Perceptions and Representations of Drought in the Oued El Abid Watershed

Driving effects of ecosystems and social systems on water supply and demand in semiarid areas

Triangle of Environment, Water and Energy: A Sociological Appraisal

As water scarcity becomes the new norm in the Western United States, states such as California have increased their efforts to improve water resilience. Achieving water security under climate change and population growth requires an integrated multi-sectoral approach, where adaptation strategies combine water supply and demand management interventions. Yet, most studies consider supply-side and demand-side water management strategies separately. Further, publicly available data to assess the effectiveness of these strategies and their dependency on individual and collective human behavior is often hard to find and unstructured. Water conservation efforts are driven by water scarcity and policy requirements, with conservation targets and water use restrictions often designed assuming a degree of rationality of human behavior and based on cost-effective options and ease of implementation. In this work, we develop a data-driven analysis aimed at evaluating historical synergies and possible trade-offs between water supply and demand management strategies in California. Our analysis is based on CaRDS – the statewide California Residential water Demand and Supply open dataset, which contains monthly values of water supply and residential water demand for 404 water suppliers in California from 2013 to 2021. In this time span, Californian water agencies had to adapt and mitigate the effects of two droughts (in 2012-2016 and 2020-2022) through residential water demand reductions, as well as address rapid changes in demand associated with the global COVID-19 pandemic (2020). Our trade-off analysis integrates the following three sequential steps: (i) trend analysis – we use Random Forest regression to control for seasonal factors (i.e., temperature and precipitation) that affect water supply and demand at the utility scale; (ii) multi-criteria trade-off analysis – we examine the temporal relationship between water supply and demand by utilizing Dynamic Time Warping to identify trade-offs and management patterns. Next, we cluster water suppliers in 6 groups based on their combined management patterns; (iii) and driver analysis – we utilize explainable Machine Learning by combining SHAP (Shapley values) with LGBM (Light Gradient Boosting Method) to identify the drivers of each cluster. Potential drivers include climatic region, water supply portfolio, indoor vs. outdoor water use, local and state policies,  population, supplier size, and income. We finally validate the results of our analysis by comparing our findings with responses from water supplier interviews carried out in 2017 and reveal differences between intended and actual water management outcomes. This research contributes insights into the combined effects of policies on water supply and demand at a statewide level. Further it facilitates the formulation of adaptive resilience strategies for human actors in water management and decision makers alike to address vulnerability of small and large water systems to a rapidly changing climate and a society with non-linear changes in human behavior.

Lower reaches of the Amu Darya River Basin (LADB) is one of the typical regions which is facing the problem of water shortage in Central Asia. During the past decades, water resources demand far exceeds that supplied by the mainstream of the Amu Darya River, and has resulted in a continuous decrease in the amount of water flowing into the Aral Sea. Clarifying the dynamic relationship between the water supply and demand is important for the optimal allocation and sustainable management of regional water resources. In this study, the relationship and its variations between the water supply and demand in the LADB from the 1970s to 2010s were analyzed by detailed calculation of multi-users water demand and multi-sources water supply, and the water scarcity indices were used for evaluating the status of water resources utilization. The results indicated that (1) during the past 50 years, the average total water supply (TWS) was 271.88 × 108 m3/y, and the average total water demand (TWD) was 467.85 × 108 m3/y; both the volume of water supply and demand was decreased in the LADB, with rates of −1.87 × 108 m3/y and −15.59 × 108 m3/y. (2) percentages of the rainfall in TWS were increased due to the decrease of inflow from the Amu Darya River; percentage of agriculture water demand was increased obviously, from 11.04% in the 1970s to 44.34% in 2010s, and the water demand from ecological sector reduced because of the Aral Sea shrinking. (3) the supply and demand of water resources of the LADB were generally in an unbalanced state, and water demand exceeded water supply except in the 2010s; the water scarcity index decreased from 2.69 to 0.94, indicating the status changed from awful to serious water scarcity. A vulnerable balanced state has been reached in the region, and that water shortages remain serious in the future, which requires special attention to the decision-makers of the authority.

