Total Water Use Research Articles

Limited stomatal regulation of the largest-size class of Dryobalanops aromatica in a Bornean tropical rainforest in response to artificial soil moisture reduction.

The physiological response of trees to drought is crucial for understanding the risk of mortality and its feedbacks to climate under the increase in droughts due to climate change, especially for the largest trees in tropical rainforests because of their large contribution to total carbon storage and water use. We determined the response of the mean canopy stomatal conductance per unit leaf area (gs) and whole-tree hydraulic conductance (Gp) of the largest individuals (38-53m in height) of a typical canopy tree species in a Bornean tropical rainforest, Dryobalanops aromatica C.F.Gaertn., to soil moisture reduction by a 4-month rainfall exclusion experiment (REE) based on the measurements of sap flux and leaf water potentials at midday and dawn. In the mesic condition, the gs at vapor pressure deficit (D) = 1kPa (gsref) was small compared with the reported values in various biomes. The sensitivity of gs to D (m) at a given gsref (m/gsref) was ≥ 0.6 irrespective of soil moisture conditions, indicating intrinsically sensitive stomatal control with increasing D. The REE caused greater soil drought and decreased the mean leaf water potentials at midday and dawn to the more negative values than the control under the relatively dry conditions due to natural reduction in rainfall. However, the REE did not cause a greater decrease in gs nor any clear alteration in the sensitivity of gs to D compared with the control, and induced greater decreases in Gp during REE than the control. Thus, though the small gs and the sensitive stomatal response to D indicate the water saving characteristics of the studied trees under usual mesic conditions, their limited stomatal regulation in response to soil drought by REE and the resulting decline in Gp might suggest a poor resistance to the unusually severe drought expected in the future.

Evaluation of regional water resources carrying capacity based on binary index method and reduction index method

Based on the regional water resources carrying capacity (WRCC) evaluation principles and evaluation index system in the National Technical Outline of Water Resources Carrying Capacity Monitoring and Early Warning (hereafter referred to as the Technical Outline), this paper elaborates on the collection and sorting of the basic data of water resources conditions, water resources development and utilization status, social and economic development in basins, analysis and examination of integrity, consistency, normativeness, and rationality of the basic data, and the necessity of WRCC evaluation. This paper also describes the technique of evaluating the WRCC in prefecture-level cities and city-level administrative divisions in the District of the Taihu Lake Basin, which is composed of the Taihu Lake Basin and the Southeastern River Basin. The evaluation process combines the binary index evaluation method and reduction index evaluation method. The former, recommended by the Technical Outline, uses the total water use and the amount of exploited groundwater as evaluation indices, showing stronger operability, while the latter is developed by simplifying and optimizing the comprehensive index system with greater systematicness and completeness. The mutual validation and adjustment of the results of the above-mentioned two evaluation methods indicate that the WRCC of the District of the Taihu Lake Basin is overloaded in general because some prefecture-level cities and city-level administrative divisions in the Taihu Lake Basin and the Southeastern River Basin are in a severely overloaded state. In order to explain this conclusion, this paper analyzes the causes of WRCC overloading from the aspects of basin water environment, water resources development and utilization, water resources regulation and control ability, water resources utilization efficiency, and water resources management.

Changes in water use structure in Shandong Province in the past 20 years

This paper analyzes the changes of water use structure in Shandong Province from 2000 to 2017 in Shandong Province, reveals the driving factors that lead to changes in water use structure. The results show that in the past 20 years, the total water use has firstly increased and then slowly decreased; the agricultural water use has decreased continually; the industrial water has firstly fluctuated and then keeped stable; while the domestic water use and environmental water use has continually increased. The driving factors of water use are agricultural water saving, industrial water saving, population and water consumption per capita growing and landscaping area enlarging.

