Water Supply Patterns Research Articles

Spatial Patterns of Water Supply and Use in California

Spatial and temporal patterns of water supply and consumptive water use were analyzed from 475 Detailed Analysis Units by County (DAUCOs) spatial units across California during 2002 through 2016 to evaluate spatial and temporal variability and how it might associate with precipitation variability and other factors. Many, but not all, DAUCOs have relatively low total water supply variability compared to that of state-wide precipitation. Such low variability, in DAUCOs having sufficient diversity of water supply sources, is the result of switching between sources as needed to maintain a reliable total water supply. We used multiple approaches to explore these variations which involved four categories of water supply (local, groundwater, imported, and other) and two categories of water use (agricultural and urban). First, a cluster analysis of the volumetric water balance data identified a small set of clusters having similar magnitudes and proportions of water supply sources and water use—some of them composed of only a few DAUCOs but accounting for a disproportionate amount of the state’s water use. Second, a principal components analysis identified leading modes of anomalous water supply and water use among the 475 DAUCOs, capturing most of the time variation during 2002 to 2016. The most prominent mode exhibits a multi-year trend, most strongly involving increasing groundwater supply and agricultural water use, and decreasing urban water use and imported water supply. Over the study period, trends in both supply and use were pronounced, but differed considerably across California DAUCOs. One predominant subset of DAUCOs grew their agricultural water use with increased groundwater supply; in contrast to a widespread group of DAUCOs which reduced their urban water use. An important result for planners is our finding that variation in precipitation—itself important—is amplified by the human response to water supply availability and regulatory policy.

Land subsidence along the Beijing-Tianjin high-speed railway before and after the South-to-North water diversion project with multi-source monitoring datasets

The development of land subsidence has seriously affected the safe operation of Beijing-Tianjin high-speed railway. The South-to-North Water Diversion Project Central Route (SNWDP-CR) was officially put into operation in December 2014. It has changed the water supply pattern in Beijing and provided conditions for reducing groundwater exploitation and controlling land subsidence. In this paper, the time-series interferometric data, in situ monitoring data of recent 20 years and the basic geological datasets are combined to compare and analyze the changes of groundwater level, land subsidence and the main subsidence layers along the Beijing-Tianjin high-speed railway before and after the SNWDP-CR. The effects of the environment of Quaternary sedimentary, groundwater exploitation and soil deformation of different lithology on land subsidence along the high-speed railway under the background of new water conditions are revealed. The main conclusions are as follows: 1) The serious land subsidence area along the Beijing-Tianjin high-speed railway always concentrated in the section of DK11-DK23. After the operation of SNWDP-CR, the land subsidence along the railway generally showed a slowing trend. The maximum subsidence rate was reduced from 80 mm/yr to 49 mm/yr. The length of subsidence rate that more than 50 mm/yr of the section was reduced from 8.0 km to 0 km. 2) The groundwater level of different aquifer groups along the Beijing-Tianjin high-speed railway rose and declined before and after the SNWDP-CR. in eastern part of the plain, the groundwater level of each aquifer group has changed from a continuous decline (range 0.13–1.82 m) to a gradual rise (range 0.45–1.87 m) since 2017. However, in the southeast of the plain, the groundwater level still showed a continuous decline trend, with an average annual decline of 1.2–1.8 m. 3) From 2006 to 2019, the subsidence of the first, second and third compression layer group along the railway accounted for 2.71%, 28.29% and 69%, respectively. The third compression layer group (monitoring layer 94–182 m) had the largest subsidence proportion and was the main subsidence layer. 4) The land subsidence along the Beijing-Tianjin high-speed railway is controlled by the basement structure. The difference of groundwater exploitation intensity led to differences in the spatial distribution of land subsidence along the railway. The subsidence of the soil layer below the bearing layer (about 50 m) of the high-speed railway pile foundation exhibited the characteristics of viscoplastic or viscoelastic plasticity deformation. This section of strata is a key layer that needs to be considered for land subsidence control along the Beijing-Tianjin high-speed railway in the future.

