMFCs

Gas diffusion layer (GDL) with optimized water management capacity facilitates the electrochemical performance of proton exchange membrane fuel cells (PEMFCs). However, the impact of hydrophobicity manipulation on the mass transport capacity of GDL makes it challenging to enhance the electrochemical performance of PEMFCs effectively. In this work, we proposed a facile strategy for collectively optimizing the hydrophobicity and electrical conductivity (EC) of GDL through the hydrothermal deposition followed by a high-temperature sintering process (HDS-GDL) Specifically, surface roughness of GDL and corresponding fiber diameter firstly increases after the hydrothermal deposition (HD-GDL) and then decreases after high-temperature sintering. Surface water contact angle of the HDS-GDL (133°) increases as compared to that of the Toray GDL (CR-GDL, 125°). Meanwhile, in-plane and through-plane ECs of HDS-GDL are simultaneously enhanced as compared to the CR-GDL. Moreover, HDS-GDL with collectively enhanced hydrophobicity and ECs further improve the electrochemical performance of PEMFCs. The polarization curve implies that enhancement of the power density at the Ohmic region under a wide cathode relative humidity (RH 0–80%) is mainly dominated by the optimized hydrophobicity. The findings in this work provide a new strategy for improving the electrochemical performance of PEMFCs by precisely tailoring the water management capacity of GDL.

Hydrophobicity enhancement of gas diffusion layer induced by hydrothermal deposition process and the electrochemical performance of proton exchange membrane fuel cell

Gas diffusion layer (GDL) with balanced water management capacity facilitates the power density enhancement of proton exchange membrane fuel cells (PEMFCs). In this paper, hydrothermal deposition (HD) method was utilized to enhance the hydrophobicity of GDL, which results in enhanced water retention capacity at both the ambient and cell operation temperatures (25 and 80 ℃). The competitive working mechanism of hydrophobicity and temperature on the water transport behavior inside GDL was implied in terms of the surface hydrophobicity of carbon fiber using molecular simulations. And the surface hydrophobicity of carbon fiber in GDL was dominant by the surface roughness at working temperature. The enhanced water retention capacity of GDL further improves the electrochemical performance of fuel cell at low humidity. Fuel cell assembled with cathode HD-GDL displays higher peak power density than that of the commercial reference Toray GDL (CR-GDL) at low applied cathode humidity ranges (RH 0-20%). The findings in this paper offers a facile and practical approach for tailoring the water management capacity of GDL and further the electrochemical performance of PEMFC under low humidity.

Poly(ionic liquid) membranes preserving liquid crystalline microstructures for lithium-ion enrichment

The combination of membrane separation technology and hydrometallurgy has opened up new possibilities for the recovery and recycling of lithium from ever-growing spent lithium-ion batteries. Herein, we prepared a series of positively charged poly(ionic liquid) membranes preserving liquid crystal mesophases and investigated the monatomic ion separation capacity of the liquid crystalline membranes by diffusion dialysis experiments using the simulative spent battery leachate. The results revealed that liquid crystalline membranes with bicontinuous cubic liquid crystal structure possessed great potential as precise ion separation membranes for lithium-ion enrichment. Compared to the other topological structures, the bicontinuous cubic liquid crystal structure enhanced both the Li+ flux and ion selectivity of the membranes. The ion flux of the membrane with this structure was three times higher than that of amorphous membranes. Meanwhile, the Li+/Ni2+ selectivity was up to 7.40, which was significantly higher than that of hexagonal liquid crystalline membranes (2.59) and commercial membranes AMI-7001S (5.71). Moreover, the preservation of liquid crystal structures obviously improved the water management capacity and mechanical strength of the membranes.

Investigation of metal foam porosity and wettability on fuel cell water management by Electrochemical Impedance Spectroscopy

ABSTRACT Metal foam, as a potential alternative to conventional flow fields in proton-exchange membrane fuel cells (PEMFCs), has been adequately proven to possess high gas uniformity and water storage ability. In this study, various cathode flow fields including meatal foam and conventional parallel and serpentine flow fields are compared experimentally. Meanwhile, electrochemical impedance spectroscopy (EIS) is also used to characterize the impedances as a further evidence of water management capacity for different flow fields. The results indicate that the cell with metal foam can achieve up to over 80% power density than that of the serpentine flow field with one third pressure drop. The porosity selection of metal foam is dependent on the inlet relative humidity (RH) to reduce the polarization loss and maximize the cell performance. The inlet relative humidity is also an important factor to the PTFE loading strategy for effective water removal.

