Total Water Use Research Articles

Satellites to Sprinklers: Assessing the Role of Climate and Land Cover Change on Patterns of Urban Outdoor Water Use

AbstractOutdoor water use represents over 50% of total water demand in semiarid and arid cities and presents both challenges to and opportunities for improved efficiency and water resilience. The current work adapts a remote sensing‐based methodology to estimate growing season irrigation rates at the census block group scale in Denver, Colorado. Results show that city‐wide outdoor water use does not change significantly from 1995 to 2018, while per capita water use and total water use significantly decrease from 2000 to 2018. Because total water use, but not outdoor use, is decreasing, the percent of water used outdoors significantly increases across the city from 2000 to 2018. Climate variables account for one‐quarter of interannual variation in mean irrigation rates due primarily to changes in temperature, not precipitation. Percent impervious land cover exhibits a significant inverse nonlinear relationship with irrigation rates at the census block group scale. Finally, 38% of Denver census block groups show significantly increasing irrigation rates between 1995 and 2018 driven primarily by increasing temperatures. The increasing proportion of water used for irrigation highlights the importance of outdoor demand management for urban water systems as indoor efficiencies improve. We advocate that resilient water systems necessitate integrated land use, infrastructure, and water planning in the face of urban growth and climate change. While minimizing irrigated urban areas may reduce demand, remaining green spaces should be designed to maximize multiple benefits including reductions in water demand and urban heat islands, stormwater management, and recreation to improve the sustainability of growing cities.

Dissecting and modelling the comparative adaptation to water limitation of sorghum and maize: role of transpiration efficiency, transpiration rate and height

Abstract Maize is considered less drought-tolerant than sorghum, but sorghum is commonly grown as a short triple dwarf (3dwarf) type, so difference in plant height confounds the species comparison. The objectives of this study were to experimentally determine effects of species and plant height differences on transpiration efficiency (TE) and transpiration rate per unit green leaf area (TGLA) and use findings to explain input parameters in a simulation study on the comparative adaptation of 3dwarf sorghum and maize in environments with contrasting water availability. Maize, tall double dwarf (2dwarf) and short 3dwarf sorghum genotypes were grown in two lysimeter experiments in 2011 in SE Queensland, Australia. Each plant was harvested after anthesis and total transpiration, shoot and root dry mass were measured to estimate TE. Daily TGLA was used to compare transpiration rates. Species and height had limited effect on TE, but significantly affected TGLA. This was associated with differences in biomass allocation. The similar TE but higher TGLA in maize compared with 3dwarf sorghum meant it potentially produces more biomass, consistent with published differences in biomass accumulation and radiation use efficiency (RUE). The simulation study, which used similar TE for maize and 3dwarf sorghum, but captured differences in TGLA through differences in RUE, predicted crossover interactions for grain yield between species and total water use. The greater TGLA of maize decreased grain yield in water-limited environments, but increased yields in well-watered situations. Results highlight that similarity in TE and differences in TGLA can influence comparative adaptation to water limitation.

Drip irrigation of the apple orchard in the conditions of Tashkent region in Uzbekistan

This article presents the results of long-term theoretical experimental field studies on drip irrigation of Apple orchard of the cultivar “Golden” in the conditions of Tashkent region. Based on the analysis of climate, soil, hydrogeological, hydrological and economic conditions of the experimental plot and biological features of the garden is determined by the values of total water use, scarcity of water, irrigation, irrigation norms and number of irrigations bioclimatic method.

