Water Shortage In Regions Research Articles

The spatial effects of city-level water-energy nexus: A case study of Hebei Province, China

As the basis of urban social-economic development, water and energy resources are indivisible and interrelated in the production and consumption activities of cities. The frequent intercity trade of energy-related goods aggravates water withdrawal in neighboring cities and causes the spatial transfer of resources. The spatial correlation of water withdrawal and energy consumption is rarely considered in the city-level water-energy nexus. As one of China's most serious water shortage regions, Hebei Province is the third-largest energy consumer in China and is a major supplier of mineral resources, industrial raw materials, water resources, electricity, and agricultural products to Beijing and Tianjin. The spatial Durbin model with the two-way fixed effects is applied to explore spatial effects of water-energy nexus in cities of Heibei province. Seven influencing factors, including energy consumption, energy structure, population, GDP, water withdrawal intensity, urbanization, and agriculture structure were considered. Results showed that all factors had positive impacts on water withdrawal except energy structure. Water withdrawal intensity made the most considerable contribution to water withdrawal, followed by urbanization, energy consumption, GDP, industrial structure, and population. The urbanization level of neighboring cities exerted the most significant positive spatial spillover impact on local water withdrawal, whereas the energy consumption showed a negative impact. The exploration of city-level spatial correlation regarding water withdrawal and energy consumption provides a reference for regional cooperation to improve resource utilization efficiency, establishing sustainable energy and water systems, and promoting sustainable development.

Determining evapotranspiration and crop coefficients of young and mature pomegranate trees under drip irrigation*

AbstractIn spite of the importance of increasing water shortages in most pomegranate production regions, there is not sufficient information about the water requirement and crop coefficients (Kc) of pomegranate trees under various conditions (e.g., plant cultivar and age and irrigation system). The aim of this study was to measure evapotranspiration during three growing seasons (2013, 2015, and 2016) and to determine Kc of young and mature pomegranate (Punica granatum L.) trees under drip irrigation in Iran. The soil water balance approach was applied to determine crop evapotranspiration (ETc) using soil water content measured during the growing seasons. The ratio of measured ETc to reference evapotranspiration calculated according to the Penman–Monteith equation provided the Kc values. According to the findings, from bud burst to peak season, daily Kc values for young pomegranate trees ranged from 0.18 to 0.70, 0.22 to 0.89, and 0.23 to 0.95 in 2013, 2015, and 2016, respectively. For mature pomegranate trees, these values varied between 0.26 to 1.15, 0.21 to 1.25, and 0.30 to 1.08 in 2013, 2015, and 2016, respectively. From bud burst to peak season, the total ETc for young pomegranate trees was 711, 905, and 934 mm and for mature pomegranate trees 1,172, 1,086, and 1,138 in 2013, 2015, and 2016, respectively. The results of this study are applicable to accurate water allocation, precision irrigation scheduling, and design of irrigation systems in pomegranate orchards.

Quantification of surface water and groundwater salinity sources in irrigated lowland area of North China Plain

AbstractSeasonally variation of water salinity is observed worldwide, the mechanisms of water salinity are not well understood due to natural factors and anthropogenic activities. Quantification water salinity source are challenging since complex influence factors, especially in agricultural regions irrigated with multi‐water sources. In the lowland area of North China Plain, transferred water, brackish shallow groundwater and fresh deep groundwater were combinative utilized to relieve prominent contradictions between regional water shortages and grain production. In this study, influence factors of surface water (canal water, pond water) and shallow groundwater salinity were identified and quantified through statistical analysis, deuterium excess, and ionic relationship. Salinity of canal water and pond water increased in dry season and decreased in rainy season, while salinity of shallow groundwater decreased in dry season after water transfer and rainy season, but increased in dry season. Evaporation and mineral dissolution were main factors for surface water salinity in dry season, with mineral dissolution was the more important one. The contribution ratio of evaporation and mineral dissolution for canal salinity were 4.4 and 49.1% in dry season after water transfer, 7.1 and 34.4% in dry season, and that for pond water salinity were 12.4 and 18.3% in dry season, respectively. Precipitation and surface runoff were main factors for surface water salinity in rainy season. The contribution of surface runoff for canal water and pond water salinity were 66.1 and 45.8%, respectively. Salinity of canal water and shallow groundwater was temporary decreased by water transfer. Domestic sewage from rural areas had larger influence than agricultural activities for salinity increase of pond water and shallow groundwater. Mineral dissolution was the main contributor for shallow groundwater salinity, with contribution ratio larger than 60% in different periods. This study demonstrated and quantified salinity source of surface water and shallow groundwater and may deepen our understanding of water management under multi‐water resources utilization.

