Hasil untuk "River protective works. Regulation. Flood control"

Md Mostafizur Rahman, Jinat Ara Nasrin, Md. Mehedi Hasan Santo et al.

ABSTRACT This study investigates the factors associated with the adoption of nature‐based flood management (NbFM) practices in Chilmari Upazila, a flood‐prone area in northern Bangladesh, using the Protection Motivation Theory (PMT). A community‐based cross‐sectional survey was conducted among 589 adults aged 18 years and above, selected using a multistage nonprobability sampling strategy to capture experiences from hard‐to‐reach flood‐affected populations. Data were collected through face‐to‐face interviews using a structured questionnaire that covered sociodemographic characteristics, flood risk perceptions, response efficacy, self‐efficacy, and awareness of nature‐based solutions (NbS). Descriptive statistics revealed high awareness of flood risks: 57.39% of respondents perceived floods as extremely severe, while only 10% reported adopting NbS practices. Both stepwise backward and hierarchical multiple logistic regression analyses were employed to identify significant variables of NbS adoption. The stepwise regression identified gender, education level, primary occupation, housing type, receipt of information about NbS, perceived household vulnerability, response efficacy, and self‐efficacy as significant variables. In the hierarchical regression analysis, sociodemographic variables entered in the first step showed that males (aOR = 0.41, p = 0.019) and individuals with primary education (aOR = 0.26, p = 0.002) were less likely to adopt NbS, while those living in semi‐pucca houses (aOR = 2.87, p = 0.020) and those who had received information about NbS (aOR = 2.39, p = 0.026) were more likely to adopt these practices. Subsequent steps demonstrated that higher perceived household vulnerability and greater self‐efficacy significantly increased the likelihood of NbS adoption. The findings highlight the importance of information dissemination, education, housing conditions, perceived risk, and self‐efficacy in shaping the adoption of NbFM practices. Strengthening community awareness, improving access to NbS‐related information, and enhancing local capacity may play a critical role in promoting sustainable flood resilience in Bangladesh's flood‐prone regions.

Xuehui Ma, Shiliang Zhang, Zhiyong Sun et al.

Despite the celebrated success of stochastic control approaches for uncertain systems, such approaches are limited in the ability to handle non-Gaussian uncertainties. This work presents an adaptive robust control for linear uncertain systems, whose process noise, observation noise, and system states are depicted by ellipsoid sets rather than Gaussian distributions. We design an ellipsoid-set learning method to estimate the boundaries of state sets, and incorporate the learned sets into the control law derivation to reduce conservativeness in robust control. Further, we consider the parametric uncertainties in state-space matrices. Particularly, we assign finite candidates for the uncertain parameters, and construct a bank of candidate-conditional robust control problems for each candidate. We derive the final control law by aggregating the candidate-conditional control laws. In this way, we separate the control scheme into parallel robust controls, decoupling the learning and control, which otherwise renders the control unattainable. We demonstrate the effectiveness of the proposed control in numerical simulations in the cases of linear quadratic regulation and tracking control.

Joseph L. Gutenson, Michael L. Follum, Kathleen A. Staebell et al.

ABSTRACT Synthetic rating curves (SRCs) are often used to translate streamflow forecasts into flood inundation maps. Previous studies have investigated the development and errors in SRCs at local, regional, and continental scales. In this analysis, we used the latest global methodology and datasets to develop SRCs for use in flood inundation map forecasting. Using the Yellowstone River Basin and the 2022 floods that affected the region, we analyzed the error in the SRCs assessment of stage and water surface elevation (WSE). We then investigated the error in flood inundation maps produced using the SRCs. Comparing SRCs to locally derived rating curves from 29 U.S. Geological Survey (USGS) stream gages, median error in SRC stage ranged from 0.45 to 0.65 m and SRC error was greatest at higher magnitude streamflows. This error increased to a median of 1.98–2.30 m when converting the stage to a WSE. After using the SRC WSE estimates to create an estimated flood inundation map, the WSE error at observed high‐water marks (1.99 m) was nearly proportional to average WSE error at the stream gage locations along the same river reach. Our results provide the first regional assessment of globally derived SRCs that are used in flood inundation mapping.

