scholarly journals Comparison of Crop Evapotranspiration and Water Productivity of Typical Delta Irrigation Areas in Aral Sea Basin

2022 ◽  
Vol 14 (2) ◽  
pp. 249
Author(s):  
Zhibin Liu ◽  
Tie Liu ◽  
Yue Huang ◽  
Yangchao Duan ◽  
Xiaohui Pan ◽  
...  

The intensity of agricultural activities and the characteristics of water consumption affect the hydrological processes of inland river basins in Central Asia. The crop water requirements and water productivity are different between the Amu Darya and Syr Darya river basins due to the different water resource development and utilization policies of Uzbekistan and Kazakhstan, which have resulted in more severe agricultural water consumption of the Amu Darya delta than the Syr Darya delta, and the differences in the surface runoff are injected into the Aral Sea. To reveal the difference in water resource dissipation, water productivity, and its influencing factors between the two basins, this study selected the irrigation areas of Amu Darya delta (IAAD) and Syr Darya delta (IASD) as typical examples; the actual evapotranspiration (ETa) was retrieved by using the modified surface energy balance algorithm for land model (SEBAL) based on high spatial resolution Landsat images from 2000 to 2020. Land use and cover change (LUCC) and streamflow data were obtained to analyze the reasons for the spatio-temporal heterogeneity of regional ETa. The water productivity of typical crops in two irrigation areas was compared and combined with statistical data. The results indicate that: (1) the ETa simulated by the SEBAL model matched the crop evapotranspiration (ETc) calculated by the Penman–Monteith method and ground-measured data well, with all the correlation coefficients higher than 0.7. (2) In IAAD, the average ETa was 1150 mm, and the ETa had shown a decreasing trend; for the IASD, the average ETa was 800 mm. The ETa showed an increasing trend with low stability due to a large amount of developable cultivated land. The change of cultivated land dominated the spatio-temporal characteristics of ETa in the two irrigation areas (3). Combined with high spatial resolution ETa inversion results, the water productivity of cotton and rice in IAAD was significantly lower than in IASD, and wheat was not significantly different, but all were far lower than the international average. This study can provide useful information for agricultural water management in the Aral Sea region.

Author(s):  
S. Nazrul Islam

Chapter 4 provides a few case studies of rivers to illustrate the consequences of the Commercial approach. These rivers are: the Colorado River of the United States; the Murray-Darling river system of Australia; the Amu Darya and Syr Darya of the former Soviet Union; the Nile River of Africa; and the Indus River of South Asia. It shows that in each case, the application of the Commercial approach has led to river fragmentation and excessive withdrawal of water, leading to exhaustion of rivers, which in turn led to salinity intrusion and erosion, subsidence, and desiccation of the deltas. The ecology of the river basins has been damaged, including loss of aquatic and terrestrial biodiversity. In case of the Amu Darya and Syr Darya Rivers, this damage includes the destruction of the Aral Sea, once considered the second-largest inland waterbody of the world. In each case, the Commercial approach has led to conflicts among co-riparian countries.


2009 ◽  
Vol 31 (2) ◽  
pp. 195 ◽  
Author(s):  
S. E. Cook ◽  
M. S. Andersson ◽  
M. J. Fisher

Recent concern over food prices has triggered a renewed interest in agricultural production systems. While attention is focused mainly on cropping, a complete analysis of food production systems should recognise the importance of livestock as major consumers of resources – in particular water – and as providers of food and other products and services. We propose that there is a need to examine not just food systems in isolation, but combined food and water systems, both of which are described as in a critical condition. From this broader perspective, it appears even more important to understand livestock systems because first, a total evaluation of agricultural water productivity – the gain from water consumed by agriculture – cannot be made without understanding the complexities of livestock-containing systems and; second, because in most tropical river basins, livestock systems are the major consumers of water. To identify total water productivity of livestock-containing systems, we describe concepts of agricultural water productivity and review the complexities of tracking the flow of water through livestock-containing systems: from inputs as evapotranspiration (ET) of forage and crops to outputs of valued animal products or services. For the second part, we present preliminary results from water use accounts analysis for several major river basins, which reveal that for Africa at least, livestock systems appear to be the major water consumers. Yet, little is known about the fate of water as it passes through these systems. We propose that livestock-containing systems offer substantial scope for increasing total water productivity and that there is considerable merit in improving the capacity to analyse water consumption and water productivity through such systems. Without removing this major source of uncertainty, the potential for systemic improvement to meet the world food and water crisis remains undefined and hence under-acknowledged.


