Local Catchment Research Articles

In this June issue

In line with several other journals we co-publish the Australian Commission on Safety and Quality in Health Care Low Back Pain Clinical Care Standard. It describes the early clinical management of people who present with a new acute episode of low back pain. The background to how the standard was developed and finalised are described in an introductory editorial. Coronial findings and royal commissions have repeatedly identified deficiencies in the emergency health care provided to prisoners in Australia. These deficiencies are operational, clinical and stigmatic and not limited to a single prison or jurisdiction. Applying a health quality of care framework focused on prevention and chronic health management appropriate assessment and escalation when urgent medical assistance is requested, and a structured audit framework could avoid future preventable deaths in prisons. We publish an editorial on this topic to accompany the paper written by a team from Victoria and Queensland. A group from the neurosurgery department of the Royal Brisbane and Women's Hospital report that the availability of cranial access equipment outside Queensland tertiary centres is limited. Inter-hospital transfers are likely to persist in Queensland and so improving access to cranial access equipment in hospitals where it is currently lacking is highly warranted. They surveyed senior theatre nurse or surgical service directors from rural and regional Queensland hospitals located outside the local catchment of a tertiary centre and had a CT scanner. Questions regarded availability, location and storage conditions of mechanical cranial access kits, as well as last usage, and associated patient outcomes. Life-threatening thoracic trauma requires emergency pleural decompression, and thoracostomy and chest drain insertion are core trauma procedures. Reliably determining a safe site for pleural decompression in children is challenging, even for experienced clinicians. A team from Melbourne report that the Mid-Arm-Point (MAP) technique, a procedural aid for use with injured adults, is also a safe site for pleural decompression in children <4 years and with a very minor modification is safe in children ≥4 years. An excellent study from Queensland describes the demographics, presentation characteristics, clinical features and cardiac outcomes for Aboriginal and Torres Strait Islander patients who present to a regional cardiac referral centre ED with suspected acute coronary syndrome (ACS). The authors conclude this cohort with suspected ACS have a high burden of traditional cardiac risk factors, regardless of whether they are eventually diagnosed with ACS. These patients may benefit from assessment for coronary artery disease regardless of age at presentation. In a nice paper, James Mallows explores the concept of collegiality, something considered to be any extra-role behaviour that is discretionary, not recognised by a formal reward system and that promotes the effective functioning of the organisation. There are few studies examining collegiality in the medical profession and none looking at collegiality among emergency physicians (EPs). He explores the perceptions of different ED health care professionals on the meaning of collegiality among EPs, the benefits of collegiality and behaviours they identify as indicative of collegiality. He identifies distinct themes and behaviours indicative of collegiality among EPs. Promoting these behaviours could improve staff well-being, ED efficiency, patient safety and productivity. Continuing with the previous theme, team culture underpins team performance. Psychological safety is a critical component of team culture for high performing teams. A group from the Gold Coast Hospital decided to explore this further. They conclude that familiarity of team members and leaders is critical to the development of psychological safety within the ED. Fostering familiarity should be a focus for frontline leadership each shift and a priority in broader departmental decisions for those seeking to enhance the psychological safety of their teams. The focus in this issue is on the anaesthetic component of the Fellowship training programme.

Per- and polyfluorinated alkyl substances (PFAS) in Pennsylvania surface waters: A statewide assessment, associated sources, and land-use relations

The objectives of this study are to identify per- and polyfluoroalkyl substances (PFAS) in Pennsylvania surface waters, corresponding associations with potential sources of PFAS contamination (PSOC) and other parameters, and compare raw surface water concentrations to human and ecological benchmarks. Surface water samples from 161 streams were collected in September 2019 and were analyzed for 33 target PFAS and water chemistry. Land use and physical attributes in upstream catchments and geospatial counts of PSOC in local catchments are summarized. The hydrologic yield of the sum of 33 PFAS (∑PFAS) for each stream was computed by normalizing each site's load by the drainage area of the upstream catchment. Utilizing conditional inference tree analysis, the percentage of development (>7.58 %) was identified as a primary driver of the ∑PFAS hydrologic yields. When percentage of development was removed from analysis, ∑PFAS yields were closely related to surface water chemistry associated with landscape alteration (e.g., development or agricultural cropland), such as concentrations of total nitrogen, chloride, and ammonia, but also to count of water pollution control facilities (agricultural, industrial, stormwater, and/or municipal waste pollution abatement facilities). In oil and gas development regions, ∑PFAS yields were associated with combined sewage outfalls. Sites surrounded by ≥2 electronic manufacturing facilities had elevated ∑PFAS yields (median = 241 ng/s/km2). Study results are critical to guide future research, regulatory policy, best practices that will mitigate PFAS contamination, and the communication of human health and ecological risks associated with PFAS exposure from surface waters.

