Your search found 3 records
1 Tang, Y.; Zhang, F.; Engel, B. A.; Liu, X.; Yue, Q.; Guo, P. 2020. Grid-scale agricultural land and water management: a remote-sensing-based multiobjective approach. Journal of Cleaner Production, 265:121792. (Online first) [doi: https://doi.org/10.1016/j.jclepro.2020.121792]
Farmland ; Water management ; Remote sensing ; Irrigation water ; Sustainable agriculture ; Crop water use ; Water requirements ; Water use efficiency ; Water allocation ; Water productivity ; Water supply ; Virtual water ; Evapotranspiration ; Precipitation ; Ecosystem services ; Economic aspects / China / Heihe River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H049765)
(4.19 MB)
This paper developed a remote-sensing-based multiobjective (RSM) approach to formulate sustainable agricultural land and water resources management strategies at a grid scale. To meet the spatial resolution and accuracy need of agricultural management, downscaled precipitation data sets were obtained with the help of global precipitation measurement (GPM) data and other spatial information. Spatial crop water requirement information were obtained via the combination use of the Penman-Monteith method, remote sensing information (MOD16/PET) and virtual water theory. Through integrating these spatial data and considering the impact of different spatial environments on crop growth, a grid-based integer multiobjective programming (GIMP) model was developed to determine best suitable crop planting types at all grids. GIMP can simultaneously consider several conflicting objectives: crop growth suitability, crop spatial water requirements, and ecosystem service value. Further, GIMP results were inputted into a grid-based nonlinear fractional multiobjective programming (GNFMP) model with three objectives: maximize economic benefits, maximize water productivity, and minimize blue water utilization, to optimize irrigation-water allocation. To verify the validity of the proposed approach, a real-world application in the middle reaches of Heihe River Basin, northwest China was conducted. Results show that the proposed method can improve the ecosystem service value by 0.36 × 108 CNY, the economic benefit by 21.85%, the irrigation-water productivity by 25.92%, and reduce blue water utilization rate by 24.32% comparing with status quo.
2 Qiao, X.; Schmidt, A. H.; Xu, Y.; Zhang, H.; Chen, X.; Xiang, R.; Tang, Y.; Wang, W. 2021. Surface water quality in the upstream-most megacity of the Yangtze River Basin (Chengdu): 2000–2019 trends, the COVID-19 lockdown effects, and water governance implications. Environmental and Sustainability Indicators, 10:100118. [doi: https://doi.org/10.1016/j.indic.2021.100118]
Surface water ; Water quality ; Water management ; River basins ; Water governance ; COVID-19 ; Urban areas ; Water pollution ; Faecal coliforms ; Nitrogen ; Phosphorus ; Economic growth ; Downstream ; Monitoring / China / Yangtze River Basin / Chengdu / Sichuan Basin / Min Basin / Tuo Basin
(Location: IWMI HQ Call no: e-copy only Record No: H050539)
https://www.sciencedirect.com/science/article/pii/S2665972721000192/pdfft?md5=019ccf161166ca9e1fe600744729056a&pid=1-s2.0-S2665972721000192-main.pdf
https://vlibrary.iwmi.org/pdf/H050539.pdf
https://vlibrary.iwmi.org/pdf/H050539.pdf
(2.99 MB) (2.99 MB)
Water is essential for a sustainable economic prosperity, but rapid economic growth and intensive agricultural activities usually cause water pollution. The middle and lower reaches of China’s Yangtze River Basin were urbanized and industrialized much earlier than the upper reach and have been suffering from water pollution. In the past two decades, economic growth accelerated in the upper reach due to several national economic initiatives. Based on analyzing water quality changes from 2000 to 2019 and during the COVID-19 lockdown in 2020 for Chengdu in the upper reach, we hope to provide some water governance suggestions. In 2019, water at 66% of 93 sites in Chengdu did not achieve the national III standards using measurements of 23 water quality parameters. The top two pollutants were total nitrogen (TN) and fecal coliform (FC). From 2000 to 2019, water quality was not significantly improved at the non-background sites of Chengdu's Min Basin, and the pollution in this basin was mainly from local pollutants release. During the same period, water quality deteriorated in Chengdu’s Tuo Basin, where pollution was the result of pollutant discharges in Chengdu in addition to inter-city pollutant transport. During the COVID-19 lockdown, water quality generally improved in the Min Basin but not in the Tuo Basin. A further investigation on which pollution sources were shut down or not during the lockdown can help make pollution reduction targets. Based on the results, we provide suggestions to strengthen inter-jurisdictional and inter-institutional cooperation, water quality monitoring and evaluation, and ecological engineering application.