Rethinking water resources management from water-energy nexus perspective — a research and comparison of Jing-Jin-Ji Region of China and California of the United States

The relationship between water and energy is extremely close and complex, especially in water use system. However, the energy consumption of water systems has been ignored in water resources management due to the lack of deep understanding of the water-energy nexus. Based on analysis of waterrelated energy in water use, this paper selected Jing-Jin-Ji region of China and California of the United States to conduct a research study and found that the energy consumption of water use systems accounted for about 16% and 20% of the total electricity consumption of Jing-Jin-Ji region and California, respectively, water use has shifted more energy-intensive. This paper systematically quantified the urban water–energy relationship, analyzed the water supply structure and the energy efficiency and energy consumption in different water system sectors, and found that California’s total water use is 3.3 times that of Jing-Jin-Ji region, but the energy consumption of California’s water systems is only 2.3 times that of Jing-Jin-Ji region. This study suggests that water conservation is a cost-effective way to save energy, and it is necessary to quantitatively analyze the water-energy nexus for a more comprehensive and deep understanding of water resources management.

An Input-Output Analysis of Water Consumption Effects of Tourism Industry in Turkey

In this study, the production and water consumption impacts of the year 2018 investment and income targets of Turkey’s tourism industry is explored through the use of input-output model. In this respect, the input-output table published by TURKSTAT for 2012 was used and total demand, output and water use of tourism industry was obtained through industrial aggregation. In the analyses, tourism industry’ place in water resources and water consumption was considered in relation to the linkages with the other industries in Turkey which is as a water scarce country and in which the volume and quality of water is decreasing due to global warming and urbanization. When the impact assessment findings with regard to an increase in private sector investment and foreign tourism income are analyzed, plastic, agriculture, fisheries, chemistry and various services industries are observed to consume more water following tourism industry’s own water consumption.

Management of Water Resources in Agriculture in Chile and its Challenges

Water is a strategic resource for agricultural development, particularly in the arid and semiarid regions of central and northern Chile. Currently, irrigated surfaces contribute between 60 and 65% of the country’s agricultural GDP. Associated with Chile’s economic growth, total consumptive water use has increased, which, together with population growth, urbanization, water contamination and pollution, has led to important water stress situations that are triggering a greater number of conflicts and social, economic, and environmental vulnerability. The above phenomena will be exacerbated by climate change. At present, surface water deficit covering irrigation demands exists in the central and northern regions. This deficit is projected to increase as a result of climate change, which would increase the challenges for satisfying agricultural water requirements. The objective of this article is to integrally review the key aspects of Chilean water and agricultural water management policies, considering their interphases, providing the reader with a general overview of the main features of this model, an evaluation of its effectiveness and the main challenges agricultural water management faces. Resolving the challenges of the future requires a thorough reconsideration of water management policies and institutions and how water is managed in the agricultural sector in the broader context of overall water resource management in Chile.

Effect of Plastic Film and Straw Mulch on Wheat Yield, Water Use Efficiency and Soil Properties in Punjab, Pakistan

A two years (2014-15 and 2015-16) field experiment was performed to find out the effect of plastic film and straw mulching on yield, water use efficiency (WUE) of wheat (Triticum aestivum L.) and selected soil properties. There were three treatments i.e. control, plastic film and straw mulch. No mulch was added in control. Rice straw was applied on the surface at a rate of 5 Mg ha-1. Soil samples in 0-15 cm and 15-30 cm depths were taken and analyzed. Soil water contents at 20 cm interval every 7 days were determined in 0-160 cm soil depth before sowing, after harvesting and during growing seasons. Results showed that grain yield was increased significantly by 29.8 in 2014-15 and 35.6% in 2015-16 over that of control under straw mulch. Straw mulch also decreased total water use with an increase in WUE. Soil bulk density was decreased significantly with a significant increase in porosity, water stable aggregates, active carbon, organic matter and soil water contents after harvesting. Soil water storage was higher under straw mulch for most sampling times. In conclusion, mulching soil with straw can sustain wheat yield and improve WUE and soil properties.

