Journal articles on the topic 'Arid rivers'
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1
Juanico, Marcelo, and Eran Friedler. "Wastewater Reuse for River Recovery in Semi-Arid Israel." Water Science and Technology 40, no. 4-5 (August 1, 1999): 43–50. http://dx.doi.org/10.2166/wst.1999.0573.
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Most of the water has been captured in the rivers of Israel and they have turned into dry river-beds which deliver only sporadic winter floods. In a semi-arid country where literally every drop of water is used, reclaimed wastewater is the most feasible water source for river recovery. Two topics are addressed in this paper: water quality management in rivers where most of the flowing water is treated wastewater, and the allocations of reclaimed wastewater required for the recovery of rivers and streams. Water quality management must consider that the main source of water to the river has a pollution loading which reduces its capability to absorb other pollution impacts. The allocation of treated wastewater for the revival of rivers may not affect negatively the water balance of the region; it may eventually improve it. An upstream bruto allocation of 122 MCM/year of wastewater for the recovery of 14 rivers in Israel may favor downstream reuse of this wastewater, resulting in a small neto allocation and in an increase of the water resources available to the country. The discharge of effluents upstream to revive the river followed by their re-capture downstream for irrigation, implies a further stage in the intensification of water reuse.
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Atazadeh, Ehsan, Andrew Barton, Mozhgan Shirinpour, Mahdi Zarghami, and Abbas Rajabifard. "River management and environmental water allocation in regulated ecosystems of arid and semi-arid regions – A review." Fundamental and Applied Limnology / Archiv für Hydrobiologie 193, no. 4 (June 23, 2020): 327–45. http://dx.doi.org/10.1127/fal/2020/1286.
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Rivers make a significant contribution in providing goods and services for human well-being. Today, many rivers and streams have been heavily regulated to ensure adequate provision of water resources for anthropogenic uses. Riverine ecosystems, especially those in arid and semi-arid regions, are experiencing severe stress due to the increasing demands on the ecosystem services they provide, coupled with anthropogenic catchment-scale impacts and factors associated with natural and human-induced climate variability and change. In this paper, the various flow components in regulated riverine ecosystems and the methods to determine environmental flows are reviewed. The review also focuses on the concurrent developments of eco-hydrological models and on the new opportunities for improving environmental flows of rivers by sustainably adjusting consumptive flows to fine-tune environmental flows and maximize the ecological benefit. In fact, the present paper highlights the role of consumptive flows, towards improving environmental flows, which has largely been neglected by river scientists and water managers. Indeed, consumptive flows can provide an opportunity to improve and support environmental flows in regulated riverine ecosystems. Addressing these challenges may aid water management efforts in finding sustainable solutions in riverine ecosystems by balancing environmental/ecological and human water requirements.
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Woodhouse, Connie A., and Bradley Udall. "Upper Gila, Salt, and Verde Rivers: Arid Land Rivers in a Changing Climate." Earth Interactions 26, no. 1 (January 2022): 1–14. http://dx.doi.org/10.1175/ei-d-21-0014.1.
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Abstract The major tributary of the lower Colorado River, the Gila River, is a critical source of water for human and natural environments in the southwestern United States. Warmer and drier than the upper Colorado River basin, with less snow and a bimodal precipitation regime, the Gila River is controlled by a set of climatic conditions that is different from the controls on upper Colorado River flow. Unlike the Colorado River at Lees Ferry in Arizona, the upper Gila River and major Gila River tributaries, the Salt and Verde Rivers, do not yet reflect significant declines in annual streamflow, despite warming trends. Annual streamflow is dominated by cool-season precipitation, but the monsoon influence is discernable as well, variable across the basin and complicated by an inverse relationship with cool-season precipitation in the Salt and Verde River basins. Major multiyear streamflow droughts in these two basins have frequently been accompanied by wet monsoons, suggesting that monsoon precipitation may partially offset the impacts of a dry cool season. While statistically significant trends in annual streamflow are not evident, decreases in autumn and spring streamflow reflect warming temperatures and some decreases in spring precipitation. Because climatic controls vary with topography and the influence of the monsoon, the impact of warming on streamflow in the three subbasins is somewhat variable. However, given relationships between climate and streamflow, current trends in hydroclimate, and projections for the future, it would be prudent to expect declines in Gila River water supplies in the coming decades. Significance Statement This research investigates the climatic controls on the Gila River and its major tributaries, the Verde and Salt Rivers, to gain insights on how trends in climate may impact future water supply. The Gila River is the major tributary of the lower Colorado River, but, unlike the situation for the upper Colorado River, no significant decreasing trends in annual streamflow are evident despite warming temperatures. Climate–streamflow relationships are more complex in this part of the Colorado River basin, and several factors may be buffering streamflow to the impact of warming. However, given the key climatic controls on streamflow, current and emerging trends in climate, and projections for the future, declines in streamflow should be expected in the future.
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Khaleghi, Somaiyeh, and Nicola Surian. "Channel Adjustments in Iranian Rivers: A Review." Water 11, no. 4 (March 31, 2019): 672. http://dx.doi.org/10.3390/w11040672.
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Channel adjustments in Iranian rivers have been intense over the last decades due to natural and human factors. Iran has six major basins, all with different climates, from very humid to very arid. This work is a review of the available studies and data about channel adjustments in Iranian rivers, and aims to reconstruct a first outline, at a national scale, of types, magnitude, and causes of adjustments. The results show that most of the rivers have undergone incision (1 to 2 m and, in some cases, up to 6 to 7 m) and narrowing (from 19% to 73%), although widening (from 22% to 349%) has occurred in some rivers. Narrowing is due to dams and sediment mining; widening is due to climate change and sediment mining. Incision is due to gravel and sand mining, dams, channelization, with in-channel mining being the main cause of incision. Channel adjustments have occurred in basins with different climates, but it seems that widening has been more intense in arid and semi-arid climates. Such adjustments have several negative effects (e.g., damage to bridges, degradation of river ecosystems, and instability of banks). The comparison between Iran and other countries shows that narrowing and incision have been the dominant processes in most of the rivers, while damming and in-channel mining have been used as the main controlling factors. Data about adjustments in Iranian rivers are neither homogeneous nor complete for all the rivers. This lack of completeness implies that our understanding of channel changes, and their causes, should be improved by further investigation.
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Chan, Chun-Ngai, Hongyan Shi, Boyi Liu, and Lishan Ran. "CO2 and CH4 Emissions from an Arid Fluvial Network on the Chinese Loess Plateau." Water 13, no. 12 (June 8, 2021): 1614. http://dx.doi.org/10.3390/w13121614.
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The emissions of greenhouse gases (GHGs) from inland waters are an important component of the global carbon (C) cycle. However, the current understanding of GHGs emissions from arid river systems remains largely unknown. To shed light on GHGs emissions from inland waters in arid regions, high-resolution carbon dioxide (CO2) and methane (CH4) emission measurements were carried out in the arid Kuye River Basin (KRB) on the Chinese Loess Plateau to examine their spatio-temporal variability. Our results show that all streams and rivers were net C sources, but some of the reservoirs in the KRB became carbon sinks at certain times. The CO2 flux (FCO2) recorded in the rivers (91.0 mmol m−2 d−1) was higher than that of the reservoirs (10.0 mmol m−2 d−1), while CH4 flux (FCH4) in rivers (0.35 mmol m−2 d−1) was lower than that of the reservoirs (0.78 mmol m−2 d−1). The best model developed from a number of environmental parameters was able to explain almost 40% of the variability in partial pressure of CO2 (pCO2) for rivers and reservoirs, respectively. For CH4 emissions, at least 70% of the flux occurred in the form of ebullition. The emissions of CH4 in summer were more than threefold higher than in spring and autumn, with water temperature being the key environmental variable affecting emission rates. Since the construction of reservoirs can alter the morphology of existing fluvial systems and consequently the characteristics of CO2 and CH4 emissions, we conclude that future sampling efforts conducted at the basin scale need to cover both rivers and reservoirs concurrently.
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Makhmudova, U., A. Djuraev, and T. Khushvaktov. "Environmental flows in integrated sustainable water resource management in Tuyamuyin water reservoir, Uzbekistan." IOP Conference Series: Earth and Environmental Science 937, no. 3 (December 1, 2021): 032024. http://dx.doi.org/10.1088/1755-1315/937/3/032024.
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Abstract Climate change is causing extreme recession of the mountain glaciers in Central Asia. Also increased evapotranspiration from higher temperatures in arid and semi-arid zones in Uzbekistan. Additionally, climate change has an effect increased exceptional water deficits. In such scenarios Environmental despite for a more sustainable water supply system, available reservoir capacity. Central Asia unlock watershed region, its main rivers are the Amu Darya and the Syr Darya, and its key problems of the region the efficient use of water from these rivers. Supplying water to the Khorezm oasis and Karakalpakstan, Tuyamuyin reservoir is the main water resource. With an increasing population of the region and Aral Sea ecological problems, mounting demand exists for a more sustainable water supply system. Water reservoirs of Central Asian river contribute to the improvement of water resources management in the lower part of the region and thus, play a strategic role in regional water supplication. 70% of Central Asia is arid and semi-arid regions and therefore, water supply for irrigation and population purposes is the main water sector of all Central Asian countries.