Evaluation of seasonal patterns of hydraulic redistribution in a humid subtropical area, East China

AbstractAntecedent soil moisture or soil moisture status has a great impact on hydrological processes. Hydraulic redistribution (HR), a widely observed phenomenon, is defined as water distributed (typically at night) from moist soil to drier soil via plant roots, which plays an important role in soil moisture replenishment. Knowledge on seasonal patterns of HR and on the relationship between HR and soil water use is not fully understood. We investigated temporal variations in HR and total daily water use (Δθ) at stands of camphor and peach by monitoring soil moisture content in a humid region in eastern China. HR at the three locations reached its maximum values in summer (0.68 mm d−1 to 1.15 mm d−1) at depths of 15 cm and 35 cm. Redistributed water replenished 41% of water depleted in the soil at a 5–45‐cm depth. Interestingly, normalized HR (i.e., HR/Δθ) showed a constant pattern during the growing season implying it is independent of seasonal climate alterations. This also indicated that HR had a stable effect on the replenishment of daily water use. Positive linear relationships between HR and Δθ were found at three measuring locations (camphor: R2 = .35, p < .01; peach1: R2 = .57, p < .01; peach2: R2 = .63, p < .01), suggesting a relatively stable inherent linkage between HR and Δθ. This study suggested that hydrological processes involving soil moisture status or antecedent soil moisture, needs to take the HR effect into account across timescales from intraday to seasonal.

Water-energy nexus in China’s industrial parks

Industrial parks are main sites for industrial sectors and are critical clients for water and energy management. However, the water-energy nexus at the industrial park-level is still poorly understood. This study established high-resolution profiles of water use and energy consumption and their linkages in Chinese industrial parks for the first time. Based on this inventory, the water use and energy consumption of 209 Chinese national industrial parks were uncovered from a life-cycle perspective. The total water use of these parks accounted for 6% of national industrial water use, while the total energy consumption accounted for 10% of national energy consumption. Surface water and coal played an undeniably dominant role in direct water and energy structures, with a share of 95% and 74%, respectively. The water-energy nexus was then analyzed, and we observed that the indirect water use embodied in the energy sector (29% of the total water use) was much more significant than the indirect energy consumption induced by the water sector (nearly 0% of the total energy consumption). Moreover, water and energy were closely linked and positively correlated in industrial parks; energy-intensive parks generally tended to be water-intensive. Finally, water use and energy consumption in the parks toward 2020 and 2030 were targeted, according to cap and intensity controls highlighted in national strategies. The results indicated that to achieve the governing goals, water and energy should be managed jointly, particularly considering the indirect water use embodied in the energy sector.

Maximizing blue water use efficiency of wheat (Triticum aestivum) through irrigation and mulching

A field study was conducted in sub-humid Eastern Ghats region of India to investigate the effect of different soil moisture conservation practices, viz. no-mulch (NM) as a control, ridge and furrow (RF), Gliricidia mulch (GM) and Lantana mulch (LM) on water productivity, and yield of wheat (Triticum aestivum L.) under three levels of irrigation (CPE100 = 100%, CPE80 = 80% and CPE60 = 60% ). Total water use by wheat was 270.1–365.6 mm during 2016–17 and 210.4–302.5 mm during 2015–16. Averaging both years, wheat used was 88.35 mm (26.8%) and 44.9 mm (13.6%) more water at CPE100 over CPE60 and CPE80, respectively. Among the irrigation levels, higher water productivity (WP) was observed in CPE60 (13.6, 9.8 kg/m3) compared to CPE80 (12.8, 9.3 kg/m3) and CPE100 (11.3, 8.9 kg/m3) for both years, respectively. CPE60 resulted in 5.9 and 15.8% greater WP over CPE80 and CPE100, respectively. Mulching increased WP by 27.8% in GM and 23.3% in LM treatments compared to NM. Irrigation with mulching treatments, CPE60 + GM exhibited WP of 15.9 and 14.7 kg/m3, and CPE60 + LM WP of 11.0 and 10.6 kg/m3 during 2015–16 and 2016–17, respectively. On an average, mulching treatment produced additional total WP of 2.2–2.6 kg/m3, green WP of 0.5–0.7 kg/m3 and blue WP of 1.7–2.0 kg/m3 over NM. Thus CPE80+ GM could be successfully applied during post-monsoon (Rabi) season in wheat production allowing a water savings of 20% without any yield loss.