Rationale for alternative water sources for mining regions with high environmental footprint on the example of Levikha village of the Sverdlovsk region

Introduction. Mine drainage has always been one of the main threats to the hydrosphere of mining areas, both during and after active mining. The most common method of mine water neutralization is associated with the slaked lime. On the abandoned Levikha copper-sulphide mine territory (Sverdlovsk region), acid mine drainage discharge reaches 3,000 m³/day. To neutralize acid waters, more than 400 m³/day of water with a neutral pH is required (to produce the slaked lime). Due to the worn out state of water pipe from the river Tagil, heavy losses, and frequent accidents, the neutralization station receives no more than half of the required amount of water. As a result, the neutralization technology is violated, acid mine drainage is not properly cleaned, the regulatory requirements for wastewater are not achieved, and sulfate waters with increased mineralization and metal concentrations are discharged into the river Tagil. Research objective is to substantiate the possibility of finding sources of drinking, household and process water supply for Levikha village and acid mine drainage neutralization stations by applying groundwater. Methods of research include a comprehensive approach containing research results analysis and field and laboratory research data processing. Results and discussion. Promising areas have been identified representing private catchment areas of potential water intakes with the most favorable conditions for underground runoff. A combination of the following factors was the criterion for promising areas and load points: favorable geological and tectonic conditions (the presence of tectonic faults); groundwater inflow testing results (relatively high specific flow rates of wells); geomorphological position (confinement to low relief areas, location near surface sources of groundwater recharge); hydrochemical sampling data (satisfactory chemical composition of groundwater); sanitary and hygienic situation (absence of potential sources of pollution in the local catchment area). Conclusions. The total resources of the five promising sites are 1,340 m3 /day, including 282 m3 /day for drinking purposes. Exploration and development of promising areas no. II (favorable geological and tectonic conditions within it are confirmed by the groundwater inflow testing results) and no. III (favorable sanitary and hygienic conditions) seem to be the most reasonable. These sites might cover half of the village water needs for drinking and household purposes.

An overlooked effect: domestic violence and alcohol policies in the night-time economy.

Restrictive late-night alcohol policies are aimed at reducing alcohol-related violence but, to date, no evaluations of their impact on family and domestic violence have been conducted. This study aimed to measure whether modifying the drinking environment and restricting on-site trading hours affected reported rates of family and domestic violence. This study used a non-equivalent control group design with two treatment sites and two matched control sites with pre- and postintervention data on rates of family and domestic violence assaults within local catchment areas of four late-night entertainment precincts in New South Wales, Australia, covering a population of 27309 people. Participants comprised monthly counts of police-recorded incidents of domestic violence assaults from January 2001 to December 2019. Two variations of restrictive late-night interventions were used: restricted entry to late-night venues after 1:30 a.m., trading ceasing at 3:30 a.m. and other restrictions on alcohol service (Newcastle); and restricted entry to late-night venues after 1 a.m. and a range of restrictions on alcohol service (Hamilton). The comparators were no restrictions on late-night trading or modifications of the drinking environment (Wollongong and Maitland). Measurements involved the rate, type and timing of reported family and domestic violence assaults. Reported rates of domestic violence assaults fell at both intervention sites, while reported domestic violence assaults increased over time in the control sites. The protective effects in Newcastle were robust and statistically significant across three main models. The relative reduction associated with the intervention in Newcastle was 29% (incidence rate ratio = 0.71, 95% confidence interval: 0.60-0.83) and an estimated 204 assaults were prevented across the duration of the study. The protective effects found in Hamilton were not consistently supported across the three main models. Increases to late-night alcohol restrictions may reduce rates of domestic violence.