Assessing shallow groundwater level using RTI model and long-term MODIS data in Ejina Basin, Northwest China

The present study aims to exploit the thermal inertia model to assess the shallow groundwater level distribution, as an attempt to address agricultural water shortage and ecological degradation in arid and semi-arid regions. Apparent thermal inertia (ATI) model is one of the most commonly used and successfully implemented models, whereas in some cases, the scales of the results achieved on different dates are inconsistent, which poses a serious difficulty when monitoring soil moisture over time. To address this restriction, we introduce a soil moisture indicator, called RTI, which derives an approximation of soil thermal inertia, from flexible multi-temporal MODIS observations covering a 2-year period. Taking the Ejina Basin in arid area as an example, to more accurately assess the shallow groundwater level distribution, ATI and RTI models were adopted based on the long time series MODIS data to assess the multi-temporal soil moisture content in the study area. The data of groundwater level measured by observation well and thermal inertia were employed to generate scatter diagrams. Subsequently, a nonlinear equation was developed. Based on the thermal inertia, the temporal and spatial distribution map of the shallow groundwater level in the whole study area was generated with the inverse calculation of the nonlinear equation. It was found that the shallow groundwater level distribution in Ejina Basin tended to be shallower from south to north, as well as from summer to winter. As revealed from the results, both ATI and RTI models can effectively assess the shallow groundwater level in arid areas. The RTI model could better reflect the seasonal changes of soil moisture content and groundwater level.

Did water-saving irrigation protect water resources over the past 40 years? A global analysis based on water accounting framework

Water-saving technologies have long been seen as an effective method to reduce irrigation water use and alleviate regional water shortage. However, growing reports of more severe water shortage and increasing application of water-saving technologies across the world have necessitated reassessment of agricultural water-saving. This study develops a simple method based on satellite-based ET partitions to estimate water withdrawal, water consumption and return flow from the 1980s to 2010s, and quantifies water-savings across globe and four hot-spot irrigated areas at both field and regional scales based on water accounting framework. The results show that global irrigation water flows keep increasing from the 1980s to 2010s, with over 50% increase from the expansion in irrigated lands. While water-saving technologies are found mainly applied in originally old irrigated lands, traditional flooding irrigation is still dominant in newly-developed irrigated lands. Non-beneficial water consumption (soil evaporation) is effectively reduced by water-saving technologies, but return flow has increased at the same time. At field scale, water-saving technologies fail to save water because the accumulated increased return flow is more than the accumulated decreased non-beneficial water consumption. At regional scale, however, water is saved because the return flow percolated to fresh aquifers is seen as beneficial rather than loss. At the same time, the accumulated increase of beneficial water consumption (crop transpiration) exceeds regional water savings, which explains the paradox between wide application of water-saving technologies and more severe regional water shortage. This study provides key new evidence for the paradox of irrigation efficiency and helps reconsidering water-saving technologies and their impacts on regional water resources.

Optimal water allocation at different levels of climate change to minimize water shortage in arid regions (Case Study: Zayandeh-Rud River Basin, Iran)

