Water Level Recorder Research Articles

Inflow Analysis into Bili-Bili Reservoir

Bili-bili Reservoir was built with the main objective of controlling flooding in Makassar City. With a flood control capacity of 41 million m3 with an initial capacity of 347.82 million cubic to 239.76 million cubic due to increased sediment in the reservoir so that if there is high rainfall it has the potential to cause flooding. The research entitled “Inflow Analysis to Bili-Bili Reservoir”, has a problem formulation of how the relationship between rainfall and inflow (discharge) entering the reservoir and how the comparison between inflow based on rainfall data and AWLR (Automatic Water Level Recorder). The purpose of this study was to analyze the relationship between rainfall and inflow discharge into the reservoir and to compare the inflow discharge based on the results of rainfall analysis with the inflow based on AWLR. This study uses secondary data from the Pompengan Jeneberang River Basin Center (BBWS). The regional average rainfall analysis used the Thiessen method, while the Synthetic Unit Hydrograph (HSS) Gama I method was used for flood discharge analysis. For flood discharge analysis, the maximum annual rainfall was selected according to the maximum inflow recorded at the Bilibili Dam AWLR. From the calculation of the HSS Gama 1 parameter, the rise time is 2.72 hours and the peak ordinate is 10.290 m3/second. When compared with the inflow (discharge) data on the Bili-Bili AWLR, the results of the calculation of the discharge with HSS Gama I are smaller in value with a difference of 20.50% to 31.46%.

THE CHARACTERISTIC OF WATERSHED MORPHOMETRY DATA FOR SUPPORTING THE MODIFICATION MODELING OF NAKAYASU SYNTHETIC UNIT HYDROGRAPH

This research aimed to investigate the characteristics of watershed morphometry that affect the main parameter that forms the Nakayasu Synthetic Unit Hydrograph (SUH). The result is will support the modification modeling of Nakayasu SUH. The formulation of time like (in the Nakayasu SUH) itself consists of the physical characteristic such as the main river length (L) that is limited regarding the category of main river length such as L > 15 km and L < 15 km. Due to the specific characteristics of the Nakayasu SUH formulation, this research will focus on the development of the Nakayasu SUH formulation by modification by adding the watershed characteristic parameter to the time lag (tg). This research was conducted in the 23 watersheds in Indonesia, which have the Automatic Water Level Recorder (AWLR) and Automatic Rainfall Recorder (ARR). However, this research is conducted on the 7 morphometry and time lag data that are watershed area (A), the length of the main river (L), river slope (I), river density (D), the river length to the eight point of watershed (Lc), the factor of H (H = L.Lc), watershed perimeter (O = O), and time lag. The time lag of each watershed is analyzed using the straight line method; however, the watershed morphometry data is analyzed by using the software of ArcGIS and analyzing the river/drainage density and the factor of river length and river length to the weight point of watershed. The results show five morphometry variables that very influenced the time lag (one of the variables in the Nakayasu SUH model): A, Lc, H, L, and O. The other two variables are not affected by the time lag: D and K.

Multi-factor tracking of tidal processes in an intermittently open estuarine lake

A multi-factor approach to the assessment of the dynamics of the entrance of small, intermittently open and closed estuarine lakes and lagoons, utilising publicly available data, has been developed. Both conventional and novel methodologies have been employed to provide a more robust evaluation and to expand the range of timescales that can be resolved from these databases. This has been applied to an example on the south coast of NSW, Australia (Durras Lake) to illustrate the methodology. A 20 year water level record was available, including 10 closure and breaching events and with ample time for long period patterns to be identified and studied. The study has shown that these intermittent estuaries have a sequence of regime states, with progression from one regime to another, driven by external forcing. Forcing processes are primarily catchment inflow, ocean waves and ocean tide. The study develops and demonstrates a novel sequence of qualitative and quantitative methods to provide an understanding of varying processes in an intermittently open estuarine lake system. From these analyses, a more comprehensive classification and sequence of different entrance regime states is developed. The analyses and the regimen identified may be applied to any similar estuarine system, facilitating the making of more complete and more robust predictions of entrance conditions. Links to the software are given.