Identifying driving processes of drought recovery in the southern Andes natural catchments

Study regionThe natural river basins of Chile. Study focusDrought effects on terrestrial ecosystems produce hydroclimatic stress with variable extensions. Particularly, hydrological drought duration can provide a better understanding of recovery together with catchment characteristics and climatology. This study focuses on the impacts of the multi-year drought experienced in Chile for more than a decade.The recovery of relevant catchment variables to quantify the drought termination (DT) and drought termination duration (DTD) after the hydrological drought is presented. A composite analysis of natural catchments using the CAMELS-CL data set discharge (1988–2020), k-NDVI (2000–2020), and soil moisture (1991–2020) provides the average response of the recovery after severe droughts. New hydrological insights for the regionThis study demonstrates that local catchment properties can explain the recovery of studied variables after a hydrological drought.Explanatory variables from CAMELS-CL to derive the DT using random forest regression (RFR) were used with a strong correlation of 0.92, 0.84, and 0.89 for discharge, vegetation productivity, and soil moisture, respectively.The discharge patterns show longer recovery over environments dominated by shrublands with less precipitation and higher temperatures, in central Chile, while higher latitudes with higher vegetation cover, increasing precipitation, and lower temperatures present shorter recovery times. The vegetation productivity shows longer recovery over highly vegetated mountains in central Chile. The soil moisture recovery spatial distribution presented patterns that connect them with the discharge recovery. This work enables the identification of drought vulnerability, which is valuable for managing water resources and ecosystems and is helping to predict drought recovery periods in regions with a lack of observations.

Controls on methylmercury concentrations in lakes and streams of peatland‐rich catchments along a 1700 km permafrost gradient

AbstractPermafrost thaw may increase the production of neurotoxic methylmercury (MeHg) in northern peatlands, but the downstream delivery of MeHg is uncertain. We quantified total mercury (THg) and MeHg concentrations in lakes and streams along a 1700 km permafrost transect in boreal western Canada to determine the influence of regional permafrost extent compared to local lake and catchment characteristics. In lakes, we assessed sediment microbial communities and modeled potential rates of water column photodemethylation (PD). Regardless of permafrost conditions, peatlands were the primary sources of MeHg across the transect as MeHg concentrations in streams increased with aromatic dissolved organic carbon (DOC), iron, and lower pH. Higher DOC and greater catchment peatland extent were further associated with higher stream %MeHg (MeHg/THg). Peatland lakes were potential MeHg sinks, with lower MeHg concentrations than streams (mean ± 1SD: 0.19 ± 0.23 and 0.47 ± 0.77 ng MeHg L−1, respectively), and larger stream catchments had lower %MeHg where PD may occur in abundant small lakes. Microbial communities in lake sediments showed that abundance of Hg reducing genes (merA) predominated over Hg methylating (hgcA) and MeHg demethylating (merB) genes. The effects of permafrost extent on MeHg processes in lakes were secondary to the influence of local catchment characteristics, but lakes in regions with less permafrost had higher DOC concentrations, higher %MeHg, and lower potential rates of PD. Our study highlights a need to understand the impacts of climate change on MeHg source and sink processes, particularly as mediated through changes to peatland DOC, to improve projections of future MeHg concentrations in northern catchments.

Hydrological drought in two largest river-connecting lakes in the middle reaches of the Yangtze River, China

Abstract Poyang and Dongting Lakes are two important river-connecting lakes with a complicated water system pattern in the middle reaches of the Yangtze River, China. Recently, extreme drought events occurred frequently in the two lakes. This study analyzed the characteristics and differences of hydrological droughts in Poyang and Dongting Lakes during the period of 1964–2016 and explored the correlation between drought and large-scale climate indices. The results showed that the hydrological droughts of Poyang and Dongting Lakes became increasingly serious. Especially after 2003, both lakes entered the dry season earlier and the intensity of drought was increased. The hydrological drought of Poyang Lake was more serious than that of Dongting Lake in spring (16.40%) and winter (14.26%), while the autumn drought in Dongting Lake (32.46%) was severer than that in Poyang Lake (27.65%). The spring droughts in the two lakes were significantly associated with droughts in their local catchments with the joint probabilities of 10.84 and 9.52%, while the autumn droughts were consistent with the hydrological droughts of the Yangtze River with large joint probabilities (26.39 and 27.76%). The changes in large-scale climate indices more significantly affected the drought in Poyang Lake than that in Dongting Lake, especially in autumn and winter.

