F. Maina, Alan Michael Rhoades, E. Siirila‐Woodburn, P. Dennedy‐Frank
Abstract. In California, it is essential to understand the evolution of water resources in response to a changing climate to sustain its economy and agriculture and build resilient communities. Although extreme conditions have characterized the historical hydroclimate of California, climate change will likely intensify hydroclimatic extremes by the End of Century (EoC). However, few studies have investigated the impacts of EoC extremes on watershed hydrology. We use cutting-edge global climate and integrated hydrologic models to simulate EoC extremes and their effects on the water-energy balance. We assess the impacts of projected driest, median, and wettest water years under a Representative Concentration Pathway (RCP) 8.5 on the hydrodynamics of the Cosumnes river basin. High temperatures (> 2.5 °C) and precipitation (> 38 %) will characterize the EoC extreme water years compared to their historical counterparts. Also, precipitation, mostly in the form of rain, is projected to fall earlier. This change reduces snowpack by more than 90 %, increases peak surface water and groundwater storages up to 75 % and 23 %, respectively, and makes these peak storages occur earlier in the year. Because EoC temperatures and soil moisture are high, both potential and actual evapotranspiration (ET) increase. The latter, along with the lack of snowmelt in the warm EoC, cause surface water and groundwater storages to significantly decrease in summer, with groundwater showing the highest rates of decrease. Besides, the changes in the precipitation phase lead the lower-order streams to dry out in EoC summer whereas the mainstream experiences an increase in storage.
{"title":"Projecting the impacts of end of century climate extremes on the hydrology in California","authors":"F. Maina, Alan Michael Rhoades, E. Siirila‐Woodburn, P. Dennedy‐Frank","doi":"10.5194/hess-2021-472","DOIUrl":"https://doi.org/10.5194/hess-2021-472","url":null,"abstract":"Abstract. In California, it is essential to understand the evolution of water resources in response to a changing climate to sustain its economy and agriculture and build resilient communities. Although extreme conditions have characterized the historical hydroclimate of California, climate change will likely intensify hydroclimatic extremes by the End of Century (EoC). However, few studies have investigated the impacts of EoC extremes on watershed hydrology. We use cutting-edge global climate and integrated hydrologic models to simulate EoC extremes and their effects on the water-energy balance. We assess the impacts of projected driest, median, and wettest water years under a Representative Concentration Pathway (RCP) 8.5 on the hydrodynamics of the Cosumnes river basin. High temperatures (> 2.5 °C) and precipitation (> 38 %) will characterize the EoC extreme water years compared to their historical counterparts. Also, precipitation, mostly in the form of rain, is projected to fall earlier. This change reduces snowpack by more than 90 %, increases peak surface water and groundwater storages up to 75 % and 23 %, respectively, and makes these peak storages occur earlier in the year. Because EoC temperatures and soil moisture are high, both potential and actual evapotranspiration (ET) increase. The latter, along with the lack of snowmelt in the warm EoC, cause surface water and groundwater storages to significantly decrease in summer, with groundwater showing the highest rates of decrease. Besides, the changes in the precipitation phase lead the lower-order streams to dry out in EoC summer whereas the mainstream experiences an increase in storage.\u0000","PeriodicalId":341866,"journal":{"name":"Hydrology and Earth System Sciences Discussions","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130458119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sarah A. Bourke, M. Shanafield, P. Hedley, S. Chapman, S. Dogramaci
Abstract. Persistent surface water pools along non-perennial rivers represent an important water resource for plants, animals, and humans. While ecological studies of these features are not uncommon, these are rarely accompanied by a rigorous examination of the hydrological and hydrogeological characteristics that create or support the pools. Here we present an overarching framework for understanding the hydrology of persistent pools. We identified perched water, alluvial through flow and groundwater discharge as mechanisms that control the persistence of pools along river channels. Groundwater discharge is further categorized into that controlled by a geological contact or barrier (not previously described in the literature), and discharge controlled by topography. Emphasis is put on clearly defining through-flow pools and the different drivers of groundwater discharge, as this is lacking in the literature. A suite of diagnostic tools (including geological mapping, hydraulic data and hydrochemical surveys) is generally required to identify the mechanism(s) supporting persistent pools. Water fluxes to pools supported by through-flow alluvial and bedrock aquifers can vary seasonally and resolving these inputs is generally non-trivial. This framework allows the evaluation of the susceptibility of persistent pools along river channels to changes in climate or groundwater withdrawals. Finally, we present three case studies from the Hamersley Basin of north-western Australia to demonstrate how the available diagnostic tools can be applied within the proposed framework.
