Intra-annual dynamics of water stress in the central Indian Highlands from 2002 to 2012

India’s continued development depends on the availability of adequate water. This paper applies a data-driven approach to estimate the intra-annual dynamics of water stress across the central Indian Highlands over the period 2002–2012. We investigate the spatial distribution of water demanding sectors including industry, domestic, irrigation, livestock and thermal power generation. We also examine the vulnerability of urban centers within the study area to water stress. We find that 74 % of the area of the central Indian Highlands experienced water stress (defined as demand exceeding supply) for 4 or more months out of the year. The rabi (winter) season irrigation drives the intra-annual water stress across the landscape. The Godavari basin experiences the most surface water stress while the Ganga and Narmada basins experience water stress due to groundwater deficits as a result of rabi irrigation. All urban centers experience water stress at some time during a year. Urban centers in the Godavari basin are considerably water stressed, for example, Achalpur, Nagpur and Chandrapur experience water stress 8 months out of the year. Irrigation dominates water use accounting for 95 % of the total water demand, with substantial increases in irrigated land over the last decade. Managing land use to promote hydrologic functions will become increasingly important as water stress increases.     

Assessment of irrigation system sustainability using the Theil–Sen estimator of slope of time series

Agriculture, especially the irrigated sector, is the mainstay of Sudan’s economy as it accounts for 40 % of gross domestic product (GDP) and employs 70 % of the workforce. The economic viability of irrigated schemes is dependent on three factors: crop yield, water management and cropped area. The research question of this study was whether or not the current status of these factors can be sustained in order to maintain the economic viability of irrigation systems? To answer this question, a new (to the best of the author’s knowledge) approach was developed based on time series analysis, and on the Theil–Sen estimator of slope. The study defined sustainability conceptually as “the ability of an irrigation system to sustain crop yields using the optimum cropped area and water consumption to realize the economic viability of the irrigation system without a decline in soil quality and environment”. Time series datasets of crop yields, cropped area and irrigation water consumption are collected routinely by statistical departments. Any abrupt years in the development of trends were detected and related to their driving forces/causes, of which climatic conditions and marketing policies were found to be the most important. The simple approach developed proved its suitability for quantifying the progress of irrigated schemes’ towards sustainability development as tested under the conditions of Gezira irrigated scheme in Sudan—the largest singly managed irrigation scheme in the world. The scheme was found to be sustainable under the condition that the crop yield is considered as the top priority; otherwise, the sustainability of the scheme is jeopardized.     

Perceptions of using low-quality irrigation water in vegetable production in Morogoro,Tanzania

This study was conducted to examine perceptions of the farmers and key informants on the use of low-quality irrigation water for vegetable production in urban and peri-urban areas in Morogoro, Tanzania. The methods used to collect data were farmer surveys (n = 60), focus group discussions (n = 4) and key informants interviews (n = 15). The results showed that the respondents had a positive perception on using low-quality irrigation water for vegetable production. The reported benefits include availability of water throughout the year, highest soil and crop nutrients in irrigation water, less costs of buying commercial fertilizers, vegetable production all year round, sustainable income generation from selling vegetables and also jobs creation in the community among farmers and vegetable sellers. Findings from Mann–Whitney U test and Kruskal–Wallis test score on farmers perception scales indicate an association between the source of low-quality water used and the respondents’ sex. Accordingly, female farmers had higher positive perception on the benefits of low-quality water compared to male farmers. Higher perception score was also observed among farmers who used polluted river water in irrigation vegetable production compared to farmers who used wastewater. Since low-quality irrigation water is a good strategy of coping with scarcity of freshwater for communities which have no alternative source of irrigation water, the study recommends multi-sectorial agencies across the country to be involved in formulating policies and creating health promotion awareness for safe use of low-quality water for benefit maximization and health risk reduction.     