Analysis of Flood Peak Discharge Based on Watershed Shape Factors

Regression analysis can develop unit hydrograph modeling by approaching the peak discharge (Qp) and time to peak (Tp) parameters. The main aim of this study is to design a model of peak discharge based on watershed shape factors. The watersheds used in this study are Bontojai Watershed, Jonggoa Watershed, Kampili Watershed, Maccini Sombala Watershed, and Jenelata Watershed, which have slopes criteria below 10% and have complete recorded data of Automatic Water Level Recorder (AWLR) and Automatic Rainfall Recorder (ARR). The validation results of corrected peak discharge data produce Root Mean Squared Error (RMSE). Then, the peak discharge model was conducted by regression analysis and validated with observed unit hydrographs. The results of this study indicate that the coefficient of determination R2 is 0.963. It means that the independent variable (x), namely the area of the watershed, the length of the main river, and the shape factor of the watershed, influences the peak discharge (Qp) of 96.3%

KAJIAN POLA CURAH HUJAN DURASI PANJANG TERKAIT DENGAN WAKTU KEJADIAN BANJIR DI KABUPATEN ACEH UTARA

North Aceh Regency almost every year experiences flooding due to heavy rains, both due to rain in the area and flooding of shipments due to heavy rains in neighboring districts namely Bener Meriah. Judging from the time of the incident, heavy rains always occur in the final months of each year. The duration of rainfall is two, namely: (a) short duration and (b) long duration. The second limit is the duration of rain 24 hours (1 day), so that the duration of rainfall is long if the time of occurrence is longer than 24 hours. For tropical climates such as the Aceh region known to experience two seasons, namely: a) the rainy season and b) the dry season in terms of climatology, the rainy season is identical to the occurrence of flooding. The dry season or rainy season are related to the time of year, for example the flood season occurs in the final months of each year, the dry season occurs in the middle of the year, especially for the North Aceh region. The objectives of this study are (a) to obtain information on the relatively heavy rainfall distribution pattern for long duration rainfall events, namely 1-day, 3-day, 5-day and 7-daily. (b) Knowing the timing of flood events is calculated based on the movement of the sun. The data used is daily rainfall data obtained from the Lhokseumawe Meteorological Station from 1986 to 2016. The results of the analysis are to find out the maximum rainfall for 1-day, 3-day, 5-day, and 7 daily. Because what was investigated was the pattern of rain, the partial series method was used, namely the possibility of some data being taken in one year. The results of processing data show that the highest incidence of 1-day maximum rainfall occurs in the IV quadrant or week 52 which is equal to 45.9%, in this case the highest number of flood events will occur when the sun moves towards the south. To identify heavy rain events that can cause flooding based on station rainfall data correlated with debits recorded on AWLR (Automatic Water Level Recorder). From the results of the identification that there was an increase in river discharge in November and December.

Determining Extreme Still Water Levels for Design and Planning Purposes Incorporating Sea Level Rise: Sydney, Australia

This paper provides an Extreme Value Analysis (EVA) of the hourly water level record at Fort Denison dating back to 1915 to understand the statistical likelihood of the combination of high predicted tides and the more dynamic influences that can drive ocean water levels higher at the coast. The analysis is based on the Peaks-Over-Threshold (POT) method using a fitted Generalised Pareto Distribution (GPD) function to estimate extreme hourly heights above mean sea level. The analysis highlights the impact of the 1974 East Coast Low event and rarity of the associated measured water level above mean sea level at Sydney, with an estimated return period exceeding 1000 years. Extreme hourly predictions are integrated with future projections of sea level rise to provide estimates of relevant still water levels at 2050, 2070 and 2100 for a range of return periods (1 to 1000 years) for use in coastal zone management, design, and sea level rise adaptation planning along the NSW coastline. The analytical procedures described provide a step-by-step guide for practitioners on how to develop similar baseline information from any long tide gauge record and the associated limitations and key sensitivities that must be understood and appreciated in applying EVA.