Metal distribution in first flush in highway runoff of one of the busiest motorway junctions in the UK

We observed an unexpectedly high proportion of Fe2+dis in accumulated highway runoff, which could be attributed to local catchment characteristics.

Recent and future hydrological trends of aapa mires across the boreal climate gradient

Aapa mires are boreal peatland complexes comprised of wet, typically patterned fens in the center and Sphagnum bog vegetation at the margins. Their distribution is controlled by climate and local catchment hydrology. The daily discharge of twelve aapa mires across the boreal zone was explored for 1961–2099, with the CPIsnow model using observational weather data and projections based on climate models (CMIP5) and emission scenarios (RCP4.5 and RCP8.5). Mire hydrology was assessed for climate-zonal differences, seasonal patterns, and longer-term trends. The results indicated past and future changes in hydrology, particularly related to the duration and magnitude of snow cover and the timing of snowmelt. Increasing winter discharge and decreasing spring discharge were detected in recent past in the southern sites, and these trends were indicated to continue in the future throughout the study area. By the end of the 21st century, the typical seasonality of discharge is indicated to weaken throughout the study area and to largely disappear in the south boreal catchments. In the northernmost sites, a mismatch between past trends and future projections of spring discharge was discovered, indicating complexity and uncertainty of snow process modeling. The hydrological changes indicated in this study, together with direct impacts of increasing temperatures, threaten aapa mires, affecting biodiversity and greenhouse gas balance. In changing climate, special attention should be paid to winter conditions and snow, essential for the hydrological cycle in the north but under-explored in mire hydrology studies.

Can annual streamflow volumes be characterised by flood events alone?

Can total annual streamflow in any given year be largely characterised by a relatively small number of high flow events? A comprehensive assessment of this is of high value as there is evidence to suggest that as flood events increase in rarity a more consistent response between streamflow extremes and temperatures increases can be established — providing greater reliability in projections of rare events. We propose here a novel methodology to characterise streamflow regimes in the context of total annual streamflow for water supply. Using the Australian Bureau of Meteorology’s Hydrologic Reference Station database, we developed annual event flow distributions that standardise the relationship between total annual streamflow and event flows. It was found that the annual event flow distributions are primarily a function of local climate and catchment size and were largely insensitive to interannual variability represented by the El Niño Southern Oscillation Index, mean annual temperature, or total annual rainfall volume. Statistically significant trends were found in the timeseries of annual event flow distribution values, signalling a move to a less even distribution in the southern latitudes and a more even distribution in the northern latitudes. Our results show that total annual streamflows can be characterised by a small number of high flow events. This suggests that for Australia’s most critical surface drinking water supply catchments the streamflow yields can be represented by changes in a few, high flow events, independent of interannual variability. As these relationships are non-stationary, they may provide a basis for understanding changes in water supply into the future.

Dynamics in impervious urban and non-urban areas and their effects on run-off, nutrient emissions, and macroinvertebrate communities

Urbanization is a key factor driving water quality and biological communities in freshwater systems. While urbanization impacts on water resources were well-studied in urban areas, few studies have examined the growing impacts in non-urban areas. Here we investigate the spatiotemporal trends of urbanization using high-resolution impervious surface data of both urban and non-urban areas across Germany, and evaluate the urbanization impacts on changes of run-off, nutrient emissions, and macroinvertebrate communities. The emission changes were modelled using the MONERIS-PCRaster tool, while the macroinvertebrate community responses to urbanization were determined using Generalized Least Square models. We find that urbanization expanded by 3.2% from 2006 to 2015 nationwide, and primarily occurred in less-populated regions. The non-urban areas contributed 19.3–19.6% of the imperviousness expansion nationwide, which were equivalent to the ‘unaccounted’ increases of 15.5–15.9% of run-off, 10.6–11.0% of total nitrogen, and 12.5–12.9% of total phosphorus when only emissions from urban areas were modelled. Incorporating the emissions from both urban and non-urban areas revealed significant impacts of urbanization on macroinvertebrate community composition changes, with increases in more pollution-resistant and non-native species (particularly in large rivers), and reductions of more sensitive taxa. The community responses were jointly determined by local catchment characteristics and urbanization stressors. Our results suggest neglected effects of non-urban impervious surfaces and the importance of using impervious surface data instead of urban land classes to better represent urbanization processes and impacts in long-term planning and management of freshwater systems.