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Whiting, J. P., M. F. Lambert, A. V. Metcalfe, P. T. Adamson, S. W. Franks, and G. Kuczera. "Relationships between the El-Niño Southern Oscillation and spate flows in southern Africa and Australia." Hydrology and Earth System Sciences 8, no. 6 (December 31, 2004): 1118–28. http://dx.doi.org/10.5194/hess-8-1118-2004.
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Abstract. The flow records of arid zone rivers are characterised by a high degree of seasonal variability, being dominated by long periods of very low or zero flow. Discrete flow events in these rivers are influenced by aseasonal factors such as global climate forcings. The atmospheric circulations of the El-Niño Southern Oscillation (ENSO) have been shown to influence climate regimes across many parts of the world. Strong teleconnections between changing ENSO regimes and discharges are likely to be observed in highly variable arid zones. In this paper, the influence of ENSO mechanisms on the flow records of two arid zone rivers in each of Australia and Southern Africa are identified. ENSO signals, together with multi-decadal variability in their impact as identified through seasonal values of the Interdecadal Pacific Oscillation (IPO) index, are shown to influence both the rate of occurrence and the size of discrete flow episodes in these rivers. Keywords: arid zones, streamflow, spates, climate variability, ENSO, Interdecadal Pacific Oscillation, IPO
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Cockayne, B. J., D. Sternberg, D. W. Schmarr, A. W. Duguid, and R. Mathwin. "Lake Eyre golden perch (Macquaria sp.) spawning and recruitment is enhanced by flow events in the hydrologically variable rivers of Lake Eyre Basin, Australia." Marine and Freshwater Research 66, no. 9 (2015): 822. http://dx.doi.org/10.1071/mf14242.
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Understanding the links between fish recruitment and riverine flows is integral for setting priorities for river-management strategies, particularly in hydrologically variable and unpredictable arid and semi-arid zone rivers. In the present study, we used daily and annual otolith age estimates to identify relationships between riverine flow and spawning and recruitment of Lake Eyre golden perch (Macquaria sp.); an endemic fish of the Lake Eyre Basin, central Australia. We found a close association between Lake Eyre golden perch spawning and periods of increased river flow, with most of spawning occurring 0–35 days after the start of these flow events. Spawning occurred throughout the year but was commonly observed during the first flow events proceeding consecutive months of no-flow when water temperatures exceeded 26°C. Spawning was not dependent on floodplain inundation, with most spawning occurring during within-channel flow events. Annual average year-class strength was related to the number of flow events per year, but not total annual discharge, or the number of low-flow days per year. These results highlight the importance of natural within-channel flow patterns to Lake Eyre golden perch spawning and recruitment and demonstrate the importance of maintaining the natural flow regime of Australia’s arid- and semi-arid-zone rivers.
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Wang, Hailong, Yu Shen, Li Liang, Yubin Yuan, Yuan Yan, and Guanghui Liu. "River Extraction from Remote Sensing Images in Cold and Arid Regions Based on Attention Mechanism." Wireless Communications and Mobile Computing 2022 (August 22, 2022): 1–18. http://dx.doi.org/10.1155/2022/9410381.
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The extraction of rivers in cold and arid regions is of great significance for applications such as ecological environment monitoring, agricultural planning, and disaster warning. However, there are few related studies on river extraction in cold and arid regions, and it is still in its infancy. The accuracy of river extraction is low, and the details are blurred. The rapid development of deep learning has provided us with new ideas, but with lack of corresponding professional datasets, the accuracy of the current semantic segmentation network is not high. This study mainly presents the following. (1) According to the characteristics of cold and arid regions, a professional dataset was made to support the extraction of rivers from remote sensing images in these regions. (2) Combine transfer learning and deep learning, migrate the ResNet-101 network to the LinkNet network, and introduce the attention mechanism to obtain the AR-LinkNet network, which is used to improve the recognition accuracy of the network. (3) A channel attention module and a spatial attention module with residual structure are proposed to strengthen the effective features and improve the segmentation accuracy. (4) Combining dense atrous spatial pyramid pooling (DenseASPP) with AR-LinkNet network expands the network receptive field, which can extract more detailed information and increase the coherence of extracted rivers. (5) For the first time, the binary cross-entropy loss function combined with the Dice loss function is applied to river extraction as a new loss function, which accelerates the network convergence and improves the image quality. Validation on the dataset shows that, compared with typical semantic segmentation networks, the method performs better on evaluation metrics such as recall, intersection ratio, precision, and F 1 score, and the extracted rivers are clearer and more coherent.
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Wang, Yichu, Jinren Ni, Yao Yue, Jiaye Li, Alistair G. L. Borthwick, Ximing Cai, An Xue, Li Li, and Guangqian Wang. "Solving the mystery of vanishing rivers in China." National Science Review 6, no. 6 (February 11, 2019): 1239–46. http://dx.doi.org/10.1093/nsr/nwz022.
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Abstract A major controversy was sparked worldwide by a recent national water census claiming that the number of Chinese rivers with watersheds ≥100 km2 was less than half the previous estimate of 50 000 rivers, which also stimulates debates on the potential causes and consequences. Here, we estimated the number of rivers in terms of stream-segmentation characteristics described by Horton, Strahler and Shreve stream-order rules, as well as their mixed mode for named rivers recorded in the Encyclopedia of Rivers and Lakes in China. As a result, the number of ‘vanishing rivers’ has been found to be highly relevant to statistical specifications in addition to the erroneous inclusion of pseudo-rivers primarily generated in arid or frost-thaw areas. The modified Horton stream-order scheme reasonably depicts the configuration of complete natural streams from headwater to destination, while the Strahler largely projects the fragmentation of the named river networks associated with human aggregation to the hierarchical river systems.
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Burford, Michele A., Andrew J. Cook, Christine S. Fellows, Stephen R. Balcombe, and Stuart E. Bunn. "Sources of carbon fuelling production in an arid floodplain river." Marine and Freshwater Research 59, no. 3 (2008): 224. http://dx.doi.org/10.1071/mf07159.
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Dryland rivers are characterised by highly pulsed and unpredictable flow, and support a diverse biota. The present study examined the contribution of floodplain sources to the productivity of a disconnected dryland river; that is a waterhole, after a major overland flood event. Rate measures of productivity were combined with stable isotope and biomass data on the food web in the waterhole and floodplain. The present study estimated that 50% of the fish carbon in the waterhole after flooding was derived from floodplain food sources. In the few months after retraction of the river to isolated waterholes, the large biomass of fish concentrated from the flooding decreased by 80%, most likely as a result of starvation. Based on the development of a carbon budget for the waterhole, mass mortality is hypothesised to be the cause of the high rates of heterotrophic production in the waterhole. The present study suggests that floodplain inputs are important for fuelling short-term production in waterholes, but via an unconventional pathway; that is, fish mortality. The episodic nature of flooding in dryland rivers means that changes in flow regimes, such as water regulation or abstraction, will reduce flooding and hence floodplain subsidies to the river. This is likely to have significant impacts on river productivity.
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Costelloe, J. F., J. R. W. Reid, J. C. Pritchard, J. T. Puckridge, V. E. Bailey, and P. J. Hudson. "Are alien fish disadvantaged by extremely variable flow regimes in arid-zone rivers?" Marine and Freshwater Research 61, no. 8 (2010): 857. http://dx.doi.org/10.1071/mf09090.
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The proliferation of alien fish in dryland rivers potentially obstructs the maintenance of river health. Modified flow regimes are hypothesised to facilitate invasions by alien fish but in unregulated dryland rivers, large floods provide a recruitment advantage for native over alien species whereas droughts favour alien species. We tested these hypotheses by using data from a 3-year study (2000–2003) of fish populations in the unmodified rivers of the Lake Eyre Basin (LEB) of Australia. Results from a lower reach of Cooper Creek were compared with those of an earlier study (1986–1992). During both periods, large floods occurred, with return periods ranging from >1 in 5 to >1 in 25 years. In the lower Cooper, decreases in the abundance of alien species relative to native species, and dramatic increases in recruitment of native species, were observed during a 1–3-year period following large floods. In two other rivers in 2000–2003, there was no statistically significant change in the already low abundances of alien species. We suggest that the naturally variable hydrological regimes and native-dominant fish assemblages of the unregulated LEB rivers afford some resistance to the establishment and proliferation of alien fish through flood and drought conditions.
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Garrick, Dustin, Lucia De Stefano, Fai Fung, Jamie Pittock, Edella Schlager, Mark New, and Daniel Connell. "Managing hydroclimatic risks in federal rivers: a diagnostic assessment." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 371, no. 2002 (November 13, 2013): 20120415. http://dx.doi.org/10.1098/rsta.2012.0415.