Climate change is one of the most important factors influencing the future of the world's environment. The most important impacts of climate change are changes in water supply and demand in different regions of the world. In this study, different climate change patterns in two RCP4.5 and RCP8.5 emission scenarios (RCP: Representative Concentration Pathway), were adopted for the Zayandeh-Rud River Basin, Iran, through weighting of GCMs (General Circulation Models). These climate change patterns are including ideal, medium, and critical patterns. Using the LARS-WG model (Long Ashton Research Station Weather Generator), the outputs of the GCMs were downscaled statistically and the daily temperature and precipitation time series were generated from 2020 to 2044. Then, based on this information, the inflow volume into the Zayandeh-Rud Reservoir was predicted by the IHACRES model (Identification of unit Hydrograph and Component flows from Rainfall, Evaporation and Streamflow) and the agricultural water demand was also estimated based on future evapotranspiration. Finally, using GAMS (General Algebraic Modeling System) software, water resources in this basin were allocated based on the basic management scenario (B) and the water demand management scenario (D). The results showed that the average monthly temperature will increase by 0.6 to 1.3 °C under different climate change patterns. On the other hand, on the annual basis, precipitation will decrease by 6.5 to 31% and inflow volume to the Zayandeh-Rud Reservoir will decrease by 21 to 38%. The results also showed that the water shortages based on the baseline management scenario (B) will be between 334 and 805 MCM (Million Cubic Meters). These range of values varies between 252 and 787 MCM in the water demand management scenario (D). In general, the water shortage can be reduced in the Zayandeh-Rud River Basin with water demand control, but complete resolution of this problem in this region requires more integrated strategies based on a sustainable development, such as a fundamental change in the cropping pattern, prevention of population growth and industrial development.

Influence of salinity stress on morphological, nutritional and physiological attributes in different cultivars of Prunus amygdalus L.

Almond (Prunus amygdalus L.) is commonly grown in water deficit and saline regions of the world, as well as in Iran. The current study aims to assess the morphological, nutritional and physiological responses of four almond cultivars (ʻTalkhʼ, ʻNonpareilʼ, ʻAzarʼ and ʻSanghiʼ) to salinity stress. Plants were grown under greenhouse conditions and irrigated with modified Hoagland solution containing of 0, 25, 50 and 75 mM NaCl for 90 days. The experimental design was factorial based on CRD. Increasing in the salinity concentration was accompanied on more leaf Na concentration and depression in K concentration in all of the cultivars, although Na+ and K+ accumulation pattern was different between cultivars. Nonpareil and Sanghi maintained better growth in salinity condition, and also nutrient concentration such as Ca, Mg and K decreased lesser, moreover antioxidant enzyme activity like APX, SOD, GR and CAT heightened more in Nonpareil and Sanghi than Talkh and Azar. According to these findings, we concluded that Nonpareil and Sanghi are more tolerant than Talkh and Azar to salinity stress, respectively. In conclusion, we deduced that characteristics such as antioxidant enzymes and macronutrients concentration might be beneficial for assessment and screening of almond cultivars.

Assessment of the need and potential for groundwater artificial recharge based on the water supply, water demand, and aquifer properties in a water shortage region of South Korea

Artificial recharge is increasingly necessary to ensure sustainable groundwater supplies and meet the needs of a growing population and crop cultivation in the age of climate change. In this study, artificial groundwater recharging using surplus water resources within the local area is considered for a water shortage area during a drought season, Shingok village, Hongsung-gun, South Korea, that lacks water sources. Based on an analysis of the monthly supply and demand with the water budget method, the current water supply is determined to be entirely dependent on groundwater wells, and water shortages occur in May (approximately 6446 m3) when rice planting begins. The surplus groundwater, which is the amount of natural recharge minus the present usage, and stream discharge are sufficient from December to June, so they are considered source waters for artificial recharge. A depth of 6 ~ 19 m is suggested as the main target region for recharge based on the composition of strata and the vertical distribution of the hydraulic conductivity, which was investigated with electric resistivity survey, drilling, and pumping test methods. Considering the permeability of layers, a vertical well, by which water can infiltrate directly into the target strata, is proposed as the main injection structure, and a ditch is also suggested as an auxiliary system to improve the effect of injection over a broad area. In the future, a detailed design for the injection scenario, injection facility, well and ditch arrangements, and pumping facility will be established through numerical modeling, field injection tests, etc. If it is impossible to obtain water from a long distance, an artificial recharge system based on local water sources may be an appropriate method of securing water considering the storage capacity of permeable strata.