A model-based estimate of the groundwater budget and associated uncertainties in Bengaluru, India

ABSTRACT Understanding the water metabolism of developing country cities is challenging because of insufficient knowledge of how social, infrastructural and hydrological dimensions are coupled. Using Bengaluru City in India, we demonstrate how fine-resolution data can inform model-based estimates of urban groundwater budgets. Groundwater levels were measured at 154 locations in 2016 and used to estimate model parameters and uncertainty. Total water use was estimated at 1470 million litres per day (MLD). Groundwater pumping meets the majority of this use (827 MLD), followed by utility water supply (643 MLD). Total recharge was estimated at 973 MLD. Natural recharge is a much smaller portion (183 MLD) compared to anthropogenic recharge from leaking water supply and wastewater systems (791 MLD). The city experienced a net negative groundwater balance (40 MLD). Natural recharge and total water use estimates showed lower uncertainty. Spatial variation in these fluxes is described and related to secondary information.

Where is the Planetary Boundary for freshwater being exceeded because of livestock farming?

Livestock production has significant impacts on the environment, including due to the use of water. In this study, we provide a spatially explicit estimation of livestock blue water use, by analyzing feed crop water use and livestock drinking water. For the past four decades, livestock water use has increased from 145 km3/year in 1971 to 270 km3/year in 2012 with an increasing trend of 1.36%/year. The proportion of livestock drinking water use has remained relatively stable at around 10% of total water use attributable to livestock production. Several hotspots of water use, including eastern China, northern India, US high plains, are identified in terms of the long-term averages, while South America and Central Africa show the most rapidly increasing trends. In USA, climate change is found to contribute most to the changes in water use attributable to livestock, while feed cropping intensity and land use change are the dominant driver in China and India, respectively. Though, in total, livestock water use makes a relatively modest contribution to the Planetary Boundary (PB) that has been proposed for anthropogenic water use (4000 km3/year), we argue that this aggregate number is not particularly meaningful, so we identify places where livestock is a major contributor to the unsustainable use of water, in northern India, part of the Middle East, Northern China and Central US. 7% of rivers where excessive water withdrawals mean that there is insufficient residual flow to sustain the aquatic environment (which we take to be the local manifestation of a PB) have been tipped over that boundary because of livestock farming, whilst in a further 34% of rivers, livestock farming on its own exceeds the water PB. Our results provide new and more geographically specific evidence about the impact that the meat industry makes on the PB for water.

Water Use in Global Livestock Production—Opportunities and Constraints for Increasing Water Productivity

AbstractIncreasing population, change in consumption habits, and climate change will likely increase the competition for freshwater resources in the future. Exploring ways to improve water productivity especially in food and livestock systems is important for tackling the future water challenge. Here we combine detailed data on feed use and livestock production with Food and Agriculture Organization of the United Nations (FAO) statistics and process‐based crop‐water model simulations to comprehensively assess water use and water productivity in the global livestock sector. We estimate that, annually, 4,387 km3 of blue and green water is used for the production of livestock feed, equaling about 41% of total agricultural water use. Livestock water productivity (LWP; protein produced per m3 of water) differs by several orders of magnitude between livestock types, regions, and production systems, indicating a large potential for improvements. For pigs and broilers, we identify large opportunities to increase LWP by increasing both feed water productivity (FWP; feed produced per m3 of water) and feed use efficiency (FUE; protein produced per kg of feed) through better crop and livestock management. Even larger opportunities to increase FUE exist for ruminants, while the overall potential to increase their FWP is low. Substantial improvements of FUE can be achieved for ruminants by supplementation with feed crops, but the lower FWP of these feed crops compared to grazed biomass limits possible overall improvements of LWP. Therefore, LWP of ruminants, unlike for pigs and poultry, does not always benefit from a trend toward intensification, as this is often accompanied by increasing crop supplementation.

Interactive role of zinc and iron lysine on Spinacia oleracea L. growth, photosynthesis and antioxidant capacity irrigated with tannery wastewater.