The increasing population, improving living standards, and expanding economic activities are responsible for rising water demands. In recent decades, the imbalance between water supply and demand has become increasingly prominent. Coupled with the unreasonable use of water resources, this has led to serious water scarcity problems that affect the sustainable development of modern society. Under this background, water scarcity has become an important environmental issue for our sustainable planet. Water scarcity is affected by regional water resource endowments and the ways in which water resources are developed and utilized by human beings. Quantity-induced water scarcity occurs when the quantity of water resources is insufficient. Meanwhile, pollution can cause water scarcity as the services provided by polluted water are not equivalent to that of clean water. Quality-induced water scarcity occurs when the pollutants exceed the environmental carrying capacity. Since Marlin Falkenmark first proposed the concept and assessment method of water scarcity in the 1980s, water scarcity assessment has developed for nearly 40 years. With the development of new theories, progress has been made, such as development of different approaches for assessing water scarcity, identification of influencing factors of water scarcity, revealing the formation mechanism, and exploring strategies to cope with water scarcity. As a result, water scarcity assessment has experienced an evolutionary pathway from a one-dimensional model emphasizing only quantity-induced water scarcity to a two-dimensional model (considering both quantity-induced and quality-induced water scarcity), toward a three-dimensional (3D) model (or 3D water scarcity theory) that considers water quantity, water quality, and environmental flows simultaneous. Based on a systematic review of water scarcity assessment in the literature, this study demonstrates the 3D water scarcity theory and elaborates on its basic concepts, principles, and core methods. The 3D water scarcity theory was first proposed by Chinese scholars and then accepted by international scholars. The quantity-induced water scarcity is assessed based on the ratio of water consumption to water availability, and the quality-induced water scarcity is quantified by comparing gray water footprint (the amount of water required to dilute pollutants in wastewater sufficiently to meet environmental water quality standards) with local available water resources. Environmental flow requirements are quantified based on the characteristics of climatic and hydrological conditions rather than the traditionally adopted simple approach by assuming that they are equal to 80% of water resources. Hence, the 3D water scarcity theory and assessment method can consider water quantity, water quality, and environmental flow requirements comprehensively. Finally, four main future research directions of water scarcity assessment are summarized: The further development and improvement of the theoretical framework of 3D water scarcity, applications of the assessment methods on multiple spatial scales, explicit consideration of the impacts of physical and virtual water flow, and mechanism of the evolution of water scarcity. 3D water scarcity is a key to achieving sustainable and harmonious development between humanity and water resources, and its assessment framework can break through the limitations of the traditional one- or two-dimensional models. Water scarcity theory provides methodological support for measuring the state of water resources on global, national, and regional scales, and it will help formulate appropriate water mitigation measures for integrated water resources management.

Rising agricultural water scarcity in China is driven by expansion of irrigated cropland in water scarce regions

The Greater Himalayas hold the largest mass of ice outside polar regions and are the source of the 10 largest rivers in Asia. Rapid reduction in the volume of Himalayan glaciers due to climate change is occurring. The cascading effects of rising temperatures and loss of ice and snow in the region are affecting, for example, water availability (amounts, seasonality), biodiversity (endemic species, predator-prey relations), ecosystem boundary shifts (tree-line movements, high-elevation ecosystem changes), and global feedbacks (monsoonal shifts, loss of soil carbon). Climate change will also have environmental and social impacts that will likely increase uncertainty in water supplies and agricultural production for human populations across Asia. A common understanding of climate change needs to be developed through regional and local-scale research so that mitigation and adaptation strategies can be identified and implemented. The challenges brought about by climate change in the Greater Himalayas can only be addressed through increased regional collaboration in scientific research and policy making.

Water scarcity assessments are crucial for sustainable water management in the future. Previously, such assessments were mainly conducted through simple statistical analyses and water resource models, which apply minimal observational data on socioeconomic factors. Here, we present a data-driven method to evaluate water scarcity, and reveal the interplaying mechanisms between its key driving factors. We selected Beijing as a case study for its complex human–water system representative of other megacities. We collected annual parameters from government’s statistics and yearbooks during 2000–2021 and designed a system dynamics (SD) framework to characterize the key human–water coupling components. The framework was then used to project water demand and supply changes under different shared socioeconomic pathways (SSPs) (2024–2050) using meteorological forcing from CMIP6. Results show that the SD framework performs reasonably in reproducing historical water supply and demand variability, showing continuously mitigated water scarcity severity due to government efforts to constrain agricultural and industrial water demand. Future projections indicate that water scarcity severity will be gradually mitigated until 2030, particularly under SSP1, SSP2, and SSP3 scenarios. After 2030, water scarcity is intensified across all scenarios except for SSP5. This is associated with increased (decreased) sectoral water demand, together with reduced (increased) total water supply under each scenario. Sensitivity analyses, by keeping key parameters constant, highlight the distinct roles of climatological and socioeconomic factors in shaping the timing and variability of water scarcity, and offer valuable policy implications. The SD framework in this study has unique strength in simulating the temporal evolutions of sectoral water demands and their complex interactions, and thus can improve the realism of water demand estimation, which is essential for water resource modeling and assessment studies.