Microbiological Analysis and pH Determination of Drinking Water Samples from Public Schools in the Municipality of Recife/PE

Water is considered a finite natural resource and one of the essential elements of life. It is used in various work activities such as agriculture, industry, livestock, public supply, energy generation, among others [15]. According to SPERLING (2006) [38], only 2.493% of the water on the planet is suitable for the consumption of humans and animals and 0.0007% of the water accessible for consumption is present in the atmosphere, rivers and lakes. It is estimated that more than one billion people worldwide do not have access to treated water, as its supply is not made on an equal basis due to population growth, economic activities and uneven distribution contrasted with different populations. between rural and urban areas [3, 21,33,]. Problems related to water shortages in the metropolitan regions of Brazilian states are increasingly present in everyday life, and can be attributed to factors involving administrative processes, such as the high cost of drinking water treatment, pollution of water tables, increased demand for water. consumption and climatic factors. In this sense, the use of water for poor quality consumption is an alternative for regions experiencing shortages and has a direct impact on the health of individuals, especially workers and students, as about 80% of the infectious and parasitic diseases that affect developing countries are due to poor quality water, directly impacting the individual’s health [10,17,18,28,36,37]. The water potability standards in Brazil are described in Ordinance GM / MS No. 2,914, of December 12, 2011, which portrays the main physical-chemical and microbiological quality control processes aimed at ensuring water safety and quality. for human consumption [5-8,42].In relation to water-borne infectious-parasitic diseases, their main route of transmission is via the oro-fecal route, that is, ingestion of water contaminated by excreta in drinks or food. According to PEIL et al (2015) [29], the main diseases resulting from contaminated water are typhoid fever, cholera, leptospirosis, giardiasis, enterobacteriosis, among others. In 2015, this type of disease was responsible for 2.35% of hospital admissions in Brazil, generating expenses for the Unified Health System (SUS) [28]. Among the diseases that affect individuals in the school phase, childhood diarrhea stands out for being responsible for hospitalizations and if left untreated, it can evolve to death. Childhood diarrhea is a serious public health problem in developing countries, such as Brazil, and is related to the lack of basic sanitation, ingestion of contaminated water and the precariousness of health services [35,40]. Vidal et al (2016) [43] comment that 88% of diarrhea cases are attributed to the consumption of contaminated water and children under five years of age are the most affected. The city of Recife, capital of the state of Pernambuco, has a large number of individuals in school, about 248,408 students are enrolled in the public school system. As a result, it is important to monitor and monitor the water used for consumption in schools. This work proposes to carry out microbiological analysis and pH determination of water for consumption in public schools located in the city of Recife/PE supplied by Pernambuco Sanitation Company (COMPESA).