Untreated wastewater contains toxic amounts of heavy metals such as chromium (Cr), which poses a serious threat to the growth and physiology of plantswhen used in irrigation. Though, Cr is among the most widespread toxic trace elements found in agricultural soils due to various anthropogenic activities. To explore the interactive effects of micronutrients with amino acid chelators [iron-lysine (Fe-lys) and zinc-lysine (Zn-lys)], pot experiments were conducted in a controlled environment, using spinach (Spinacia oleracea L.) plant irrigated with tannery wastewater. S. oleracea was treated without Fe and Zn-lys (0mg/L Zn-lys and 0mg/L Fe-lys) and also treated with variouscombinations of (interactive application)Fe and Zn-lys (10mg/L Zn-lys and 5mg/L Fe-lys), when cultivated at different levels [0 (control) 33, 66 and 100%) of tannery wastewater in the soil having a toxic level of Cr in it. According to the results, we have found that, high concentration of Cr in the soil significantly (P < 0.05) reduced plant height, fresh biomass of roots and leaves, dry biomass of roots and leaves, root length, number of leaves, leaf area, total chlorophyll contents, carotenoid contents, transpiration rate (E), stomatal conductance (gs), net photosynthesis (PN), and water use efficiency (WUE) and the contents of Zn and Fe in the plant organs without foliar application of Zn and Fe-lys. Moreover, phytotoxicity of Cr increased malondialdehyde (MDA) contents in the plant organs (roots and leaves), which induced oxidative damage in S. oleracea manifested by the contents of hydrogen peroxide (H2O2) and membrane leakage. The negative effects of Cr toxicity could be overturned by Zn and Fe-lys application, whichsignificantly (P < 0.05) increase plant growth, biomass, chlorophyll content, and gaseous exchange attributes by reducing oxidative stress (H2O2, MDA, EL) and increasing the activities of various antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD) catalase (CAT) and ascorbate peroxidase (APX). Furthermore, the supplementation of Zn and Fe-lys increased the contents of essential nutrients (Fe and Zn) and decreased the content of Cr in all plant parts compared to the plants cultivated in tannery wastewater without application of Fe-lys. Taken together, foliar supplementation of Zn and Fe-lys alleviates Cr toxicity in S. oleracea by increased morpho-physiological attributes of the plants, decreased Cr contents and increased micronutrients uptake by the soil, and can be an effective inheavy metal toxicity remedial approach for other crops.

Regional difference of water use in a significantly unbalanced developing region

Abstract With a service for the most developed economy and dense population in China, the water use of Guangdong province shows distinct regional difference and is subject to multiple driving forces. The regional differences of total water use (TWU) and water use efficiency (WUE) for Guangdong province and its four sub-regions (i.e. Pearl River Dealt region (PRD), Eastern Wing (YD), Western Wing (YX), and Northern Mountain Region (YB)) were quantified by Theil index, and the influence of various variables on WUE was evaluated through multiple linear regression (MLR) models. Overall, Theil index of TWU showed a decreasing trend whereas Theil index of WUE increased in recent decades, suggesting that Guangdong province has experienced an enlarging regional difference of WUE along with a gradually weakened regional difference of TWU. The PRD has the most significant regional differences of WUE and TWU and accounts for a predominated proportion in the total regional difference. Theil indexes of GDP of industry, per capita GDP and per capita value-added by agriculture had positive regression coefficients and were found to have the most significant impact on the regional difference of WUE. This study has the potential to promote a balanced and coordinated regional development in terms of even regional WUE and TWU.

Physiological Characteristic Changes and Full-Length Transcriptome of Rose (Rosa chinensis) Roots and Leaves in Response to Drought Stress.