{"title":"A hydrological framework for persistent river pools","authors":"Sarah A. Bourke, M. Shanafield, P. Hedley, S. Chapman, S. Dogramaci","doi":"10.5194/hess-2021-461","DOIUrl":"https://doi.org/10.5194/hess-2021-461","url":null,"abstract":"Abstract. Persistent surface water pools along non-perennial rivers represent an important water resource for plants, animals, and humans. While ecological studies of these features are not uncommon, these are rarely accompanied by a rigorous examination of the hydrological and hydrogeological characteristics that create or support the pools. Here we present an overarching framework for understanding the hydrology of persistent pools. We identified perched water, alluvial through flow and groundwater discharge as mechanisms that control the persistence of pools along river channels. Groundwater discharge is further categorized into that controlled by a geological contact or barrier (not previously described in the literature), and discharge controlled by topography. Emphasis is put on clearly defining through-flow pools and the different drivers of groundwater discharge, as this is lacking in the literature. A suite of diagnostic tools (including geological mapping, hydraulic data and hydrochemical surveys) is generally required to identify the mechanism(s) supporting persistent pools. Water fluxes to pools supported by through-flow alluvial and bedrock aquifers can vary seasonally and resolving these inputs is generally non-trivial. This framework allows the evaluation of the susceptibility of persistent pools along river channels to changes in climate or groundwater withdrawals. Finally, we present three case studies from the Hamersley Basin of north-western Australia to demonstrate how the available diagnostic tools can be applied within the proposed framework.\u0000","PeriodicalId":341866,"journal":{"name":"Hydrology and Earth System Sciences Discussions","volume":"48 9","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133658406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract. Glaciers continuously affected by climate change are of great concern; their supply and runoff variation tendency under the pressure of increasing populations, especially in dryland areas, should be studied. Due to the difficulty of observing glacier runoff, little attention has been given to establishing high-resolution and long-term series datasets established for glacial runoff. Using the latest dataset using digital elevation models (DEMs) to obtain regional individual glacier mass balance, simulating the spatiotemporal regime of glacier runoff in oases that support almost the entire income in the dryland areas of China (DAC) could be possible. The simulations quantitatively assess glacier runoff, including meltwater runoff and delayed runoff, in each basin of the DAC at a spatial resolution of 100 m from 1961 to 2015, classify glaciers according to the potential climatic risks based on the prediction results. The total glacier runoff in the DAC is (98.52 ± 67.37) × 108 m3, in which the meltwater runoff is (63.43 ± 42.17) × 108 m3, accounting for 64.38 %. Most basins had continuously increasing tendencies of different magnitudes from 1961 to 2015, except for the Shiyang River basin, which reached its peak in approximately 2000. Glacier runoff nurtured nearly 143,939.24 km2 of oasis agricultural areas (OAA) until 2015, while 19 regions with a total population of 14 million were built alongside the oases, where glacier runoff occupies an important place in agricultural, industrial and municipal water consumption. Therefore, providing a long time series of glacier runoff for different river basins is of great significance to the sustainable development of the oasis economy in the arid zones.
{"title":"The Spatiotemporal Regime of Glacier Runoff in Oases Indicates the Potential Climatic Risk in Dryland Areas of China","authors":"Xue Leng, Xiaoming Feng, B. Fu, Yu Zhang","doi":"10.5194/hess-2021-377","DOIUrl":"https://doi.org/10.5194/hess-2021-377","url":null,"abstract":"Abstract. Glaciers continuously affected by climate change are of great concern; their supply and runoff variation tendency under the pressure of increasing populations, especially in dryland areas, should be studied. Due to the difficulty of observing glacier runoff, little attention has been given to establishing high-resolution and long-term series datasets established for glacial runoff. Using the latest dataset using digital elevation models (DEMs) to obtain regional individual glacier mass balance, simulating the spatiotemporal regime of glacier runoff in oases that support almost the entire income in the dryland areas of China (DAC) could be possible. The simulations quantitatively assess glacier runoff, including meltwater runoff and delayed runoff, in each basin of the DAC at a spatial resolution of 100 m from 1961 to 2015, classify glaciers according to the potential climatic risks based on the prediction results. The total glacier runoff in the DAC is (98.52 ± 67.37) × 108 m3, in which the meltwater runoff is (63.43 ± 42.17) × 108 m3, accounting for 64.38 %. Most basins had continuously increasing tendencies of different magnitudes from 1961 to 2015, except for the Shiyang River basin, which reached its peak in approximately 2000. Glacier runoff nurtured nearly 143,939.24 km2 of oasis agricultural areas (OAA) until 2015, while 19 regions with a total population of 14 million were built alongside the oases, where glacier runoff occupies an important place in agricultural, industrial and municipal water consumption. Therefore, providing a long time series of glacier runoff for different river basins is of great significance to the sustainable development of the oasis economy in the arid zones.\u0000","PeriodicalId":341866,"journal":{"name":"Hydrology and Earth System Sciences Discussions","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114893702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. Benoit, L. Sichoix, A. Nugent, M. Lucas, T. Giambelluca