Improving water ecosystem sustainability of urban water system by management strategies optimization

Water management strategies play an important role in water shortage alleviation. This study evaluates the cost and water ecosystem benefit of 14 water management strategies in Beijing in the future scenarios for 2020 and 2035. In addition, optimal implements of abatement strategies are obtained within the context of legislated targets, with the consideration of interaction among strategies. The result shows that Beijing can meet its commitments for total water use and pollution control by the water management strategies implementation in both 2020 and 2035. For 14 water management strategies analyzed in this study, 5 options with negative abatement cost value achieve 12.2–24.1% of the total water ecosystem benefit in 2020 and 2035. Wastewater reclamation is the most efficient strategy in water ecosystem impact (WEI) reduction, which contributes 38.4% of the total WEI reduction with an abatement cost of 1.6 Yuan/m3 H2O -eq. However, the sequence of optimal strategy implementation rate is not in accordance with the abatement cost of the strategies. The most cost-effective option is the water-efficient shower head, while the highest implementation rate is found for promotion of production technologies. A comparison between water management optimization with and without the consideration of interactions among strategies shows that taking the interaction among strategies into account imposes almost no influence on the total WEI reduction. But it has impacts on optimal implementation rate of each water management option and the cost estimation (+10.8%) of water management implementation. Such a systematic analysis of water management strategies provides general recommendations on sustainable water resource management in water scarce regions.

Quantifying Phosphorus and Water Demand to Attain Maximum Growth of Solanum tuberosum in a CO2-Enriched Environment.

Growth promotion by ambient CO2 enrichment may be advantageous for crop growth but this may be influenced by soil nutrient availability. Therefore, we quantified potato (Solanum tuberosum L.) growth responses to phosphorus (P) supply under ambient (a[CO2]) and elevated (doubled) CO2 concentration (e[CO2]). A pot experiment was conducted in controlled-environment chambers with a[CO2] and e[CO2] combined with six P supply rates. We obtained response curves of biomass against P supply rates under a[CO2] and e[CO2] (R2 = 0.996 and R2 = 0.992, respectively). A strong interaction between [CO2] and P was found. Overall, e[CO2] enhanced maximum biomass accumulation (1.5-fold) and water-use efficiency (WUE) (1.5-fold), but not total water use. To reach these maxima, minimum P supply rate at both [CO2] conditions was similar. Foliar critical P concentration (i.e., minimum [P] to reach 90% of maximum growth) was also similar at nearly 110 mg P m−2. Doubling [CO2] did not increase P and water demand of potato plants, thus enabling the promotion of maximum growth without additional P or water supply, but via a significant increase in WUE (9.6 g biomass kg−1 water transpired), presumably owing to the interaction between CO2 and P.

Mid-latitude freshwater availability reduced by projected vegetation responses to climate change

Plants are expected to generate more global-scale runoff under increasing atmospheric carbon dioxide concentrations through their influence on surface resistance to evapotranspiration. Recent studies using Earth System Models from phase 5 of the Coupled Model Intercomparison Project ostensibly reaffirm this result, further suggesting that plants will ameliorate the dire reductions in water availability projected by other studies that use aridity metrics. Here we complicate this narrative by analysing the change in precipitation partitioning to plants, runoff and storage in multiple Earth system models under both high carbon dioxide concentrations and warming. We show that projected plant responses directly reduce future runoff across vast swaths of North America, Europe and Asia because bulk canopy water demands increase with additional vegetation growth and longer and warmer growing seasons. These runoff declines occur despite increased surface resistance to evapotranspiration and vegetation total water use efficiency, even in regions with increasing or unchanging precipitation. We demonstrate that constraining the large uncertainty in the multimodel ensemble with regional-scale observations of evapotranspiration partitioning strengthens these results. We conclude that terrestrial vegetation plays a large and unresolved role in shaping future regional freshwater availability, one that will not ubiquitously ameliorate future warming-driven surface drying. Projected responses of plants to rising atmospheric CO2 concentrations reduce runoff in large parts of the mid-latitudes as bulk canopy water demands grow, suggests an analysis of precipitation partitioning in climate model simulations.