Rose (Rosa chinensis) is the most important ornamental crops worldwide. However, the physiological and molecular mechanism of rose under drought stress remains elusive. In this study, we analyzed the changes of photosynthetic and phytohormone levels in the leaves and roots of rose seedlings grown under control (no drought), mild drought (MD) and severe drought stress. The total chlorophyll content and water use efficiency were significantly enhanced under MD in rose leaves. In addition, the concentration of ABA was higher in the leaves compared to the roots, whereas the roots accumulated more IAA, methylindole-3-acetic acid and indole-3-propionic acid. We also constructed the first full-length transcriptome for rose, and identified 96,201,862 full-length reads of average length 1,149 bp that included 65,789 novel transcripts. A total of 3,657 and 4,341 differentially expressed genes (DEGs) were identified in rose leaves and roots respectively. KEGG pathway analysis showed enrichment of plant hormone, signal transduction and photosynthesis are among the DEGs. 42,544 alternatively spliced isoforms were also identified, and alternative 3' splice site was the major alternative splicing (AS) event among the DEGs. Variations in the AS patterns of three genes between leaves and roots indicated the possibility of tissue-specific posttranscriptional regulation in response to drought stress. Furthermore, 2,410 novel long non-coding RNAs were detected that may participate in regulating the drought-induced DEGs. Our findings identified previously unknown splice sites and new genes in the rose transcriptome, and elucidated the drought stress-responsive genes as well as their intricate regulatory networks.

Tolerance of Combined Drought and Heat Stress Is Associated With Transpiration Maintenance and Water Soluble Carbohydrates in Wheat Grains.

Wheat (Triticum aestivum L.) production is increasingly challenged by simultaneous drought and heatwaves. We assessed the effect of both stresses combined on whole plant water use and carbohydrate partitioning in eight bread wheat genotypes that showed contrasting tolerance. Plant water use was monitored throughout growth, and water-soluble carbohydrates (WSC) and starch were measured following a 3-day heat treatment during drought. Final grain yield was increasingly associated with aboveground biomass and total water use with increasing stress intensity. Combined drought and heat stress immediately reduced daily water use in some genotypes and altered transpiration response to vapor pressure deficit during grain filling, compared to drought only. In grains, glucose and fructose concentrations measured 12 days after anthesis explained 43 and 40% of variation in final grain weight in the main spike, respectively. Starch concentrations in grains offset the reduction in WSC following drought or combined drought and heat stress in some genotypes, while in other genotypes both stresses altered the balance between WSC and starch concentrations. WSC were predominantly allocated to the spike in modern Australian varieties (28–50% of total WSC in the main stem), whereas the stem contained most WSC in older genotypes (67–87%). Drought and combined drought and heat stress increased WSC partitioning to the spike in older genotypes but not in the modern varieties. Ability to maintain transpiration, especially following combined drought and heat stress, appears essential for maintaining wheat productivity.

Soil moisture based deficit irrigation management for sugarcane (Saccharum officinarum L.) in semiarid environment

Sugarcane is a high biomass crop which requires large amounts of water. In a semiarid environment deficit irrigation is inevitable to produce acceptable yields. The field experiments were conducted for two seasons (2015 and 2016) on Sugarcane (Saccharum officinarum L.)by applying water deficit in three regimes (0%, 30% and 60% water deficit) during three phenological stage (tillering, grand growth and maturity) such that the effect of a specified water deficit during a specified phenological stage can be investigated separately. The experiment formed 27 irrigation schedules replicated twice in Randomized Block Design. The irrigations were provided based on water deficit underlined in each irrigation schedule during different phenological stages on the basis of actual soil moisture in root zone. The demonstrated data indicated that the net increase in growth characters with net water used within a phenological stage was to great extent affected by the grand growth stage. The yield contributing characters and cane yield reduced with increase in water deficit imposed mainly in grand growth followed by tillering stage. A water deficit imposed in maturity stage only marginal affected the yield. The highest yield of sugarcane obtained underwater deficit free schedule (181.5 tha−1); 30% and 60% water deficit throughout season noticed with significantly lower cane yield as 157.1 and 107.4 tha−1, respectively. The relative cane yield reduction over water deficit free schedule registered between 0.7% and 40.6% with relative decrease in the water use by 2.5–33.4%. A deficit irrigation strategy with 0% water deficit at tillering, 30% at grand growth and 60% at maturity stage was found appropriate as it represents the non-significant reduction in yield over water deficit free condition, beside it leads to a 13.3% lesser water use. Based on soil moisture, the total water use of sugarcane underwater deficit free and best deficit conditions were estimated as 1339 and 1160 mm respectively. The study recommends to practice appropriate irrigation scheduling under water shortage situation for maximizing water use by providing irrigations as per requirement, applying less water than required, such that the overall productions are optimized.

