Proportion Of Water Use Research Articles

Trends in the future evolution of rural settlements in oasis-desert areas under water use simulation scenarios: Take the Hexi Corridor region of China as an example

The uncontrolled expansion of rural settlements caused by the imbalance in the matching of land and water resources has hindered the realization of the goal of sustainable rural development in the oasis-desert area. In this study, “water resources-land resources-oasis rural settlements” are integrated into the same framework of symbiosis development, and the evolution of rural settlements in the context of water and land resources constraints is predicted. We used the coupled “SD-SOS-FLUS” (“system dynamics-suitable oasis structure-future land use simulation”) model to predict the differences in rural settlement sizes and their spatial distribution under the inertial development water use scenario (ID) and sustainable development water use scenario (SD) in the northeast part of the Hexi Corridor in China. In addition, we explored differences in oasis circle structure and land use structure under different water allocation scenarios. Compared with a single model, the coupled model “SD-SOS-FLUS” can better simulate the symbiosis relationship between “water resources-land resources- oasis rural settlements”. Through the prediction, the proportion of water used for production in the ID scenario is still as high as 86.30 %, while the proportion of ecological water use is only 11.50 %, and the continuous imbalance of the water use structure results in the area of arable land and rural settlements will be increased to 7,473.21 km2 and 487.16 km2. It increased by 115.63 km2 and 41.28 km2 respectively compared to 2020, which in turn made the oasis area expanding outward, and the radius R of the oasis also increased from 53.65 km in 2020 to 54.79 km in 2030. The area of arable land and rural settlements under water and land resource constraints in the SD scenario decreased to 5223.56 km2 and 105.04 km2. The contraction of the oasis increases the transition zone circle width B2 from 19.88 km in 2020 to 24.58 km in 2030, an increase of 5 km compared to the ID scenario. As a result of the spatial reconfiguration, the number of rural settlement patches decreased from 1.04 × 104 to 0.15 × 104 in 2020, saving 3.41 × 104 ha of land after optimization.

Root efficiency and water use regulation relating to rooting depth of winter wheat

It is well-recognized that deep roots play a vital role in increasing soil water availability to crop water use, their ability in regulating the allocation of the crop water use during the growing season would also influence crop yield and water productivity. Experiments were conducted using tubes of 0.5, 1.0, 1.5 and 2.0 m in depth (with an inner diameter of 30.5 cm) and irrigation amounts varying from 90 to 500 mm for two seasons of winter wheat (2019–2020 and 2020–2021). The combinations of the different tube depth and irrigation created different situations in terms of maximum rooting depth and soil water availability to assess the functions of deep roots on regulation of soil water availability to crops, and if the deep root growth being economic or not in relating to crop production and water productivity (WP). The results showed that under the same seasonal evapotranspiration (ET), the shallower the root depth was, the lower the yield. Higher WP was achieved with deep root systems. Further analysis showed that higher proportion ET occurred during the reproductive stage for the treatments with deep roots, which increased the leaf photosynthetic rate and the duration of the greenness, resulting in higher harvest index and WP. Deep roots not only increased the soil water availability for crop water use, but also regulated the timing of the soil water use to favor an increased proportion of water use during the reproductive stage. The root: shoot ratio was slightly increased from the 0.5 m tube to 1.0 m tube, but under a sufficient water supply, root: shoot ratio gradually decreased in the 1.5 m and 2.0 m tubes, resulting in less root length corresponding to the unit grain production. The treatments with deep root systems increased the root efficiency. The results indicated that both the total available water and the allocation of the water consumption during the crop growing season influenced the yield and water productivity. Increasing rooting depth was an efficient regulation measure to optimize the allocation of water consumption and increase soil water availability to crops without increasing metabolic input in root growth.

Economic Sustainability of Irrigation‐Dependent Ecosystem Services Under Growing Water Scarcity. Insights From the Reno River in Italy

AbstractAs water scarcity grows, irrigators are adopting modern irrigation systems to increase the proportion of water use consumed by crops and mitigate impacts on production. This increased beneficial consumption is fundamentally sourced by lower return flows‐runoff and percolation‐back into the environment, which are critical to sustain wetlands and other irrigation‐dependent green infrastructures that supply valuable ecosystem services. We adopt an innovative multi‐model ensemble of mathematical programming models to assess irrigators' responses to pecuniary compensations designed to sustain irrigation‐dependent ecosystem services (Payments for Watershed Services‐PWS), under multiple scenarios. The upshot is a database of forecasts that represents the range of plausible future states, which is used to assess economic performance and identify a robust adaptation strategy to growing scarcity. Our analysis of the Reno River Land Reclamation and Irrigation Board in NE Italy shows that, under most models and scenarios, the conservationist strategy has a superior economic performance than the autonomous adaptation strategy where modern irrigation systems are adopted. The conservationist strategy is also found more robust than the autonomous strategy. However, unless sensible incentives are put in place, irrigators may adopt irrigation technologies nonetheless. Under mild to moderate climate change scenarios, removing existing subsidies to modern irrigation systems is sufficient to deter their adoption. Under severe climate change scenarios, additional PWS to irrigators will be necessary to ensure the sustainability of irrigation‐dependent ecosystem services.