2020 ◽  
Author(s):  
Haiyang Shi ◽  
Geping Luo ◽  
Hongwei Zheng ◽  
Chunbo Chen ◽  
Jie Bai ◽  
...  

Abstract. The previous comparative studies on watersheds were mostly based on the comparison of dispersive characteristics, which lacked systemicity and causality. We proposed a causal structure-based framework for basin comparison based on the Bayesian network (BN), and focus on the basin-scale water-energy-food-ecology (WEFE) nexuses. We applied it to the Syr Darya river basin (SDB) and the Amu Darya river basin (ADB) that caused the Aral Sea disaster. The causality of the nexuses was effectively compared and universality of this framework was discussed. In terms of changes of the nexuses, the sensitive factor for the water supplied to the Aral Sea changed from the agricultural development during the Soviet Union period to the disputes in the WEFE nexuses after the disintegration. The water-energy contradiction of SDB is more severe than that of ADB partly due to the higher upstream reservoir interception capacity. It further made management of the winter surplus water downstream of SDB more controversial. Due to this, the water-food-ecology conflict between downstream countries may escalate and turn into a long-term chronic problem. Reducing water inflow to depressions and improving the planting structure prove beneficial to the Aral Sea ecology and this effect of SDB is more significant. The construction of reservoirs on the Panj river of the upstream ADB should be cautious to avoid an intense water-energy conflict as SDB. It is also necessary to promote the water-saving drip irrigation and to strengthen the cooperation.


2020 ◽  
Vol 36 (1) ◽  
pp. 11-24 ◽  
Author(s):  
Vikram Kumar ◽  
Sumit Sen

HighlightsSpring flows are the primary source of water for rural Himalayan communities.An attempt was made to understand the potential of spring discharge as an alternative irrigation source.Improved management of resources is vital to account for agricultural water use.Managing water resources is a collective endeavor for achieving water security.Abstract.With increasing population and restricted water and land resources, there is a growing concern for better planning of the available water and land resources. In the mountainous regions or mountains, there is limited land with uncertain water availability as the rainfall patterns pose a major threat to the livelihood of the people. Therefore, it becomes necessary to quantify and manage the available water resources in a sustainable way. People in the Himalayas are mainly dependent on the springs for drinking water, but not much attention has been dedicated to the development and conservation of these springs. A spring in the Tehri-Garhwal district of Uttarakhand state of India, has been continuously monitored to quantify the available water for domestic use and agriculture. In this study, an attempt is made to understand the potential of a spring for agricultural water use by evaluating the crop water requirement and potential improved strategies to increase the water productivity. Analysis proves that crop evapotranspiration is higher (946-1062 mm) for crops with extended duration (165-180 days) as compared to evapotranspiration (92.91 mm) of short duration (60 days) crops. The total water requirement for major crops in the area is 6411.35 mm and the monitored spring has the potential to supplement this water requirement. Adopting the system of rice intensification to increase the rice yield (by 49%), increases the water productivity. The sensitivity analysis of benefit to cost suggests that, an increase in the crop yield by 30% can increase the revenue in the study area by Rs.3687197, which is 217% more than the input costs. Therefore, it is essential to optimize the available water and area for irrigation to achieve the global water security for increasing population. Further, utilizing springs as potential irrigation sources will support rural community in meeting domestic water requirement and achieving environmental sustainability. Findings of this study will help in planning and implementing management strategies that are resilient in the face of future changes and improve the economic condition of farmers. Keywords: Crop evapotranspiration, Himalaya, Optimization, Sensitivity analysis, Spring.


2020 ◽  
Vol 15 (2) ◽  
pp. 136-147

For many decades, Uzbekistan has been one of the largest cotton producers in the world. The irrigation water needed for these high production levels has been delivered by the massive diversion of the Amu Darya and Syr Darya rivers, which naturally flowed into the Aral Sea. This diversion for agriculture was the main cause of the rapid decline of the Aral Sea, which is at only 10% of its original size today. The traditional method of irrigation, which relies on simple open canal systems, is highly inefficient for managing the region’s critical and limited water resource. It has been qualitatively estimated, for example, that irrigation water lost to evaporation and system inefficiencies is quite large. With the future availability of water at risk for agriculture in Central Asia, primarily due to the loss of glacial volume from global warming, along with declines in seasonal snowpack, it is clear that new approaches to water management are needed. Any serious efforts to restore the Aral Sea and its ecological services would also reduce supplies of irrigation water for Uzbekistan. While regional conflict over water is unlikely, it must be considered since Uzbekistan is a downstream country among several that rely on the Amu Darya and Syr Darya rivers for most of their water supplies. To insure against these risks to cotton production and the underlying economy, better irrigation technologies are needed across Uzbekistan. However, these technologies can be quite expensive, especially given that water is still nearly free. In this case study we explore the use of real options analysis (ROA) to look for optimal investment strategies in efficient irrigation technologies in light of variable climate and policy uncertainties.