Analysis of Households’ Water Access and Consumption in Differential Urban Neighbourhoods of Osogbo, Nigeria

The study focused on scrutinizing the sources and consumption patterns of domestic water supply in Osogbo, with an emphasis on households' socio-economic characteristics. Data were collected from three deliberately chosen residential neighborhoods representing low, medium, and high-density areas, with a cumulative population of 134,159 and an estimated 26,829 households. Employing a multistage sampling technique, 25% of streets in each neighborhood were randomly selected, and systematic sampling was utilized to distribute 268 structured questionnaires (1% of households) to gather information. Descriptive analyses, such as means and percentages, were employed to scrutinize socio-economic characteristics and water consumption patterns. The study also utilized inferential statistics, specifically Multiple Analysis of Variance (MANOVA), to assess the impact of residential densities and water sources on water consumption volume. Results highlighted hand-dug wells (46%), public taps (22.4%), and boreholes (15.7%) as thepredominant water sources. MANOVA revealed a statistically significant influence of residential densities and water sources on water consumption volume (p=0.049). In low-density areas, households consumed an average of 960 liters per day, compared to 735 and 517.5 liters in medium- and high-density areas, respectively. Across Osogbo, the average household consumed 664.7 liters daily. Correlation analysis indicated a positive and statistically significant relationship between resident population and water consumption (p<0.05). The study concluded by emphasizing the pivotal roles of government, communities, NGOs, and individuals in addressing water provision challenges in the area.

Quantifying climate change impacts on future water resources and salinity transport in a high semi-arid watershed

High salinity mobilization and movement from salt-laden deposits in semi-arid landscapes impair soils and water resources worldwide. Semi-arid regions worldwide are expected to experience rising temperatures and lower precipitation, impacting water supply and spatio-temporal patterns of salinity loads and affecting downstream water quality. This study quantifies the impact of future climate on hydrologic fluxes and salt loads in the Gunnison River Watershed (GRW) (14,608 km2), Colorado, using the APEX-MODFLOW-Salt hydro-chemical watershed model and three different CMIP5 climate models projection downscaled by Multivariate Adaptive Constructed Analogs (MACA) for the period 2020–2099. The APEX-MODFLOW-Salt model accounts for the reactive transport of major salt ions (SO42−, Cl−, CO32−, HCO3−, Ca2+, Na+, Mg2+, and K+) to streams via surface runoff, rainfall erosional runoff, soil lateral flow, quick return flow and groundwater-stream exchange. Model results are analyzed for spatial and temporal trends in water yield and salt loading pathways. Although streamflow is primarily derived from surface runoff (65%), the predominant source of salt loads is the aquifer (73%) due to elevated concentrations of groundwater salt. Annual salt loading from the watershed is 582 Mkg, approximately 10% of the salt load in the Colorado River measured at Lee's Ferry, AZ. For future climate scenarios, annual salt loads from the watershed increased between 4.1% and 9.6% from the historical period due to increased salt loading from groundwater and quick return flow. From the results, applying the APEX-MODFLOW-Salt model with downscaled future climate forcings can be a helpful modeling framework for investigating hydrology and salt mobilization, transport, and export in historical and predictive settings for salt-affected watersheds.

Water supply following drought: Effects on drougt legacy and resilience in a tropical forest - A case study in Xishuangbanna, China

Climate change has made it essential to understand the effects of drought on carbon dynamics in tropical forest ecosystems. However, research on the postdrought (PD) period is relatively limited, particularly with regard to the resilience of the carbon cycle affected by available water. To determine the effects of water availability during PD on resilience and legacy effects in tropical forests, we used a spatially explicit individual-based dynamic global vegetation model (SEIB-DGVM) to simulate gross primary productivity (GPP) to proxy the process. We established multiple water supply scenarios based on ecological water demands and regional climatic standard precipitation through the composite of gradients in quantity and duration to characterize variations in environmental water availability after droughts end. Under different PD water supply patterns, the degree of GPP resilience and its legacy effects varied significantly. Specifically, ecosystem resilience to drought was positively correlated with the percentage of PD water supply and negatively correlated with the duration until water conditions returned to normal, while the negative legacy effect of drought on GPP exhibited the opposite relationship. After a drought, a rapid high-level water supply promoted stronger GPP resiliency and moderated the drought legacy effects. Although legacy effects varied with water supply patterns, the negative legacy effect on GPP appeared only in the first year after drought. Observing biomass changes in roots, leaves, woody plants, and herbaceous plants after droughts, it is clear that tropical forest ecosystems can adjust their carbon allocation strategies in response to differences in water availability. To more accurately predict the fate of tropical forests in response to climate change, it is necessary to assess the impact of PD environmental climate condition changes on their dynamic resilience processes.