'Burr holes in the bush': Clinician preparedness for undertaking emergency intracranial haematoma evacuation surgery in rural and regional Queensland.

Delayed inter-hospital transfers of deteriorating neurotrauma patients from rural and regional hospitals to tertiary centres have seen the need for non-neurosurgeons to undertake emergency intracranial haematoma evacuation surgery locally. In the present study, the authors contributed to the paucity in the literature regarding the widespread availability of cranial access equipment in non-tertiary centres and patient outcomes in Queensland. We surveyed delegates (senior theatre nurses or surgical service directors) from rural and regional Queensland hospitals if they were located outside the local catchment of a tertiary centre and had a CT scanner. Questions regarded availability, location and storage conditions of mechanical cranial access kits, as well as last usage, and associated patient outcomes. Twenty-six delegates from eligible hospitals responded. Eighteen hospitals offered surgical services. Eleven hospitals housed complete mechanical cranial access kits. Five hospitals housed incomplete kits. Thirteen hospitals housed their equipment sterile in the operating theatre or ED. Eleven hospitals reported using the equipment, with last usage ranging from 4months to over 30 years. Two hospitals reported using the equipment within 12 months while a further five reported using it within 10 years. Two hospitals reported 'good' outcomes, two 'ok' and one 'poor'. The availability of cranial access equipment outside Queensland tertiary centres has been limited. Inter-hospital transfers are likely to persist in Queensland and haematoma evacuation surgery has been a life-saving endeavour, so improving access to cranial access equipment in hospitals where it is currently lacking is highly warranted.

Street network morphology and active mobility to school: Applying space syntax methodology in Shiraz, Iran

BackgroundPrevious research has found that built environment features (e.g., density, diversity and design) influence children's mode of transportation choice during school excursions. However, little is known about how and to what extent neighbourhood street morphology impacts students' commuting patterns. MethodsWe studied the commuting patterns of children from 18 primary schools in three distinct urban fabric zones (inner, middle, and outer) in Shiraz, Iran. Parents with children in primary grades of 1–6 (n = 1503) were chosen to report on their children's school journey diaries. To examine street network layout, five well-known indices based on the Space Syntax methodology were used: Connectivity, Integration, Control, Intelligibility, and Choice. In order to select a local catchment area for each individual student, an inventory GIS model was created. ResultsIntelligibility and Integration are found to have a positive association with students' walking distances of 400 and 800 m among local morphological elements. Students are more likely to stroll when the space's readability, continuity, and coherence improve. Control and Choice, on the other hand, had a detrimental influence on the walking of students. ConclusionActive mobility to school is associated with urban layout characteristics among Iranian Students, especially within a radius of 800 m. This study discovered that increasing the movement potential of space within an 800 m radius had a greater impact on a child's ability to walk than increasing the movement potential of space within a 400 m radius, and that the Integration (R3), Choice (R3), and Intelligence of the street network within an 800 m radius of students' homes was linked to better walking between home and school. Improving the readability, cohesion, and spatial continuity of the local street network might boost their propensity to walk to school.

Which child to which school? How local politicians shape catchment areas, school choice and diversity

Growing global debates surrounding parental school choice underscore the relevance of school place allocation. While there is much research on school choice, the enactment of such allocation policy is rarely analysed. Responding to this research gap, this article investigates how local politicians in Berlin put public primary school place allocation into practice. Building on approaches of policy enactment and policy field analysis, this article examines the ‘doing’ of Berlin primary school place allocation with the concurrency of catchment areas and parental school choice. Methodologically, this article draws on semi-structured interviews with three inner-city district school department heads in Berlin. Using qualitative content analysis, their political objectives, scope and strategies are analysed. The findings demonstrate that local politicians can interpret the allocation process in line with their political objectives. Consequently, there is surprising variation between the districts’ enactment of primary school place allocation policy. Policymakers’ political preferences for either school choice or social diversity are influential, as is the local context (e.g. school place shortages). The study highlights the importance of local actors and identifies three political strategies used to influence school place allocation, which might inform local politicians’ strategies elsewhere.