Abstract. Stochastic rainfall generators are probabilistic models of rainfall space-time behavior. During parameterization and calibration, they allow the identification and quantification of the main modes of rainfall variability. Hence, stochastic rainfall models can be regarded as probabilistic conceptual models of rainfall dynamics. As with most conceptual models in Earth Sciences, the performance of stochastic rainfall models strongly relies on their adequacy in representing the rain process at hand. On tropical islands with high elevation topography, orographic rain enhancement challenges most existing stochastic models because it creates localized rains with strong spatial gradients, which break down the stationarity of rain statistics. To allow for stochastic rainfall modeling on tropical islands, despite non-stationarity, we propose a new stochastic daily rainfall generator specifically for areas with significant orographic effects. Our model relies on a preliminary classification of daily rain patterns into rain types based on rainfall space and intensity statistics, and sheds new light on rainfall variability at the island scale. Within each rain type, the spatial distribution of rainfall through the island is modeled following a meta-Gaussian approach combining empirical spatial copulas and a Gamma transform function, which allows us to generate realistic daily rain fields. When applied to the stochastic simulation of rainfall on the islands of O‘ahu (Hawai‘i, United States of America) and Tahiti (French Polynesia) in the tropical Pacific, the proposed model demonstrates good skills in jointly simulating site specific and island scale rain statistics. Hence, it provides a new tool for stochastic impact studies in tropical islands, in particular for watershed water resources management and downscaling of future precipitation projections.
{"title":"Stochastic daily rainfall generation on tropical islands with complex topography","authors":"L. Benoit, L. Sichoix, A. Nugent, M. Lucas, T. Giambelluca","doi":"10.5194/hess-2021-453","DOIUrl":"https://doi.org/10.5194/hess-2021-453","url":null,"abstract":"Abstract. Stochastic rainfall generators are probabilistic models of rainfall space-time behavior. During parameterization and calibration, they allow the identification and quantification of the main modes of rainfall variability. Hence, stochastic rainfall models can be regarded as probabilistic conceptual models of rainfall dynamics. As with most conceptual models in Earth Sciences, the performance of stochastic rainfall models strongly relies on their adequacy in representing the rain process at hand. On tropical islands with high elevation topography, orographic rain enhancement challenges most existing stochastic models because it creates localized rains with strong spatial gradients, which break down the stationarity of rain statistics. To allow for stochastic rainfall modeling on tropical islands, despite non-stationarity, we propose a new stochastic daily rainfall generator specifically for areas with significant orographic effects. Our model relies on a preliminary classification of daily rain patterns into rain types based on rainfall space and intensity statistics, and sheds new light on rainfall variability at the island scale. Within each rain type, the spatial distribution of rainfall through the island is modeled following a meta-Gaussian approach combining empirical spatial copulas and a Gamma transform function, which allows us to generate realistic daily rain fields. When applied to the stochastic simulation of rainfall on the islands of O‘ahu (Hawai‘i, United States of America) and Tahiti (French Polynesia) in the tropical Pacific, the proposed model demonstrates good skills in jointly simulating site specific and island scale rain statistics. Hence, it provides a new tool for stochastic impact studies in tropical islands, in particular for watershed water resources management and downscaling of future precipitation projections.\u0000","PeriodicalId":341866,"journal":{"name":"Hydrology and Earth System Sciences Discussions","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115407765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abdul Wahab Siyal, Winnie Gerbens-Leenes, M. Aldaya, R. Naz
Abstract. The water footprint (WF) concept is a generally accepted tool introduced in 2002. Many studies applied water footprinting, indicating impacts of human consumption on freshwater, especially from agriculture. Although the WF includes supply chains, presently it excludes irrigation supply chains and non-beneficial evapotranspiration, and calculations for agriculture start from crop water requirements. We present a conceptual framework distinguishing between traditional (net) WFs and proposed gross WFs, defined as the sum of net WFs and irrigation supply chain related blue WFs and as the sum of green WFs and green WFs of weeds. Many water management studies focused on blue water supply efficiency, assessing water losses in supply chain links. The WF concept, however, excludes water flows to stocks where water remains available and recoverable, e.g. to usable groundwater, in contrast to many water management approaches. Also, many studies focused on irrigation technology improvement to save water. We argue that not only irrigation technology should be considered, but whole water supply chains, also distinguishing between surface and groundwater, to improve efficient blue water use in agriculture. This framework is applied to the Pakistani part of the Indus basin that includes the largest man-made irrigation network in the world. The gross blue WF is 1.6 times the net blue WF leading to a K value (ratio of gross and net blue WF) of 0.6. Surface water losses vary between 45 and 49 %, groundwater losses between 18 and 21 %. Presently, efficient irrigation receives much attention. However, it is important to take irrigation supply chains into account to improve irrigation efficiency. Earlier WF studies showing water scarcity in many regions underestimate agricultural water consumption if supply chains are neglected. More water efficient agriculture should take supply chain losses into account probably requiring water management adaptations, which is more a policy than an agriculture task.