Life Cycle Water Use for Oxy Fuel Combustion Power Generation with CO2 Capture and Storage

The water scarcity is becoming a growing concern. Regarded as a potential CO emission mitigation technology for coal-fired power plants, oxy-fuel combustion, a typical CCS technology, theoretically consumes a large amount of water, which increases the severity of the water scarcity. Therefore, revealing the water use of oxy-fuel coal-fired power plants is of great importance for the deployment of CCS technologies under water resource constraint in the future. In this respect, the aim of this study is to evaluate the life cycle water use of oxy-fuel CO capture, transport and storage via a 600 MW coal fired oxy-fuel power plant in China. By using a tiered hybrid life cycle assessment, both direct and indirect water use are calculated. Results show 22.9L H O/kg of CO and the oxy-fuel power plant stage dominates the total water use, while the water intensity for power generation is calculated as 3233.3 L H O/MWh, which is higher than the conventional power plants. Sensitivity analysis is performed in this research and indicates that the variation of tap water use affects the water intensity immensely. Furthermore, the use of the membrane method for air separation decreases the overall water use 14.21% respectively. China is continually increasing its efforts to reduce carbon emissions due to both domestic and international pressure. Hence the development and implement of the CCS technology is of great urgency. At the end of this study possible solutions such as using wasted or discarded wind power for the separation of oxygen to minimize water use in oxy-fuel power plant stage are put forward.

The influence of spring grazing management on yield and water use of rainfed lucerne

Flexible spring grazing management can increase the use of lucerne on farms. However, the negative impacts of set stocking on the survival of plants usually preclude its use. In this experiment, crops of ‘Stamina 5’ lucerne at Ashley Dene, Lincoln University were rotationally grazed, semi-set stocked or set stocked from September to December 2011. Dry matter (DM) yield to December was 6.3 t DM/ha, and consistent among crops. However, the larger leaf area of the semi-set- and set-stocked crops intercepted 45% more solar radiation and transpired 25% more water than the rotationally grazed crop. The set-stocked regime had a lower efficiency of resource use. This was probably due to greater respiration and/or partitioning of DM to the root mass. Set-stock regimes required continual initiation of new shoots from basal buds, which remobilised and, therefore depleted, stored assimilates. To minimise this impact, farmers should maintain a canopy cover of 2 to 2.5 t DM/ha (~20 cm tall) on any set-stocked lucerne. This will maximise radiation interception and compensate for reserve losses. In the study year, grazing management did not influence feed supply through the manipulation of water use because soil evaporation losses were inversely related to crop water use. Consequently, total water use was consistent among crops, with higher soil evaporation from frequent rewetting of the soil for rotationally grazed crops. For farmers, these results suggest continuous grazing of lucerne is possible, but it should be managed to maintain full canopy cover and minimise reserve depletion that will reduce DM yields and stand persistence.

Urban land and sustainable resource use: Unpacking the countervailing effects of urbanization on water use in China, 1990–2014

Despite substantial attention paid to the environmental outcomes of urbanization, explanations and evidence have been surprisingly mixed. Drawing on political economy arguments and the ecological modernization theory, this study addresses the gap in the literature by conceptualizing urbanization as an intertwining process of population concentration and land use intensification, and examines how these two dimensions influence water use at the local level. Panel data for total water use, per capita water use, and water use efficiency are analyzed using random effects and fixed effects panel regression models for 286 Chinese cities from 1990 to 2014. The findings suggest that population concentration and urban land use have countervailing effects on water use and per capita use, while both improve water use efficiency. The results confirm the inner tussle within urbanization, and imply that cities with smaller population size and intense land use show potential for sustainable water use.