Reallocating water from canal irrigation for environmental flows: benefits forgone in the Upper Ganga Basin in India

This paper assesses the potential loss of irrigation benefits in reallocating water from irrigation to meet requirements for environmental flows (e-flows) in the Upper Ganga Basin (UGB) in northern India. The minimum requirement for e-flows in the UGB is 32 billion cubic meters (BCM), or 42 % of the mean annual runoff. The current runoff during the low-flow months falls below the minimum requirement for e-flows by 5.1 BCM. Depending on irrigation efficiency, reallocation of 41–51 % of the water from canal irrigation withdrawals can meet this deficit in minimum e-flows. The marginal productivity of canal irrigation consumptive water use (CWU), estimated from a panel regression with data from 32 districts from 1991 to 2004, assesses the potential loss of benefits in diverting water away from crop production. In the UGB, canal irrigation contributes to only 8 % of the total CWU of 56 BCM, and the marginal productivity of canal irrigation CWU across districts is also very low, with a median of 0.03 USD/m³. Therefore, at present, the loss of benefits is only 1.2–1.6 % of the gross value of crop production. This loss of benefits can be overcome with an increase in irrigation efficiency or marginal productivity.     

Economic implications of groundwater exploitation in hard rock areas of southern peninsular India

The present paper analyses the consequences of groundwater exploitation by using field-level data collected from two distinct well irrigated areas of Karnataka. The study results show that the consequences arising out of groundwater overexploitation are severe in high well interference area compared to low well interference area. The burden of well failure is more or less equally shared by all categories of farmers but small farmers are the worst victims of resource scarcity. As a result, overexploitation of groundwater has different impacts on different categories of farmers in terms of access to groundwater, cost and returns to groundwater irrigation and its negative externality cost. The study suggests maintaining inter-well distance to prevent resource mining and calls for supply and demand side interventions. The institutional reform is necessary to restore surface water bodies to facilitate aquifer recharge.     

Health risks from large-scale water pollution: trends in Central Asia

Limited data on the pollution status of spatially extensive water systems constrain health-risk assessments at basin-scales. Using a recipient measurement approach in a terminal water body, we show that agricultural and industrial pollutants in groundwater-surface water systems of the Aral Sea Drainage Basin (covering the main part of Central Asia) yield cumulative health hazards above guideline values in downstream surface waters, due to high concentrations of copper, arsenic, nitrite, and to certain extent dichlorodiphenyltrichloroethane (DDT). Considering these high-impact contaminants, we furthermore perform trend analyses of their upstream spatial-temporal distribution, investigating dominant large-scale spreading mechanisms. The ratio between parent DDT and its degradation products showed that discharges into or depositions onto surface waters are likely to be recent or ongoing. In river water, copper concentrations peak during the spring season, after thawing and snow melt. High spatial variability of arsenic concentrations in river water could reflect its local presence in the top soil of nearby agricultural fields. Overall, groundwaters were associated with much higher health risks than surface waters. Health risks can therefore increase considerably, if the downstream population must switch to groundwater-based drinking water supplies during surface water shortage. Arid regions are generally vulnerable to this problem due to ongoing irrigation expansion and climate changes.     

Estimation of emission reduction potential in China’s industrial sector

The industrial sector is usually the largest economy sector for carbon emissions in many countries, which made it the sector with greatest potential for carbon reduction although the process duration might be very long. Studying the potential of industrial emission reduction has great significance in estimating the carbon emission peak of China on the one hand, and adjusting its strategy in international climate change negotiations. By employing the economic accounting method, this article estimates the emission reduction potential of China’s Industrial sector for the period of 2010–2050. It reveals that, taking 2030 as the year when the emission reaches the peak, the total reduction can be 8.38 billion tons (bts) for the period of 2010–2030, with 3.12 bts from structural reduction while 5.26 bts from intensity reduction. Afterwards, reduction will continue with a total amount of 6.59 bts for the period of 2030–2050, where the structural reduction accounts for 2.47 bts, and intensity reduction 4.115 bts. If both industrial and energy consumption structures are improved during the above period, the reduction potential can be even greater, e.g. the emission peak can arrive five years earlier (in the year of 2025) and the peak value can decline by about 8% as compared to the original estimation. Reviewing the trajectory of emission changes in developed countries indicates that the industry sector can contribute to the overall reduction targets through the dual wheels of structural reduction and intensity reduction, even beyond the emission peak. This article concludes with the following policy suggestions. (1) Our estimation on the emission peak of the industrial sector suggests that China should avoid any commitment earlier than 2030 on the timeline of the overall emission peak; (2) the great potential of industrial emission reduction can improve the situation of China in climate change negotiation, where the intensity reduction can serve as an important policy option. (3) Reduction potential can be further enhanced through technology advancement, which requires furthering of market oriented reforms and improvement of institutional design. (4) To secure the reduction effects of the industrial structure adjustment, the balanced development among different regions should be encouraged in order to avoid the reverse adjustment caused by industrial transferring. (5) International cooperation promoting the application and development of industrial emission reduction technologies, including carbon capture, utilization and storage, should be encouraged.     