{"title":"A conceptual framework for including irrigation supply chains in the water footprint concept: gross and net blue and green water footprints in agriculture in Pakistan","authors":"Abdul Wahab Siyal, Winnie Gerbens-Leenes, M. Aldaya, R. Naz","doi":"10.5194/hess-2021-388","DOIUrl":"https://doi.org/10.5194/hess-2021-388","url":null,"abstract":"Abstract. The water footprint (WF) concept is a generally accepted tool introduced in 2002. Many studies applied water footprinting, indicating impacts of human consumption on freshwater, especially from agriculture. Although the WF includes supply chains, presently it excludes irrigation supply chains and non-beneficial evapotranspiration, and calculations for agriculture start from crop water requirements. We present a conceptual framework distinguishing between traditional (net) WFs and proposed gross WFs, defined as the sum of net WFs and irrigation supply chain related blue WFs and as the sum of green WFs and green WFs of weeds. Many water management studies focused on blue water supply efficiency, assessing water losses in supply chain links. The WF concept, however, excludes water flows to stocks where water remains available and recoverable, e.g. to usable groundwater, in contrast to many water management approaches. Also, many studies focused on irrigation technology improvement to save water. We argue that not only irrigation technology should be considered, but whole water supply chains, also distinguishing between surface and groundwater, to improve efficient blue water use in agriculture. This framework is applied to the Pakistani part of the Indus basin that includes the largest man-made irrigation network in the world. The gross blue WF is 1.6 times the net blue WF leading to a K value (ratio of gross and net blue WF) of 0.6. Surface water losses vary between 45 and 49 %, groundwater losses between 18 and 21 %. Presently, efficient irrigation receives much attention. However, it is important to take irrigation supply chains into account to improve irrigation efficiency. Earlier WF studies showing water scarcity in many regions underestimate agricultural water consumption if supply chains are neglected. More water efficient agriculture should take supply chain losses into account probably requiring water management adaptations, which is more a policy than an agriculture task.\u0000","PeriodicalId":341866,"journal":{"name":"Hydrology and Earth System Sciences Discussions","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114965273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract. The travel time distribution (TTD) is a lumped representation of groundwater discharge and solute export responding to rainfall. It reflects the mixing process of water parcels and solute particles of different ages and characterizes reactive transport progress in hillslope aquifers. As a result of the mixing process, groundwater leaving the system at a certain time is an integration of multiple water parcels of different ages from different historical rainfall events. Under nonstationary rainfall input condition, the TTD varies with transit groundwater flow, leading to the time-variant TTD. Most methods for estimating time-variant TTD are constrained by requiring either the long-term continuous hydrogeochemical data or the intensive computations. This study introduces a multi-fidelity model to overcome these limitations and evaluate time-variant TTD numerically. In this multi-fidelity model, groundwater age distribution model is taken as the high-fidelity model, and particle tracking model without random walk is taken as the low-fidelity model. Non-parametric regression by non-linear Gaussian process is applied to correlate the two models and then build up the multi-fidelity model. The advantage of the multi-fidelity model is that it combines the accuracy of high-fidelity model and the computational efficiency of low-fidelity model. Moreover, in groundwater and solute transport model with low P'eclet number, as the spatial scale of the model increases, the number of particles required for multi-fidelity model is reduced significantly compared to random walk particle tracking model. The correlation between high and low-fidelity models is demonstrated in a one dimensional pulse injection case. In a two dimensional hypothetical model, convergence analysis indicates that the multi-fidelity model converges well when increasing the number of high-fidelity models. Error analysis also confirms the good performance of the multi-fidelity model.