Determining the location of River Dam Group based on set cover Model: A case study of Zambezi River Basin

Taking the Zambezi River Basin as a typical case, this paper studied the location problem of dam group. Based on the topographical and elevation maps of the Zambezi River Basin, we evaluated each region by five indicators (Water head difference elevation, Geological environment, Climatic environment, Population distribution and Biodiversity), and selected the 22 candidate dam sites. Meanwhile, the relative feasibility index of dam construction is calculated by the entropy weight-grey correlation analysis. On this basis, combined with the water management capacity of the dam, a set coverage model of dam selection is established, and the neighborhood adaptive particle swarm optimization algorithm (NAPSO) is used to solve the 12 most suitable dam sites. Comparing with the water management capacity of the original Kariba Dam, the new dams’ water storage and flood control capacity, hydroelectric power generation capacity, domestic water supply capacity and other water supply capacity have been increased by 235.92%, 250.62%, 189.66% and 223.61% respectively. Our study can provide some guidance for the site selection project of river dam group.

Performance degradation of 1 kW proton exchange membrane fuel cell stack using graphitized carbon supported Pt nanoparticle catalyst

Graphitic carbon-supported Pt nanoparticles (Pt/GC) are used as high durability catalysts in 1 kW proton exchange membrane fuel cell (PEMFC) stack. Accelerated degradation tests (ADT) with different protocols at the half-cell and single cell level show that Pt/GC catalysts exhibited better durability than commercial Pt/C. After 458 h of dynamic drive cycle durability testing, the PEMFC stack exhibits a voltage degradation rate at 1000 mA cm−2 of 5.3% and 85 μV/h. The results show that the majority of degradation was due to the contact angles of the hydrophilicity of the catalyst layer (CL) and the substrate layer (SL) is enhanced, which means the decrease in PEMFC stack durability also comes from the increase in mass transfer resistance and the reduction in the water management capacity of the cell. Partly, another reason is the collapse of the CL, which comes from the uneven assembly force and the structural change of CL. However, the structure and the size of the Pt/GC catalyst and electrochemically active surface area (ECSA) of CL is found hardly changed after 458 h, which indicates excellent stability of the catalyst and MEA under these practical conditions. Herein, this further supports that Pt/GC catalyst makes practical PEMFC applications possible.

Pressure-equalised façade systems: Evaluation of current watertightness test standards used to assess the performance of enclosure components

Watertightness test standards are used to evaluate enclosure components in terms of water penetration resistance. Currently, there is a wide variety of watertightness tests in use for façades elements and wall systems; however, none of them specifically addresses and evaluates the drainage capacity in pressure-equalised façade systems. In addition, recent research has revealed many inconsistencies in the possibility of these test standards to represent all possible conditions that can occur under different operating conditions, varying building configurations and at different locations. As such, the three main variables for water penetration testing (water spray rate, pressure differential and duration of the pressure application) have been called into question. Nonetheless, these studies do not bring up the protocols and other technical specifications incorporated in the test standard procedures. Furthermore, neither are concerns raised about the influence that these other parameters might have on the outcomes of the watertightness test, which is the aim of this research. To this end, the article provides a critical review of current watertightness tests standards from around the world in the first section. Thereafter, a thorough comparison of the information incorporated in the protocols of the test standards has been carried out. The evaluation and discussion of the test parameters and technical specifications incorporated in the tests standards is undertaken based on the state of the art and laboratory experiments of three mock-ups with pressure-equalised façade systems, where the water management capacity of the system is assessed. As a result of this research work, a guideline was prepared for the establishment of test procedures when developing new watertightness standards for pressure-equalised façade systems.

Greening Actions and the Related Potential Impacts on Outdoor Comfort in a Dense Built Environment

The increasing attention paid to the effects of climate change on the dense urban fabric of contemporary cities had led Public Authorities to develop local adaptation plans in order to suggest some effective measures to mitigate and reduce the impacts of urban heat island [UHI] and heat waves as well as to improve water management capacity. Among the suggested actions, the greening of in-between spaces of the built environment and the introduction of new green surfaces (roof and/or facades) in the framework of wider regeneration plans offers interesting perspectives and impacts. The paper reports the outcomes of a research activity run by the Department of Architecture and the Municipality of Bologna to investigate how to define/optimize the most effective arrangement of greening solutions with the aim to improve outdoor comfort conditions. The study takes into account several aspects including paved/green surfaces extension, the use of material, the geometry of the site, etc. and simulate the potential effects of changes using simulation software ENVIMET. Once the main features of each site are modelled the different deriving scenarios can be compared evaluating the different architectural, economical and practical constraints. The results are then compared with other factors, related to the social aspects, the use of the spaces, the perception of the sites, etc. A district of the city of Bologna is used as test bed in order to test the proposed methodology and the related potential impacts.