Wastewater re-use for peri-urban agriculture: a viable option for adaptive water management?

Urbanization is known to spur land modification in the form of conversion of common land to human settlements. This factor, combined with climate variability, can alter the duration, frequency and intensity of storm drain overflows in urban areas and lead to public health risks. In peri-urban regions where these risks are especially high it has been argued that, when domestic wastewater is managed, better prospects for freshwater water savings through swaps between urban water supply and irrigated agriculture may be possible. As a consequence of re-use of domestic wastewater, expenditure on inorganic inputs by farmers may decline and source sustainability of water supply could be enhanced. Given the fact that, at present, approximately 20 million ha of land worldwide is being cultivated by re-using domestic wastewater, this paper draws on evidence from India to explore: (1) the economic costs–benefits of wastewater reuse in the context of hypothesized links to climate variability; (2) the role of local farming practices, market conditions and crop variety in influencing wastewater reuse in agriculture; and (3) the role of inter-governmental financing in influencing the selection of technical adaptation options for collection, treatment and disposal of wastewater.     

Efficiency of common-pool resource institutions: focusing on water users associations in South Africa

Despite of the promulgation of new water laws post-apartheid by the South African government, some parts of the country are still faced with inequitable, inefficient and inadequate water supply. Water institutions in South Africa and other developing countries are faced with various and multi-faceted challenges that consequently lead to their failure to provide water resources effectively. The evident responsibility of governing water resources in developing countries is commonly played by local and national institutions, using the water sector’s fundamental regulations, policies as well as statutory enactments. This paper draws lessons from the international examples to analyse the motivation for WUAs and the challenges they are faced with. The method for data generation used in this article is document analysis. A narrative approach using the literature and document analysis provided an insight into the economic and institutional history of WUAs. The analytical framework to study path dependency and power relations in connection with WUAs in South Africa was drawn from a literature review of transition studies and NIE. This study established that the current and future decisions made by the WUAs in South Africa are not entirely independent of those made in the past under irrigation boards. The study argues that establishing WUAs cannot automatically substitute for the domains of relations which existed within irrigation boards.     

Ecological and economic impacts of different irrigation and fertilization practices: case study of a watershed in the southern Iran

Best management practices, such as conservation tillage, the optimum level of irrigation, fertilization, are frequently used to reduce non-point source pollution from agricultural land and improve water quality. In this study, we used the soil and water assessment tool to model the impacts of different irrigation (adjusted to crop need), cropping and fertilization practices on total nitrogen loss. The economic impacts of these practices on crop net farm income were also evaluated. For this purpose, the model was calibrated through comparing model outputs with observations to ensure reliable hydrologic, crop yield and nitrate leaching simulations. The results showed that by reducing water or fertilizer or combination of both, we can reduce nitrate leaching. For wheat and corn, the best scenario was S1n1 (combination between reduction by 10 % of water and nitrogen fertilizer application, simultaneously) and S2n3 (combination of 20 and 30 % reduction in water and fertilizer application), respectively. These scenarios are both ecologically and economically desirable. Also, decreasing nitrogen fertilization by 50 % for corn would decrease the nitrate pollution from 101.1 to 32.3 kg N ha^?1; therefore, this strategy is ecologically desirable but economically unsound. So, there are opportunities for environmental decision makers to encourage farmers to implement these strategies. Also, since the nitrogen leaching cannot decrease without a reduction in net farm income for crops such as corn; hence, the losses of farmers should be compensated.     