{"title":"Quantifying time-variant travel time distribution by multi-fidelity model in hillslope under nonstationary hydrologic conditions","authors":"Rong Mao, J. Jiao, Xin Luo, Hailong Li","doi":"10.5194/hess-2021-430","DOIUrl":"https://doi.org/10.5194/hess-2021-430","url":null,"abstract":"Abstract. The travel time distribution (TTD) is a lumped representation of groundwater discharge and solute export responding to rainfall. It reflects the mixing process of water parcels and solute particles of different ages and characterizes reactive transport progress in hillslope aquifers. As a result of the mixing process, groundwater leaving the system at a certain time is an integration of multiple water parcels of different ages from different historical rainfall events. Under nonstationary rainfall input condition, the TTD varies with transit groundwater flow, leading to the time-variant TTD. Most methods for estimating time-variant TTD are constrained by requiring either the long-term continuous hydrogeochemical data or the intensive computations. This study introduces a multi-fidelity model to overcome these limitations and evaluate time-variant TTD numerically. In this multi-fidelity model, groundwater age distribution model is taken as the high-fidelity model, and particle tracking model without random walk is taken as the low-fidelity model. Non-parametric regression by non-linear Gaussian process is applied to correlate the two models and then build up the multi-fidelity model. The advantage of the multi-fidelity model is that it combines the accuracy of high-fidelity model and the computational efficiency of low-fidelity model. Moreover, in groundwater and solute transport model with low P'eclet number, as the spatial scale of the model increases, the number of particles required for multi-fidelity model is reduced significantly compared to random walk particle tracking model. The correlation between high and low-fidelity models is demonstrated in a one dimensional pulse injection case. In a two dimensional hypothetical model, convergence analysis indicates that the multi-fidelity model converges well when increasing the number of high-fidelity models. Error analysis also confirms the good performance of the multi-fidelity model.\u0000","PeriodicalId":341866,"journal":{"name":"Hydrology and Earth System Sciences Discussions","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124408270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jonatan Godinez Madrigal, N. van Cauwenbergh, Jaime Hoogesteger, Pamela Claure Gutierrez, P. van der Zaag
Abstract. Managers of urban water systems constantly make decisions to guarantee water services by overcoming problems related to supply-demand imbalances. A preferred strategy has been supply augmentation through hydraulic infrastructure development. However, despite considerable investments, many systems seem to be trapped in lackluster development pathways making some problems seem like an enduring, almost stubborn, characteristic of the systems: over-exploitation and pollution of water sources, distribution networks overwhelmed by leakages and non-revenue water, and unequal water insecurity. Because of these strategies and persistent problems, water conflicts have emerged, whereby social actors oppose these strategies and propose alternative technologies and strategies. This can create development pathways crossroads of the urban water system. To study this development pathway crossroads, we selected the Zapotillo conflict in Mexico where a large supply augmentation project for two cities experiencing water shortages is at stake. The paper concludes that urban water systems that are engaged in a trajectory characterized by supply-side strategies may experience a temporal relief but neglect equally pressing issues that stymie the human right to water in the medium and long run. However, there is not a straightforward, self-evident development pathway to choose from, only a range of multiple alternatives with multiple trade-offs that need to be thoroughly discussed and negotiated between the stakeholders. We argue that this development pathway crossroads can cross-fertilize technical disciplines such as socio-hydrology, and social disciplines based on hydrosocial studies, which both ambition to make their knowledge actionable and relevant.
{"title":"The limits to large scale supply augmentation: Exploring the crossroads of conflicting urban water system development pathways","authors":"Jonatan Godinez Madrigal, N. van Cauwenbergh, Jaime Hoogesteger, Pamela Claure Gutierrez, P. van der Zaag","doi":"10.5194/hess-2021-431","DOIUrl":"https://doi.org/10.5194/hess-2021-431","url":null,"abstract":"Abstract. Managers of urban water systems constantly make decisions to guarantee water services by overcoming problems related to supply-demand imbalances. A preferred strategy has been supply augmentation through hydraulic infrastructure development. However, despite considerable investments, many systems seem to be trapped in lackluster development pathways making some problems seem like an enduring, almost stubborn, characteristic of the systems: over-exploitation and pollution of water sources, distribution networks overwhelmed by leakages and non-revenue water, and unequal water insecurity. Because of these strategies and persistent problems, water conflicts have emerged, whereby social actors oppose these strategies and propose alternative technologies and strategies. This can create development pathways crossroads of the urban water system. To study this development pathway crossroads, we selected the Zapotillo conflict in Mexico where a large supply augmentation project for two cities experiencing water shortages is at stake. The paper concludes that urban water systems that are engaged in a trajectory characterized by supply-side strategies may experience a temporal relief but neglect equally pressing issues that stymie the human right to water in the medium and long run. However, there is not a straightforward, self-evident development pathway to choose from, only a range of multiple alternatives with multiple trade-offs that need to be thoroughly discussed and negotiated between the stakeholders. We argue that this development pathway crossroads can cross-fertilize technical disciplines such as socio-hydrology, and social disciplines based on hydrosocial studies, which both ambition to make their knowledge actionable and relevant.\u0000","PeriodicalId":341866,"journal":{"name":"Hydrology and Earth System Sciences Discussions","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134642090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Saúl Arciniega-Esparza, C. Birkel, Andrés Chavarría-Palma, B. Arheimer, A. Breña-Naranjo
Abstract. Streamflow simulation across the tropics is limited by the lack of data to calibrate and validate large-scale hydrological models. Here, we applied the process-based, conceptual HYPE (Hydrological Predictions for the Environment) model to quantitively assess Costa Rica’s water resources at a national scale. Data scarcity was compensated using adjusted global topography and remotely-sensed climate products to force, calibrate, and independently evaluate the model. We used a global temperature product and bias-corrected precipitation from CHIRPS (Climate Hazards Group InfraRed Precipitation with Station data) as model forcings. Daily streamflow from 13 gauges for the period 1990–2003 and monthly MODIS (Moderate Resolution Imaging Spectroradiometer) potential evapotranspiration (PET) and actual evapotranspiration (AET) for the period 2000–2014 were used to calibrate and evaluate the model applying four different model configurations. The calibration consisted in step-wise parameter constraints preserving the best parameter sets from previous simulations in an attempt to balance the variable data availability and time periods. The model configurations were independently evaluated using hydrological signatures such as the baseflow index, runoff coefficient, and aridity index, among others. Results suggested that a two-step calibration using monthly and daily streamflow was a better option instead of calibrating only with daily streamflow. Additionally, including PET and AET in the calibration improved the simulated water balance and better matched hydrological signatures. Thus, the constrained parameter uncertainty increased the confidence in the simulation results. Such a large-scale hydrological model has the potential to be used operationally across the humid tropics informing decision making at relatively high spatial and temporal resolution.