干旱半干旱区不同林型人工林水源涵养能力比较研究

PDF HTML阅读 XML下载 导出引用 引用提醒 干旱半干旱区不同林型人工林水源涵养能力比较研究 DOI: 10.5846/stxb202004170921 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家重点研发计划重点专项（2017YFC0504604） Comparative study on water conservation capacity of different forest types of artificial forest in arid and semi-arid area Author: Affiliation: Fund Project: the National Key Research and Development Plan Projects of China 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:通过引入模糊物元模型优化水源涵养能力估算方法，从而为研究区林分结构调整、水源涵养能力提升提供科学依据。运用欧式贴近度，以青海省大通县塔尔沟小流域6种不同林型人工林云杉×白桦混交林（YB）、云杉×青杨混交林（YQ）、云杉×落叶松混交林（YL）、云杉纯林（Y）、落叶松纯林（L）、青杨纯林（Q）作为研究对象，定量评价其水源涵养能力。结果表明：欧式贴近度大小排序为YB （0.794） > YQ （0.723） > YL （0.655） > Y （0.494） > L （0.416） > Q （0.270），欧式贴近度越大，该林分类型水源涵养能力更强。6种林型中，白桦×青杨混交林水源涵养能力最强，青杨林水源涵养能力最差。 Abstract:Drought, as a natural phenomenon of abnormal regional water shortage, has a profound impact on the ecological environment. As the global climate changes and the frequency of abnormal climate events increases, the form of drought in my country will become increasingly severe in the future. The degree of forest canopy closure, forest density, tree species composition and age composition in this study area are extremely unreasonable, the structure and function of the plantation are single and the stability is poor, and problems such as pests, pests and rodents continue to appear. Due to the lack of tending management, the unadjusted structure of the initial timber forest has led to its low comprehensive ecological function. In order to ensure the long-term and stable ecological function of the forest, it is urgent to evaluate its water conservation function and regulate and manage it. This paper combines the fuzzy matter-element model and establishes an evaluation system consisting of 16 indicators including forest evapotranspiration, forest canopy water retention characteristics, soil physical properties, water retention characteristics, litter physical properties, and water retention characteristics. Evaluate the weight of different indicators and evaluate the water conservation capacity. In this paper, 6 different forest types in the Targou, Datong County, Qinghai Province, spruce×birch mixed forest (YB), spruce×green poplar mixed forest (YQ), spruce×larch mixed forest (YL), spruce Pure forest (Y), pure larch forest (L), and pure poplar forest (Q) are the research objects to quantitatively evaluate their water conservation capacity. The results show that the order of European closeness is YB (0.794) > YQ (0.723) > YL (0.655) > Y (0.494) > L (0.416) > Q (0.270). The greater the European closeness, the water source of this forest stand type. Stronger ability to conserve. Among the six forest types, the birch×poplar mixed forest has the strongest water conservation capacity, and the Qing poplar forest has the worst water conservation capacity. By assessing the water conservation capacity of forests, exploring the water balance of the basin, and paying attention to the hydrological effects of forests, it is of great significance for regulating the runoff of the basin and improving the local microclimate. In this paper, the fuzzy matter-element model is used to analyze and study the water conservation capacity of different forest types of plantations, and provide a scientific reference for the selection of local afforestation tree species, the improvement of forest water conservation capacity, the transformation of inefficient forests and the adjustment of stand structure. 参考文献 相似文献 引证文献

Increased photosynthesis and grain yields in maize grown with less irrigation water combined with density adjustment in semiarid regions.

In order to design a water-saving and high-yield maize planting model suitable for semiarid areas, we conducted trials by combining supplementary irrigation with different planting densities. Three planting densities (L: 52,500, M: 75,000, and H: 97,500 plants ha–1) and four supplementary irrigation modes (NI: no irrigation; IV: 375 m3 ha–1 during the 11-leaf stage; IS: 375 m3 ha–1 in the silking stage; and IVS: 375 m3 ha–1 during both stages) were tested. The irrigation treatments significantly increased the leaf relative water content, but the high planting density significantly decreased the relative water content during the silking and filling stages. After supplementary irrigation during the 11-leaf stage, IV and IVS significantly increased the photosynthetic capacity, but decreased the leaf water use efficiency. IS and IVS significantly increased the photosynthetic capacity after supplementary irrigation in the silking stage over two years. During the filling stage, IV, IS, and IVS increased the two-year average net photosynthetic rate by 17.0%, 27.2%, and 30.3%, respectively. The intercellular CO2 concentration increased as the density increased, whereas the stomatal conductance, transpiration rate, net photosynthetic rate, and leaf water use efficiency decreased, and the high planting density significantly reduced the leaf photosynthetic capacity. The highest grain yield was obtained using the IVS treatment under the medium planting density, but it did not differ significantly from that with the IS treatment. Furthermore, the IVS treatment used two times more water than the IS treatment. Thus, the medium planting density combined with supplementary irrigation during the silking stage was identified as a suitable water-saving planting model to improve the photosynthetic capacity and grain yield, and to cope with drought and water shortages in semiarid regions.

Connectivity of bacterial assemblages along the Loa River in the Atacama Desert, Chile.