Water balance model as a tool for building participation and joint water use promotion at the river basin level*

AbstractTo promote collaboration on water management between farmers and government agencies, both parties must have a mutual understanding of the measurement and management of available water resources using existing infra‐ and non‐infrastructure management tools. They are required to provide collaborative water management through appropriate technology, with capacity building and knowledge management. In this study, the water balance model was used as a tool to induce participation and the promotion of a joint water use at the river basin level. The amount and proportion of water use from different types of water sources were calculated based on this water balance model. Moreover, farmers were encouraged to help with water flow measurements using technologies and principles that were simple but accurate in terms of engineering aspects. According to the analyses of water use proportions, a large amount of water from pumping stations was used during the dry season at high cost. When aware of the proportion of water used, farmers collaboratively established guidelines on an effective water management in the area, including large‐scale viewpoints applicable beyond the actual areas. Overall, these guidelines will eventually bring positive results to other downstream water users.

Isotopic variation in groundwater across the conterminous United States – Insight into hydrologic processes

AbstractGroundwater supplies a significant proportion of water use in the United States and is critical to the maintenance of healthy ecosystems and environmental processes, thus characterizing aquifer hydrology is important to managing and preserving these resources. While groundwater isotopes provide insight into hydrologic and ecologic processes, their application is limited to where measurements exist. To help overcome this limitation, we used the random forest algorithm to develop a predictive model for shallow groundwater isotopes in the conterminous United States. Our model uses environmental variables (e.g. temperature, elevation, precipitation isotopes) as predictors. We used our model to develop the first shallow groundwater isoscape of δ2H and δ18O for the conterminous United States. We describe the patterns in groundwater isotopes using both observations and our modelled isoscape. We find that throughout much of the Eastern United States, groundwater isotopes are close to annual amount weighted precipitation, while groundwater isotopes are significantly depleted relative precipitation across much of the High Plains and Western United States. Furthermore, we compare the observations compiled for this study to isotopes of precipitation, which allows us to determine the relative recharge efficiency (i.e. ratio of groundwater recharge to precipitation) between seasons and the proportion of annual recharge that occurs in a given season. Our findings suggest that winter recharge is generally more efficient than summer recharge; however, the dominant recharge season is more varied as it is the product of both seasonal recharge efficiency and the seasonal timing of precipitation. Parts of the central United States have summer dominant recharge, which is likely the result of heavy summer precipitation/nocturnal summer precipitation. Interestingly, parts of coastal California appear to have summer dominant recharge, which we suggest could be due to recharge from fog‐drip. Our results summarize spatial patterns in groundwater isotopes across the conterminous United States, provide insight into the hydrologic processes affecting shallow groundwater, and are valuable information for future ecologic and hydrologic studies.

Deficit irrigation enhances contribution of shallow groundwater to crop water consumption in arid area

Agricultural water conservation is important in arid and semi-arid areas where water resources are deficient and agriculture irrigation accounts for a high proportion of water use. Thus, efficient deficit irrigation methods, which the supplied water is less than potential evapotranspiration have been developed. In semi-arid areas, groundwater can contribute to crop’s water consumption but less is known about impact of deficit irrigation on the contribution. We conducted, therefore, a two-year field experiments with deficit flood irrigation for maize in an arid district with shallow groundwater in China. Four irrigation practices were tested with water applied at approximately 82.5%, 75%, 67.5% and 60% of the 540mm potential evapotranspiration (PET) in 2014 and the 500mm in 2013 over the crop growing season. We found that the upward flux between soil water and groundwater varied from 5mm with input water of 488mm to 60mm with input water of 353mm. The yield of maize decreased by only 15% from 10.0 to 8.5t/ha for the WS treatment (irrigated at 60% of PET) compared with the WH treatment (irrigated at 82.5% of PET) due to more groundwater contribution to the crop growing with less irrigation. As a consequence, the water use efficiency (WUE), defined as quotient of the yield and plant evapotranspiration was not significantly different among different irrigation treatments. However, the irrigation water use efficiency (IWUE), which is the yield per unit of water applied, increased significantly with the decreasing amount of water applied due to the contribution of upward fluxes. The implication is that deficit irrigation enhances the contribution of groundwater to crop water use and will not produce an obvious reduction of yield within a stable shallow groundwater level.