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Hydroclimatic risks and adaptive capacity are not distributed evenly in large river basins of federal countries, where authority is divided across national and territorial governments. Transboundary river basins are a major test of federal systems of governance because key management roles exist at all levels. This paper examines the evolution and design of interstate water allocation institutions in semi-arid federal rivers prone to drought extremes, climatic variability and intensified competition for scarce water. We conceptualize, categorize and compare federal rivers as social–ecological systems to analyse the relationship between governance arrangements and hydroclimatic risks. A diagnostic approach is used to map over 300 federal rivers and classify the hydroclimatic risks of three semi-arid federal rivers with a long history of interstate allocation tensions: the Colorado River (USA/Mexico), Ebro River (Spain) and Murray–Darling River (Australia). Case studies review the evolution and design of water allocation institutions. Three institutional design trends have emerged: adoption of proportional interstate allocation rules; emergence of multi-layered river basin governance arrangements for planning, conflict resolution and joint monitoring; and new flexibility to adjust historic allocation patterns. Proportional allocation rules apportion water between states based on a share of available water, not a fixed volume or priority. Interstate allocation reform efforts in the Colorado and Murray–Darling rivers indicate that proportional allocation rules are prevalent for upstream states, while downstream states seek reliable deliveries of fixed volumes to increase water security. River basin governance arrangements establish new venues for multilayered planning, monitoring and conflict resolution to balance self governance by users and states with basin-wide coordination. Flexibility to adjust historic allocation agreements, without risk of defection or costly court action, also provides adaptive capacity to manage climatic variability and shifting values. Future research should develop evidence about pathways to adaptive capacity in different classes of federal rivers, while acknowledging limits to transferability and the need for context-sensitive design.
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Fang, Yu, Xulian Wang, Yufei Cheng, and Zhongjing Wang. "Oasis Change Characteristics and Influencing Factors in the Shiyang River Basin, China." Sustainability 14, no. 21 (November 2, 2022): 14354. http://dx.doi.org/10.3390/su142114354.
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The variability of the natural environment and the complexity of human activities result in dynamic changes in oasis areas, which is directly related to the sustainable development of arid and semi-arid areas. In order to better balance economic development and environmentally sustainable development, based on land use data and social and economic data from 1980 to 2015, this paper analyzed the oasis change characteristics under natural and human factors in the Shiyang River Basin in Northwest China. The results indicated that the oasis in the Shiyang River Basin showed an expansion trend from 1980 to 2015, with the expansion mainly occurring in the diluvial and alluvial fan, and along the middle and lower reaches of the river. The oasis changed actively in areas at an elevation of 1350 m, with a slope of 2°, at the distance of 1500 m to rivers, and with precipitation of 120 mm and temperature of 15 °C. Furthermore, the oasis mainly evolved towards gentler slopes and lower altitudes, and migrated closer to rivers before 1992 and farther away from rivers afterwards. Population growth and economic development were the important inducers of oasis change, and government policies on agricultural benefits and ecological conservation also influenced the oasis change, especially after 2000. The evolution patterns of oasis distribution revealed in this study can provide a reference for promoting oasis ecological restoration and sustainable development.
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Choy, S. C., C. B. Thomson, and J. C. Marshall. "Ecological condition of central Australian arid-zone rivers." Water Science and Technology 45, no. 11 (June 1, 2002): 225–32. http://dx.doi.org/10.2166/wst.2002.0399.
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Australian arid-zone rivers are known to be ecologically variable and go through “boom and bust” cycles based on highly variable and unpredictable flow regimes. They are facing increasing pressure from land and water resources development and, whilst they are considered to be still in relatively good condition, no studies have yet been carried out to verify this. Such baseline studies are crucial if we are to assess any ecological changes in response to development and management interventions. The ecological condition of four of these endorheic rivers (Georgina, Diamantina, Cooper-Thomson and Bulloo) flowing into the Lake Eyre and Bulloo Basins in central Australia was assessed using several criteria (level of human influence, habitat condition, water chemistry and aquatic macroinvertebrate composition). Using criteria based on the level of human influence, most of the sites were assessed to be relatively unimpacted (reference) condition. The most discernible and widespread impact was riparian and bank damage by stock access. However, the level of this impact was considered to be only moderate. Most aquatic macroinvertebrates found in the area are considered to be opportunistic and tolerant of a wide range of environmental conditions, but with their life histories known to be linked to flow conditions. Their trophic guild was dominated by collectors and predators. The AusRivAS modelled observed to expected values of macroinvertebrate composition indicated that there were differences in ecological condition between sites (e.g. different waterholes) and between times (e.g. seasons and years). Overall, 75% of sites were assessed to be good condition with the remainder being mildly impaired. Water chemistry of the sites was characterised by high spatial and temporal variability with low conductivity and alkaline pH, relatively high turbidity, total nitrogen and total phosphorus, and wide-ranging dissolved oxygen. Given the high variability in water quality and ecological condition within a catchment, there was little evidence of any overall difference in these factors between the catchments. However, given that the hydrology of each river system is distinctly different, one might expect some differences in ecological structure and function at finer scale. Periods of hydrological isolation (eg. to allow natural dryouts) as well as the maintenance of natural connectivity (eg. instream, overbank and floodplain wetting) are both necessary for the maintenance of ecological integrity of these systems.
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Ji, Li, Yuan Li, Guixiang Zhang, and Yonghong Bi. "Anthropogenic Disturbances Have Contributed to Degradation of River Water Quality in Arid Areas." Water 13, no. 22 (November 22, 2021): 3305. http://dx.doi.org/10.3390/w13223305.
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The earth has been reshaped for millennia. The accelerating pace of anthropogenic activities has generated enormous impacts on the water environment. As one of the main drivers of landscape change, anthropogenic disturbance has brought many negative effects on rivers. Studying the relationship between anthropogenic disturbances and river water quality is of significance for regional conservation and ecosystem management, while the relationship remains poorly understood in the current. In this study, we quantified anthropogenic disturbances by introducing the concept of the hemeroby index and evaluated rivers’ water quality in eight sub-watersheds on the Loess Plateau. The results indicated that 37.5% of the sub-watersheds were in Eutrophic status, and 62.5% were in Marginal water quality index. The river water quality was most poor in the southwestern region near the Yellow River with high-level anthropogenic disturbance. A correlation analysis between water quality indicators and hemeroby suggested that anthropogenic disturbance contributed to a significant water quality deterioration trend (p < 0.01). The river water quality was relatively sensitive to the changes of completely disturbed land-use covers, including urban and industrial land. Our findings provide theoretical guidance for regional water resources conservation and ecosystem management in arid areas.
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Gkenas, Christos, Maria Filomena Magalhães, Nazaret Campos-Martin, Filipe Ribeiro, and Miguel Clavero. "Desert pumpkinseed: diet composition and breadth in a Moroccan river." Knowledge & Management of Aquatic Ecosystems, no. 422 (2021): 34. http://dx.doi.org/10.1051/kmae/2021033.
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The widely invasive North American pumpkinseed sunfish, Lepomis gibbosus, is currently established in desert rivers in Morocco. The success of pumpkinseed in novel ecosystems has been associated with its generalist diet, but this trait remains unevaluated in arid regions. Desert rivers are harsh environments with limited water and prey availability which may adversely constrain the diet of fish. Here we studied the diet of pumpkinseed across 4 sites in the Draa River, embracing a 450 m elevational gradient covering from extremely dry lowlands to relatively humid highlands. We described pumpkinseed diet through the analysis of stomach contents of 82 individuals, collected in the fall of 2013. Pumpkinseed diet was dominated by Chironomidae in dry lowlands, while Ephemeroptera, Heteroptera, Trichoptera and Odonata were relevant prey in more humid highlands. Population diet breadth expanded with elevation, but individual specialization in diet was low among all sites. Our results highlight considerable changes in diet composition and breadth with aridity, suggesting that feeding plasticity and use of exclusive, locally abundant prey rather than generalized feeding may be associated with the success of pumpkinseed in most arid areas in desert rivers.
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Wang, Yuanjian, Enhui Jiang, Xinjie Li, and Xin Wang. "Theory and Practice of water and sediment regulation in flood season of Yellow River in 2018." MATEC Web of Conferences 246 (2018): 01048. http://dx.doi.org/10.1051/matecconf/201824601048.
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In recent years, the water and sediment pattern of the Yellow River has changed significantly, and a preliminary water and sediment regulation system was constructed. Based on a summary of the regulation principles of water and sediment in the Middle Yellow River, this paper proposes three key technologies to determine the water and sediment control thresholds, the artificial creation of a long-distance density current, and an engineering regulation for water and sediment control of the Yellow River. Taking the actual flood and sedimentation regulation of the Yellow River Basin in 2018 as an example, the practical applications of these relevant technologies are analyzed. This study provides an important theoretical and practical reference for the flood and sediment regulation of sediment-laden rivers in arid and semi-arid areas during flood season.