Effect of Microsprinkler Irrigation under Plastic Film on Photosynthesis and Fruit Yield of Greenhouse Tomato

The aim of this study is to exam the effect of microsprinkler irrigation technology under plastic film (MSPF) and to evaluate the reasonable micropore group spacing and capillary arrangement density in the greenhouse. Compared with drip irrigation under plastic film (DIPF) and microsprinkling irrigation (MSI) conditions, the effects of different micropore group spacing (L1: 30 cm micropore group spacing, L2: 50 cm micropore group spacing) and capillary arrangement density (C1: one pipe for one row, C2: one pipe for two rows, and C3: one pipe for three rows) with the MSPF on photosynthetic characteristics and fruit yield of tomatoes were studied using completely randomized trial design. The results showed that under the same irrigation amount, compared with DIPF and MSI, the photosynthetic rate of tomatoes treated with L1C2 increased by 8.24% and 13.55%, respectively. The total dry matter accumulation, yield, and water use efficiency at condition of L1C2 increased by 12.16%, 19.39%, and 10.03% compared with DIPF and 26.38%, 20.46%, and 31.02% compared with MSI, respectively. The results provide evidence that the MSPF can be applied to greenhouse tomatoes. The photosynthetic rate, total dry matter accumulation, yield, and water use efficiency of tomato leaves cultivated at a micropore group spacing of 30 cm were 1.07, 1.13, 1.14, and 1.13 times higher than those of 50 cm, respectively. With the decrease in capillary arrangement density, the photosynthetic characteristics of the tomato leaves, the total dry matter accumulation, and yield of tomatoes all experienced a decline. It is recommended to use a combination of one pipe for two rows of capillaries at a 30 cm micropore group spacing as the technical parameter of greenhouse tomato with MSPF in arid and semiarid sandy loam soils.

The Impact of Municipal Water Use Restrictions on the Pricing of Water-Sensitive Features in Single-Family Homes

We investigate the impact of municipal water restrictions in response to a drought on the pricing of water-sensitive home features by homebuyers. In our empirical investigation, we focus on Cape Town, South Africa, which imposed a series of increasingly tightening restrictions ranging from limiting outdoor water usage at the beginning of 2016 to limiting the total water use per person per day to 50 liters (approximately 13 gallons) at the beginning of 2018. Using spatial autoregression with autoregressive errors (SARAR) and a sample of 16,223 transactions over the period of 2015 to 2018, we find that increasing water restrictions reduce the willingness of homebuyers overall to pay for outdoor water-sensitive features such as swimming pools and higher quality gardens. However, pricing effects differ between homebuyers in the low- and high-price segment. In the low-price segment, the premiums for lot size and number of full bathrooms disappear while homebuyers penalize the presence of half bathrooms as water restrictions increase. However, homebuyers prioritize garden quality, which yields a premium irrespective of water restrictions. In the high-price segment, the premiums for half baths, garden quality and swimming pools disappear while the premiums for a larger lot and more full bathrooms are robust to tightening restrictions. Our findings suggest that municipal water restriction policies have an impact on pricing decisions of homebuyers, which has implications for policymakers and real estate developers in developed and emerging countries.