Rhys Kelly, Ute Kelly

Abstract This paper discusses the development and initial trials of a readiness assessment methodology intended to support more informed, ethical and effective processes of project development and stakeholder engagement within an evolving and increasingly challenging context of Flood and Coastal Erosion Risk Management (FCERM) in England and Wales. In particular, it considers how and to what extent this approach to readiness assessment can be considered an example of social innovation. Drawing on scholarship about social innovation, the paper also considers challenges within the design and implementation of readiness assessment processes. In turn, this supports an exploration of obstacles to and limitations of social innovation, particularly in the context of far‐reaching social‐ecological change.

Zetai Yang, Suzhen Feng, Kaixiang Fu et al.

ABSTRACT The concomitant vibration of flood discharge, which would cause structure damages to hydraulic infrastructure and thus incurs threats to nearby communities, has rarely been addressed yet cries for an effective solution in discharge scheduling of sluice gates. This work improves on the traditional practice (Model‐I) that mainly aims to restrain start‐up and shutdown actions of spillway gates with a new model (Model‐II) that includes a flexible vibration damping rule, in which the sluice gates are grouped in priority to be sequentially committed, and in the same group, a reference gate is prioritised to enforce a uniform discharge from the active outlets and the gates are paired to ensure a symmetrical opening. The case studies in the Xiangjiaba Dam (XD) demonstrate the excellent adaptability of the model to gate opening patterns concluded with field experiments and site monitoring, and comparing the two models reveals that Model‐II can enforce preferable operational rules to deliver safer discharge scheduling and potentially to reduce risks from the concomitant vibration of hydraulic facilities and the turbulent flow field around the dam during flood discharging, though leading to a much higher frequency of starting up and shutting down of sluice gates than the traditional Model‐I.

Prabhasri Herath, Barry Croke, Roslyn Prinsley et al.

ABSTRACT Forest cover within catchments is a widely adopted Nature‐based Solution (NbS) for flood mitigation, offering hydrological benefits such as rainfall interception, enhanced infiltration, and reduced overland flow. Despite its recognized potential, quantitative reviews remain limited, especially at the catchment scale, with effectiveness varying by spatial scale, forest type, and climate. This review synthesizes 50 international case studies involving forest‐based NbS, selected through structured screening based on intervention type, catchment characteristics, and availability of quantitative flood metrics, and presents a detailed bibliometric and content analysis. Forest cover consistently impacts peak flow across catchments of all sizes, with a generalized linear relationship where the effect magnitude is approximately half the forest cover change. For example, a 20% increase in forest cover tends to reduce peak flow by 10% across small, medium, and large catchments. Across a range of catchment sizes, there are only minor differences in the mean peak flow reductions for different event intensities (up to 1% AEP). An asymmetric hydrological response is evident: deforestation consistently increases peak flows, whereas afforestation yields gradual reductions, which are shaped by forest maturity, spatial distribution, and modeling assumptions. Upstream distributed forest placements offer distinct hydrological benefits. These outcomes highlight the importance of conserving mature forests, preventing deforestation, and optimizing forest placement, while acknowledging potential adverse impacts on water availability during dry periods.

Slobodan P. Simonovic, Brian Perry

ABSTRACT This review, based on 231 articles, focuses on studies relevant to Canada that assess fluvial, pluvial, and coastal flood hazards at national and broader scales. It evaluates the application of remote sensing and artificial intelligence methods for flood mapping within the Canadian context. The review highlights a growing trend in large‐scale flood modeling, with increasing relevance for Canadian flood risk management. Methods for downscaling coarse‐resolution flood estimates from physically based models to finer spatial scales are particularly important for Canada's diverse hydrological regions. Global estimates of flood defense standards often rely on socio‐economic indicators, but for Canada, physical hazard factors should also be integrated. Advances in LiDAR and radar remote sensing have improved the accuracy of Canadian flood models by providing detailed topographic data. Artificial intelligence techniques show strong potential for predicting flood inundation and enhancing flood hazard mapping across Canadian landscapes.

Mohamed Elshamy, Youssef Loukili, John W. Pomeroy et al.