摘要由于缺乏校准和验证大尺度水文模型的数据，热带地区的径流模拟受到限制。在这里，我们应用基于过程的概念HYPE(环境水文预测)模型在全国范围内定量评估哥斯达黎加的水资源。利用调整后的全球地形和遥感气候产品来强制、校准和独立评估模型，补偿了数据的缺乏。我们使用全球温度产品和CHIRPS (Climate Hazards Group InfraRed precipitation with Station data)的偏置校正降水作为模式强迫。利用1990-2003年期间13个测量站的日流量和2000-2014年期间MODIS(中分辨率成像光谱仪)每月的潜在蒸散发(PET)和实际蒸散发(AET)对模型进行了校准和评估，采用了4种不同的模式配置。校准包括逐步参数约束，保留以前模拟的最佳参数集，试图平衡可变数据可用性和时间段。模型配置使用水文特征(如基流指数、径流系数和干旱指数等)进行独立评估。结果表明，使用月流量和日流量进行两步校准比仅使用日流量进行校准更好。此外，在校正中加入PET和AET可以改善模拟水平衡，更好地匹配水文特征。因此，约束参数的不确定性增加了仿真结果的置信度。这种大尺度水文模型有可能在整个潮湿热带地区以相对较高的空间和时间分辨率为决策提供信息。
{"title":"Remote sensing-aided large-scale rainfall-runoff modelling in the humid tropics","authors":"Saúl Arciniega-Esparza, C. Birkel, Andrés Chavarría-Palma, B. Arheimer, A. Breña-Naranjo","doi":"10.5194/hess-2021-428","DOIUrl":"https://doi.org/10.5194/hess-2021-428","url":null,"abstract":"Abstract. Streamflow simulation across the tropics is limited by the lack of data to calibrate and validate large-scale hydrological models. Here, we applied the process-based, conceptual HYPE (Hydrological Predictions for the Environment) model to quantitively assess Costa Rica’s water resources at a national scale. Data scarcity was compensated using adjusted global topography and remotely-sensed climate products to force, calibrate, and independently evaluate the model. We used a global temperature product and bias-corrected precipitation from CHIRPS (Climate Hazards Group InfraRed Precipitation with Station data) as model forcings. Daily streamflow from 13 gauges for the period 1990–2003 and monthly MODIS (Moderate Resolution Imaging Spectroradiometer) potential evapotranspiration (PET) and actual evapotranspiration (AET) for the period 2000–2014 were used to calibrate and evaluate the model applying four different model configurations. The calibration consisted in step-wise parameter constraints preserving the best parameter sets from previous simulations in an attempt to balance the variable data availability and time periods. The model configurations were independently evaluated using hydrological signatures such as the baseflow index, runoff coefficient, and aridity index, among others. Results suggested that a two-step calibration using monthly and daily streamflow was a better option instead of calibrating only with daily streamflow. Additionally, including PET and AET in the calibration improved the simulated water balance and better matched hydrological signatures. Thus, the constrained parameter uncertainty increased the confidence in the simulation results. Such a large-scale hydrological model has the potential to be used operationally across the humid tropics informing decision making at relatively high spatial and temporal resolution.\u0000","PeriodicalId":341866,"journal":{"name":"Hydrology and Earth System Sciences Discussions","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121899323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vincent Pons, R. Benestad, E. Sivertsen, T. Muthanna, J. Bertrand-Krajewski
Abstract. A strategy to simulate rainfall by the means of different Multiplicative random Cascades (MRC) was developed to evaluate their applicability to produce inputs for green roof infrastructures models taking into account climate change. The MRC reproduce a (multi)fractal distribution of precipitation through an iterative and multiplicative random process. The initial model was improved with a temperature dependency and an additional function to improve its capability to reproduce the temporal structure of rainfall. The structure of the models with depth and temperature dependency was found to be applicable in eight locations studied across Norway (N) and France (F). The resulting time-series from both reference period and projection based on RCP 8.5 were applied to two green roofs (GR) with different properties. The different models lead to a slight change in the performance of GR, but this was not significant compared to the range of outcomes due to ensemble uncertainty in climate modelling and the stochastic uncertainty due to nature of the process. The moderating effect of the green infrastructure was found to decrease in most of the Norwegian cities, especially Bergen (N), while increasing in Lyon (F).