Essays in Ecological Economics

Water supply sustainability and adaptation strategies under anthropogenic and climatic changes of a meso-scale Mediterranean catchment

Today's water world is pebbledashed with two main trepidations of water security/ scarcity, which need in-depth elaboration. Developing countries are particularly facing the impacts of water contamination and scarcity but lack the required impetus and technical infrastructure, thus necessitating swift actions to evaluate the effects of water security/ scarcity on the environment and water resources. In this study, an effort has been made to assess the water security/ scarcity situation in the twin cities of Rawalpindi/ Islamabad, elucidating the water quality/ quantity parameters in the Rawal Lake reservoir in Pakistan by analysing the contamination. The samples were collected/ tested during spring/ monsoon seasons to analyse temporal/fluvial impacts on water discharge. The results were compared with Pakistan's and WHO's drinking water standards before and after the water treatment. Almost all the testing parameters of the raw water samples from the Rawal Lake reservoir feeding streams exceeded the standard limits or fell close to the upper threshold limits, suggesting that this water was unsuitable for drinking without extensive treatment and an efficient distribution system. The contamination, untreated sewage disposal, non-regulated water utilisation, drawdown and supply/ demand gaps are the grave factors causing the water security/ scarcity in the capital/ twin cities of Islamabad/ Rawalpindi. Pakistan has already entered the water scarcity threshold of 1014 m3/ person/ annum in 2018, reduced from water availability of 5260 m3/ person/ annum in 1950 and will likely reach a drought level by 2050 due to increased population and reduced water resources. The study proposes an organisational implementation model for catchment-level river management to ensure good quality of water, construction of 5-10 small dams, and the provision of water from Terbella Dam suggested as the long-term strategy to prevent water scarcity.

Agent-based modelling of water balance in a social-ecological system: A multidisciplinary approach for mountain catchments

To mitigate climate change at local, regional, and global scales, we must begin to think beyond greenhouse gases.

Arid and semi-arid regions such as the Middle East and North Africa are increasingly suffering from water scarcity, exacerbated by climate change and population growth. This trend calls for new strategies for managing water demand and supply to face global changes in social-economic development, water system expansions, and cross-border differences.In this work, we explore the potential to mitigate the existing conflicts over the Nile River Basin, interconnecting water demand and supply using novel technological solutions, such as desalination and aquaponics, combined with traditional uses (i.e., groundwater extraction and water reuse). We analyse the complex dynamics and tradeoffs between energy production and irrigation water supply in Ethiopia, Sudan, and Egypt. We propose innovative portfolios of interventions that combine the coordinated operation of large water dams (i.e., the Grand Ethiopian Renaissance, Merowe, and High Aswan) and the main irrigation diversions with smart water demand management options. Desalination involves the process of removing salt and other minerals from seawater, making it suitable for irrigation and other domestic uses. Aquaponics involves the cultivation of fish and plants in a symbiotic environment, with the waste produced by the fish providing nutrients for the plants and the plants purifying the water for the fish. This technology can be an efficient and sustainable way to produce food with very low water consumption.Our approach is used to study current and future tradeoffs, generating solutions that are efficient and resilient to future hydroclimatic and demographic scenarios. We first quantified the impacts of dynamically downscaled and bias-adjusted climate projections for three Representative Concentrated Pathways (i.e., RCP2.6, RCP4.5 and RCP8.5) on the runoffs of the main tributaries of the Nile. We also considered stochastic projections of water demand based on Shared Socioeconomic Pathways (SSPs), and a strategic model that reallocates crops according to future climatic and demographic scenarios, according to a balanced diet and agricultural intensification strategy to generate a positive impact on food self-sufficiency.Our results show that the Nile River Basin features both strong tradeoffs and synergies across riparian countries, with the irrigation supply in Sudan playing a major role in allocating water between competing sectors. The results show a decrease of up to 20% of the Nile River's runoff and a doubling of the Egyptian municipal demand in the most severe scenario that leads to exacerbating tensions between the three countries. Notably, the potential reduction of the Egyptian water demand through different combinations of aquaponics, desalination, reuse, and groundwater pumping in the Nile Delta, along with a substantial decrease in Sudan irrigation demand through crop reallocation, can contribute to mitigating existing and future conflicts. Further technological improvements are needed for attaining large water demand reductions via soilless agriculture and desalination, which today cannot completely substitute reuse and groundwater contributions, whose high exploitation can induce relevant environmental risks.