Abstract The Yukon River Basin (YRB) is one of the most important river networks shared between Canada and The United States, and is one of the largest river basins in the subarctic region of North America. The Canadian part of the YRB is characterized by steeply sloped, partly glaciated mountain headwaters that generate considerable runoff during melt of glaciers and seasonal snowcover. Snow redistribution, snowmelt, glacier melt and freezing–thawing soil processes in winter and spring along with summertime rainfall‐runoff and evapotranspiration processes are thus key components of streamflow generation in the basin, making conceptual rainfall‐runoff models unsuitable for this cold region. Due to the remote high latitudes and high altitudes of the basin, there is a paucity of observational data, making heavily calibrated conceptual modeling approaches infeasible. At the request of the Yukon Government, this project developed and operationalized a streamflow forecasting system for the Yukon River and several of its tributary rivers using a distributed land surface modeling approach developed for large‐scale implementation in cold regions. This represents a substantial advance in bringing operational hydrological forecasting to the Canadian subarctic for the first time. This experience will inform future research to operation improvements as Canada develops a nationally coordinated flood forecast system.

Ludmila Kuksina, Pelagiya Belyakova, Valentin Golosov et al.

Flash floods are one of the most dangerous hydrometeorological events in the world. The current study investigates flash floods on the northern Black Sea Coast. The data about stochastic and relatively stable factors of flash flood formation (such as hydrological, meteorological, lithological, geomorphological, and anthropogenic parameters) were collected for 22 events. The main trigger of flash floods is heavy rainfall of high intensity in the region but in some cases flash flood occurrence is connected with combinations of several “non-critical” factors. The small watershed area (≤351 km2) of river basins experiencing flash floods promotes very rapid flow concentration. Analysis of extreme precipitation demonstrates significant increasing trends in river basins on the Crimean Peninsula and decreasing a maximum precipitation amount in 5 days (r5d) and 1 day (r1d) in river basins in the Caucasus Black Sea Coast in the 21st century as determined by processing of Integrated Multi-satellite Retrievals for Global precipitation measurement (IMEGR) satellite data. At the same time land network data indicates increasing r5d at the Anapa and r1d at the Tuapse meteorological stations in 1961–2020. More frequent occurrence of flash floods has been suggested in the area due to statistical analysis of the longest precipitation ranges. The main reason for significant social and economic damage is uncontrolled human activity in flooded areas on the northern Black Sea Coast.

Thomas Thaler, Sebastian Seebauer

ABSTRACT Flood risk is often unequally distributed. These inequalities highly depend on socio‐political decisions. The recognition of the needs of individuals within a floodplain needs to be considered as a precondition for reaching justice in flood risk management, especially as people differ in their vulnerabilities and capacities to deal with floods. This paper addresses the question of how vulnerable population groups are recognized in flood risk management used in the federal state of Upper Austria. We use a qualitative research method, which is based on policy, legal documents and strategies and on 32 semi‐structured interviews conducted at different levels. Even though clearly stating the overall policy goal of reducing social vulnerability and inequality, most risk reduction strategies neglect these aspects, which creates an implementation gap regarding recognition justice. Strict adherence to the principle of equality leads to, among others, uniform design levels and cost contributions that undermine the notion of differentiated vulnerability. By contrast, disaster aid payments do use eligibility criteria that recognize social inequalities. However, even if justice principles are implemented, they lack transparency and accountability, which creates a legitimacy gap. Restricting the role of civil servants in the public administration through hybrid governance may narrow implementation and legitimacy gaps.

Cary Coglianese, Colton R. Crum

Foundation models and generative artificial intelligence (AI) exacerbate a core regulatory challenge associated with AI: its heterogeneity. By their very nature, foundation models and generative AI can perform multiple functions for their users, thus presenting a vast array of different risks. This multifunctionality means that prescriptive, one-size-fits-all regulation will not be a viable option. Even performance standards and ex post liability - regulatory approaches that usually afford flexibility - are unlikely to be strong candidates for responding to multifunctional AI's risks, given challenges in monitoring and enforcement. Regulators will do well instead to promote proactive risk management on the part of developers and users by using management-based regulation, an approach that has proven effective in other contexts of heterogeneity. Regulators will also need to maintain ongoing vigilance and agility. More than in other contexts, regulators of multifunctional AI will need sufficient resources, top human talent and leadership, and organizational cultures committed to regulatory excellence.