Spatial and hydrological analysis of the water supply system in as-Sila'/Sela (Tafila, Jordan) based on a 3D model

The research described below proposes a spatial analysis of the hydraulic infrastructure, and settlement remains, as well as a topographic analysis of the site of as-Sila'/Sela on the southern Transjordan plateau. The authors designed Sela's first photogrammetric model from aerial photographs provided by the "Aerial Photographic Archive for Archaeology in the Middle East (APAAME)" project. This modelling has enabled the research team to locate new hydraulic structures, settlement remains, marks on vertical facing, and elevated or levelling platforms hitherto unidentified by a pedestrian survey; it was also possible to obtain more detailed direct and indirect relationships between these features. The 3D model has provided a reference for locating the various elements and correlating their surface with the topographic coordinates recorded by the total station during fieldwork. Additionally, a Digital Elevation Model (DEM) was derived from the 3D model to depict the flow direction of run-off. Through our analysis, we identified spaces for accessing, managing, and utilising available water resources, including settlement density and flooding zones. The hydrological analysis revealed potential run-off and flood-prone areas, guiding the location of hydraulic structures to prevent water contamination. This study highlights the importance of Sela's water supply systems and the technical expertise of ancient communities in their construction and management. The applicability and feasibility of the applied methodology emphasise its use as a powerful and indispensable tool to obtain a complete overview of the site. The results yield a comprehensive site mapping with a broader scope than previous research and provide a basis for further research, as well as for understanding the site's water supply and settlement patterns. Thus, this study enhances the hydro-technological investigation of Sela's water management and culture and contributes to its holistic analysis. Future studies can use the data to propose effective water management strategies and shed light on the social structures involved in water supply practices.

Optimising water and nitrogen management for greenhouse tomatoes in Northeast China using EWM−TOPSIS−AISM model

Unreasonable irrigation and nitrogen application reduce tomato yield and waste resources. This study explored the effects of water conservation and nitrogen reduction on tomato yield, dry matter, quality, water productivity and nitrogen use efficiency in Northeast China. Experiments were conducted during 2020 and 2021 at three irrigation levels (85–95 %, 75–85 %, and 65–75 % θFC) and three nitrogen application levels (120, 180, and 240 kg hm−2). The optimal water and nitrogen supply patterns were obtained by establishing a newly evaluated Entropy Weight Method−Technique for Order Preference by Similarity to Ideal Solution−Adversarial Interpretive Structure Model (EWM−TOPSIS−AISM). The results showed that the amount of irrigation and nitrogen application significantly affected tomato quality (P ≤ 0.5). Proper deficit irrigation improved tomato quality. Reducing the nitrogen application rate improved nitrogen use efficiency but decreased the tomato yield. Increasing the amount of irrigation increased tomato yield and nitrogen use efficiency. Tomato yield was negatively correlated with water productivity (R= −0.25 in 2020 and R= −0.37 in 2021) and nitrogen use efficiency (R= −0.30 in 2020 and R= −0.20 in 2021). The evaluation results showed that the best water and nitrogen supply mode for our experiment was irrigation at 75–85 % θFC and nitrogen application rate of 180 kg hm−2. The study could promote the sustainable production of greenhouse tomatoes in Northeast China.