Technology improvements and value changes for sustainable happiness: a cross-development analytical model

This paper develops an analytical model to calculate the amount by which individuals are expected to modify their values (the relationship between lifestyle and happiness, as measured by subjective well-being, SWB) and to adopt innovative technologies (to increase the sustainability of production and consumption, measured by the ecological footprint, EF) to allow current and future generations to achieve sustainable happiness (the pursuit of happiness that does not exploit other people, the environment, or future generations). The paper also examines the dependence of these changes on an individual’s concern for future generations and on their country’s current state of economic development. It is shown that individuals in better-off developed countries and individuals in worse-off developing countries can achieve sustainability with a reasonable level of value change (0–30 %) and a feasible degree of technological innovation (10–40 %), respectively. In contrast, individuals in better-off developing countries and individuals in worse-off developed countries must rely to an impractical degree of technological innovation (50–70 %) and to an unreasonable level of value change (40–70 %), respectively. Finally, individuals in developing countries differ from individuals in developed countries in terms of their potential to achieve sustainable happiness, by achieving sustainability at a low SWB (about 10 % of its maximum) and a high SWB (about 80 % of its maximum), respectively.     

可持续发展的给水工业系统分析

本文建立了给水工业的系统框架 ,分析了给水工业的宏观和中观系统结构及其内在关系 ,讨论了不同层次的系统对给水工业可持续发展的影响 ,为制定我国水工业发展的政策和管理体系提供了理论基础     

Implications of climate change in sustained agricultural productivity in South Asia

One of the targets of the United Nations ‘Millennium Development Goals’ adopted in 2000 is to cut in half the number of people who are suffering from hunger between 1990 and 2015. However, crop yield growth has slowed down in much of the world because of declining investments in agricultural research, irrigation, and rural infrastructure and increasing water scarcity. New challenges to food security are posed by accelerated climatic change. Considerable uncertainties remain as to when, where and how climate change will affect agricultural production. Even less is known about how climate change might influence other aspects that determine food security, such as accessibility of food for various societal groups and the stability of food supply. This paper presents the likely impacts of thermal and hydrological stresses as a consequence of projected climate change in the future potential agriculture productivity in South Asia based on the crop simulation studies with a view to identify critical climate thresholds for sustained food productivity in the region. The study suggests that, on an aggregate level, there might not be a significant impact of global warming on food production of South Asia in the short term (<2°C; until 2020s), provided water for irrigation is available and agricultural pests could be kept under control. The increasing frequency of droughts and floods would, however, continue to seriously disrupt food supplies on year to year basis. In long term (2050s and beyond), productivity of Kharif crops would decline due to increased climate variability and pest incidence and virulence. Production of Rabi crops is likely to be more seriously threatened in response to 2°C warming. The net cereal production in South Asia is projected to decline at least between 4 and 10% under the most conservative climate change projections (a regional warming of 3°C) by the end of this century. In terms of the reference to UNFCCC Article 2 on dangerous anthropogenic (human-induced) interference with the climate system, the critical threshold for sustained food productivity in South Asia appears to be a rise in surface air temperature of ~2°C and a marginal decline in water availability for irrigation or decrease in rainfall during the cropping season.     

Climate change and village adaptation impact on reliability of irrigation wells in China

This paper builds a water supply reliability econometric model to analyze climate changes and adaptation impact factors on water supply reliability of irrigation wells by using 100 villages’ three-year (2010–2012) field survey data of five middle and eastern provinces of China. The results show that long-run climate change factors, adaptation measures, village-level organizations of irrigation management, as well as extreme climate factors affect the water supply reliability of irrigation wells significantly. Meanwhile, there are significant differences impacting different crops and provinces. This paper suggests that agriculture meteorological disaster monitoring and warning systems should be strengthened by increasing irrigation facilities construction and maintenance, promoting reform of agricultural irrigation water management system, and developing various forms of peasant cooperation organization in order to improve agricultural production capacity to adapt to climate change.     