Humic Acid and Water Management to Decrease Ferro (Fe2+) Solution and Increase Productivity of Established New Rice Field

The purpose of this research was to gain a technological breakthrough in controlling Fe toxicity (Fe2+) on Ultisol in a new established rice field by using humic acid from rice straw compost and water management, so that optimal production of rice plants could be achieved. The experiment was designed using a 2 × 4 factorials with 3 replications in a split plot design. The main plot was water management consists of 2 levels: continuous and intermittent irrigation (2 weeks flooded and 2 weeks field capacity). Small plot was humic acid which was extracted from rice straw compost by NaOH 0.5 N which consists of 4 levels: 0, 200, 400, and 600 mg kg-1. The results showed that applications of humic acid from 0 to 600 mg kg-1 that was followed by 2 weeks of intermittent irrigation decreased Fe2+ concentration. It was approaching levels that were not toxic to plants, with soil Fe2+ between 180-250 mg kg-1. The best treatment was found at the application of 600 mg kg-1 humic acid extracted from rice straw compost combined with 2 week flooded – 2 weeks field capacity of water management. Those treatment decreased Fe2+ concentration from 1,614 to 180 mg kg-1 and increased the dry weight of grain from 5.15 to 16.73 g pot-1 compared to continuous flooding and without humic acid application.

Defining rural–urban interfaces for understanding ecohydrological processes in West Java, Indonesia: Part II. Its application to quantify rural–urban interface ecohydrology

Part II of this two-part article aims to quantify the state of rural–urban interface ecohydrology using the Cirebon Metropolitan Region (CMR) in West Java, Indonesia as a case study. The methodology proposed in this study used 11 socio-economic and spatial variables related to open spaces distribution, biodiversity and ecosystem services, water supply requirement, water quality risks, water management capacity and climate change pressures. Regional rural–urban classifications from the eight spatial classification methods (part I of this article) and 2010 national census were validated using three rural–urban water indicators from random sampling of the rural–urban household survey in the CMR. Six proxy ecohydrological indicators were identified and a composite index using these indicators to quantify the state of ecohydrology at rural–urban interface was developed and applied to 45 sub-districts of CMR. The index indicates that all urban sub-districts have very low capacity in providing ecosystem services and will need peri-urban ecosystem services for enhancing urban sustainability and liveability. In general, urban and urban–peri-urban transition sub-districts in the CMR have significant higher values of composite index related to socio-economic aspects compared to those in the peri-urban and rural sub-districts. This indicates lower significantly open spaces distribution, higher water supply requirement, greater water quality risks, and higher climate change pressures. The six proxy indicators identified in this study and methodology developed for calculating the composite index is potentially useful for an objective assessment of ecohydrology of an urbanising landscape and thus for developing effective urban planning of future cities and their outskirts.

Water poverty in upper Bagmati River Basin in Nepal

Water Poverty Index (WPI) is a simple and transparent tool to measure water stress at the household and village levels so that local an'd national water agencies can manage problem of access to water, quality and variability; water uses and capacity for water management considering environmental aspects. The research aims to calculate WPI in the upper Bagmati river Basin of Nepal in order to analyse the real water situation in the project area. WPI was estimated using five key components through the consultation with wide range of stake holders, policy makers and scientists for resource, access, capacity, use and environment.The WPI was calculated for the upper Bagmati river Basin together with High–Medium–Low category scale and interpretations. WPI intensity scale depicts Sundarijal and Lubhu are in a range of very low water poverty, which means the water situation is better in these two areas. Daman region has a medium level, meaning this region is located into poor-accessible water zone. Kathmandu, Sankhu and Thankot have a low to medium low WPI, what characterize them as neutral. WPI can be used as an effective tool in integrated water resources management and water use master plan for meeting sustainable development goals. Based on the observation, the water agencies required to focus over water-poverty interface, water for sanitation, hygiene and health, water for production and employment generation, sustainable environmental management, gender equality, and water rights.