Complex network-based analysis of inter-basin water transfer networks

Driven by water resources scarcity, inter-basin water transfer (IBWT) projects have emerged and evolved, thereby shaping the current water supply framework. As IBWT projects increase, they gradually acquire network characteristics, giving rise to IBWT networks. However, the impact of the development of IBWT networks on water-supply patterns remains unclear? Analyzing the spatial and temporal growth patterns of IBWT networks through the lens of complex network theory can help answer this question. This study established a framework for analyzing IBWT networks using complex network analysis (CNA). Within this framework, we analyzed the spatial and temporal development characteristics of the IBWT network by quantifying its global properties across three dimensions: efficiency, elasticity, and coordination. Six centrality indicators were employed to measure the significance of individual nodes. Finally, the Infomap method was employed for network community detection. The results demonstrated that the CNA-based framework effectively captured the comprehensive development of the IBWT network, which underwent six stages from inception to high-speed, near-term, and long-term Stages. IBWT network efficiency, elasticity, and coordination all showed growth, which was most pronounced in 2013–2022, where the scaled global efficiency, network efficiency, average node connectivity, and average betweenness centrality metrics all grew by a factor of greater than 4. Importantly, the total percentage of centrality greater than 0.2 in the Huang-Huai-Hai-Chang Basin was 63.0%. The 125 initial IBWT projects in the IBWT network contained 58 communities, while the subsequent construction of 57 projects added only 12 communities. Future new IBWT network projects will tend to joined existing communities.

Spatial and Temporal Patterns of Ecosystem Services and Trade-Offs/Synergies in Wujiang River Basin, China

Analysis of the relationships among ecosystem services (ESs) can help ensure that benefits from ecosystems are consistent over time. This study explored the spatial and temporal patterns of water supply (WS), grain supply (GS), carbon storage (CS), water conservation (WC), soil conservation (SC), and habitat quality (HQ) in the Wujiang River Basin (WJRB) from 2000 to 2020 and the trade-off/synergy relationships of ESs. The ESs in the WJRB are downstream > midstream > upstream in space, with the greatest increase and decrease in the upstream and midstream temporal dimensions, respectively. The WS, WC, and SC underwent a trend shift in 2005 due to climatic influences, whereas GS and HQ underwent a trend shift in 2010 due to human social development. GS formed a trade-off with other ESs in the spatial pattern, whereas WS formed a trade-off with CS and WC in the temporal dimension. Adjusting the GS spatial pattern reduces the trade-off between ESs in the spatial pattern, allowing for focusing on monitoring soil and water erosion-prone areas to prevent extensive soil erosion during heavy precipitation years; this reduces the trade-off between ESs in the time dimension in the WJRB. This provides a theoretical basis for achieving high-quality WJRB development.

Microbial profile and antibiotic resistance pattern of water supply in a tertiary care hospital of Uttarakhand.

In healthcare settings, hospital water and water-related devices can act as a reservoir for waterborne infections. Potable water, sinks, faucet aerators, showers, tub immersion, toilets, dialysis water, water baths, eyewash stations, and dental-unit water stations have all been linked to nosocomial outbreaks. This study aimed to determine the microbial profile and pattern of antibiotic resistance in the water supply of a tertiary care hospital in Uttarakhand. This is a 1-year prospective study which was carried out by the Department of Microbiology and Immunology at Sri Mahant Indersh Hospital (SMIH), Dehradun. A total of 154 water samples were collected from the AC outlets, ventilators in the Intensive care unit (ICUs), Operation theatre (OTs), and High dependency unit (HDUs), scrub stations, pantry, and blood bank, patient's bathroom, private ward, septic ward, labour room, transplant unit, laboratory, scope rinse water, the dialysis unit and tank throughout the hospital, including tap water (pre and post flush [25%]), tap swabs (24%), drinking water (9%), AC outlets (13%), and other areas (3%). 30 of the 154 (19.5%) water samples tested were culture-positive. The most contaminated water samples were tap swabs (27%, n = 8/30). A total of nine organisms were isolated, of which the most predominant was Pseudomonas aeruginosa (40%; 12/30), followed by Legionella pneumophila (13%; 4/30), Acinetobacter baumanii (10%; 3/30), Klebsiella pneumoniae (10%; 3/30), Escherichia coli (7%; 2/30), Enterococcus faecalis (7%; 2/30), Aspergillus flavus (7%; 2/30), Stenotrophomonas (3%; 1/30), and Fusarium spp. (3%; 1/30). Gram-negative bacilli and non-lactose fermenting (GNB and NLF) showed a high rate of contamination, 53.3% (n = 16/30). P. aeruginosa showed resistance to gentamicin and amikacin (42%), imipenem (50%), levofloxacin (58%), and colistin (25%), while Acinetobacter baumanii showed resistance to gentamicin and amikacin (67%), minocycline (63%), and levofloxacin, imipenem and colistin (33%). The study's findings show that a variety of microorganisms are contaminating hospital water supplies and can be a source of hospital-acquired infections. A suitable and robust surveillance program for hospital water supplies, as well as strict adherence to infection control practices, is strongly advised.