Decadal Response of Dokriani Glacier using High-resolution Hydrological Data, Indian Himalaya

Abstract Hydrological studies of glaciers in the Indian Himalaya are very important for understanding the melting processes and assessing the influences of climate change. The diurnal variation in the melt-runoff is controlled by the glacial drainage system. To understand the response of such systems continuous monitoring of hydrological and meteorological data is essential. In the present paper, we have studied the high-resolution data for the assessment of hydrological response of Dokriani Glacier in the upper Ganga basin of Garhwal Himalaya. The data were collected for a period of two years (2011-2012) by establishing an Automatic Weather Station (AWS) and discharge gauging site with the provision of automatic water level recorder (AWLR) near the snout of the glacier. A considerable amount of runoff has been observed at nighttime during the glacial ablation with maximum discharge in the evening and minimum in the morning. The depletion of snow from the glacier surface results into exposure of glacier surface ice and reduction in the holding capacity of water in the glacier. Such variations in the physical condition of a glacier attribute to the changes in the hydrological response of the glacier over time. The effect on the hydrological response has also been studied by analyzing diurnal hydrographs for each ablation month. The hydrological response of the glacier becomes faster with the advancement of the ablation season. Significant changes in the hydrological response of the Glacier are observed over a decade.

Mineralogical, geochemical, and magnetic susceptibility variations in the loess-paleosol sequence from Pattan, Kashmir Valley, India record an enhanced Indian summer monsoon around 35 ka

We present multi-proxy records of bulk chemistry, clay mineralogy, stable isotope composition of soil organic matter (δ13CSOM) and pedogenic carbonate (δ18OSC), and mineral magnetic parameters of a loess-paleosol sequence from Kashmir Valley, India, to infer paleoclimate and paleovegetation during Late Pleistocene. 14C AMS dating brackets the age of paleosols between 40 and 19.6 ka and suggests loess to be > 40 ka. Our study shows that a cold/dry climate prevailed at >40 ka (Late Pleistocene), during which the loess accumulation took place, and a warm/humid climate after that led to the development of soil units, with a prominent warm/humid phase around 35 ka. The range of Chemical Index of Alteration (72–78) and significant amounts of illite and chlorite in the section indicate moderate weathering. High kaolinite content, low chlorite, increased K/C, I/C, K/(I + C) ratio, and presence of poorly crystalline and Al-rich illite by ∼36 ka indicates increasing weathering intensity, likely due to an enhanced Indian Summer Monsoon (ISM). High magnetic susceptibility during 35–32 ka indicates enhanced pedogenesis due to a warm-humid climate. Paleotemperature estimates reveal a relatively warmer (by ∼7 °C) climate during pedogenesis than that at >40 ka. δ13CSOM values (−17‰ to −22.2‰) suggest C3 plants dominated the Kashmir Valley through the Late Pleistocene, however, a short period of enhanced summer monsoon at ∼35 ka favored C4 plant growth. The paleoclimate variability in the loess-paleosol sequence presented here agrees with the Guliya Ice Core δ18O record and high lake water levels in the Tibetan Plateau.

Modification of basic hydrology formulation based on an approach of the rational method at field measurement

The rational method was a simple technique for estimating the design discharge of a small watershed and can be used in a probabilistic approach. The main parameter in the rational method formula was the C coefficient. The rational method was the primary method for determining the peak discharge from surface runoff flow. At the end of the dry season and the beginning of the rainy season, it placed an automatic water level recorder and automatic rain gauges for the initial water level. This field research aimed to correct a simple hydrological formulation with field measurements and build a numerical rainfall modelling based on rainfall simulation, infiltration, land use, and flow parameters according to the relationship model of precipitation. The hypothesis in this study, the basic formulation of hydrology, is simple: it requires experience to fit the theoretical hydrological formula so simply (simplicity). The theory needs to be simplified because it is an experience of field necessary to explain.

Flow Behavior of Boyong River as Revealed by Long-term Hydro-monitoring System

Boyong River is one of many rivers originating from Mt. Merapi, flows across three autonomy administrative of Sleman Regency, Yogyakarta City, and Bantul Regency. The river experiences flood in the form of lava flow several times, and the 1994 and 2010 occurrences were considered the biggest ones along with the river history. In line with the rapid development of information and communication technology, efforts to develop the early warning system due to the Mt. Merapi disaster have been implemented by the Hydraulic Laboratory of Gadjah Mada University 2006. This paper presents the study results of Boyong River flow behavior by analyzing the data obtained from the monitoring system. The Gemawang Weir at Boyong River was selected as the river control point understudy; those include the catchment boundary, the catchment characteristics, and the hydraulic features. Monitoring equipment consists of an automatic water level recorder (AWLR), the flow visualization using a Brinno camera, and the hydrophone monitoring system. The flow hydrograph characteristics and its corresponding sediment transport rate are considered two parameters for identifying the flow behavior. The results show that the precursive and recession times of the flood hydrograph are about 1-3 hours and 3.5-5 hours, respectively.