The Loa River is the only perennial artery that crosses the Atacama Desert in northern Chile. It plays an important role in the ecological and economic development of the most water-stressed region, revealing the impact of the mining industry, which exacerbate regional water shortages for many organisms and ecological processes. Despite this, the river system has remained understudied. To our knowledge, this study provides the first effort to attempt to compare the microbial communities at spatial scale along the Loa River, as well as investigate the physicochemical factors that could modulate this important biological component that still remains largely unexplored. The analysis of the spatial bacterial distribution and their interconnections in the water column and sediment samples from eight sites located in three sections along the river catchment (upper, middle and lower) was conducted using 16S rRNA gene-based Illumina MiSeq sequencing. Among a total of 543 ASVs identified at the family level, over 40.5% were cosmopolitan in the river and distributed within a preference pattern by the sediment substrate with 162 unique ASVs, while only 87 were specific to the column water. Bacterial diversity gradually decreased from the headwaters, where the upper section had the largest number of unique families. Distinct groupings of bacterial communities often associated with anthropogenic disturbance, including Burkholderiaceae and Flavobacteriaceae families were predominant in the less-impacted upstream section. Members of the Arcobacteraceae and Marinomonadaceae were prominent in the agriculturally and mining-impacted middle sector while Rhodobacteraceae and Coxiellaceae were most abundant families in downstream sites. Such shifts in the community structure were also related to the influence of salinity, chlorophyll, dissolved oxygen and redox potential. Network analyses corroborated the strong connectivity and modular structure of bacterial communities across this desert river, shedding light on taxonomic relatedness of co-occurring species and highlighting the need for planning the integral conservation of this basin.

Approaches for the evaluation of future-oriented technologies and concepts in the field of water reuse and desalination

Abstract Against the background of drastically rising global water demand and increasing pollution and overexploitation of regional water resources, the demand-driven water supply of households and industry is of central importance. Water reuse and desalination are seen as key technologies to overcome potential regional and local water shortage. In the joint projects funded by the German Federal Ministry of Education and Research (BMBF) ‘Future-oriented Technologies and Concepts to Increase Water Availability by Water Reuse and Desalination (WavE)’, evaluation approaches for analysing innovative technologies and concepts are being developed and assessed. All evaluation methods and criteria used were selected based on the decision situation at hand and the decision-makers preferences. Based on the analysis of six multi-criteria evaluation concepts used in selected WavE projects, this paper presents a general approach for comparative multi-criteria evaluation of water reuse systems consisting of prerequisites, minimum requirements, evaluation criteria (qualitative, semi-quantitative or quantitative) and a final aggregation of results. Exemplary sets of criteria for the application in a more industrial, municipal and/or international context are presented as an aid for the application of holistic evaluation approaches for (process) concept and technology selection in the context of water reuse and desalination.

Impacts of regional water shortage information disclosure on public acceptance of recycled water — evidences from China’s urban residents

Recycled water is an effective method to rescue regional water shortages and promote environmental protection. As for end users of recycled water, public attitudes and acceptance are important links in water recycling projects. Recycled water in this paper refers to the use of recycled water other than for drinking. Six regions with different water scarcity levels in China were selected as the study areas. Randomly selected samples from the residents of the six cities were obtained. Data were collected through a questionnaire survey. Based on the social cognitive theory of “environment–cognition–behavioral,” this study employs structure equation modelling and analyzes public environmental cognitions and their impacts on public acceptance of recycled water to identify the influencing factors and their influencing paths on public acceptance of recycled water. On the basis of these, this study further explores how regional water shortage information disclosure affects public acceptance of recycled water through public perceptions. The results are as follows: (1) Regional water shortage information disclosure and public awareness of water environment protection positively affect public acceptance of recycled water, and regional water shortage information disclosure indirectly affects public acceptance of recycled water by influencing public awareness of water environment protection; (2) public perceptions of health risks of recycled water negatively affect public acceptance of recycled water; and (3) regional water shortage information disclosure can boost the public’s environment cognitions and thus promotes the public’s awareness of water environment protection; ultimately, this will boost the public acceptance of recycled water.

Energy industrial water withdrawal under different energy development scenarios: A multi-regional approach and a case study of China

Increasing water demand for energy industries has raised concerns for the compliance of energy industry development and water resources constraints. The regional characteristics of uneven distribution of energy and water resources exacerbates regional energy-related water shortage. This paper focus on quantitative analysis of energy development impacts on water resources that considers regional characteristics. A supply-demand-integrated method is proposed to assess water stress of energy industry for multiple regions and multiple energy types under different energy development scenarios. China has a typical mismatch characteristic of energy and water resources. Case studies of China are conducted at both regional and energy-base scales. Results show that the water stress of energy industry in northwest regions (40%) is higher than that of the national average value (24%) in 2015. The carbon emission reduction measures can save the energy industrial water withdrawal by about 16%–33% in 2030, compared with the Business as Usual Scenario. Interregional power transmission would result in an over 100% value of the water stress in energy output areas. The coal chemical industry is high-water-consuming and accounts for a large proportion of the water demand in energy bases. The technological progress and capacity reduction of high-water-consuming technologies can reduce the water stress. Both water demand side and water supply side measures are suggested to reach the coordinated development of energy industry with water resources.