Climate change threats to environment in the tropical Andes: glaciers and water resources

Almost all of the world’s glaciers in the tropical latitudes are located in the Central Andes (Peru, Bolivia, Ecuador and Colombia). Due to their high altitude, to the high level of radiation and to the tropical climate dynamics, they all are particularly threatened by climate change, as a result of not only warming, but also of changing variability of precipitation. Many glaciers are of crucial importance for the livelihood of the local populations and even for three capitals, Lima (Peru), La Paz (Bolivia) and Quito (Ecuador), which depend on them for water and energy supplies. This paper shows that after a period of increased flow due to the glacier melt disequilibrium, the available water resource will decrease along with the rapid shrinking of the glaciers considered as water reservoirs. The case of the Cordillera Blanca (Peru) is analyzed more in detail with the mid-term (20 years) and long-term (1–2 centuries) impact of the glacier shrinking on the local water resources. Associated risks for the population and consequences for the human activities (tourism, hydropower, agriculture and stock-breeding, large-scale irrigation) are described at each stage of the mountain range.     

Improvement in irrigation water use efficiency: a strategy for climate change adaptation and sustainable development of Vietnamese tea production

Irrigation is indispensable to overcome insufficient rainfall and to achieve a stabilized yield for tea production. As the severe scarcity of water resources because of climate change, water conservation through efficient irrigation has turned into a vital strategy for tea sector in solving this rising challenge. This paper analyzes irrigation water use efficiency of small-scale tea farms in Vietnam and identifies its determinants applying stochastic frontier analysis. Results showed that under decreasing returns to scale, the mean irrigation water use efficiency was 42.19 %, indicating the existence of substantial water waste. If farmers become more efficient in using water, saving 57.81 % of irrigation water is possible unaccompanied by reducing the observed output. The factors affecting tea farms’ irrigation water use efficiency were investigated by Tobit model. Gender, water shortage awareness, soil and water conservation practice, off-farm income share, extension services access and well water utilization showed significant influence on the efficiency of irrigation water. The study’ results provide insights to policymakers in implementing better water resource management amid climate change.     

Present to future sediment transport of the Brahmaputra River: reducing uncertainty in predictions and management

The Brahmaputra River in South Asia carries one of the world’s highest sediment loads, and the sediment transport dynamics strongly affect the region’s ecology and agriculture. However, present understanding of sediment conditions and dynamics is hindered by limited access to hydrological and geomorphological data, which impacts predictive models needed in management. We here synthesize reported peer-reviewed data relevant to sediment transport and perform a sensitivity analysis to identify sensitive and uncertain parameters, using the one-dimensional model HEC-RAS, considering both present and future climatic conditions. Results showed that there is considerable uncertainty in openly available estimates (260–720 Mt yr^?1) of the annual sediment load for the Brahmaputra River at its downstream Bahadurabad gauging station (Bangladesh). This may aggravate scientific impact studies of planned power plant and reservoir construction in the region, as well as more general effects of ongoing land use change and climate change. We found that data scarcity on sediment grain size distribution, water discharge, and Manning’s roughness coefficient had the strongest controls on the modelled sediment load. However, despite uncertainty in absolute loads, we showed that predicted relative changes, including a future increase in sediment load by about 40 % at Bahadurabad by 2075–2100, were consistent across multiple model simulations. Nevertheless, for the future scenarios we found that parameter uncertainty almost doubled for water discharge and river geometry, highlighting that improved information on these parameters could greatly advance the abilities to predict and manage current and future sediment dynamics in the Brahmaputra river basin.     