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Hu, Yuxian, Ke Zhang, Yuan Li, Yanan Sun, Hongyan Li, and Gaiqiang Yang. "Human Activities Increase the Nitrogen in Surface Water on the Eastern Loess Plateau." Geofluids 2021 (June 1, 2021): 1–9. http://dx.doi.org/10.1155/2021/9957731.
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Human activities have greatly accelerated the input of nitrogen into waters, resulting in water quality degradation. Facing the water crisis of nitrogen pollution, the state of surface water in arid areas needs close attention. Although numerous studies have indicated that waters’ nitrogen is often impacted by land use covers, the correlation between the two remains obscure. This paper explored the spatial relationship between anthropogenic activity and waters’ nitrogen on the eastern Loess Plateau, based on the Geographic Information System (GIS) spatial analysis using land use covers. There were 3 human land use types and 2 nitrogen indices used to assess the rivers’ state at the watershed scale. The results showed that rivers’ nitrogen was closely associated with human land use covers. Nitrogen pollution was most serious in urban areas. This study provided new evidence for the relationship between anthropogenic activities and river ecology. The findings may be helpful for policymakers to make strategic decisions of water resource management and land use planning in arid areas.
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Schmandt, Jurgen, Gerald R. North, and George H. Ward. "How Sustainable are Engineered Rivers in Arid Lands?" Journal of Sustainable Development of Energy, Water and Environment Systems 1, no. 2 (June 2013): 78–93. http://dx.doi.org/10.13044/j.sdewes.2013.01.0006.
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Qiao, Changlu, Guotao Cai, Yanxue Liu, Junfeng Li, and Fulong Chen. "Study of the Flood Frequency Based on Normal Transformation in Arid Inland Region: A Case Study of Manas River in North-Western China." Mobile Information Systems 2022 (July 13, 2022): 1–17. http://dx.doi.org/10.1155/2022/5229348.
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Flood disaster is one of the natural disasters which cause the most serious economic losses, the most casualties, and the greatest social impact. Flood frequency analysis is very important for reducing flood disaster. In this paper, based on the flood data of Manas River and tools of Box–Cox and Johnson normal transformation, the nonparametric statistical method for flood frequency analysis is studied in order to analyze the adaptability between it and the rivers in arid region of north-western China. The calculation result of the fitness index is divided into two parts: high flood discharge and low flood discharge. One of the two evaluation indexes has an advantage in fitting, and the number of advantages of the three methods in each part has been counted. After analysis, for the flood peak discharge frequency of rivers in arid region of north-western China, the frequency curve of Johnson transformation fits best with empirical data. The high flood discharge advantage is 6, and the low flood discharge is 4. For the flood volume frequency of rivers in arid region of north-western China, Box–Cox transform fits well with empirical data at the high flood discharge frequency curve, and its advantage is 12; Johnson transformation has a better fit between the low flood discharge frequency curve and empirical data, and its advantage is 12. Therefore, it is the way of improving the precision of flood frequency analysis to use the method of P-III distribution and normal transformation comprehensively.
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Costelloe, J. F., J. T. Puckridge, J. R. W. Reid, J. Pritchard, P. Hudson, V. Bailey, and M. Good. "Environmental flow requirements in arid zone rivers – a case study from the Lake Eyre Basin, central Australia." Water Science and Technology 48, no. 7 (October 1, 2003): 65–72. http://dx.doi.org/10.2166/wst.2003.0425.
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The ARIDFLO project takes a multi-disciplinary approach to the collection and analysis of data required to formulate appropriate environmental flow requirements for rivers in the Lake Eyre Basin. The key drivers of the ecological processes underpinning the health of these rivers are identified by modelling whole-of-ecosystem biological responses to hydrological events over a range of spatial and temporal scales. First, the hydrology of these poorly gauged (often ungauged) rivers needs to be modelled and validated to mimic real flow and inundation patterns at the catchment, reach and waterbody scale. Modelled and actual discharge data are then used to provide a suite of hydrological predictor variables which, in conjunction with other environmental variables, are used to model observed biotic responses. The key hydrologic and environmental drivers identified by the statistical models need to be taken into account when determining environmental flow requirements for these river systems. Further work is required to assess the predictive power of the models in the highly variable, complex systems of the Lake Eyre Basin rivers.
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Min, Leilei, Peter Yu Vasilevskiy, Ping Wang, Sergey P. Pozdniakov, and Jingjie Yu. "Numerical Approaches for Estimating Daily River Leakage from Arid Ephemeral Streams." Water 12, no. 2 (February 12, 2020): 499. http://dx.doi.org/10.3390/w12020499.
Full textAbstract:
Despite the significance of river leakage to riparian ecosystems in arid/semi-arid regions, a true understanding and the accurate quantification of the leakage processes of ephemeral rivers in these regions remain elusive. In this study, the patterns of river infiltration and the associated controlling factors in an approximately 150-km section of the Donghe River (lower Heihe River, China) were revealed using a combination of field investigations and modelling techniques. The results showed that from 21 April 2010 to 7 September 2012, river water leakage accounted for 33% of the total river runoff in the simulated segments. A sensitivity analysis showed that the simulated infiltration rates were most sensitive to the aquifer hydraulic conductivity and the maximum evapotranspiration (ET) rate. However, the river leakage rate, i.e., the ratio of the leakage volume to the total runoff volume, of a single runoff event relies heavily on the total runoff volume and river flow rate. In addition to the hydraulic parameters of riverbeds, the characteristics of ET parameters are equally important for quantifying the flux exchange between arid ephemeral streams and underlying aquifers. Coupled surface/groundwater models, which aim to estimate river leakage, should consider riparian zones because these areas play a dominant role in the formation of leakage from the river for recharging via ET. The results of this paper can be used as a reference for water resource planning and management in regulated river basins to help maintain riparian ecosystems in arid regions.
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Tzoraki, Ourania. "Operating Small Hydropower Plants in Greece under Intermittent Flow Uncertainty: The Case of Tsiknias River (Lesvos)." Challenges 11, no. 2 (August 3, 2020): 17. http://dx.doi.org/10.3390/challe11020017.
Full textAbstract:
In arid and semi-arid parts of the world, river exploitation is intensive, involving water storage for irrigation or hydropower generation. In Greece, 100 small hydropower plants (SHPs) take advantage of less than 10% of the hydropower potential of low flow streams (<2 m3/s), a very small amount in relation to the 70% of the European Union. The energy policy of complete decarbonization of the country by 2023 on a national scale opens the road for new investments in SHP projects, especially in intermittent-flow streams of the Greek islands. Simulated flows by the Modello Idrologico SemiDistribuito in continuo (MISDc model) are used to construct the annual flow duration curve (FDC) to study and assess the hydropower potential of an intermittent stream (Tsiknias river, Lesvos, Greece). For Tsiknias River, but also for six other intermittent-flow rivers of Crete island, the capacity factor (CF), which represents the mean annual power of the hydropower plant, should remain >75% to exploit the river’s potential. The FDC and CF are essential in designing SHP projects in intermittent-flow streams with long no-flow periods. The development of public participatory approaches and a closer cooperation among policy makers and stakeholders should work to promote hydropower exploitation and accelerate licensing procedures.
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Doiteau, Benjamin, Meredith Dournaux, Nadège Montoux, and Jean-Luc Baray. "Atmospheric Rivers and Associated Precipitation over France and Western Europe: 1980–2020 Climatology and Case Study." Atmosphere 12, no. 8 (August 21, 2021): 1075. http://dx.doi.org/10.3390/atmos12081075.
Full textAbstract:
Atmospheric rivers are important atmospheric features implicated in the global water vapor budget, the cloud distribution, and the associated precipitation. The ARiD (Atmospheric River Detector) code has been developed to automatically detect atmospheric rivers from water vapor flux and has been applied to the ECMWF ERA5 archive over the period 1980–2020 above the Atlantic Ocean and Europe. A case study of an atmospheric river formed in the East Atlantic on August 2014 that reached France has been detailed using ECMWF ERA5 reanalysis, ground based observation data, and satellite products such as DARDAR, AIRS, GPCP, and GOES. This atmospheric river event presents a strong interaction with an intense upper tropospheric jet stream, which induced stratosphere–troposphere exchanges by tropopause fold. A 1980–2020 climatology of atmospheric rivers over Europe has been presented. The west of France, Iberian Peninsula, and British Islands are the most impacted regions by atmospheric rivers with an occurrence of up to four days per month during the October–April period. Up to 40% of the precipitation observed on the west European coast can be linked to the presence of ARs. No significant trend in the occurrence of the phenomena was found over 1980–2020.
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Strauch, G., R. Oyarzún, F. Reinstorf, J. Oyarzún, M. Schirmer, and K. Knöller. "Interaction of water components in the semi-arid Huasco and Limarí river basins, North Central Chile." Advances in Geosciences 22 (October 13, 2009): 51–57. http://dx.doi.org/10.5194/adgeo-22-51-2009.