G. Bornette, Charles P. Henriot, F. Arthaud

Spate floods control sediment, nutrient and biodiversity patterns in river floodplains, but the diachronic effects of spate floods on these compartments are rarely assessed. The effects of a 10-year flood spate on substrate characteristics and aquatic vegetation (community composition and life-history traits) were assessed before and after the spate in eleven former river channels that had become wetlands and varied in flood frequency. The effects of spate flooding on sediment and vegetation were expected to be greater in the less frequently flooded channels. For life-history traits, we expected a greater effect of the flood on tall evergreen species with high leaf area, while species with ruderal traits were expected to be less affected. For sediments, the flood reduced fine sediment cover and organic carbon content, but did not affect nutrient content. Vegetation cover decreased particularly in the most and least frequently flooded channels. Species richness and functional indices were little affected. The disturbance had a significant effect on plant traits, reducing tall evergreen species. This effect on plant characteristics increased as the frequency of overflow increased. The results highlight the key role of erosive floods in maintaining poorly competitive aquatic plants and limiting successional processes in riverine wetlands. Given the importance of plants in maintaining spate floodplain biodiversity, these erosive spate floods are essential to maintain or restore in a context of extreme river regulation.

مریم سلیمانی پراپری آزاد, میر مسعود خیرخواه زرکش, علیرضا مجیدی

مقدمهرشد سریع شهرها و روند صنعتی‌شدن، مشکلات محیط‌زیستی زیادی را در بسیاری از مناطق جهان ایجاد کرده است. آگاهی از روند تغییرات پوشش و کاربری اراضی طی دوره‌‌های زمانی طولانی برای برنامه‌‌ریزان و مدیران به‌منظور ارزیابی و پیش‌‌بینی مشکلات ناشی از این تغییرات بسیار با اهمیت است. سنجش‌ازدور، ابزار مؤثری برای پایش تغییرات پوشش اراضی در مناطق شهری و حوالی آن است. شهر تهران در چند دهه اخیر به واسطه رشد و به دنبال مهاجرت افراد، گسترش زیادی پیدا نموده و اثرات فراوانی بر محیط‌زیست پیرامون خود بر جای گذاشته است. ازاین‌رو، پژوهش حاضر به ارائه مدلی مبتنی بر الگوریتم درخت تصمیم (Decision Tree) جهت طبقه‌بندی و پایش تغییرات کاربری اراضی با استفاده از تصاویر سنجنده TM و MSS در محدوده غرب شهر تهران در فاصله سال‌های 1975 تا 2011 پرداخته است. مواد و