Agriculture production is directly dependent on climate change and weather. Possible changes in temperature, precipitation and CO2 concentration are expected to significantly impact crop growth and ultimately we lose our crop productivity and indirectly affect the sustainable food availability issue. The overall impact of climate change on worldwide food production is considered to be low to moderate with successful adaptation and adequate irrigation. Climate change has a serious impact on the availability of various resources on the earth especially water, which sustains life on this planet. The global food security situation and outlook remains delicately imbalanced amid surplus food production and the prevalence of hunger, due to the complex interplay of social, economic, and ecological factors that mediate food security outcomes at various human and institutional scales. Weather aberration poses complex challenges in terms of increased variability and risk for food producers and the energy and water sectors. Changes in the biosphere, biodiversity and natural resources are adversely affecting human health and quality of life. Throughout the 21st century, India is projected to experience warming above global level. India will also begin to experience more seasonal variation in temperature with more warming in the winters than summers. Longevity of heat waves across India has extended in recent years with warmer night temperatures and hotter days, and this trend is expected to continue. Strategic research priorities are outlined for a range of sectors that underpin global food security, including: agriculture, ecosystem services from agriculture, climate change, international trade, water management solutions, the water-energy-food security nexus, service delivery to smallholders and women farmers, and better governance models and regional priority setting. There is a need to look beyond agriculture and invest in affordable and suitable farm technologies if the problem of food insecurity is to be addressed in a sustainable manner. Introduction Globally, agriculture is one of the most vulnerable sectors to climate change. This vulnerability is relatively higher in India in view of the large population depending on agriculture and poor coping capabilities of small and marginal farmers. Impacts of climate change pose a serious threat to food security. “Food security exists when all people, at all times, have physical and economic access to sufficient, safe and nutritious food that meets their dietary needs and food preferences for an active and healthy life” (World Food Summit, 1996). This definition gives rise to four dimensions of food security: availability of food, accessibility (economically and physically), utilization (the way it is used and assimilated by the human body) and stability of these three dimensions. According to the United Nations, in 2015, there are still 836 million people in the world living in extreme poverty (less than USD1.25/day) (UN, 2015). And according to the International Fund for Agricultural Development (IFAD), at least 70 percent of the very poor live in rural areas, most of them depending partly (or completely) on agriculture for their livelihoods. It is estimated that 500 million smallholder farms in the developing world are supporting almost 2 billion people, and in Asia and sub-Saharan Africa these small farms produce about 80 percent of the food consumed. Climate change threatens to reverse the progress made so far in the fight against hunger and malnutrition. As highlighted by the assessment report of the Intergovernmental Panel on Climate change (IPCC), climate change augments and intensifies risks to food security for the most vulnerable countries and populations. Few of the major risks induced by climate change, as identified by IPCC have direct consequences for food security (IPCC, 2007). These are mainly to loss of rural livelihoods and income, loss of marine and coastal ecosystems, livelihoods loss of terrestrial and inland water ecosystems and food insecurity (breakdown of food systems). Rural farmers, whose livelihood depends on the use of natural resources, are likely to bear the brunt of adverse impacts. Most of the crop simulation model runs and experiments under elevated temperature and carbon dioxide indicate that by 2030, a 3-7% decline in the yield of principal cereal crops like rice and wheat is likely in India by adoption of current production technologies. Global warming impacts growth, reproduction and yields of food and horticulture crops, increases crop water requirement, causes more soil erosion, increases thermal stress on animals leading to decreased milk yields and change the distribution and breeding season of fisheries. Fast changing climatic conditions, shrinking land, water and other natural resources with rapid growing population around the globe has put many challenges before us (Mukherjee, 2014). Food is going to be second most