Freshwater use in China: relations to economic development and natural water resources availability

ABSTRACTUnderstanding the patterns and driving factors of water use is vital for developing adequate and sustainable water management strategies. This study examines the relations of provincial freshwater use in China to economic development and natural water availability in both space and time. The panel data model fitting results indicate that temporal variability of per capita total and sectoral water use shows an environmental Kuznets curve and is negatively correlated with water availability. In space, water availability has a significant positive effect on provincial water use. The results aids in diagnosing historical water use and elucidating relevant policy implications.

Grain Yield and Resource Use Efficiencies of Upland and Lowland Rice Cultivars under Aerobic Cultivation

Aerobic rice has the potential to replace transplanted flooded rice, as rice cultivation is seriously threatened by environmental and social factors. Although the recently released upland rice cultivars have higher drought tolerance, low yield potential of these cultivars makes them less feasible for high-yielding rice planting regions under aerobic cultivation. In this study, typical lowland rice cultivars (Huanghuazhan and Yangliangyou6) were evaluated for grain yield and resource use efficiencies under aerobic cultivation as compared with upland rice cultivars (Lvhan1 and Hanyou3). Averaged across different years, lowland rice cultivars recorded 26.9%, 14.6%, and 26.6% higher grain yield, water productivity, and nitrogen use efficiency for grain production (NUEg), respectively, as compared with upland cultivars. The higher grain yield of lowland rice cultivars under aerobic cultivation was mainly attributed to the higher aboveground biomass and the spikelet number per panicle, along with a higher harvest index and panicle number per unit area with respect to upland rice cultivars. During the entire growing season in aerobic cultivation, rainfall accounted for 60% to 85% of the total water use, which indicates that lowland rice cultivars could make better use of the rainfall because of a longer growth duration and a higher growth potential. In summary, this study suggests that with appropriate irrigation, lowland rice cultivars could grow well and furnish higher yield than the current upland rice cultivars under aerobic cultivation.

Study on Water Distribution Scheme Across Regions

For a long time, water conservancy projects across administrative region is mostly invest in the construction by superior government, each side unconditional benefit, this is difficult to arouse the enthusiasm of benefited party to investment, and makes the government faces a great financial pressure, at the same time, it is easy to produce regional imbalance and contradiction of water resources. Finally, it will affect the resource efficiency and investment efficiency of the project. The transregional water allocation is an important basis for implementing the total water use control system in drainage basin and regions and an important content for implementing tough water management measures. This article summarily analyses the typical engineering way of water allocation, and the basic principle of the water allocation, takes Qingxi Reservoir water allocation on concrete analysis, puts forward the main factors of Qingxi Reservoir water allocation, including the area of the Qingxi river basin in each administrative regions, water resources, effect of reservoir engineering constructions, the water demand and water deficit in each administrative regions, input factors, and then puts forward proposals on water allocation. Based on two water allocation proposals, this article puts forward proportion and recommended of water allocation in each administrative region. Each administrative region should own the same right to use water resources and shoulder the same responsibility based on the same proportion, same right, same profit and same responsibility. The water allocation plan can be used as reference for Qingxi Reservoir water allocation.

Comprehensive Environmental Assessment of Potato as Staple Food Policy in China.