روش‌هادر این پژوهش، ابتدا یک تصویر سنجنده MSS و سه تصویر سنجنده TM ماهواره لندست است که در ماه خرداد اخذ شد‌‌ه و سپس داده‌‌های کمکی یعنی مدل رقومی ارتفاع مستخرج از نقشه توپوگرافی 1:25000 سازمان نقشه‌برداری است مورداستفاده قرار گرفته است. بعد از انجام پیش‌پردازش‌ها، با استفاده از شاخص‌های پوشش اراضی از جمله شاخص پوشش گیاهی، روش DT و ترکیب آن با روش طبقه‌بندی حداکثر احتمال طبقه‌های کاربری اراضی استخراج شد. سپس، دقت تصاویر طبقه شده حاصل از DT با کمک ضریب کاپا و دقت کلی ارزیابی صحت شد و در پایان با استفاده از روش مقایسه تصاویر در زمان‌های موردمطالعه تغییرات طبقه‌های مختلف کاربری اراضی محاسبه شد. نتایج و بحثبر اساس یافته‌‌های این پژوهش، صحت کلی طبقه‌‌بندی برای سال 2011، 82 درصد است. همچنین، نتایج پایش تغییرات نشان داد که تراکم فضاهای ساخت‌وساز شده طی دوره زمانی 36 ساله دارای روندی مثبت و رو به افزایش است و در پی آن سایر اراضی در حال کاهش بوده‌اند. تراکم فضاهای ساخت‌وساز شده در سال 1975 با مساحت 2166 هکتار که معادل 8 درصد بوده به 8125 هکتار یعنی 29 درصد در سال 2011 رسیده است. در مجموع درصد تغییرات نسبی آن 21 درصد معادل 5959 هکتار است. با بررسی تغییرات کاربری اراضی در غرب شهر تهران از سال 1975 تا سال 2011 که در نقشه‌ها نمایش داده شده است، می‌‌توان گفت که با توسعه شهرنشینی و افزایش نیاز افراد به خدمات مختلف و نبود فضای کافی برای جوابگویی به این نیازها فضاهای باز و سبز غرب شهر تهران تخریب شده و جایگزین کاربری‌های مختلف شده است.نتیجه‌گیریپژوهش حاضر با هدف پایش پوشش و کاربری اراضی محدوده غرب تهران با دقت بالای طبقه‌بندی از طریق مدل مبتنی بر الگوریتمDT  و تلفیق نتایج طبقه‌بندی حداکثر احتمال با آن به انجام رسید. برای انجام پژوهش از تصاویر ماهواره‌‌ای چندزمانه سنجنده TM و MSS ماهواره لندست و داده‌های کمکی استفاده شده و پس از تهیه نقشه کاربری اراضی هر دوره زمانی، نقشه تغییرات پوشش و کاربری اراضی استخراج شد. نتایج این پژوهش نشان می‌‌دهد که داده‌‌های سنجش‌ازدور همراه با فن‌های طبقه‌‌بندی ترکیبی از توانایی بالایی در استخراج انواع نقشه‌‌های کاربری اراضی و همچنین ارزیابی تغییرات کاربری برخوردارند و همچنین پتانسیل داده‌‌های سنجنده MSS و TM ماهواره لندست را به‌عنوان یک ابزار مناسب و اقتصادی برای تصویر نمودن و تجزیه‌وتحلیل تغییرات پوشش اراضی در طی زمان نشان می‌‌دهد. همچنین نتایج پژوهش حاضر حاکی از آن است که استفاده از روش شاخه‌‌ای یا چندمرحله‌ای برای طبقه‌‌بندی تصاویر ماهواره‌‌ای، دارای مزایایی از جمله کاستن زمان پردازش، بهبود صحت طبقه‌های تعلیم کوچک، به‌کارگیری منابع متفاوتی از داده‌‌ها، مجموعه‌‌های مختلف از خصوصیات و حتی الگوریتم‌‌های متفاوت در هر مرحله از تصمیم‌‌گیری است.