Water management capacity building to support rapidly developing mining economies

Many developing countries are experiencing rapid expansion in mining with associated water impacts. In most cases mining expansion is outpacing the building of national capacity to ensure that sustainable water management practices are implemented. Since 2011, Australia's International Mining for Development Centre (IM4DC) has funded capacity building in such countries including a program of water projects. Five projects in particular (principally covering experiences from Peru, Colombia, Ghana, Zambia, Indonesia, Philippines and Mongolia) have provided insight into water capacity building priorities and opportunities. This paper reviews the challenges faced by water stakeholders, and proposes the associated capacity needs. The paper uses the evidence derived from the IM4DC projects to develop a set of specific capacity-building recommendations. Recommendations include: the incorporation of mine water management in engineering and environmental undergraduate courses; secondments of staff to suitable partner organisations; training to allow site staff to effectively monitor water including community impacts; leadership training to support a water stewardship culture; training of officials to support implementation of catchment management approaches; and the empowerment of communities to recognise and negotiate solutions to mine-related risks. New initiatives to fund the transfer of multi-disciplinary knowledge from nations with well-developed water management practices are called for.

Can Integrated Water Resources Management Increase Adaptive Capacity to Climate Change Adaptation? A Critical Review

Integrated Water Resources Management (IWRM) is now a global paradigm. While conceptions of IWRM principles vary between contexts, it primarily aims to ensure more coordinated management between different aspects of water issues such as water quality, land management and habitat protection. However, one increasingly significant cross-cutting management issue is climate change adaptation which presents multiple problems for IWRM approaches. This paper therefore seeks to gauge the extent to which IWRM principles can, and indeed are, enhancing the adaptive capacity of water management through reducing vulnerability and increasing the resilience of social-ecological systems. A review of research into vulnerability and resilience to date suggests that IWRM has significant potential for supporting some of the key determinants of adaptive capacity. However, despite IWRM being promoted as an attractive approach, our assessment argues that IWRM, as currently practiced, cannot readily enhance flexibility and adaptability, which is required for climate change adaptation. Normative recommendations for future policy are then provided.

The role of drought preparedness in building and mobilizing adaptive capacity in states and their community water systems

The likely intensification of extreme droughts from climate change in many regions across the United States has increased interest amongst researchers and water managers to understand not only the magnitude of drought impacts and their consequences on water resources, but also what they can do to prevent, respond to, and adapt to these impacts. Building and mobilizing ‘adaptive capacity’ can help in this pursuit. Researchers anticipate that drought preparedness measures will increase adaptive capacity, but there has been minimal testing of this and other assumptions about the governance and institutional determinants of adaptive capacity. This paper draws from recent extreme droughts in Arizona and Georgia to empirically assess adaptive capacity across spatial and temporal scales. It combines quantitative and qualitative methodologies to identify a handful of heuristics for increasing adaptive capacity of water management to extreme droughts and climate change, and also highlights potential tradeoffs in building and mobilizing adaptive capacity across space and time.

Climate change and mountain water resources: overview and recommendations for research, management and policy

Abstract. Mountains are essential sources of freshwater for our world, but their role in global water resources could well be significantly altered by climate change. How well do we understand these potential changes today, and what are implications for water resources management, climate change adaptation, and evolving water policy? To answer above questions, we have examined 11 case study regions with the goal of providing a global overview, identifying research gaps and formulating recommendations for research, management and policy. After setting the scene regarding water stress, water management capacity and scientific capacity in our case study regions, we examine the state of knowledge in water resources from a highland-lowland viewpoint, focusing on mountain areas on the one hand and the adjacent lowland areas on the other hand. Based on this review, research priorities are identified, including precipitation, snow water equivalent, soil parameters, evapotranspiration and sublimation, groundwater as well as enhanced warming and feedback mechanisms. In addition, the importance of environmental monitoring at high altitudes is highlighted. We then make recommendations how advancements in the management of mountain water resources under climate change could be achieved in the fields of research, water resources management and policy as well as through better interaction between these fields. We conclude that effective management of mountain water resources urgently requires more detailed regional studies and more reliable scenario projections, and that research on mountain water resources must become more integrative by linking relevant disciplines. In addition, the knowledge exchange between managers and researchers must be improved and oriented towards long-term continuous interaction.