Mechanisms of vegetation restoration at landslides caused by a catastrophic earthquake in Central Taiwan

The vegetation restoration of a large-scale landslide, triggered by the catastrophic earthquake on 21 September 1999, in Jiujiu Peaks, Central Taiwan with an impacted area of 821 ha recovered 80% by 2020 was studied using self-organizing map (SOM) coupled with multi-temporal SPOT satellite images and a terrain-based distribution index for a 20-year period. Although disturbed by several typhoons during two decades of natural vegetation succession, the landslide restoration rate has reached 87.5% with the invasion or regrowth of vegetation gradually. A predicted logarithmic model with statistically significant difference was derived to estimate the restoration trend of the landslide in the studied area. Most of the poorly vegetated areas are located along the ridgelines, as verified by field surveys. Landslide restoration was carried out in three stages, (1) vulnerable landslides and fast-growing invasive vegetation (1999/9 - 2005/9); (2) stabilized landslides and slow-growing vegetation toward the vegetated strips (2005/9 - 2009/11); and (3) more stabilized landslides and vegetation toward secondary forest (2009/11–2020/2). Topographic location, water supply, typhoon disturbance, invasive or residual vegetation patterns and succession time are the main factors of landslide restoration. The evaluated results indicate that nature itself is a complex ecological balance system with a strong capacity for vegetation recovery at landslides, and can be used by government agencies to add in the recovery of landslide areas.

A new method for estimating multi-source water supply considering joint probability distributions under uncertainty

A new method integrating techniques of copula and interval estimation to estimate multi-source water supply was proposed. Using the copula theory, joint probability distributions of multiple water sources were constructed for the estimation of water supply. In addition, the interval estimation was used to obtain the interval of water supply under uncertainty for the formulation of water-diversion strategies and the efficient allocation of water resources. This method can give an in-depth investigation on correlations and synchronous–asynchronous characteristics of runoff variations for multiple water sources, thus solving the uncertainty problem of water supply. To demonstrate its applicability, the method was applied to a case study in the Xiong’an New Area, a future metropolis in North China. The results showed that log-normal distributions for the marginal distributions of source 2 (i.e., the Water Diversion Project from the Yellow River to Baiyangdian Lake) and source 3 (i.e., the South-to-North Water Diversion Project) were feasible. The combined channel source, composed of source 2 and source 3, provided [5.20, 12.10] × 108 m3, and reservoir source provided [0.76, 3.60] × 108 m³ of water resources to the Xiong’an New Area per year. Furthermore, without the implementation of multi-source combined water supply pattern in the Xiong’an New Area, there would be a large water supply deficit. This research can provide effective practical suggestions and guidance on water-resource planning and management.

Quantifying Water Provision Service Supply, Demand, and Spatial Flow in the Yellow River Basin