Peak flood volume and its suspended sediment at various rainfall in Kedungbulus catchment in Gombong, Central Java, Indonesia

Flood is a natural disaster that frequently happens and causes many material and immaterial losses. During flooding, the suspended sediment is carried along by the streamflow. The amount of sediment transported varies and depends on natural and anthropogenic factors. Limited studies have been conducted regarding the relationship between peak flood volume and its sediment content. Therefore, a study with the purpose to understand the relationship of rainfall characteristics, peak flood volume, and suspended sediment was undertaken in Kedungbulus Catchment in Gombong, Central Java, Indonesia. The size of Kedungbulus catchment is 37.8 km2. To collect the required data, an automatic stream water level recorder was installed in the outlet of the catchment. In addition, an automatic and two conventional rain gauges were set up inside the catchment. Hydrograph and statistical analysis were conducted on 2016-2017 data. The results showed that during the study period, the highest peak flood volume occurred on October 8, 2016. The flood duration was 490 minutes, with the time to peak was 135 minutes. At the highest peak flood volume, the stream water was 5,091,221 m3, and the suspended sediment was around 2,394 tons. Rainfall depth significantly affects the peak flood volume and its suspended sediment. The rainfall intensity and Antecedent Soil Moisture Content (ASMC) weakly correlate with peak flood volume and its suspended sediment content.

Using Rose’ and Manning’s Equations to Spatially Quantify Soil Erosion in Lagawe River Sub- Watershed, Ifugao, Philippines

A dynamic, physical model was created to predict soil erosion of Lagawe River Sub-watershed, a sub-watershed of Magat River Watershed, Philippines. Tipping-bucket rain gauge was installed to gather event-based rainfall data and a water-level recorder was installed on a straight segment of Lagawe River to gather water depth. Sediment samples were taken during rainstorm events and were used to calibrate the model. Manning’s equation was used to calculate surface runoff and stream flow velocity. Rose’ and Freebairn’s Equation was used to calculate sediment mass. Geographic Information System was utilized as a tool for modelling using PCRaster Software. The model estimated a total of 57,905,000 m3 of eroded sediments which was generated during Typhoon Koppu (local name, Lando) in year 2015. A Welch Two Sample t-value of -0.25 and a p-value of 0.81 was achieved on the statistical analysis between the measured sediment yield and the output of the model. Since the p-value is greater than 0.05 (5%), there is no significant difference between the output of the physical dynamic model and the measured value for sediment yield. Likewise, the correlation analysis supports this conclusion with a linearly positive R2 value of 0.74.

Application of modified managed aquifer recharge model for groundwater management in drought-prone water-stressed Barind Tract, Bangladesh

The core challenge of Barind Tract (BT), located in the northwest region of Bangladesh, is to make water available for agricultural, drinking, domestic, and other uses and ultimately for the survival of flora and fauna. Over extraction of groundwater for irrigation, less rainfall, fewer sources of surface water, high temperature, and thick top clay that limits the natural recharge are the major causes of continuous depletion of groundwater level (GWL) in the BT, which demands managed aquifer recharge (MAR) technique as the modified form matching with the lithology as well as the aquifer condition of the area. So, the study aimed to design, construct a recharge well (RW) and a water filtration unit as a specific MAR method to evaluate their performance for groundwater recharging through rooftop rainwater harvesting in the Barind Multipurpose Development Authority (BMDA) Mohanpur office campus, Rajshahi under the BT region. In this view, necessary data and information like rainfall, GWL, lithology, and other information related to the study were collected from the BMDA Mohanpur office and field investigation. Lithological samples of the Mohanpur office campus were collected through drilling arrangement, and grain sizes of the aquifer samples were analyzed in the laboratory, then designed the RW and installed at the BMDA Mohanpur office campus accordingly. A water filtration unit was designed considering the average maximum daily rainfall. Rooftop rain waters were collected from the office building and a training shed near the uPVC pipeline, filtered through the sand-gravel filtration media of the filtration unit, and finally recharged to the groundwater through RW. GWL fluctuation of the observation well (OW) installed near the RW was monitored using Auto Water Level Recorder (AWLR). Performances were evaluated based on groundwater recharge, GWL fluctuation with the rainfall, and quality of water. The study found that groundwater recharging occurred significantly, groundwater level rose when rainwater was infiltrated into the groundwater, and water quality parameters remained within the acceptable limit for drinking use according to standards like Bangladesh Drinking Water Standard (2005) and WHO (2008).