2021 ◽  
Vol 25 (2) ◽  
pp. 901-925
Author(s):  
Haiyang Shi ◽  
Geping Luo ◽  
Hongwei Zheng ◽  
Chunbo Chen ◽  
Olaf Hellwich ◽  
...  

Abstract. The previous comparative studies on watersheds were mostly based on the comparison of dispersive characteristics, which lacked systemicity and causality. We proposed a causal structure-based framework for basin comparison based on the Bayesian network (BN) and focus on the basin-scale water–energy–food–ecology (WEFE) nexus. We applied it to the Syr Darya River basin (SDB) and the Amu Darya River basin (ADB), of which poor water management caused the Aral Sea disaster. The causality of the nexus was effectively compared and universality of this framework was discussed. In terms of changes in the nexus, the sensitive factor for the water supplied to the Aral Sea changed from the agricultural development during the Soviet Union period to the disputes in the WEFE nexus after the disintegration. The water–energy contradiction of the SDB is more severe than that of the ADB, partly due to the higher upstream reservoir interception capacity. It further made management of the winter surplus water downstream of the SDB more controversial. Due to this, the water–food–ecology conflict between downstream countries may escalate and turn into a long-term chronic problem. Reducing water inflow to depressions and improving the planting structure prove beneficial to the Aral Sea ecology, and this effect of the SDB is more significant. The construction of reservoirs on the Panj River of the upstream ADB should be cautious to avoid an intense water–energy conflict such as the SDB's. It is also necessary to promote the water-saving drip irrigation and to strengthen the cooperation.


Author(s):  
Renat Nazarov

The potential of water resources throughout Central Asia consists of water resources of two rivers-the Amu Darya and Syr Darya, the Aral sea basin, and is 117…123 km3 per year. Approximately half of these water resources, according to intergovernmental agreements with other Central Asian States, are used by the most populous Republic of Uzbekistan in the region, where the area of irrigated arable land today is 3296 thousand hectares. Of these, up to 1137 thousand hectares are allocated annually for grain crops, and about 1033 thousand hectares of irrigated arable land are allocated for cotton.


2012 ◽  
Vol 9 (11) ◽  
pp. 12691-12727 ◽  
Author(s):  
A. F. Lutz ◽  
W. W. Immerzeel ◽  
A. Gobiet ◽  
F. Pellicciotti ◽  
M. F. P. Bierkens

Abstract. Central Asian water resources largely depend on (glacier) melt water generated in the Pamir and Tien Shan mountain ranges, located in the basins of the Amu and Syr Darya rivers, important life lines in Central Asia and the prominent water source of the Aral Sea. To estimate future water availability in the region, it is thus necessary to project the future glacier extent and volume in the Amu and Syr Darya river basins. The aim of this study is to quantify the impact of uncertainty in climate change projections on the future glacier extent in the Amu and Syr Darya river basins. The latest climate change projections provided by the fifth Coupled Model Intercomparison Project (CMIP5) generated for the upcoming fifth assessment report of the Intergovernmental Panel on Climate Change (IPCC) are used to model future glacier extent in the Central Asian region for the two large river basins. The outcomes are compared to model results obtained with the climate change projections used for the fourth IPCC assessment (CMIP3). We use a regionalized glacier mass balance model to estimate changes in glacier extent as a function of glacier size and projections of temperature and precipitation. The model is developed for implementation in (large scale) hydrological models, when the spatial model resolution does not allow for modelling of individual glaciers and data scarcity is an issue. Both CMIP3 and CMIP5 model simulations point towards a strong decline in glacier extent in Central Asia. However, compared to the CMIP3 projections, the CMIP5 projections of future glacier extent in Central Asia provide a wider range of outcomes, mostly owing to greater variability in precipitation projections among the latest suite of climate models. These findings have great impact on projections of the timing and quantity of water availability in glacier melt dominated rivers in the region. Uncertainty about the size of the decline in glacier extent remains large, making estimates of future Central Asian glacier extent and downstream water availability uncertain.


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