Quantifying and spatial mapping the ecosystem services driven by land use change will help better manage land and formulate relevant ecological protection policies. However, most studies to date just focused on water supply services, and ignore water demand services and their supply–demand coupling mechanisms. Ecosystem service flow could be used to evaluate the imbalance between water supply and demand. Therefore, this study takes the Yellow River Basin as the research object to quantify the supply, demand, and spatial flow of water provision services. The results showed that land use and land cover (LULC) played a critical role in the spatial distributions of water supply and demand in the Yellow River Basin. The total water supply was 3.03 × 1011 m3, with a range of 3.29 × 108 m3 to 7.35 × 1010 m3 for different sub-watersheds. The spatial patterns of water supply were strongly different from those in water demand, resulting in obvious spatial mismatches. There was a higher water demand for constructional areas and agricultural lands, which had relatively lower water supply. Most water areas and natural lands provide much more water supply than demand. We used a water flow process to assess the water provision service between water supply side and demand side. The water flow process suggested that the Yellow River Basin had an obvious imbalance between water supply and demand depending on land use and populations, which would help policy makers to manage water resources through optimizing land management in different cities and finally achieving a balance between water supply side and demand site.

Identification of pathways that lead to continuous or intermittent water supply by conducting a qualitative comparative analysis of rural water utilities in China

Abstract Ensuring a continuous water supply (CWS) for households is beneficial for the current global drinking water, sanitation, and hygiene agenda. Despite improvements in water supply, intermittent water supply (IWS) remains prevalent in rural areas. To determine the factors that lead to different water supply modes for villages, we select 38 village-level water utilities covered by the Chinese Safe Drinking Water Project for fuzzy set qualitative comparative analysis to identify causal configurations (‘pathways’) that lead to IWS or CWS across systems. Six configurations of water supply mode are identified on the basis of the outcomes of each case. Among these, three configurations for adopting CWS are determined. Configuration 1 features water utility with government subsidy and bills using a water meter. Configuration 2 features water utility with small population coverage, government subsidy, and villager participation in the management. Configuration 3 features a water utility collectively managed and owned by a rich village and water-saving initiatives. Configurations that lack meter-based bills, government subsidies, and water-saving initiatives are the main paths for IWS. Results highlight the uniqueness of the configurational approach in understanding different water supply patterns across various cases and emphasise the importance of government subsidies, villager participation, water-saving programmes, and water meter-based billing to achieve CWS.

Irrigation Water Supply Patterns in Several Land Uses with Automated Application of Soil Moisture Monitoring Based on Dielectric Technology

Indonesia is necessary to develop an increase in soil productivity. The decline in soil productivity for agriculture can be caused by several factors, namely land conversion to a decrease in groundwater quantity. The actual pattern of providing irrigation water with the application of dielectric sensor technology is carried out in soil cultivation to create efficiency in providing irrigation water. This research was conducted using a single factor experimental method with repeated measurements on three types of land use, such as land without vegetation, soil with tomato cultivation, and soil with grass. Measurements were carried out using an automated application of soil moisture monitoring based on dielectric technology with two measuring periods. Each measuring period consists of two weeks or fourteen days. Soil sample analysis was carried out at the Bengkulu University soil laboratory. The results of the observations were analyzed using variance (ANOVA) on the 5% F test table, the LSD test was carried out at the 5% level on data that had a significant effect. The results showed that the daily irrigation water for vegetated land was lower than for tomato cultivation and without vegetation in each measurement period. The frequency of irrigation water application in the two observation periods also showed that the land without vegetation had a higher amount and frequency of water application compared to the other two types of land use.

Hydraulic Ram Pump Integration into Water Distribution Systems for Energy Recovery Application

This study presents the potential of integrating Hydrams in modern water distribution systems (WDSs) for managing excess pressure and reducing energy costs. Hydrams, which are also termed Hydraulic ram pumps in the literature, is a cyclic water pump powered by hydropower, generally used to pump drinking and irrigation water in mountainous and rural areas having short of power. The Hydrams is introduced as a sustainable low-cost alternative solution to the more conventional pressure reducing valves (PRVs) approach for managing pressure zones in WDSs. Unlike PRVs, where the pressure is lost and not put into good use, Hydrams mitigate excess pressure at high-pressure zones and direct it to much-needed low-pressure zones. In addition, Hydrams are cheap, simple, environmentally friendly, and require little maintenance. The proposed approach integrates a Hydram in parallel to the original centrifugal pump, where they can be operated interchangeably according to the system’s hydraulic needs. Nevertheless, it is vital to correctly size the Hydram at the feed line and accompany it with a proper storage tank at the low-pressure zone. The storage tank serves as a buffer between the intermittent water supply and consumer demand pattern. Moreover, the tank introduces flexibility into the system that allows more sustainable operating schedules. Two case study applications of increasing complexity are presented to demonstrate the potential of this Hybrid system, later referred to as Hybrid Pumping Unit (HPU). The Hydram and tank sizing is done by a simple heuristic approach, while the operation of the system is dictated by a genetic algorithm. The results demonstrate the potential of integrated Hydrams in reducing excess pressures and energy costs.