سارا حشمتی, بیژن نظری, محمد رضا نیکو

مقدمه تغییرات اقلیمی و فعالیت‌های انسانی ازجمله عوامل تأثیرگذار بر جریان رودخانه هستند. مشخص کردن سهم تغییرات اقلیمی و فعالیت‏‌های انسانی می‌تواند به مدیریت پایدار منابع آبی کمک کند. تغییرات اقلیمی با تغییرات دما و بارش همراه است که منجر به تغییرات توزیع مکانی و زمانی و الگو بارش می‏‌شود. فعالیت‏‌های انسانی نیز به‌صورت مستقیم و غیرمستقیم بر منابع آب تأثیر می‏‌گذارد. استفاده معقول از منابع آب ازجمله رواناب‏‌ها امری ضروری است. هدف از این پژوهش، تعیین سهم تغییرات اقلیمی و فعالیت‌های‏ انسانی در تغییرات رواناب‏ واقع در شوره‏زار دشت قزوین است.   مواد و روش‌‌ها  دشت قزوین با مساحتی حدود 450000 هکتار در محدوده‏ طول جغرافیایی 49 درجه و 25 دقیقه تا 50 درجه و 35 دقیقه شرقی و عرض جغرافیایی 35 درجه 25 دقیقه تا 36 درجه و 25 دقیقه شمالی، قرار دارد. در این پژوهش ارزیابی روند در مقادیر سالانه بارش، رواناب، دمای هوا و تبخیر و تعرق پتانسیل در دوره زمانی 98-1369 به‌وسیله آزمون من- کندال (Mann-kendall) انجام شد. در ادامه، به‏‌منظور تعیین نقطه تغییر مقدار رواناب از آزمون پتیت و روش منحنی تجمعی دوگانه بارش-رواناب استفاده شد. درنهایت، با استفاده از روش تحلیل حساسیت هیدرولوژیک مبتنی بر فرضیه بودیکو- ژانگ سهم اثرات فعالیت‌های انسانی و تغییراقلیم بر تغییرات رواناب مشخص شد.   نتایج و بحث نتایج تحلیل آزمون من-کندال نشان داد که رواناب در سطح معنی‌داری 0.01 روند کاهشی دارد؛ درحالی‌که دمای متوسط سالانه و تبخیر و تعرق پتانسیل در سطح معنی‌داری 0.01 روند افزایشی را نشان می‌دهد. با وجود کاهش بارش متوسط سالانه در سطح حوضه، روند آماری معنی‌دار بارش مشاهده نشد. همچنین، نتایج براساس آزمون پتیت و  منحنی تجمعی دوگانه بارش-رواناب نشان داد که نقطه تغییر در سری رواناب سالانه، سال 1375 است. درنهایت، با استفاده از روش تحلیل حساسیت هیدرولوژیک مبتنی بر فرضیه بودیکو- ژانگ مشخص شد که  درصد تأثیر تغییر اقلیم و فعالیت‏‌های انسانی به‏ترتیب برابر 0.21- میلی‌متر معادل 61.2- درصد و 0.08 میلی‌متر معادل 61.2 درصد است.   نتیجه‌‌گیری ارزیابی روند در منطقه مورد مطالعه نشان داد که مقادیر رواناب روند کاهشی و دمای متوسط سالانه و تبخیر تعرق پتانسیل روند افزایشی دارند. با بررسی مقادیر آبدهی در سطح شوره‌زار سال 1375، به‌عنوان نقطه تغییر سری زمانی آبدهی متوسط سالانه به‌دست آمد. بر اساس نتایج به‌دست آمده با استفاده از روش بودیکو-ژانگ، اثر تغییر اقلیم بر تغییرات رواناب به‌صورت کاهنده است. همچنین فعالیت‌های انسانی موجب افزایش آبدهی در سطح شوره‌زار شده است.