Determination of Mining-Induced Changes in Hydrogeological Parameters of Overburden Aquifer in a Coalfield, Northwest China: Approaches Using the Water Level Response to Earth Tides

The determination of changes in hydrogeological properties (e.g., permeability and specific storage) of aquifers disturbed by mining activity is significant to groundwater resource and ecological environment protection in coal mine areas. However, such parameters are difficult to continuously measure in situ using conventional hydrogeological methods, and their temporal changes associated with coal mining are not well understood. The response of well water level to Earth tides provides a unique probe to determine the in situ hydrogeological parameters and their variations. In this study, the tidal responses of well water level were employed to characterize the changes in hydrogeological parameters of the overburden aquifer induced by longwall mining in a coalfield, northwest China. Based on the long-term hourly recorded water level data, two analytical models were used to determine the temporal changes of permeability and specific storage of the overburden aquifer. The results showed that the hydrogeological parameters changed with the longwall coal face advance. When the longwall coal face approached the wells, the aquifer permeability increased several to dozens of times, and the response distance ranged from 80 m to 300 m. The specific storage decreased before the coal face reached wells and recovered after the coal face passed. The results of this study indicate that the hydrogeological parameter changes induced by coal mining are related to the location of the well relative to the coal face and the stress distribution in the overburden aquifer. This study revealed the changes in permeability and specific storage associated with the mining disturbance which could have great significance for quantitative assessment of the impact of mining on overburden aquifer.

Groundwater recharge quantification using multiproxy approaches in the agrarian region of Bundelkhand, central India

The Bundelkhand region is one of the most important agricultural regions in central India, where increasing water demand has put tremendous pressure on groundwater resources. The groundwater is the primary source for domestic, agricultural and industrial purposes in the Bundelkhand region. Here, we focus on the Jhansi district, located in the Bundelkhand region. The study area comes under the semi-arid zone and facing a variable climate condition that has been worsened due to the irregular rainfall. We have compiled numerous datasets such as; depth to water level record, rainfall, surface and subsurface water structures and satellite imagery from various sources. We have prepared spatial plots of groundwater levels using depth to water level data for 1996 and 2016. We have observed marked spatial variation in depth to water level maps during pre- and post-monsoon of 1996 and 2016. The time-series plot of groundwater levels shows both declining and rising trends between 1996 and 2016. We have also estimated groundwater abstraction and recharge during 2016 and correlated them with land use and land cover (LULC) activities and lithological units of the study area. The estimated net groundwater abstraction is about 50943 ha m (ham) during 2016; show marked spatial variation. The estimated recharge for the Jhansi district is about 73464 ham during 2016, of which 63% is from irrigation return flow due to groundwater pumping, 17% from irrigation return due to surface water structures, and remaining from seepage from canal and surface water structures. Our results suggest that the groundwater recharge and abstraction are directly linked to the LULC and lithological units. In addition, results obtained from the present study suggest a ‘safe’ category of groundwater development stage for the Jhansi district during 2016, except for Mauranipur and Bangra blocks. Our results can also be useful for better groundwater resource development and sustainable management.