Patterns of Water Use in California

Recent patterns of water use and supply in California are presented based on a new data set compiled from the California Department of Water Resources water balance data for 2002 through 2016. The water use and supply include surface water and groundwater, although groundwater reporting has been incomplete. These data are used to support the Water Plan released every 3 to 5 years and are the most comprehensive and finest spatial- and temporal-scale data set for California water resources. First, using the Bay–Delta watershed as a case example, we show that recent fluctuations in water use are highly correlated with variations in precipitation. Developed water supplies and use show these fluctuations, but they are modified by reservoir inflows and releases, groundwater supplies, and Delta outflows. Second, although the annually precipitated water supply in the Bay–Delta varies by about 30%, the developed water supply damps this considerably. The water management system maintained nearly constant agricultural water use even in periods of intense drought, with year-to-year variation of about 7%. Variability in urban water use is higher (∼20%), largely from conservation during periods of drought. Finally, this information can help improve water resource management because it connects regional-scale data to meaningful policy decision-making at county and sub-county levels. At a time when water policy and management are being re-evaluated across the American West in the light of changing climate, decision-making informed by science and data is urgently needed. The statewide water balance data provide the means to establish a consistent, quantitative framework for water resource analysis throughout the state.

WATER VENDORS PARTICIPATION IN DOMESTIC WATER SUPPLY IN UNGUWA UKU, TARAUNI LOCAL GOVERNMENT, KANO STATE, NIGERIA

Water vending is seen as a signing of a failure in piped-borne water supply systems, it still plays significant role in providing water especially to urban dwellers in many parts of developing countries, Nigeria inclusive. Therefore, this study examined water vendors participation in domestic water supply in Unguwa Uku, Tarauni LGA Kano state. The data used in this research collected from both primary and secondary sources. The data collected was analyzed using descriptive statistics, where simple percentages and tables used. The data analysis revealed that 57.4% of the residents in the study area patronized the services of water vendors. Patronage of vendor service dominated the frequency with 64.9% of respondent’s patronage of vended water. Seasonal variation in vended water supply patterns exist in the study area, with dry season account for the highest water demand and most supplies occurred during morning and evening hours. Based on the challenges bedevilled water-vending activities, the study recommends that vendors should be recognized as an integral part of the system as this may help in the design and implementation of more comprehensive policies that better serve poor end-users, by ensuring greater accessibility and affordability of water vendor’s service.

Water resources allocation model based on ecological priority in the arid region

Based on the characteristics of arid regions in the central and southern Ningxia，firstly we constructed the theoretical framework about rational allocation of water resources based on ecological priority, which supplemented and improved the theoretical system on rational allocation of water resources for sustainable development. On the basis of theoretical research, depending on its characteristic of water resources：pumping water from Yellow River in the north, piloting water from Jing River in the south and regional water resources, which formed a mixing water supply pattern of “pumping, piloting, storage”. The theory of water resource allocation system was perfected. Then the mathematical model for the rational allocation of water resources was established on the basis of biggest benefit combined with economy, society and ecology. The model coincided the ecological water and domestic water benefit into the overall benefits, and provides them larger benefit coefficient and the priority order coefficient to realize the reasonable allocation of water resources on ecological priority mode. Finally, the results of allocation are analysed in detail, which provides constructive suggestions and guiding direction for the study of the rational allocation of regional water resources.

Shifts in Irrigation Water Demand and Supply Pattern During Sensitive Crop Growth Phases in South Asia

Shifts in Irrigation Water Demand and Supply Pattern During Sensitive Crop Growth Phases in South Asia