Full textAbstract:
Abstract. For sustainable water resource management in semi-arid regions, sound information is required about interactions between the different components of the water system: rain/snow precipitation, surface/subsurface run-off, groundwater recharge. Exemplarily, the Huasco and Limarí river basins as water stressed river catchments have been studied by isotope and hydrochemical methods for (i) the origin of water, (ii) water quality, (iii) relations of surface and groundwater. Applying the complex multi-isotopic and hydrochemical methodology to the water components of the Huasco and Limarí basins, a differentiation of water components concerning subsurface flow and river water along the catchment area and by anthropogenic impacts are detected. Sulphate and nitrate concentrations indicate remarkable input from mining and agricultural activities along the river catchment. The 2H-18O relations of river water and groundwater of both catchments point to the behaviour of river waters originated in an arid to semi-arid environment. Consequently, the groundwater from several production wells in the lower parts of the catchments is related to the rivers where the wells located, however, it can be distinguished from the river water. Using the hydrological water balance and the isotope mixing model, the interaction between surface and subsurface flows and river flow is estimated.
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Wang, Yichu, Danlu Liu, Enhang Liang, and Jinren Ni. "Structural Characteristics of Endorheic Rivers in the Tarim Basin." Remote Sensing 14, no. 18 (September 9, 2022): 4502. http://dx.doi.org/10.3390/rs14184502.
Full textAbstract:
Endorheic rivers as landlocked systems with no hydrological connections to marine environments are suffering from water and ecosystem crisis worldwide, yet little is known about their structural characteristics with complex geomorphic and climatic dependence. Based on the river networks identified from 30 m resolution digital elevation models and surface water dynamic information derived from Landsat images, we investigate the hierarchical characteristics of 60 sub-basins in the Tarim Basin, the largest endorheic river basin in China. In the Tarim River basin, endorheic rivers exhibit a self-similarity only in the range of stream-orders 1–4, compared to the range of stream-orders 1–5 observed in exorheic rivers, owning to the limited stream power to maintain the similar aggregation of rivers in the arid regions. Moreover, the Tarim River networks demonstrate lower bifurcation ratio (2.48), length ratio (2.03), fractal dimension (1.38), and drainage density (0.24 km−1) in representative sub-basins, with a significant decay in median values compared with those derived from exohreic rivers at similar scales, suggesting sparser and imperfect developed branching river networks in endorheic basins. Further analysis on the Tarim reveals that endorheic river structure is more related to glacier extent (r = 0.67~0.84), potential evapotranspiration (r = 0.63~0.81), and groundwater type index (r = 0.64~0.73), which is essentially different from the structure of exorheic river represented by the Yellow River largely controlled by surface runoff, precipitation, and vegetation coverage. This study stresses the differences in intrinsic structural characteristics and extrinsic drivers of endorheic and exorheic rivers and highlights the necessity of differentiated strategies for endorheic river management in fragile ecosystems.
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Khan, Usman, Hammad Tariq Janjuhah, George Kontakiotis, Adnanul Rehman, and Stergios D. Zarkogiannis. "Natural Processes and Anthropogenic Activity in the Indus River Sedimentary Environment in Pakistan: A Critical Review." Journal of Marine Science and Engineering 9, no. 10 (October 12, 2021): 1109. http://dx.doi.org/10.3390/jmse9101109.
Full textAbstract:
The Indus River is Asia’s longest river, having its origin in the Tibet Mountain northwest of Pakistan. Routed from northern Gilgit and flowing to the plains, the river passes through several provinces and is connected by numerous small and large tributaries. The river was formed tectonically due to the collusion of the Indian and Eurasian plates, which is referred to as the Indus suture Plains zone (ISPZ). The geological setting of the study area is mainly composed of igneous and metamorphic rocks. The river passed through a variety of climatic zones and areas, although the predominant climate is subtropic arid and sub arid to subequatorial. Locally and globally, anthropogenic activities such as building, dams, and water canals for irrigation purposes, mining exploration, and industries and factories all affected the physical and chemical behaviors of the sediments in various rivers. The main effect of human activities is the reworking of weathered soil smectite, a chemical weathering indicator that rises in the offshore record about 5000 years ago. This material indicates increased transport of stronger chemically weathered material, which may result from agriculture-induced erosion of older soil. However, we also see evidence for the incision of large rivers into the floodplain, which is also driving the reworking of this type of material, so the signal may be a combination of the two. Sediments undergo significant changes in form and size due to clashing with one another in the high-charge river.
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Khan, Saifullah, Mahmood Ul Hasan, and Muhammad Aslam Khan. "Precipitation and Temperature Oscillation and its Effects on the Flow of Indus Water System and Adaptation in the Arid Region, Pakistan (1940-2000)." International Journal of Economic and Environmental Geology 10, no. 2 (September 4, 2019): 79–86. http://dx.doi.org/10.46660/ijeeg.vol10.iss2.2019.266.
Full textAbstract:
The study evaluates the water discharge of the Indus and its sub-rivers in the arid region of Pakistan from1940-2004 using the annual changes in addition to seasonal flux and inconsistencies in culmination of the water flow.Currently, in Pakistan, the gross per capita water availability shows notable dwindle during 1951 till 2000. Owing todecline in precipitation (0.6inch or 15.2mm) and amplify in degree of hotness of 1.60C for the period of 1960-2000, thewater discharge throughout Pakistan particularly in the arid region reveals a susceptible stipulation from 1940-2004.During Rabi season, the decline in the water discharge of the Indus River and its tributaries show a drasticdecline/reduction, while it remains stable in Kharif season and could do with adaptation instantly. The annual waterdischarge indicates a positive deviation in the Kabul River, while it is negative in Indus, Jhelum, Chenab, and Ravirivers. Most of the rivers in Baluchistan are altered into seasonal torrents and the water scarcity for agriculture sectorand domestic use will be at climax in the future. The decrease in the water discharge of the Indus drainage system willinfluence the crop pattern and its production in the rain fed as well as canals fed arid areas in the lower Punjab andSindh province. The specific adaptations to cope with the problem are, improvement in the irrigation system, edifice ofnew water dams and reservoirs, construction of water course guards, innovation in sanitation and sewerage system,public awareness, policy and implementation, establishment of research and development fund, crop choices, glacierretreat and planning for water resources.
30
Khan, Saifullah, Mahmood Ul Hasan, and Muhammad Aslam Khan. "Precipitation and Temperature Oscillation and its Effects on the Flow of Indus Water System and Adaptation in the Arid Region, Pakistan (1940-2000)." International Journal of Economic and Environmental Geology 10, no. 2 (September 4, 2019): 79–86. http://dx.doi.org/10.46660/ojs.v10i2.266.
Full textAbstract:
The study evaluates the water discharge of the Indus and its sub-rivers in the arid region of Pakistan from1940-2004 using the annual changes in addition to seasonal flux and inconsistencies in culmination of the water flow.Currently, in Pakistan, the gross per capita water availability shows notable dwindle during 1951 till 2000. Owing todecline in precipitation (0.6inch or 15.2mm) and amplify in degree of hotness of 1.60C for the period of 1960-2000, thewater discharge throughout Pakistan particularly in the arid region reveals a susceptible stipulation from 1940-2004.During Rabi season, the decline in the water discharge of the Indus River and its tributaries show a drasticdecline/reduction, while it remains stable in Kharif season and could do with adaptation instantly. The annual waterdischarge indicates a positive deviation in the Kabul River, while it is negative in Indus, Jhelum, Chenab, and Ravirivers. Most of the rivers in Baluchistan are altered into seasonal torrents and the water scarcity for agriculture sectorand domestic use will be at climax in the future. The decrease in the water discharge of the Indus drainage system willinfluence the crop pattern and its production in the rain fed as well as canals fed arid areas in the lower Punjab andSindh province. The specific adaptations to cope with the problem are, improvement in the irrigation system, edifice ofnew water dams and reservoirs, construction of water course guards, innovation in sanitation and sewerage system,public awareness, policy and implementation, establishment of research and development fund, crop choices, glacierretreat and planning for water resources.
31
Toledo, Cristian Epifanio, Emanuelly De Moura Silva Almeida, Alexandre Vicente Lopes Neto, Thályta Lharyssa Gonçalves Rodrigues Gonçalves Rodrigues Silva, and Filipe Augusto Rodrigues Santos. "Water loss in transit in an intermittent river in brazilian semi-arid." REVISTA AGRO@MBIENTE ON-LINE 12, no. 3 (October 29, 2018): 177. http://dx.doi.org/10.18227/1982-8470ragro.v12i3.5090.
Full textAbstract:
Riverwater often comes into contact with the underground flow in aquifers. When this contact
occurs, the river and aquifer are considered to be hydraulically connected. In recent decades, there has
been great interest in trying to to improve understanding of the interactions occuring between superficial and
subterranean water systems. A variety of analytical solutions have been proposed to describe the interaction of
confined and free aquifers with adjacent rivers, including the quantification of the decrease of river flow along
its course. The objective of the current study was to calibrate and validate a loss-in-transit flow model for rivers,
and to evaluate the minimum flow that still permits connectivity between water sources in the Alto Jaguaribe
basin. The methodology used was based on the equation of continuity and mass balance along the study river.