{"title":"Temporal downscaling of precipitation time-series projections to forecast green roofs future detention performance","authors":"Vincent Pons, R. Benestad, E. Sivertsen, T. Muthanna, J. Bertrand-Krajewski","doi":"10.5194/hess-2021-381","DOIUrl":"https://doi.org/10.5194/hess-2021-381","url":null,"abstract":"Abstract. A strategy to simulate rainfall by the means of different Multiplicative random Cascades (MRC) was developed to evaluate their applicability to produce inputs for green roof infrastructures models taking into account climate change. The MRC reproduce a (multi)fractal distribution of precipitation through an iterative and multiplicative random process. The initial model was improved with a temperature dependency and an additional function to improve its capability to reproduce the temporal structure of rainfall. The structure of the models with depth and temperature dependency was found to be applicable in eight locations studied across Norway (N) and France (F). The resulting time-series from both reference period and projection based on RCP 8.5 were applied to two green roofs (GR) with different properties. The different models lead to a slight change in the performance of GR, but this was not significant compared to the range of outcomes due to ensemble uncertainty in climate modelling and the stochastic uncertainty due to nature of the process. The moderating effect of the green infrastructure was found to decrease in most of the Norwegian cities, especially Bergen (N), while increasing in Lyon (F).\u0000","PeriodicalId":341866,"journal":{"name":"Hydrology and Earth System Sciences Discussions","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134124707","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract. Despite recent developments in modelling global soil erosion by water, to date no substantial progress has been made towards more dynamic inter- and intra-annual assessments. In this regard, the main challenge is still represented by the limited availability of high temporal resolution rainfall data needed to estimate rainstorms rainfall erosivity. As this data scarcity is likely to characterize the upcoming years, the suitability of alternative approaches to estimate global rainfall erosivity using satellite-based rainfall data was explored. For this purpose, the high spatial and temporal resolution global precipitation estimates obtained with the NOAA CDR Climate Prediction Center MORPHing technique (CMORPH) were used. Alternatively, the erosivity density (ED) concept was used to estimate global rainfall erosivity as well. The obtained global estimates of rainfall erosivity were validated against the pluviograph data included in the Global Rainfall Erosivity Database (GloREDa). Overall, results indicated that the CMORPH estimates have a marked tendency to underestimate rainfall erosivity when compared to the GloREDa estimates. The most substantial underestimations were observed in areas with the highest rainfall erosivity values. At continental level, the best agreement between annual CMORPH and interpolated GloREDa rainfall erosivity map was observed in Europe. Worse agreement was detected for Africa and South America. Further analyses conducted at monthly scale for Europe revealed seasonal misalignments, with the occurrence of underestimation of the CMORPH estimates in the summer period and overestimation in the winter period compared to GloREDa. The best agreement between the two approaches to estimate rainfall erosivity was found for autumn, especially in Central and Eastern Europe. Conducted analysis suggested that satellite-based approaches for estimation of rainfall erosivity appear to be more suitable for low-erosivity regions, while in high erosivity regions and seasons (> 1,000–2,000 MJ mm ha−1 h−1 yr−1), the agreement with estimates obtained from pluviograph data such as GloREDa is lower. Concerning the ED estimates, this second approach to estimate rainfall erosivity yielded better agreement with GloREDa estimates compared to CMORPH. The application of a simple-linear function correction of the CMORPH data was applied to provide better fit to the GloREDa and correct systematic underestimation. This correction improved the performance of the CMORPH but in areas with the highest rainfall erosivity rates the underestimation was still observed. A preliminary trend analysis of the CMORPH rainfall erosivity estimates was also performed for the 1998–2019 period. According to this trend analysis, increasing and statistically significant trend was more frequently observed than decreasing trend.