景德镇市行业用水演变及其驱动力分析

根据2003年至2014年景德镇市农业、工业、生活、生态环境等行业的用水量资料，分析景德镇市近12年来行业用水的变化发展，结合SPSS统计软件对引起行业用水变化的主要驱动力因子进行分析和说明。结果表明：景德镇市的水资源利用以农业用水为主，占用水总量的50.6%，工业用水占用水总量的34.5%，比重相对较大，生活用水和生态环境用水所占用水总量的比重较小，分别为13.9%和1.0%；景德镇市用水总量基本稳定，无整体上升或下降趋势，农业用水量及其所占用水总量的比重呈现整体上升的趋势，工业用水量及其所占用水总量的比重呈现出先上升而后下降的趋势，生活用水量及其所占用水总量的比重近10年来呈现逐年攀升的趋势，生态环境用水量及其所占用水总量的比重呈现略微上升的态势；因子分析的结果显示人口因素、经济发展因素和农田灌溉因素是景德镇市行业用水演变的主要驱动力。 According to the agricultural, industrial, life, public and ecological environment water use data of Jing-dezhen city from 2003 to 2014, the paper analyzes the change of water use in various industries in Jing-dezhen city during the last 12 years, and analyzes and explains the main driving factors of the develop-ment of water use in various industries by using SPSS statistical software. The results show that the water resources utilization in Jingdezhen city is mainly agricultural water use, which accounts for 50.6% of the total amount; the proportion of industrial water use is relatively larger, which accounts for 34.5% of the total amount; the proportion of water used for life, public and ecological environment is small, which accounts for 13.9% and 1.0% of the total amount. The total amount of water use in Jingdezhen is basically stable, and there is no overall rise or fall, agricultural water use, water use of the ecological environment are showing an overall upward trend and the proportion of total water use in agriculture and ecological environment is also increasing; industrial water use and its proportion of the total water use showed a trend of first increasing and then decreasing trend; water use for life and public and their proportion of the total water use in the past 10 years has been rising year by year. Factor analysis results show that the main driving force of the development of water use in various industries in Jingdezhen city is the population, economic development and farmland irrigation.

邢台市工业用水特征与节水效益分析计算

通过对邢台市工业用水和节水效益分析计算，为工业发展规划、合理高效利用水资源提供科学依据。采用邢台市2001~2012年用水量资料，对邢台市各行业用水比重、工业用水变化趋势以及万元产值净用水量进行分析。邢台市工业用水占总用水量的10.95%；工业用水量年际变化较大，工业用水量总体呈下降趋势，平均每年减少0.0056亿m3；通过对邢台市各行政区万元产值净用水量分析，各行政区之间相差较大，高用水工业万元产值用水量为12.92 m3，一般工业为5.58 m3。邢台市工业用水量减小而工业增加值逐年上升，主要措施是：实现不同行业间的循环用水，提高节水管理水平；严格实行建设项目水资源论证制度，提高水资源承载能力；大力推行水平衡测试制度，为全面总量控制、定额管理奠定了基础。 Analysis of industrial water and calculation of water saving benefit in Xingtai city provide scientific basis for the industrial development planning, and rational and effective utilization of water resources. Using data of water use in Xingtai city during 2001-2012, proportion of water use for each industry, industrial water changing trends and net duty of water for ten thousand Yuan output value are analyzed. Xingtai city industrial water accounts for 10.95% of the total amount of industrial water use; annual change of industrial water use is large and the overall industrial water use trends down decreasing 560,000 cubic meters annually; through analyzing net duty of water for ten thousand Yuan output value of each administrative region in Xingtai city, it is found that there is a large difference between administrative regions, water consumption of ten thousand Yuan output value of industry with high water use is 12.92 cubic meters, and that of general industry is 5.58 cubic meters. Industrial water use in Xingtai city is reduced and the industrial added value increases year by year. The main measures are: achieving the recycling of water between different industries, and improving the management level of water saving; strictly implementing the system of water resources argumentation of construction project, and improving the bearing capacity of water resources; vigorously promoting the water balance test system, which lays the foundation for the total amount control and quota management.