A modified Araújo and Ribeiro equation showed strong applicability to loss-in-transit generation, with a mean
loss in transit of 3.6% km-1, and a Nash and Sutcliffe Efficiency value of 0.29. On the other hand, the classbased
loss of upstream flow generated 4 classes with a mean of 2.6% km-1 and showed great improvement,
reaching an NSE of 0.74 - high efficiency. Minimum flows were below the regular flow recorded by the Ceará
Secretariat of Water Resources, showing that the ability exists in the region hydrological connectivity between
reservoirs in the Alto Jaguaribe basin and for alluvial aquifers to be recharged.
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Normandin, Cassandra, Philippe Paillou, Sylvia Lopez, Eugene Marais, and Klaus Scipal. "Monitoring the Dynamics of Ephemeral Rivers from Space: An Example of the Kuiseb River in Namibia." Water 14, no. 19 (October 6, 2022): 3142. http://dx.doi.org/10.3390/w14193142.
Full textAbstract:
Ephemeral rivers are characterized by brief episodic flood events, which recharge subterraean alluvial aquifers that sustain humans, riparian vegetation, and wildlife in the hyper-arid Namib Desert. Yet we only have a poor understanding of the dynamics and feedback mechanisms in these hydrological systems as arid and semi-arid zones are typically poorly equipped with reliable in situ monitoring stations to provide necessary information. The main objective of our study is to show the potential of satellite data to monitor the dynamics of ephemeral rivers, such as the Kuiseb located in Namibia, since remotesensing offers the advantage of adapted spatial and temporal resolutions. For this study, multi-spectral imagery (Sentinel-2), Synthetic Aperture Radar (SAR, Sentinel-1), and SAR interferometry (Sentinel-1) data were used to produce Normalized Difference Vegetation Index (NDVI) maps, backscattering maps (as σ0), and interferograms, respectively. These parameters provide information on the hydrologic and vegetation dynamics of the river. Strong variations in NDVI, σ0, and interferograms are observed during March–April 2017 and June–July 2018 in a tributary of the Kuiseb in the central Namib Desert. In those years, rain events caused the reactivation of the tributary. However, during a major flood in 2021, when no rain occured, no variations in NDVI were detected in this tributary, unlike the σ0 and interferogram anomalies after the flood. Thus, these variations cannot be explained by rains, which were non-existent during this period, but seem to be linked to the dynamics of the aquifer of the Kuiseb River, wherein floods recharge the alluvial aquifers and the rising water table levels produce a signal that is measurable by satellite radar sensors. All these results present a preliminary work that might be used by water resource managers to automate the processing and methods used to create an ephemeral river monitoring tool.
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Heritage, G., S. Tooth, N. Entwistle, and D. Milan. "Long-term flood controls on semi-arid river form: evidence from the Sabie and Olifants rivers, eastern South Africa." Proceedings of the International Association of Hydrological Sciences 367 (March 3, 2015): 141–46. http://dx.doi.org/10.5194/piahs-367-141-2015.
Full textAbstract:
Abstract. Rivers in the Kruger National Park, eastern South Africa, are characterised by bedrock-influenced "macrochannels" containing variable alluvial thicknesses and riparian vegetation assemblages. Evidence from the Sabie and Olifants rivers suggests that flows up to moderate floods (<3500 m3 s−1) tend to result in net alluviation, with sediments gradually covering the underlying bedrock. More extreme floods strip alluvium and erode bedrock, effectively exerting the primary control over long-term river morphologic development. On the Olifants River, post-flood aerial LIDAR imagery reveals that the 2012 extreme flood (~14000 m3 s−1) resulted in extensive stripping of stored alluvial sediment, exposing and eroding the underlying weathered bedrock. On the Sabie River, preliminary optically stimulated luminescence ages for remnant alluvium are all less than 1000 years, highlighting typical timescales of sediment storage. Together, these results suggest that while periods of general alluviation occur on these systems, long-term river development results from extreme flood-generated bedrock erosion.
34
Boulton, Andrew J. "Limnology and conservation of rivers in arid inland Australia." SIL Proceedings, 1922-2010 27, no. 2 (October 2000): 655–60. http://dx.doi.org/10.1080/03680770.1998.11901316.
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T. Kingsford, Richard, Rachael F. Thomas, and Alison L. Curtin. "Conservation of wetlands in the Paroo and Warrego River catchments in arid Australia." Pacific Conservation Biology 7, no. 1 (2001): 21. http://dx.doi.org/10.1071/pc010021.
Full textAbstract:
Irrigation proposals to divert water from the Paroo and Warrego Rivers in arid Australia will affect their aquatic ecosystems. These two are the last of 26 major rivers in the Murray-Darling Basin without large dams and diversions. Knowledge of the extent of their biodiversity value is critical to assessing likely impacts. During the 1990 flood, 1.73 million ha of wetlands, or 12.5% of the land surface of the Paroo and Warrego River catchments, were flooded. Flooded wetland area in the respective catchments was 781 330 ha and 890 534 ha. Most of the wetland area (97%) was floodplain, with 37 freshwater lakes (>50 ha) occupying 2.5% of the wetland area and 177 salt lakes covering 0.8%. A high diversity and abundance of biota depend on these wetlands. Only 7% of the wetland area, all in the Paroo catchment, is in conservation reserves. New South Wales has a high proportion of the wetland area on the Paroo (60%) and a substantial proportion of the wetland area on the Warrego River (23%). Queensland, the upstream state, will influence the ecology of the entire catchment areas of both river systems through its proposed water management plan. Any resulting extraction practices will have detrimental ecological consequences within a decade. Conservation of wetlands is usually site-focused and reflects a paradigm of conservation based on reservation of parcels of land. However, wetlands are dependent on water that is seldom adequately protected. Intergovernment co-operation should protect the entire catchment of the Paroo River from major diversions and stop further development on the Warrego River. This would do more for the conservation of wetlands than the formal reservation of small parts of their catchments.
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Pedro, F., L. Maltchik, and I. Bianchini Jr. "Hydrologic cycle and dynamics of aquatic macrophytes in two intermittent rivers of the semi-arid region of Brazil." Brazilian Journal of Biology 66, no. 2b (May 2006): 575–85. http://dx.doi.org/10.1590/s1519-69842006000400002.
Full textAbstract:
The dynamics of aquatic macrophytes in intermittent rivers is generally related to the characteristics of the resistance and resilience of plants to hydrologic disturbances of flood and drought. In the semi-arid region of Brazil, intermittent rivers and streams are affected by disturbances with variable intensity, frequency, and duration throughout their hydrologic cycles. The aim of the present study is to determine the occurrence and variation of biomass of aquatic macrophyte species in two intermittent rivers of distinct hydrologic regimes. Their dynamics were determined with respect to resistance and resilience responses of macrophytes to flood and drought events by estimating the variation of biomass and productivity throughout two hydrologic cycles. Twenty-one visits were undertaken in the rewetting, drying, and drought phases in a permanent puddle in the Avelós stream and two temporary puddles in the Taperoá river, state of Paraíba, Northeast Brazil. The sampling was carried out by using the square method. Floods of different magnitudes occurred during the present study in the river and in the stream. The results showed that floods and droughts are determining factors in the occurrence of macrophytes and in the structure of their aquatic communities. The species richness of the aquatic macrophyte communities was lower in the puddles of the river and stream subject to flood events, when compared to areas where the run-off water is retained. At the beginning of the recolonization process, the intensity of the floods was decisive in the productivity and biomass of the aquatic macrophytes in the Taperoá river and the Avelós stream. In intermediate levels of disturbance, the largest values of productivity and biomass and the shortest time for starting the recolonization process occurred.
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Turgumbaev, Akhan A., and Gennady T. G. Turikeshev. "ON THE DEVELOPMENT OF THE URAL RIVER BASIN IN THE CASPIAN LOWER AREA." South of Russia: ecology, development 13, no. 2 (July 1, 2018): 123–31. http://dx.doi.org/10.18470/1992-1098-2018-2-123-131.
Full textAbstract:
Aim. The aim is to study the modern and ancient basin of the Ural River and establish the cause of its shallowing, as well as the disappearance of small rivers and tributaries of the Ural River. Methods. The research method consists in the generalization and reduction to a single scale of all cartographic and space-survey documents, as well as the identification of elements of hydrography and relief created by ancient watercourses. Results. At present, many countries experience a shortage of fresh water. A person uses a huge amount of fresh water to meet his daily needs. In addition, contaminated waste technical waters are discharged into rivers and lakes. The Republic of Kazakhstan occupies most of the Caspian lowland, with the only full-flowing river, Ural (the Kazakh name is Zhayik). However, this river is becoming shallow, its level and spring floods are becoming lower. Cut-off lakes are also drying and disappearing. Small rivers that flew into the Ural river have almost disappeared and water level increases only during the melting of snow and after heavy rains. The studied territory is located in the arid climate zone, where there is little snow, and rains are rare. Conclusions. However, studying the cartographic and space imagery, we can say that there are many dry channels in the Caspian lowland. It must be assumed that this region was sufficiently moist, with a large number of rivers and lakes.