The Chinese government projected 30% of total consumed potatoes as a staple food (PSF) by 2020. We comprehensively assessed the potential impacts of PSF on rice and flour consumption, rice and wheat planting, energy and nutrient supply, irrigation-water, chemical nitrogen (N), phosphorus pentoxide (P2O5) and potassium oxide (K2O) fertilizer inputs and total greenhouse gases (GHG) emission for potatoes, rice and wheat, by assuming different proportions of potato substitutes for rice and flour. The results showed that per capita, 2.9 ± 0.3 and 4.7 ± 0.5 kg more potatoes per year would enter the Chinese staple-food diet, under the government’s target. PSF consumed are expected to reach 5.2 ± 0.7 Tg yr−1, equivalent to substituting potatoes for 4.2 ± 0.8–8.5 ± 0.8 Tg yr−1 wheat and 5.1 ± 0.9–10.1 ± 1.8 Tg yr−1 rice under different scenarios. While this substitution can increase the nutrient supply index by 63% towards nutrient reference values, it may induce no significant effect on staple-food energy supply with lower chemical fertilizer (except for K2O) and irrigation-water inputs and GHG emissions in different substitution scenarios than the business as usual scenario. The reduction in rice and wheat demands lead to wheat in the North China Plain and early rice decrease by 6.1–11.4% and 12.1–24.1%, respectively. The total GHG reduction is equal to 1.1–9.0% of CO2 equivalent associated with CH4 and N2O emitted from the Chinese agroecosystem in 2005. The saved irrigation water for three crops compared to 2012 reaches the total water use of 17.9 ± 4.9–21.8 ± 5.9 million people in 2015. More N fertilizer, irrigation-water, and GHG can be reduced, if the PSF ratio is increased to 50% together with potato yield improves to the optimal level. Our results implied that the PSF policy is worth doing not only because of the healthier diets, but also to mitigate resource inputs and GHG emissions and it also supports agricultural structure adjustments in the areas of irrigated wheat on the North China Plain and early rice across China, designed to increase the adaptability to climate change.

Sustainable product line design considering a multi-lifecycle approach

Global awareness on product lifecycle issues and competitive advantages of implementing end-of-life (EoL) recovery strategies (i.e., reuse, remanufacturing, and recycling) have driven companies to develop more sustainable product designs. Designing a product line involves developing variants of a product to address needs of different market segments. Sharing of same types of components between variants when feasible can lead to lower product cost and improved manufacturing efficiency. Prior research has considered many aspects related to sustainable product line design. However, none of them have comprehensively addressed the consideration of multi-lifecycle, closed-loop material flow for sustainable product line design; studies that incorporate pricing decisions while simultaneously considering economic and environmental objectives are also lacking. In this study, a novel approach for sustainable product line design considering the multiple lifecycle approach and EoL recovery strategies is proposed. An optimization model with economic and environmental performance objectives is developed to determine the designs and selling prices of new and hybrid products. Dynamic demand models based on the diffusion function of time and price are developed to incorporate the price-sensitivity of demand multiple lifecycles. The application of the approach is demonstrated using an industrial case study to identify the sustainable product line design of toner cartridges. The Pareto optimal solutions obtained show that the proposed methodology can identify more sustainable product line designs. The new designs have much higher total lifecycle profit, energy use, and water use compared to baseline designs that do not follow a closed-loop, multi-lifecycle flow.

Joint Assimilation of Leaf Area Index and Soil Moisture from Sentinel-1 and Sentinel-2 Data into the WOFOST Model for Winter Wheat Yield Estimation.