Responses of growth, fruit yield, quality and water productivity of greenhouse tomato to deficit drip irrigation

Agriculture is the largest consumer of scarce water resources and irrigation serves as the sole source of water for greenhouse tomato production. It is an urgent task to seek an appropriate deficit irrigation strategy that is beneficial for high marketable yield, fruit quality, saving irrigation water and ultimately improving water use efficiency. A four-season experiment was conducted on drip-irrigated greenhouse tomato during Autumn 2015-Spring 2017 with three irrigation regimes, i.e., 100 %ETc (crop evapotranspiration) (W1), 75 %ETc (W2) and 50 %ETc (W3). The results showed that aboveground biomass, leaf area index (LAI), plant height and fruit yield increased with increasing irrigation amount. However, soluble solids, vitamin C and soluble sugar of tomato fruits were lowest under W1. W2 markedly reduced unmarketable fruits and more small-sized fruits were harvested at the late stage under W1. Through fitting the relationship between cumulative temperature and aboveground biomass using logistic equations, it was found that average duration of the rapid growth period (td) and the time when growth rate reached the maximum value (tm) increased as irrigation amount decreased. Conversely, the maximum growth rate during the rapid growth period (vm) decreased with the increase of water deficit. The highest total water consumption (278.05 mm), lowest total yield water use efficiency (25.12 kg m−3) and marketable yield water use efficiency (22.87 kg m−3) were obtained under W1. The smallest total water consumption (27.01–50.75 mm) occurred at the blooming and setting stage. Based on the results of path analysis, aboveground biomass and average fruit weight were important indexes affecting yield positively. It is concluded that deficit drip irrigation with 75 %ETc has the potential of supporting tomato growth, improving marketable yield and WUE as a result of less unmarketable yield and bigger fruit size.

Sustainable Agriculture Development in the Western Desert of Egypt: A Case Study on Crop Production, Profit, and Uncertainty in the Siwa Region

The Egyptian government initiated a development project in 2015 to reclaim 1.5 million acres with the primary goal of increasing agricultural production. Siwa is one of these areas in the Western Desert of Egypt, with 30,000 acres using groundwater from the Nubian Sandstone Aquifer System (NSAS). This study investigates if government goals are achievable in the next 20 years to secure the food and water needs of the Siwa region. Results show that total required crop areas are 7154 and 6629 acres in winter and summer, respectively. These areas are less than 17,010 acres of available area for cultivation (Av). The estimated total water use is 40.6 million cubic meters (MCM), which is less than the 88 MCM that is considered available groundwater in the Nubian Aquifer System (NAS). Due to available capacity in Siwa, an optimization model is used to maximize crop production considering government policies. The Autoregressive Integrated Moving Average (ARIMA) model was applied to predict production costs and sell prices of cultivated crops. Analysis included different scenarios beyond government-recommended approaches to identify ways to further expand agriculture production under sustainable conditions. Results provide valuable insights to the ability to achieve government goals from the project and changes that may be required to enhance production.

Can China achieve its water use peaking in 2030? A scenario analysis based on LMDI and Monte Carlo method

Faced with water shortage, China has set a control target of 7000×108 m3 of water use in 2030. In the future, how to realize the 2030 water use peak target has become an urgent problem for China to solve. This study aims to predict total water use trend by 2030 under different scenarios and determine the magnitude and time of water use peak. This paper uses the LMDI (Logarithmic Mean Divisia Index) method to decompose the driving factors of the production water use and domestic water use in 2003–2017, and for the first time, combines the scenario analysis and Monte Carlo simulation to analysis the potential evolution trend of production and domestic water use. We found that: (1) Economic development is the primary factor in promoting the increase in total water use, domestic intensity and population scale play a role in promoting increase, production intensity is the primary factor in inhibiting the increase in total water use, industrial structure promotes the decrease of total water use; (2) There are significant differences in the decomposition effects among the three industries; (3) The evolution trend of production and domestic water use is different under the three scenarios. Compared with the baseline scenario, the primary and secondary industry water use decreased more, and the tertiary industry and domestic water use increased less, under the general water-saving scenario and the enhanced water-saving scenario; (4) During the period of 2003–2030, the total water use in all three scenarios experienced an inverted U-shaped. The peaks appeared in 2013, and the total water use (excluding ecological water consumption) was 6078.28×108 m3. The current total water use has reached its peak and been in a stage of stable or even declining stage. Some policy implications are put forward related to our empirical results.