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Gui, Juan, Zongxing Li, Qi Feng, Qiao Cui, and Jian Xue. "Contribution of cryosphere to runoff in the transition zone between the Tibetan Plateau and arid region based on environmental isotopes." Hydrology and Earth System Sciences 27, no. 1 (January 4, 2023): 97–122. http://dx.doi.org/10.5194/hess-27-97-2023.
Full textAbstract:
Abstract. As the transition zone between the Tibetan Plateau and arid region, the Qilian Mountains are important ecological barriers and source regions of inland rivers in northwest China. In recent decades, drastic changes in the cryosphere have had a considerable impact on the formation process of water resources in the Qilian Mountains. In this study, 2164 environmental isotope samples were used to quantify the runoff components of 11 major rivers in the Qilian Mountains and investigate the influence of cryosphere changes on mountain runoff. The results show that the mountain runoff primarily originates in the cryosphere belt, which contributes approximately 82 %, 71 %, and 80 % to the Hexi inland water system, the upper stream of the Yellow River system, and the Qinghai inland river system, respectively. The maximum contribution ratio of glacier and snow meltwater to runoff occurred in May. The contribution of supra-permafrost water to runoff gradually increased from May and reached approximately 40 % in some rivers in October. Cryosphere degradation in the Qilian Mountains after the 1990s has caused a rapid increase in runoff, changes in the peak runoff time, and an increase in winter runoff. These changes in the hydrological processes bring opportunities and challenges to managing inland river water resources, and various adaptive measures to seek advantages and avoid disadvantages have been proposed. The findings from the environmental isotope analysis provide insights into understanding water resources and realizing the nexus of life, agriculture, industry, and ecological water use.
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JANMAAT, JOHANNUS, and ARJAN RUIJS. "Sharing the load? Floods, droughts, and managing international rivers." Environment and Development Economics 12, no. 4 (July 25, 2007): 573–92. http://dx.doi.org/10.1017/s1355770x07003701.
Full textAbstract:
Rivers can be both givers of life and takers of life. Investments that provide protection against flooding are often beneficial during normal or low flows. Investments such as storage reservoirs are long lived, separating construction and management operations. With international rivers, the absence of enforcement mechanisms may preclude infrastructure collaboration. Where physical infrastructure is in an upstream nation, downstream impacts may be ignored after the structure has been completed. Using a game theoretic model, it is shown that downstream cooperation may only be rational when flooding is the primary downstream impact. A stylized arid developing region and humid developed region are compared. Potential gains from collaboration are greatest in arid regions, but may be difficult to achieve. There may be little scope for capturing the gains from basin level management if economic integration does not extend beyond water issues.
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Estévez, Edurne, Tamara Rodríguez-Castillo, Alexia María González-Ferreras, Miguel Cañedo-Argüelles, and José Barquín. "Drivers of spatio-temporal patterns of salinity in Spanish rivers: a nationwide assessment." Philosophical Transactions of the Royal Society B: Biological Sciences 374, no. 1764 (December 3, 2018): 20180022. http://dx.doi.org/10.1098/rstb.2018.0022.
Full textAbstract:
The salinization of freshwaters is a global water quality problem that leads to the biological degradation of aquatic ecosystems. However, little is known about the spatial extent of freshwater salinization and the relative contribution of each human activity (e.g. agriculture, urbanization, mining or shale-gas extraction). Here, we investigated environmental factors that explain spatio-temporal patterns of water salinity and examined the causes, the extent and the degree of salinization of Spanish rivers. Results showed a strong variation in water salinity among river typologies and between river reaches in good and poor ecological status according to the Water Framework Directive. The variation in water salinity was largely explained by a combination of natural (i.e. climate and geology) and anthropogenic (i.e. land use) factors. By contrast, land use factors as urbanization and agriculture were the main drivers of salinization, which affected more than one quarter of the rivers and streams in Spain, especially those in the most arid regions (central and southern regions) and in the main courses of the largest rivers such as the Ebro, Douro and Tajo rivers. The information provided here can be relevant to set priority regions and actions to ameliorate freshwater salinization. This article is part of the theme issue ‘Salt in freshwaters: causes, ecological consequences and future prospects’.
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Zellman, Kristine L., Piret Plink-Björklund, and Henry C. Fricke. "Testing hypotheses on signatures of precipitation variability in the river and floodplain deposits of the Paleogene San Juan Basin, New Mexico, U.S.A." Journal of Sedimentary Research 90, no. 12 (February 18, 2021): 1770–801. http://dx.doi.org/10.2110/jsr.2020.75.
Full textAbstract:
ABSTRACTMuch progress has been made in recent years towards a set of recognition criteria for river discharge variability in river channel deposits, and thus sedimentary proxies for precipitation variability. Despite this progress, there is currently no consensus on how different styles of discharge variability are reflected in river sedimentary records, and whether variable-discharge river records from different climate types can be distinguished. Herein, river discharge and precipitation variability in the Paleogene is investigated using associations between river channel and floodplain deposits across the Paleocene–Eocene boundary from the Paleocene upper Nacimiento Formation and the early Eocene San Jose Formation in the San Juan Basin, New Mexico, USA.The succession is identified as deposits of variable-discharge river systems based on shared channel-deposit characteristics with modern and ancient variable-discharge river systems and the proposed facies models, in addition to alternations of poorly drained and well-drained floodplain deposits and/or slickensides indicating alternating wet–dry cycles. A long-term stratigraphic trend toward increasingly well-drained floodplain deposits is also observed and hypothesized to indicate successively more arid conditions from the Paleocene into the early Eocene. Comparisons with modern rivers from various climate zones suggest a long-term shift from a monsoonal climate in the Paleocene, to a fluctuating subhumid climate, ultimately leading to semiarid to arid conditions in the early Eocene. These observations suggest that floodplain deposits may be a better indicator of ambient climate, whereas channel deposits are records for frequency and magnitude of high-intensity precipitation events. Therefore, the existing facies models for variable-discharge rivers that consider only channel facies may not capture critical information needed to make accurate interpretations of paleoclimatic conditions. This study also adds to a growing body of evidence from geologic records of mid-latitude Paleogene river systems suggesting increases in the magnitude or variability of river discharge coinciding with established climate perturbations.
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Wang, Huaijun, Zhongsheng Chen, Yaning Chen, Yingping Pan, and Ru Feng. "Identification of the Space-Time Variability of Hydrological Drought in the Arid Region of Northwestern China." Water 11, no. 5 (May 20, 2019): 1051. http://dx.doi.org/10.3390/w11051051.
Full textAbstract:
Drought monitoring is crucial to water resource management and strategic planning. Thus, the objective of this study is to identify the space-time variability of hydrological drought across the broad arid region of northwestern China. Seven distributions were applied to fitting monthly streamflow records of 16 gauging stations from 10 rivers. Finally, the general logistic distribution was selected as the most appropriate one to compute the Standardized Streamflow Index (SSI). The severity and duration of hydrological droughts were also captured from the SSI series. Moreover, we investigate the relationship between hydrological drought (SSI) and meteorological drought (Standardized Precipitation-Evapotranspiration Index (SPEI)) at different time scales. The results show that drought duration and severity decreased over time in the Aibihu, Irtysh, Kaidu, Aksu, Yarkand, Hoton, Shule, Heihe (upstream), and Shiyang Rivers. However, the Tarim (upstream) and Heihe (middle stream) Rivers showed increasing drought duration and severity and this can be attributed to recent decades human activities. Furthermore, two correlation coefficient patterns between SSI and SPEI were found for the rivers of interest, an “increasing-decreasing” pattern for the Irtysh, Heihe, and Shiyang Rivers, where the precipitation is the main runoff supply, and an “increasing-stable” pattern for Aibihu and the Kaidu, Aksu, Yarkand, Hotan, and Shule Rivers, where glacier melt water provided a relatively high supply of runoff. Our findings are a contribution towards implementing effective water resources evaluation and planning in this arid region.
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Chunyu, Xunzhou, Feng Huang, Ziqiang Xia, Danrong Zhang, Xi Chen, and Yongyu Xie. "Assessing the Ecological Effects of Water Transport to a Lake in Arid Regions: A Case Study of Qingtu Lake in Shiyang River Basin, Northwest China." International Journal of Environmental Research and Public Health 16, no. 1 (January 7, 2019): 145. http://dx.doi.org/10.3390/ijerph16010145.