3 Xiao, H.; Tang, Y.; Li, H.; Zhang, L.; Ngo-Duc, T.; Chen, D.; Tang, Q. 2021. Saltwater intrusion into groundwater systems in the Mekong Delta and links to global change. Advances in Climate Change Research, 12(3):342-352. [doi: https://doi.org/10.1016/j.accre.2021.04.005]
Saltwater intrusion ; Groundwater ; Climate change ; Human activity ; Surface water ; Freshwater ; Salinity ; Sea level ; Precipitation ; Pumping ; Wells ; Deltas ; Cyclones / South East Asia / Vietnam / Mekong Delta / Mekong River Basin / Tibetan Plateau
(Location: IWMI HQ Call no: e-copy only Record No: H050591)
https://www.sciencedirect.com/science/article/pii/S1674927821000708/pdfft?md5=84b9faeb3898035203d1bb3899396452&pid=1-s2.0-S1674927821000708-main.pdf
https://vlibrary.iwmi.org/pdf/H050591.pdf
https://vlibrary.iwmi.org/pdf/H050591.pdf
(2.65 MB) (2.65 MB)
In recent decades, changes in temperature, wind, and rainfall patterns of Southeast Asia induced by climate warming in the Tibetan Plateau result in many environmental changes that have serious impacts on the lower reach of the Mekong River basin, a region already battling severe water-related environmental problems such as pollution, saltwater intrusion, and intensified flooding. In the densely populated Mekong Delta located at the mouth of the Mekong River basin in southern Vietnam, the hydrogeological systems have been transformed from an almost undisturbed to a human-impacted state and saltwater intrusion into surface water and groundwater systems has grown to be a detrimental issue recently, seriously threatening freshwater supply and degrading the eco-environment. In this article, the impacts of human activities and climate change (e.g., groundwater over-exploitation, relative sea-level rise, storm surge, changing precipitation and temperature regimes, uncontrolled drainage canals, operation of hydropower dams, and rapid development of aquaculture) on saltwater intrusion into groundwater systems in the Mekong Delta are briefly reviewed. Based on current status of research findings regarding saltwater intrusion and the subsequent groundwater quality degradation under the impacts of human activities and climate change, major knowledge gaps and challenges are identified and discussed, including thickness and permeability of the silt and clay aquitard, present-day highly heterogeneous 3D distribution of saline groundwater zones, dynamic variation of saltwater/freshwater transition zone, and the most effective and economical control measure. To bridge these gaps, future work should: 1) apply environmental isotope techniques in combination with borehole tests to gain detailed hydrogeological information regarding spatial variation of permeability and thickness of the silt and clay aquitard; 2) intensify regular groundwater monitoring and collect as much groundwater samples from multiple hydro-stratigraphic units at different depths as possible to visualize the present-day highly heterogeneous 3D distribution of saline groundwater; 3) develop a series of variable-density coupled groundwater flow and salt transport models representing various scenarios of human activities and climate change for predicting future extent of saltwater intrusion; and 4) identify the dominant factor causing saltwater intrusion and determine the most effective and economical engineering technique to address saltwater intrusion problems in the Mekong Delta.
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