یحیی پرویزی, زهرا گرامی, محمود عرب‌خدری

مقدمه زوال ساختمان خاک و کاهش نفوذ آب به خاک از نشانه‌های تخریب خاک است که منجر به کاهش پایداری و کیفیت تولید و مشکلات زیست محیطی می‌شود. از روش‌های حفاظت خاک، به طور گسترده برای مهار فرایندهای تخریب خاک و بهبود ساختمان و نفوذپذیری خاک استفاده می‌شود که میزان اثربخشی این روش‌ها در بهبود این شاخص‌ها و کنترل تخریب خاک نیازمند مطالعه و ارزیابی بیشتر است. این پژوهش با هدف بررسی پایداری ساختمان خاک و نفوذپذیری خاک متاثر از عملیات مختلف مدیریت و حفاظت خاک و مقایسه آنها در حوزه آبخیز رزین استان کرمانشاه انجام شده است.   مواد و روش‌ها برای این منظور، هشت نوع عملیات احیایی و حفاظتی رایج اعمال شده در منطقه مورد مطالعه شامل قرق و مدیریت چرای دام، تبدیل دیمزار‌‌‌‌های کم بازده به مرتع، کپه‌کاری و بذرکاری اراضی مرتعی، نهال‌کاری و تغییر کاربری اراضی منابع طبیعی به باغات دیم، اصلاح کاربری اراضی دیم‌زار کم‌بازده به مرتع یا کشت علوفه، نهال‌کاری در جنگل و احداث خطوط تنسیق به منظور ممانعت از خاکورزی در اراضی مرتعی و جنگلی انتخاب و ارزیابی شد. برای ارزیابی با استفاده از الگوی نمونه‌برداری سیستماتیک تصادفی نقاطی در محدوده هر یک از عملیات مورد ارزیابی و شاهد مربوطه برای مطالعه و نمونه‌برداری انتخاب و استفاده شد و پس از حفر پروفیل و نمونه‌برداری از خاک، در آزمایشگاه شاخص‌‌‌‌های پایداری خاکدانه‌ها شامل شاخص‌‌‌های میانگین وزنی قطر (MWD)، میانگین هندسی قطر (GMD) و شاخص نسبت خاکدانه‌های پایدار بزرگتر از 0.25 میلی‌متر (WSA>0.25)، اندازه‌گیری و محاسبه شد. سرعت نفوذ نهایی نیز در عرصه عملیات و شاهد مربوطه با کمک دستگاه نفوذسنج صفحه‌ای، اندازه‌گیری شد. در نهایت، مقایسه آماری مقادیر میانگین شاخص‌های  MWD، GMD ، WSA>0.25 و سرعت نفوذ نهایی در عملیات حفاظت خاک و مناطق شاهد آنها به کمک آزمون T برای نمونه‌های مستقل و نیز مقایسه آماری میانگین شاخص‌های یاد شده در عملیات مختلف با آزمون دانکن به کمک نرم‌افزار SPSS انجام شد.   نتایج و بحث نتایج ارزیابی نشان داد که کمترین میزان شاخص MWD مربوط به تسطیح اراضی و نهال‌کاری به ترتیب به مقدار 0.15 و 0.35 میلی‌متر و بیشترین آن به میزان 1.9، 1.8 و 1.6 میلی‌متر به ترتیب مربوط به عملیات بادام‌کاری 20 و 10 ساله و منطقه جنگلی است. همچنین در عملیات علوفه‌کاری و احداث باغ و بادامکاری 10 ساله، بیشترین مقدار شاخص WSA>0.25 بوده است که نشان از تشکیل خاکدانه‌های درشت و پایدار در اثر عملیات حفاظتی است. در بین هشت عملیات‌‌ مورد بررسی، عملیات بادامکاری 20 ساله بیشترین درصد تغییرات را با شاخص‌‌های MWD و  WSA>0.25 در جهت افزایش و بهبود این شاخص‌‌ها داشته است. همچنین نتایج شاخص سرعت نفوذ نهایی نشان داد که در اثر انجام عملیات حفاظت خاک اصلاح کاربری دیمزار کم‌بازده به نهال‌کاری و تغییر کاربری مرتع به بادامکاری با سابقه10 ساله بیشترین افزایش در مقدار سرعت نفوذ نهایی، به ترتیب به میزان 21.8 و 16 درصد نسبت به شاهد، را نشان داده است.   نتیجه‌گیری در مجموع می‌توان بیان کرد که تأثیر عملیات حفاظت خاک منجر به افزایش سهم نسبی خاکدانه‌های درشت‌تر شده است. اما شاخص نفوذپذیری خاک نتایج متناقضی را نشان داد چراکه علاوه بر اثر عملیات‌های حفاظت خاک مورد ارزیابی، مولفه‌های دیگری نیز در شاخص نفوذ آب به خاک موثر بوده است که مستلزم انجام مطالعات تکمیلی است و در نتیجه بررسی نقش مدیریت، به ویژه مدیریت کاربری در کنترل یا تشدید روند تخریب خاک، ضرورتی جهت بهره‌برداری پایدار از منابع خاک است.

Mubarak Adesina, Nicholas Brake, Liv Haselbach et al.

Abstract In 2021, eight counties in Southeast Texas formed a non‐tax authority flood control partnership to provide a forum for communication, create a regional database and improve flood modeling, early warning, and flood mitigation decisions. This partnership is able to successfully deploy and manage an early warning flood system network at relatively low‐cost by: (i) assigning the university as technical expert and general network administrator so that no additional agency workforce is required to operate and maintain the system, (ii) the flood monitoring system is a simple system and (iii) the data was able to be displayed in real‐time using an existing web‐based dashboard owned and operated by another agency within the partnership. The low‐cost sensors are lightweight and easily mountable which allowed them to be rapidly deployed within a short period of time (73 sensor sites installed within 7‐month window) over a 6000 square mile area. The data is shared with the public, and local, state, and federal agencies to monitor drainage infrastructure, and provide the community with flash flood and roadway closure alerts.