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With the continuous growth of economic water consumption in arid regions, many endorheic rivers and terminal lakes have desiccated. As an important ecological engineering measure, water transport in arid regions has vital ecological significance for protecting the regional ecological environment and delaying desertification. In this study, Qingtu Lake, the terminal lake of Shiyang River, was selected to analyze the ecological effects of water transport by means of remote sensing interpretations and current year field investigations. The results demonstrated that, in July 2018, the water surface had formed and recovered to 5.68 km2. Additionally, Qingtu Lake formed a spatial gradient distribution in groundwater depth. The depth increased in gradient from the waterside to the desert edge. There was a significant increase in the overall regional vegetation coverage, which mainly occurred in the water areas because of the extensive growth in Phragmites australis, which reached 10.54 km2 in area in 2018. Furthermore, the regional vegetation formed a gradient distribution, which transitioned from hygrophytes to xerophytes. This study can provide guidelines for the protection and restoration of lakes in arid regions.
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Wilson, N. "Community-based stream conservation initiatives in British Columbia, Canada." Water Science and Technology 45, no. 11 (June 1, 2002): 171–75. http://dx.doi.org/10.2166/wst.2002.0392.
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British Columbia is a diverse province, with ecosystems ranging from semi-arid deserts to valley glaciers and vast ice fields. By world standards, BC has an abundance of fresh water in its lakes and rivers. However, rivers have been exploited for social and industrial purposes, often to the detriment of the natural values. Community groups and non-government organizations have been active in rehabilitating and restoring waterways. The Outdoor Recreation Council of BC is a provincial non-government organization that has been instrumental in river conservation issues in BC. Three key initiatives have been established by the Council since its formation in 1975. BC Rivers Day has grown into the largest river celebration of its kind in North America, and there is a move to establish a national Rivers Day in Canada based on the model established in BC. Second is the annual Endangered Rivers List compiled by the Council and released each spring. The third initiative is the River Recovery Project in which dams and impoundment structures were evaluated against a set of criteria. A short list of candidates was generated by the project that will be further studied to determine what actions should be taken to alter the management of the structures to restore ecological values of the rivers and streams on which they are built. The three initiatives described rely on local community support. The Outdoor Recreation Council of BC provides coordination, promotion, and publicity as well as some resource materials while local groups and communities take on stewardship roles for their local streams. This model may be useful for other jurisdictions.
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Barbosa, José Etham de Lucena, Elvio Sérgio Figueredo Medeiros, Jandeson Brasil, Raquel da Silva Cordeiro, Maria Cristina Basilio Crispim, and Gustavo Henrique Gonzaga da Silva. "Aquatic systems in semi-arid Brazil: limnology and management." Acta Limnologica Brasiliensia 24, no. 1 (September 4, 2012): 103–18. http://dx.doi.org/10.1590/s2179-975x2012005000030.
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Aquatic systems in semi-arid Brazil include natural shallow lakes, artificial reservoirs and intermittent streams and rivers. These systems are distinctive features in the semi-arid landscape and comprise a range of associated systems functioning as an ever-changing mosaic of dry/wet patches. Lakes and reservoirs in semi-arid Brazil are subject to important periods of water shortages, whereas rivers and streams are characterized as highly variable and driven by the extremes of water flow and its absence. Within this view a catchment-scale approach must be used to create a holistic model to conceptualize and comprehend these aquatic systems, since the aquatic environment types in the semi-arid region of Brazil incorporate broader aspects within the catchment scale such as geomorphology, vegetation, climate and land use. This paper summarizes some of the information on the aquatic systems of the Brazilian semi-arid region and shows the importance of limnological studies in this region. It also attempts to establish perspectives for future research considering the catchment as a scale for surveying biological processes and limnological characteristics of the various aquatic systems. It is presented information on their overall structure and functioning, as well as characteristics of some biological communities, such as phytoplankton, periphyton, aquatic macrophytes, benthic invertebrates and fish. The importance of the understanding of eutrophication in reservoirs and the role of the dry phase in streams is emphasized, and information on possible actions of planning and management to improve water quality of reservoirs are presented.
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Jia, Xiaopeng, and Haibing Wang. "Element Geochemical Analysis of the Contribution of Aeolian Sand to Suspended Sediment in Desert Stream Flash Floods." Scientific World Journal 2014 (2014): 1–12. http://dx.doi.org/10.1155/2014/620610.
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The interaction of wind and water in semiarid and arid areas usually leads to low-frequency flash flood events in desert rivers, which have adverse effects on river systems and ecology. In arid zones, many aeolian dune-fields terminate in stream channels and deliver aeolian sand to the channels. Although aeolian processes are common to many desert rivers, whether the aeolian processes contribute to fluvial sediment loss is still unknown. Here, we identified the aeolian-fluvial cycling process responsible for the high rate of suspended sediment transport in the Sudalaer desert stream in the Ordos plateau of China. On the basis of element geochemistry data analysis, we found that aeolian sand was similar to suspended sediment in element composition, which suggests that aeolian sand contributes to suspended sediment in flash floods. Scatter plots of some elements further confirm that aeolian sand is the major source of the suspended sediment. Factor analysis and the relation between some elements and suspended sediment concentration prove that the greater the aeolian process, the higher the suspended sediment concentration and the greater the contribution of aeolian sand to suspended sediment yield. We conclude that aeolian sand is the greatest contributor to flash floods in the Sudalaer desert stream.
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Kingsford, R. T., D. A. Roshier, and J. L. Porter. "Australian waterbirds - time and space travellers in dynamic desert landscapes." Marine and Freshwater Research 61, no. 8 (2010): 875. http://dx.doi.org/10.1071/mf09088.
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Australia’s waterbirds are mostly nomadic, capitalising on highly variable aquatic resources in the arid interior (70% of the continent) for feeding and breeding. Waterbirds, unlike most aquatic organisms, can move between catchments, exploiting habitat wherever it occurs. In Australia, patterns of resource availability for waterbirds are mostly pulsed with peaks of productivity, coinciding with flooding and differing in time and space, affecting individuals, species and functional groups of waterbirds. Australian waterbirds are no different from waterbirds elsewhere, with their behaviour reflecting broad-scale resource availability. They respond to changing patterns of resource distribution, with rapid movements at spatial and temporal scales commensurate with the dynamics of the resource. The most serious conservation threat to waterbirds is a bottleneck in resource availability, leading to population declines, increasingly forced by anthropogenic impacts. River regulation and other threats (e.g. draining) reduce the availability of wetland habitat and decrease the probability of viable resource patches. It is axiomatic that waterbirds need water and such population bottlenecks may occur when the availability of water across the continent is limited. The rehabilitation of regulated rivers with environmental flows and protection of naturally flowing rivers in the arid region are essential for long-term sustainability of Australia’s waterbird populations.
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Tooth, Stephen, and Gerald C. Nanson. "Anabranching rivers on the Northern Plains of arid central Australia." Geomorphology 29, no. 3-4 (September 1999): 211–33. http://dx.doi.org/10.1016/s0169-555x(99)00021-5.
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Clavero, Miguel, Javier Esquivias, Abdeljebbar Qninba, María Riesco, Javier Calzada, Filipe Ribeiro, Néstor Fernández, and Miguel Delibes. "Fish invading deserts: non-native species in arid Moroccan rivers." Aquatic Conservation: Marine and Freshwater Ecosystems 25, no. 1 (September 12, 2014): 49–60. http://dx.doi.org/10.1002/aqc.2487.
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Koch, Hagen, Ana Lígia Chaves Silva, Stefan Liersch, José Roberto Gonçalves de Azevedo, and Fred Fokko Hattermann. "Effects of model calibration on hydrological and water resources management simulations under climate change in a semi-arid watershed." Climatic Change 163, no. 3 (November 18, 2020): 1247–66. http://dx.doi.org/10.1007/s10584-020-02917-w.
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AbstractSemi-arid regions are known for erratic precipitation patterns with significant effects on the hydrological cycle and water resources availability. High temporal and spatial variation in precipitation causes large variability in runoff over short durations. Due to low soil water storage capacity, base flow is often missing and rivers fall dry for long periods. Because of its climatic characteristics, the semi-arid north-eastern region of Brazil is prone to droughts. To counter these, reservoirs were built to ensure water supply during dry months. This paper describes problems and solutions when calibrating and validating the eco-hydrological model SWIM for semi-arid regions on the example of the Pajeú watershed in north-eastern Brazil. The model was calibrated to river discharge data before the year 1983, with no or little effects of water management, applying a simple and an enhanced approach. Uncertainties result mainly from the meteorological data and observed river discharges. After model calibration water management was included in the simulations. Observed and simulated reservoir volumes and river discharges are compared. The calibrated and validated models were used to simulate the impacts of climate change on hydrological processes and water resources management using data of two representative concentration pathways (RCP) and five earth system models (ESM). The differences in changes in natural and managed mean discharges are negligible (< 5%) under RCP8.5 but notable (> 5%) under RCP2.6 for the ESM ensemble mean. In semi-arid catchments, the enhanced approach should be preferred, because in addition to discharge, a second variable, here evapotranspiration, is considered for model validation.