Disentangling Water Usage in the European Union: A Decomposition Analysis

The Water Framework Directive (WFD) defines common objectives for water resources throughout the European Union (EU). Given this general approach to water preservation and water policy, the objective of this paper is to analyse whether common patterns of water consumption exist within Europe. In particular, our study uses two methods to reveal the reasons behind sectoral water use in all EU countries. The first method is based on an accounting indicator that calculates the water intensity of an economy as the sum of sectoral water intensities. The second method is a subsystem input-output model that divides total water use into different income channels within the production system. The application uses data for the years 2005 and 2009 on water consumption in the production system of the 27 countries of the EU. From our analysis it emerges that EU countries are characterized by very different patterns of water consumption. In particular water consumption by the agriculture sector is extremely high in Central/Eastern Europe, relative to the rest of Europe. In most countries, the water used by the fuel, power and water sector is consumed to satisfy domestic final demand. However, our analysis shows that for some countries exports from this sector are an important driver of water consumption. Focusing on the agricultural sector, the decomposition analysis suggests that water usage in Mediterranean countries is mainly driven by final demand for, and exports of, agricultural products. In Central/Eastern Europe domestic final demand is the main driver of water consumption, but in this region the proportion of water use driven by demand for exports is increasing over time. Given these heterogeneous water consumption patterns, our analysis suggests that Mediterranean and Central/Eastern European countries should adopt specific water policies in order to achieve efficient levels of water consumption in the European Union.

Co-adaptation between modern oasis urbanization and water resources exploitation: A case of Urumqi

Water resources exploitation is always very important during the whole oasis urbanization in arid zone, adapting with urban development in between contradiction and coordination. Taking Urumqi City as a case, co-adaptation of water exploitation and urban growth is imitated by interactions between water supply and oasis city’s expands on population, economy and environment. In different urbanization stages, the co-adaptation can be represented differently, which can be summarized by five phases: elementary coordination, expanding coordination, expanding contradiction, adapting contradiction, and adapting coordination. Cost of water consumption, proportion of water use and efficiency are the main influence factors to help the co-adaptation.

The impacts of human activities on the water–land environment of the Shiyang River basin, an arid region in northwest China / Les impacts des activités humaines sur l’environnement pédo-hydrologique du bassin de la Rivière Shiyang, une région aride du nord-ouest de la Chine

The Shiyang River basin is a typical interior river basin that faces water shortage and environmental deterioration in the arid northwest of China. Due to its arid climate, limited water resources and some inappropriate water-related human activities, the area has developed serious loss of vegetation, and gradual soil salinization and desertification, which have greatly impeded the sustainable development of agriculture and life in this region. In this paper, the impacts of human activities on the water–soil environment in Shiyang River basin are analysed in terms of precipitation, runoff in branches of the river, inflow into lower reaches, water conveyance efficiency of the canal system and irrigation water use efficiency in the field, replenishment and exploitation of groundwater resources, soil salinization, vegetation cover and the speed of desertification. The results show that human activities and global climate change have no significant influence on the precipitation, but the total annual runoff in eight branch rivers showed a significant decrease over the years. The proportion of water use in the upper and middle reaches compared to the lower reach was increased from 1:0.57 in the 1960s, to 1:0.27 in the 1970s and 1:0.09 in the 1990s. A reduction of about 74% in the river inflow to the lower reaches and a 15-m drop in the groundwater table have occurred during the last four decades. Strategies for improving the water–soil environment of the basin, such as the protection of the water resources of the Qilian Mountains, sustainable use of water resources, maintenance of the balance between land and water resources, development of water-saving agriculture, diverting of water from other rivers and control of soil desertification, are proposed. The objective of this paper is to provide guidelines for reconstruction of the sustainable water management and development of agriculture in this region.

Water use efficiency of wheat in a Mediterranean-type environment. I. The relation between yield, water use and climate

The relations between wheat yield and water use were determined from field measurements in South Australia. Highest production of dry matter was 37 kg ha-1 per mm of water use and of grain was 12.7 kg ha-1 per mm. More than 70% of the total water use occurred by anthesis. Time of sowing and soil water content at sowing had a big influence on yield. The loss of water by direct evaporation was estimated to be 110 mm, equal to about one-third of the water use. The maximum efficiency of water transpired was 55 kg ha-1 mm-1 for dry matter and 20 kg ha-1 mm-1 for grain. The efficiencies of most of the crops were below this level. Yield (Y), water use (W) and evaporation (Ep) could be fitted to the de Wit formula Y = m W/Ep, but the m factor varied with the proportion of water use that was lost by direct evaporation.