Goal programming model for optimal water allocation of limited resources under increasing demands

A multi-objective model has been applied for optimal allocation of water from limited resources to meet increasing demands in multiple sectors. The study region is Saudi Arabia, while the time span is from 2020 to 2050 with interval of 10 years. The available water resources in Saudi Arabia are groundwater (GW), surface water (SW), desalinated water (DW) and treated wastewater (TWW), whereas the users are domestic, agricultural and industrial sectors. The goal programming technique has been used to formulate the model with multiple objectives. These objectives are (1) water demands satisfaction; (2) water quality control; (3) maximizing allocation of SW and TWW; and (4) minimizing extraction of GW, overproduction of DW and overall cost of water use. Allocations of GW, SW and DW in domestic sector are 508.4, 225.7 and 2174.2 MCM, respectively, in 2020, which are projected to be 585.3, 349.1 and 4494.8 MCM, respectively, in 2050. From 2020 to 2050, contribution of GW and SW in agricultural sector may reduce from 10,283.5 and 218.7 MCM to 8753 and 95.2 MCM, respectively, while this reduction is recovered by increasing contribution of TWW from 2291.9 in 2020 to 3945.8 MCM in 2050. During this period, contribution of GW in industrial sector shows increasing rate of approximately 171 MCM per year. Water quality is controlled through controlling the level of total dissolved solids to the standards. Production of DW and TWW has to be increased in order to meet the future needs. The total cost of using water is estimated as 13 billion US$ in 2020, which is predicted to be 22 billion US$ in 2050. This study attempted to suggest the possible scenarios to satisfy increasing water demands from limited resources in different regions of Saudi Arabia. Such scenarios can contribute in developing sustainable strategies for water resources management in water deficit regions.

Research on water footprint of main crops production in Baoding, China

Based on the monthly meteorological data and basic agricultural data of Baoding Meteorological Station, this paper uses the Penman formula combined with CROPWAT software, and the gray water footprint calculation manual to calculate and analyze the production water consumption coefficient and production water of the main crops in Baoding in 2018. The results show that the water consumption coefficients of the main crops in Baoding city are cotton, peanut, rice, wheat, soybean, corn and vegetables. The water requirement of wheat in the whole growth period is mainly blue water, and the corn water requirement is mainly green water; the gray water footprint of all crops is greater than the blue water footprint. In 2018, the total production water footprint of major crops in Baoding was 65.31×108m³, of which the blue water footprint was 18.93×108m³, the green water footprint was 13.06×108m³, and the gray water footprint was 33.31×108m³. The sum of the blue water and gray water footprints is much larger than Baoding’s average available water resources, and the regional water shortage is serious. Therefore, Baoding should further optimize the agricultural planting structure in order to protect the water resources and environment, and at the same time promote the reduction of pesticides and fertilizers to increase efficiency.

Importance of cryosphere water resources to China’s socio-economy: Based on multi-level basins analysis