V. Cerone, S. M. Fosson, S. Pirrera et al.

The continuous-time analysis of existing iterative algorithms for optimization has a long history. This work proposes a novel continuous-time control-theoretic framework for equality-constrained optimization. The key idea is to design a feedback control system where the Lagrange multipliers are the control input, and the output represents the constraints. The system converges to a stationary point of the constrained optimization problem through suitable regulation. Regarding the Lagrange multipliers, we consider two control laws: proportional-integral control and feedback linearization. These choices give rise to a family of different methods. We rigorously develop the related algorithms, theoretically analyze their convergence and present several numerical experiments to support their effectiveness concerning the state-of-the-art approaches.

Alessio Dallabona, Patrik Schermann, Mogens Blanke et al.

The application of nonlinear control schemes to electro-hydraulic actuators often requires several alterations in the design of the controllers during their implementation. This is to overcome challenges that frequently arise in such control algorithms owing to model nonlinearities. Moreover, advanced control solutions for this type of systems often introduce input algebraic loops that pose significant design and tuning difficulties. Conventional methods to avoid such loops introduce chatter, which considerably degrade tracking performance and has oil degradation and wear as side effects. This study presents a nonlinear control architecture for hydraulic actuators that comprises low-complexity modules that facilitate robust high performance in tracking and avoids the drawbacks of chatter. The salient feature is a dynamic input-mapping inversion module that avoids algebraic loops in the control input and is followed by dedicated position control. The stability of the closed-loop system is analyzed using arguments from Lyapunov theory for cascaded non-autonomous nonlinear systems. The effectiveness of the proposed solution is evaluated on a high-fidelity simulator of a wind turbine pitch system, and validated on a full-scale laboratory setup that includes a hydraulic pitch system and blade bearing. Appropriate quantitative metrics are used to evaluate the closed-loop system performance in comparison to a state-of-the-art nonlinear design.

Cenk Demir, Mamadou Diagne, Miroslav Krstic

Exploring novel strategies for the regulation of axon growth, we introduce a periodic event-triggered control (PETC) to enhance the practical implementation of the associated PDE backstepping control law. Neurological injuries may impair neuronal function, but therapies like Chondroitinase ABC (ChABC) have shown promise in improving axon elongation by influencing the extracellular matrix. This matrix, composed of extracellular macromolecules and minerals, regulates tubulin protein concentration, potentially aiding in neuronal recovery. The concentration and spatial distribution of tubulin influence axon elongation dynamics. Recent research explores feedback control strategies for this model, leading to the development of an event-triggering control (CETC) approach. In this approach, the control law updates when the monitored triggering condition is met, reducing actuation resource consumption. Through the meticulous redesign of the triggering mechanism, we introduce a periodic event-triggering control (PETC), updating control inputs at specific intervals, but evaluating the event-trigger only periodically, an ideal tool for standard time-sliced actuators like ChABC. PETC is a step forward to the design of practically feasible feedback laws for the neuron growth process. The PETC strategy establishes an upper bound on event triggers between periodic examinations, ensuring convergence and preventing Zeno behavior. Through Lyapunov analysis, we demonstrate the local exponential convergence of the system with the periodic event-triggering mechanism in the $L^2$-norm sense. Numerical examples are presented to confirm the theoretical findings.

Alex D. Hayes, Ryan J. Caverly

This paper presents an estimation and control framework that enables the targeted reentry of a drag-modulated spacecraft in the presence of atmospheric density uncertainty. In particular, an extended Kalman filter (EKF) is used to estimate the in-flight density errors relative to the atmospheric density used to generate the nominal guidance trajectory. This information is leveraged within a model predictive control (MPC) strategy to improve tracking performance, reduce control effort, and increase robustness to actuator saturation compared to the state-of-the-art approach. The estimation and control framework is tested in a Monte Carlo simulation campaign with historical space weather data. These simulation efforts demonstrate that the proposed framework is able to stay within 100 km of the guidance trajectory at all points in time for 98.4% of cases. The remaining 1.6% of cases were pushed away from the guidance by large density errors, many due to significant solar storms and flares, that could not physically be compensated for by the drag control device. For the successful cases, the proposed framework was able to guide the spacecraft to the desired location at the entry interface altitude with a mean error of 12.1 km and 99.7% of cases below 100 km.