Recent advances and opportunities in data assimilation for physics-based hydrological modeling

Data assimilation applications in integrated surface-subsurface hydrological models (ISSHMs) are generally limited to scales ranging from the hillslope to local or meso-scale catchments. This is because ISSHMs resolve hydrological processes in detail and in a physics-based fashion and therefore typically require intensive computational efforts and rely on ground-based observations with a small spatial support. At the other end of the spectrum, there is a vast body of literature on remote sensing data assimilation for land surface models (LSMs) at the continental or even global scale. In LSMs, some hydrological processes are usually represented with a coarse resolution and in empirical ways, especially groundwater lateral flows, which may be very important and yet often neglected. Starting from the review of some recent progress in data assimilation for physics-based hydrological models at multiple scales, we stress the need to find a common ground between ISSHMs and LSMs and suggest possible ways forward to advance the use of data assimilation in integrated hydrological models.

Problems of Local Flooding in Functional Urban Areas in Poland

The research process of developing recommendations for rural communities directly adjacent to metropolitan cities in the field of local flooding protection, especially retention fee was preceded by: analysis of secondary data in 100 communities in three Functional Urban Areas (Metropolitan Areas, MA) in Poland: Poznań MA, Wrocław MA and Łódź MA (assessment of flooding and urbanization), analysis of primary data in 18 rural communities immediately adjacent to the metropolitan centers: semi-structured telephone interviews (stormwater fee from the stakeholder perspective) and survey research (local floodings from the citizen perspectives). To illustrate the scale of the flooding problem in MAs, flood risk maps were used along with data from the State Fire Service on local threats, and for assessing the scale of suburbanization data obtained from Statistics Poland. Although residents confirmed their readiness to co-finance the activities supporting the development of water retention, local authorities were hesitant to introduce additional charges for the residents. Therefore, a better solution would be to set the fees already at the national level. However, communities should be given more power with regards to the distribution of collected funds which, in turn, should be allocated directly to the local programs for the enhancement of retention capacity in the local catchments.

Unraveling the Importance of the Yangtze River and Local Catchment on Water Level Variations of Poyang Lake (China) After the Three Gorges Dam Operation: Insights From Random Forest Modeling

Investigating the contributions of the factors influencing lake water level and their related changes with regard to hydraulic facilities is vital for understanding the driving mechanism of water level variations under the manifold pressures from anthropogenic activities and climate change. In this study, a random forest (RF) model was used to investigate the changes of the relationship between water level and discharge of the Yangtze River and local tributaries in Poyang Lake, China, based on daily hydrological data from 1980 to 2018. The results indicated that RF exhibited robust capability for water level prediction in Poyang Lake, with average R2 of 0.95, 0.88, 0.92, and 0.94 for the dry, rising, wet, and recession seasons, respectively. Predictor importance analysis showed that the discharge of the Yangtze River had greater influence on the water level than the discharge of local tributaries except for the dry season in Poyang Lake, where the influence on the water level was evident with discharge less than 5,000 m3/s. The influence of the Yangtze River also showed a clear attenuation pattern as the distance from the outlet of the lake increased, where the water level was constantly regulated by the Yangtze River. In addition, the partial dependence plots also indicated that the Yangtze River discharge changes after the TGD operation have resulted in remarkable water level decreases in the wet and recession seasons, especially for the recession period. Meanwhile, a slight increase in water level was predicted under identical discharge of local catchment in the dry season, which was only concentrated in the outlet of the lake. This study indicated the RF model as a robust technique for water level predictions and attribution analysis under multiple temporal and spatial scales. Moreover, this study confirmed the uneven influences of the Yangtze River and local tributaries on water level across different seasons, gauging stations, and phases.