摘要尽管最近在模拟全球水土流失方面取得了进展，但迄今为止，在进行更动态的年度间和年度内评估方面没有取得实质性进展。在这方面，主要的挑战仍然是估计暴雨降雨侵蚀力所需的高时间分辨率降雨数据的可得性有限。由于这种数据稀缺性很可能是未来几年的特征，因此研究了利用基于卫星的降雨数据估计全球降雨侵蚀力的替代方法的适用性。为此，使用NOAA CDR气候预测中心MORPHing技术(CMORPH)获得的高时空分辨率全球降水估算值。另外，侵蚀力密度(ED)的概念也被用于估计全球降雨侵蚀力。获得的全球降雨侵蚀力估计值与全球降雨侵蚀力数据库(GloREDa)中的降雨记录仪数据进行了验证。总体而言，结果表明CMORPH估计值与GloREDa估计值相比有明显低估降雨侵蚀力的倾向。在降雨侵蚀力值最高的地区观测到最严重的低估。在大陆水平上，欧洲的年CMORPH值与插值的GloREDa降雨侵蚀力图的一致性最好。非洲和南美洲的情况更糟。对欧洲进行的月尺度进一步分析揭示了季节失调，与GloREDa相比，CMORPH估计值在夏季被低估，而在冬季被高估。两种估算降雨侵蚀力的方法之间最一致的是秋季，特别是在中欧和东欧。进行的分析表明，基于卫星的降雨侵蚀力估算方法似乎更适合于低侵蚀力地区，而在高侵蚀力地区和季节(1000 - 2000 MJ mm ha - 1 h - 1 yr - 1)，与GloREDa等雨象仪数据的估计值的一致性较低。关于ED估算，与CMORPH相比，第二种估算降雨侵蚀力的方法与GloREDa估算结果更加吻合。应用简单线性函数对CMORPH数据进行校正，以更好地拟合GloREDa，并纠正系统低估。这种修正改善了CMORPH的性能，但在降雨侵蚀率最高的地区，仍然观察到低估。对1998-2019年CMORPH降雨侵蚀力估算值进行了初步趋势分析。根据这种趋势分析，增加和有统计学意义的趋势比减少的趋势更常见。
{"title":"Exploring the possible role of satellite-based rainfall data to estimate inter‐ and intra‐annual global rainfall erosivity","authors":"N. Bezak, P. Borrelli, Panos Panagos","doi":"10.5194/hess-2021-417","DOIUrl":"https://doi.org/10.5194/hess-2021-417","url":null,"abstract":"Abstract. Despite recent developments in modelling global soil erosion by water, to date no substantial progress has been made towards more dynamic inter- and intra-annual assessments. In this regard, the main challenge is still represented by the limited availability of high temporal resolution rainfall data needed to estimate rainstorms rainfall erosivity. As this data scarcity is likely to characterize the upcoming years, the suitability of alternative approaches to estimate global rainfall erosivity using satellite-based rainfall data was explored. For this purpose, the high spatial and temporal resolution global precipitation estimates obtained with the NOAA CDR Climate Prediction Center MORPHing technique (CMORPH) were used. Alternatively, the erosivity density (ED) concept was used to estimate global rainfall erosivity as well. The obtained global estimates of rainfall erosivity were validated against the pluviograph data included in the Global Rainfall Erosivity Database (GloREDa). Overall, results indicated that the CMORPH estimates have a marked tendency to underestimate rainfall erosivity when compared to the GloREDa estimates. The most substantial underestimations were observed in areas with the highest rainfall erosivity values. At continental level, the best agreement between annual CMORPH and interpolated GloREDa rainfall erosivity map was observed in Europe. Worse agreement was detected for Africa and South America. Further analyses conducted at monthly scale for Europe revealed seasonal misalignments, with the occurrence of underestimation of the CMORPH estimates in the summer period and overestimation in the winter period compared to GloREDa. The best agreement between the two approaches to estimate rainfall erosivity was found for autumn, especially in Central and Eastern Europe. Conducted analysis suggested that satellite-based approaches for estimation of rainfall erosivity appear to be more suitable for low-erosivity regions, while in high erosivity regions and seasons (> 1,000–2,000 MJ mm ha−1 h−1 yr−1), the agreement with estimates obtained from pluviograph data such as GloREDa is lower. Concerning the ED estimates, this second approach to estimate rainfall erosivity yielded better agreement with GloREDa estimates compared to CMORPH. The application of a simple-linear function correction of the CMORPH data was applied to provide better fit to the GloREDa and correct systematic underestimation. This correction improved the performance of the CMORPH but in areas with the highest rainfall erosivity rates the underestimation was still observed. A preliminary trend analysis of the CMORPH rainfall erosivity estimates was also performed for the 1998–2019 period. According to this trend analysis, increasing and statistically significant trend was more frequently observed than decreasing trend.\u0000","PeriodicalId":341866,"journal":{"name":"Hydrology and Earth System Sciences Discussions","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127131270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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