Cryosphere water resources (CWR) play indispensable roles in ecological security and socio-economic development in cold and arid regions of the world. The amount of melt water will continue to decrease once it reaches the maximum (peak water) due to climate change, while the sustainable and rapid development of socio-economy puts higher demand for water resources, which causes an increasing risk of regional water shortage. Therefore, a national assessment on the relationship between CWR and socio-economy is notable. The supply and demand of CWR are linked at the river basin scale, although the upper, middle and lower reaches of the river vary in the contribution of CWR to water availability. Here we analyze the spatial distribution characteristics of China’s CWR and the spatial-temporal patterns of population and GDP in cryosphere-fed-areas (CFA) at three-level basins scale. Then we present an Importance Index, which ranks all basins in terms of their water-supplying role and the downstream dependence of socio-economy. We conclude that: (1) CFA covers 7 primary basins, 38 secondary basins and 84 tertiary basins in China. (2) The top three with large glacier reserves are Tarim River, Qiangtang Plateau and the Yalu Tsangpo River Basin. Central Tibetan Plateau and the Songhua River Basin have high permafrost coverage. Songhua River Basin, northern Xinjiang and the southwest of the Tibetan Plateau have large average snow depth. (3) In 2015, population and GDP in CFA are about 263 million and 11.4 trillion yuan respectively, accounting for 23.1% and 16.5% of the total China, mainly distribute in the southeast and north of the boundary of the first and second steps and the north of the third step of topography of China. From 1995 to 2015, the proportion of population in the CFA increased from 24.4% to 26.8%, while the proportion of GDP in the whole country decreased from 21% to 19%. (4) For the CFA, the larger the socio-economic amounts, the higher the importance of water resources. However, the amount of water supply does not completely match the socio-economic distribution. Although the cryosphere water resources are abundant in the southwest of Tibetan Plateau, the socio-economic demand is small, representing a lower water service there. We have noticed that at the secondary basin scale, 26.8% of people were populated in the CFA, and nearly one-fifth (19%) of economic activities took place there in 2015. This indicates a lager dependence on CWR in socio-economy, especially in the arid northwest China. These conclusions quantitatively support the previous understanding. However, the multi-scale method we used can analyze the small watershed deeply. For example, the Huntai River Basin are of great importance due to its high water supply and demand index, which is conducive to guiding the optimal allocation of water resources and a deep understanding of the importance of water resources.

Assessment of the Water, Environmental, Economic and Social Vulnerability of a Watershed to the Potential Effects of Climate Change and Land Use Change

In semi-arid regions, where hydrological resources are very vulnerable and where there are water shortages in many regions of the world, it is of great importance to assess the vulnerability that a system is facing or will face to the potential impacts of climatic changes and changes on the use of land. For that reason, this research focuses on evaluating the global vulnerability of a hydrological basin, taking into consideration these changes. Being different from the existing methodologies that assess the vulnerability, our methodology interconnects through a new interface a distributed hydrological model, global climate models, climate change scenarios, land use change scenarios and the largest number of system variables calculated with information from official sources. Another important point of our methodology is that it quantifies the global vulnerability of the system, taking into consideration hydrological, environmental, economic and social vulnerabilities. The results obtained show that the proposed methodology may provide a new approach to analyze vulnerability in semi-arid regions. Moreover, it made it possible to diagnose and establish that the greatest current and future vulnerabilities of the system are the result of activities in agricultural areas and urban centers.

Spatiotemporal supply-demand characteristics and economic benefits of crop water footprint in the semi-arid region

The notion of water footprint provides a novel perspective for understanding the relationship between physical water and virtual water, especially in agricultural production. In this study, with the help of CROPWAT 8.0 model, we estimate the water footprint requirement (WFr) of main crops growth for 2005, 2010 and 2015 in Zhangjiakou City, an extreme water shortage region in northern China, and three new indicators are introduced, i.e., green water footprint occupancy rate (GWFor), blue water footprint deficit (BWFd), and virtual water consumption per output value (VWV). The results indicate that the total WFr increased from 1.671 billion m3 to 1.852 billion m3 during the study period, of which the green water was always about twice as the blue water. Cereals, as the main staple food, had the largest WFr, while the WFr of potatoes increased the fastest, which was the result of large-scale promotion of potato cultivation in recent years. The spatial characteristics of the GWFor and BWFd are closely related to altitude, that is, the GWFor was less than 50% in higher-altitude Bashang area, while it was more than 50% in lower-altitude Baxia area, and the BWFd was generally smaller in Bashang area than in Baxia area. Due to differences in crop types and food prices, higher water footprint food productivity does not absolutely mean higher water footprint economic productivity. Therefore, it is vital to consider from two perspectives (food yields priority or economic benefits priority) to formulate a reasonable water footprint utilization policy. This study is expected to broaden the investigation of crop water footprint and make a contribution to sustainable agricultural water management.