Integrated Flood Model in 3D Non-Orthogonal Boundary Fitted Hydrodynamic Model for Ciliwung River, Jakarta

The flood model (MuFlood) had been developed and applied as a flood early warning system in Jakarta, Indonesia. The low land Jakarta faces flood threat because of a significant land-use change in the upstream region, especially in the Katulampa catchment area. Katulampa, Bogor, is located 350 meters above Mean Sea Level (MSL). The distance from Katulampa to Manggarai Gate in Ciliwung River is approximately 91 km. The flood arrival time is about 12 hours. The output of MuFlood is as input for the ocean hydrodynamics model (MuHydro3D) using the 3D Non-Orthogonal Boundary Fitted. The paper presents the integrated model results to simulate flood events from Katulampa and the local catchment area of Jakarta. The comparison between observation and model prediction from the MuFlood hydrodynamic model is excellent for the 21-22 September 2020 case. MuHydro3D predicted that from 21-22 September 2020 case cause the water level increases up to 19 cm on West Flood Canal (KBB), and the closer the bay, the water level will gradually smaller and as same as the tide.

An environmental magnetic record of Holocene climatic variability from the Chilika Lagoon, Southern Mahanadi Delta, east coast of India

Core sediments from the Chilika Lagoon in the eastern part of the Core Monsoon Zone (CMZ) of India have provided a record of local environmental changes and catchment processes during the past 7800 cal. years B.P. Variations in the rock magnetic parameters (χlf, χhf, χARM and IRM's at varying field strengths) of sediment samples reflect climate-induced changes in the Chilika Lagoon catchment. The down-core variations in the concentration-dependent magnetic parameters indicate an intensified summer monsoon and enhanced terrigenous input to the lagoon during the Early to Mid-Holocene (∼7.8 ka to ∼ 5.5 ka B.P.). In contrast, the Mid- to Late Holocene period witnessed a weaker Indian Summer Monsoon Rainfall (ISMR) and less terrigenous input to the lagoon, with an intermediate phase of strengthened monsoon around 2 to 1 ka B.P. Spectral analysis of sedimentary magnetic susceptibility (χlf) data show significant periodicities (at 95 % significance level) of 2523, 573, 147, 93, 59, and 55 years, which are in agreement with the periodicities shown by other paleoclimatic proxies from the region.

Effects of single‐ and multi‐site calibration strategies on hydrological model performance and parameter sensitivity of large‐scale semi‐arid and semi‐humid watersheds

AbstractIn large‐scale watersheds, only the calibration of parameters for the outlet may ignore spatial heterogeneity and fail to meet the simulation accuracy of local areas. Based on the runoff observation data of three hydrological stations (Qingyang, Yangjiaping and Zhangjiashan) in the Jinghe River Watershed, single‐ and multi‐site calibration strategies were designed to investigate the performance and applicability of the Soil and Water Assessment Tool (SWAT) in predicting the monthly runoff of nested catchments and evaluate the differences in parameter sensitivity between the upstream and downstream. (i) The two calibration strategies showed little difference in the simulation accuracy of the watershed outlet; the Nash–Sutcliffe efficiency (NSE) and determination coefficient (R2) were approximately 0.8 and 0.6, respectively, and the percentage of bias (PBIAS) was mostly &lt;15%. The single‐site one‐by‐one calibration was significantly better than the multi‐site joint calibration at the interior points of the watershed. Among them, Qingyang decreased most obviously in the joint calibration with Zhangjiashan, with both NSE and R2 &lt; 0.5, whereas Yangjiaping was &gt;0.5 in combination with the other two sites. (ii) The sensitive parameters obtained by the two calibration strategies were different, and different parameters were effective for different‐sized catchments because hydrological processes exhibit astounding variability at all scales. The single‐site one‐by‐one calibration was mainly affected by the hydrological processes of the local catchment, whereas the multi‐site joint calibration was largely constrained by the sensitive parameters of the single‐site calibration. (iii) Parameters at different scales and locations were related to the problem of scaling and regionalization. The multi‐site joint calibration did not significantly improve the model performance of the watershed outlet but increased the capacity for synchronous identification of local sensitive parameters when compared to single‐site calibration. These findings are expected to provide experience for parameter calibration in other similar large‐scale watersheds and to lay a good foundation for the accurate identification of other related hydrological behaviours at watershed scales.