challenging issue for mankind in time to come. India will also begin to experience more seasonal variation in temperature with more warming in the winters than summers (Christensen et al., 2007). Climate change is posing a great threat to agriculture and food security in India and it's subcontinent. Water is the most critical agricultural input in India, as 55% of the total cultivated areas do not have irrigation facilities. Currently we are able to secure food supplies under these varying conditions. Under the threat of climate variability, our food grain production system becomes quite comfortable and easily accessible for local people. India's food grain production is estimated to rise 2 per cent in 2020-21 crop years to an all-time high of 303.34 million tonnes on better output of rice, wheat, pulse and coarse cereals amid good monsoon rains last year. In the 2019-20 crop year, the country's food grain output (comprising wheat, rice, pulses and coarse cereals) stood at a record 297.5 million tonnes (MT). Releasing the second advance estimates for 2020-21 crop year, the agriculture ministry said foodgrain production is projected at a record 303.34 MT. As per the data, rice production is pegged at record 120.32 MT as against 118.87 MT in the previous year. Wheat production is estimated to rise to a record 109.24 MT in 2020-21 from 107.86 MT in the previous year, while output of coarse cereals is likely to increase to 49.36 MT from 47.75 MT. Pulses output is seen at 24.42 MT, up from 23.03 MT in 2019-20 crop year. In the non-foodgrain category, the production of oilseeds is estimated at 37.31 MT in 2020-21 as against 33.22 MT in the previous year. Sugarcane production is pegged at 397.66 MT from 370.50 MT in the previous year, while cotton output is expected to be higher at 36.54 million bales (170 kg each) from 36.07. This production figure seem to be sufficient for current population, but we need to improve more and more with vertical farming and advance agronomic and crop improvement tools for future burgeoning population figure under the milieu of climate change issue. Our rural mass and tribal people have very limited resources and they sometime complete depend on forest microhabitat. To order to ensure food and nutritional security for growing population, a new strategy needs to be initiated for growing of crops in changing climatic condition. The country has a large pool of underutilized or underexploited fruit or cereals crops which have enormous potential for contributing to food security, nutrition, health, ecosystem sustainability under the changing climatic conditions, since they require little input, as they have inherent capabilities to withstand biotic and abiotic stress. Apart from the impacts on agronomic conditions of crop productions, climate change also affects the economy, food systems and wellbeing of the consumers (Abbade, 2017). Crop nutritional quality become very challenging, as we noticed that, zinc and iron deficiency is a serious global health problem in humans depending on cereal-diet and is largely prevalent in low-income countries like Sub-Saharan Africa, and South and South-east Asia. We report inefficiency of modern-bred cultivars of rice and wheat to sequester those essential nutrients in grains as the reason for such deficiency and prevalence (Debnath et al., 2021). Keeping in mind the crop yield and nutritional quality become very daunting task to our food security issue and this can overcome with the proper and time bound research in cognizance with the environment. Threat and challenges In recent years, climate change has become a debatable issue worldwide. South Asia will be one of the most adversely affected regions in terms of impacts of climate change on agricultural yield, economic activity and trading policies. Addressing climate change is central for global future food security and poverty alleviation. The approach would need to implement strategies linked with developmental plans to enhance its adaptive capacity in terms of climate resilience and mitigation. Over time, there has been a visible shift in the global climate change initiative towards adaptation. Adaptation can complement mitigation as a cost-effective strategy to reduce climate change risks. The impact of climate change is projected to have different effects across societies and countries. Mitigation and adaptation actions can, if appropriately designed, advance sustainable development and equity both within and across countries and between generations. One approach to balancing the attention on adaptation and mitigation strategies is to compare the costs and benefits of both the strategies. The most imminent change is the increase in the atmospheric temperatures due to increase levels of GHGs (Green House Gases) i.e. carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O) and chlorofluorocarbons (CFCs) etc into the atmosphere. The global mean annual temperatures at the end of the 20th