It is well known that timely crop growth monitoring and accurate crop yield estimation at a fine scale is of vital importance for agricultural monitoring and crop management. Crop growth models have been widely used for crop growth process description and yield prediction. In particular, the accurate simulation of important state variables, such as leaf area index (LAI) and root zone soil moisture (SM), is of great importance for yield estimation. Data assimilation is a useful tool that combines a crop model and external observations (often derived from remote sensing data) to improve the simulated crop state variables and consequently model outputs like crop total biomass, water use and grain yield. In spite of its effectiveness, applying data assimilation for monitoring crop growth at the regional scale in China remains challenging, due to the lack of high spatiotemporal resolution satellite data that can match the small field sizes which are typical for agriculture in China. With the accessibility of freely available images acquired by Sentinel satellites, it becomes possible to acquire data at high spatiotemporal resolution (10–30 m, 5–6 days), which offers attractive opportunities to characterize crop growth. In this study, we assimilated remotely sensed LAI and SM into the Word Food Studies (WOFOST) model to estimate winter wheat yield using an ensemble Kalman filter (EnKF) algorithm. The LAI was calculated from Sentinel-2 using a lookup table method, and the SM was calculated from Sentinel-1 and Sentinel-2 based on a change detection approach. Through validation with field data, the inverse error was 10% and 35% for LAI and SM, respectively. The open-loop wheat yield estimation, independent assimilations of LAI and SM, and a joint assimilation of LAI + SM were tested and validated using field measurement observation in the city of Hengshui, China, during the 2016–2017 winter wheat growing season. The results indicated that the accuracy of wheat yield simulated by WOFOST was significantly improved after joint assimilation at the field scale. Compared to the open-loop estimation, the yield root mean square error (RMSE) with field observations was decreased by 69 kg/ha for the LAI assimilation, 39 kg/ha for the SM assimilation and 167 kg/ha for the joint LAI + SM assimilation. Yield coefficients of determination (R2) of 0.41, 0.65, 0.50, and 0.76 and mean relative errors (MRE) of 4.87%, 4.32%, 4.45% and 3.17% were obtained for open-loop, LAI assimilation alone, SM assimilation alone and joint LAI + SM assimilation, respectively. The results suggest that LAI was the first-choice variable for crop data assimilation over SM, and when both LAI and SM satellite data are available, the joint data assimilation has a better performance because LAI and SM have interacting effects. Hence, joint assimilation of LAI and SM from Sentinel-1 and Sentinel-2 at a 20 m resolution into the WOFOST provides a robust method to improve crop yield estimations. However, there is still bias between the key soil moisture in the root zone and the Sentinel-1 C band retrieved SM, especially when the vegetation cover is high. By active and passive microwave data fusion, it may be possible to offer a higher accuracy SM for crop yield prediction.

Climate and Land Use Effects on Hydrologic Processes in a Primarily Rain‐Fed, Agricultural Watershed

AbstractAnticipating changes in hydrologic variables is essential for making socioeconomic water resource decisions. This study aims to assess the potential impact of land use and climate change on the hydrologic processes of a primarily rain‐fed, agriculturally based watershed in Missouri. A detailed evaluation was performed using the Soil and Water Assessment Tool for the near future (2020–2039) and mid‐century (2040–2059). Land use scenarios were mapped using the Conversion of Land Use and its Effects model. Ensemble results, based on 19 climate models, indicated a temperature increase of about 1.0°C in near future and 2.0°C in mid‐century. Combined climate and land use change scenarios showed distinct annual and seasonal hydrologic variations. Annual precipitation was projected to increase from 6% to 7%, which resulted in 14% more spring days with soil water content equal to or exceeding field capacity in mid‐century. However, summer precipitation was projected to decrease, a critical factor for crop growth. Higher temperatures led to increased potential evapotranspiration during the growing season. Combined with changes in precipitation patterns, this resulted in an increased need for irrigation by 38 mm representing a 10% increase in total irrigation water use. Analysis from multiple land use scenarios indicated converting agriculture to forest land can potentially mitigate the effects of climate change on streamflow, thus ensuring future water availability.

Water dynamics, productivity and heat use efficiency responses in wheat (Triticum aestivum) to land configuration techniques and irrigation schedules

The present study was conducted during 2012–13 and 2013–14 to investigate the effect of different land configurations and irrigation schedules on soil water depletion, ground water contribution (GWC), productivity and heat use efficiency of wheat (Triticum aestivum L. emend. Flori & Paol). Results of the two years study exhibited highest grain yield by 24.7% and 17.4%, water use efficiency (WUE) by 38.8% and 35.7%, respectively, under furrow irrigated raised beds (FIRBS) over conventional tillage (CT). Soil moisture depletion, GWC and total consumptive water use were lowered by 21% and 15%, 20% and 16%, and 12% and 9%, respectively over CT in both the years. Under zero tillage (ZT) condition, wheat accumulated highest growing degree days (GDD) of 3288°C day and 3321°C day, respectively. Furthermore, FIRBS and ZT plots accumulated additional heat units of 1000°C day-hour till maturity in both the years. Among the irrigation schedules, contribution of irrigation water towards consumptive water use was highest by 41.8% and 43.6% in IW:CPE=0.90 over others in 2 years, respectively. Irrigation water productivity (WPI) was highest by 45.8% and 43.3% in IW:CPE=0.75, respectively.