Energy and land use in worldwide agriculture: an application of life cycle energy and cluster analysis

Agriculture is expected to provide food in a sustainable manner while also partially contributing to the energy problem as well as to bio-material supply. Moreover, fossil fuels scarcity calls for an increase of energy efficiency in agricultural processes. This study evaluates patterns, trends, driving factors and trade-offs of energy use in selected agricultural systems and aims at grouping them into clusters with similar energy and social performances. Results show that in 2010 the highest power densities and energy intensities of production are found by crop sector of cluster 5 (China: 59.19 GJ/ha, 15.29 MJ/kg dm) and cluster 3 (Japan: 50.11 GJ/ha, 12.32 MJ/kg dm) as well as by livestock sector of cluster 3 (Japan: 328.47 GJ/ha, 103.08 MJ/kg dm), while the lowest values in clusters 2 and 4, including selected developing countries and USA. Cluster 3 (Japan) also shows the lowest energy intensity of economic value of crops (2.75 MJ/$), while cluster 5 (China) the highest one (23.96 MJ/$). Cluster analysis also sheds light on trends, identifying two groups: cluster 1*, gathering most European countries, USA and Japan, characterized by a decreasing trend of all energy indicators; and cluster 2*, including developing countries, the Netherlands and Spain, characterized by an increasing trend of indicators. Results highlight the importance of an integrated framework for evaluating energy use as well as of a multi-criteria approach to understand the trade-offs and interplay of performance indicators.     

Impact of Massanjore Dam on hydro-geomorphological modification of Mayurakshi River,Eastern India

Massanjore reservoir (area ~67 km²) located 84 km downstream from the most distant upstream source capacitates 620,000,000 m³ of water, and regulated flow characters are highly responsible for dam downstream alteration of hydrological, sedimentological and geomorphological characteristics of Mayurakshi River. In dam after condition, monsoon water level (mean water level during monsoon months) and pre-monsoon water level (mean water level during pre-monsoon months, i.e., March–May) have attenuated about 0.56 and 0.32 m, respectively. Maximum duration of high flow period during monsoon has reduced up to 16.5 %; coefficient of variation of diurnal fluctuation of water level during monsoon has increased from 31 to 47 %. Suspended sediment load in Mayurakshi River is reduced to 34 % in dam after period as recorded at Narayanpur gauge station. Average suspended sediment load has decreased even after Tilpara barrage construction from 4.960 to 4.350 mg/L. Average suspended sediment load is 7.875 mg/L in the sites of dam upstream course, and this average is only 4.46 mg/L in different sites of dam downstream course. Volume of discharge has decreased up to 11.3 % during monsoon time in dam after condition. Such reduction in discharge volume in turn has reduced about 24.6 % bed load-carrying capacity. As a result, huge deposition within channel invigorated channel bed aggradations (average 73.6 cm up to Saspara, site 14 at Fig. 1) in dam after condition. Narrowing of active channel, coarsening of channel bed materials, lowering of lateral stability, accelerating rise of braiding index, mixed response of the channel adjustment of the tributaries to local scale positive or negative base level change due to river bed aggradations and degradation, etc. signify the morphological alteration of dam downstream course.

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Fig. 1 Mayurakshi River basin indicating Massanjore Dam, Tilpara barrage and sample working sites

     

Salinity evolution of the Tigris River

Major modifications regulating the Tigris River, originated in the 1940s and continuing to the present, have resulted in changes in salinity in the system over time and in different portions of the river course. The increase in salinity is due to decreases in stream discharge due to dams, water management structures such as the Lake Tharthar system, irrigation return flow, and soluble minerals in the basin. This research documents the increase and evaluates the causes of the salinity increase of the river from predevelopment to present using published and previously unavailable data. The predevelopment salinity was under 600 ppm, since 1984 has exceeded the 1000 ppm threshold recommended for drinking water downstream of Amara. A minimum instream flow for the river is calculated at Baghdad and Kut at 185 cubic meters per second (cms), approximately 15% of the mean historical flow of the river, but above the lowest minimum flow recorded at 140 cms. Recommended salinity management options discussed include (1) eliminating Lake Tharthar as a water storage facility, (2) managing saline inflows from tributaries, and (3) employing a minimum instream flow for the river.