Prediksi Tinggi Permukaan Air Waduk Menggunakan Artificial Neural Network Berbasis Sliding Window

The water level in the reservoir is an important factor in the operation of a hydroelectric turbine to control water overflow so that there is no excessive degradation. This water control has an influence on the performance and production of hydroelectric energy. The daily reservoir water level (tpaw) recording of PLTA Riam Kanan is carried out through a daily direct measurement and observation process on the reservoir measuring board which is recapitulated every month in excel form. This time series historical data continues to grow every day to become a data warehouse that is still useless if only stored. Extracting knowledge from the data warehouse can be done using one of the artificial neural network data mining techniques, namely backpropagation to predict the next day's tpaw. Historical data for the tpaw time series is presented with a sliding window concept approach based on the window sizes used, namely 7, 14, 21 and 28. The window size represents the number of days as an input layer variable in the backpropagation network architecture to predict the next day's tpaw. Some backpropagation network testing is carried out using a combination of the number of window sizes against the comparison of the amount of training data and test data on the network. The prediction results obtained with the smallest mean squared error (mse) in network testing is 0.000577 as a high accuracy value of the prediction results. The network architecture with the smallest mse using 28 input layers, 10 hidden layers and 1 output layer can be a knowledge that can help the hydropower plant as an alternative in making turbine operation decisions based on the predicted results of reservoir water level.

Characteristics of Duwet Karst Spring Based on Baseflow Index Assessment and its Potential in Fresh Water Supply

<p><em>This study aims to determine the potential of Duwet springs and their availability for supplying fresh water to the surrounding community. we use hydrographs to analyze aquifer characteristics. To analyze the hydrographs, we use water level and spring discharge data. Automatic Water Level Record (AWLR) records water level data for 1 dry season and 1 rainy season every 15 minutes. We use the volumetric method to measure the spring discharge 14 times. We compare the base flow and demand over a year to analyze the potential for fresh water. The results show that the Stage discharge rating curve y = 0.0002e5,453x with R² value of 0.87. Duwet Springs is a perennial spring that has a small discharge (class VI). The largest discharge ever recorded was 0.69 L/s (March 7, 2020) and the smallest recorded was 0.12 L/s (August 21, 2020). BFI value varied between 0.05 and 1 with mean 0.801. The total base flow is 2490675.734 L (rainy season) and 1563419.873 L (dry season). These springs are sufficient for 75% of the rainy season and 84% in the dry season. This indicates that the existence of Duwet springs is very important for the surrounding community.</em></p>

Predicting the Effects of Climate Change on Water Temperatures of Roode Elsberg Dam Using Nonparametric Machine Learning Models

A nonparametric machine learning model was used to study the behaviour of the variables of a concrete arch dam: Roode Elsberg dam. The variables used were ambient temperature, water temperatures, and water level. Water temperature was measured using twelve thermometers; six thermometers were on each flank of the dam. The thermometers were placed in pairs on different levels: avg6 (avg6-R and avg6-L) and avg5 (avg5-R and avg5-L) were on level 47.43 m, avg4 (avg4-R and avg4-L) and avg3 (avg3-R and avg3-L) were on level 43.62 m, and avg2 (avg2-R and avg2-L) and avg1 (avg1-R and avg1-L) were on level 26.23 m. Four neural networks and four random forests were cross-validated to determine their best-performing hyperparameters with the water temperature data. Quantile random forest was the best performer at mtry 7 (Number of variables randomly sampled as candidates at each split) and RMSE (Root mean square error) of 0.0015, therefore it was used for making predictions. The predictions were made using two cases of water level: recorded water level and full dam steady-state at Representative Concentration Pathway (RCP) 4.5 (hot and cold model) and RCP 8.5 (hot and cold model). Ambient temperature increased on average by 1.6 °C for the period 2012–2053 when using recorded water level; this led to increases in water temperature of 0.9 °C, 0.8 °C, and 0.4 °C for avg6-R, avg3-R, and avg1-R, respectively, for the period 2012–2053. The same average temperature increase led to average increases of 0.7 °C for avg6-R, 0.6 °C for avg3-R, and 0.3 °C for avg1-R for a full dam steady-state for the period 2012–2053.

Experimental evaluation of the shore protection potential of the novel REEFS wave energy converter

REEFS is a novel multipurpose patented wave energy converter (WEC) that combines electric energy production with shore protection. The device shows some similarities with natural reefs and detached submerged breakwaters. However, unlike previous ones it is installed with an orthogonal alignment relative to coast line and with a greater freeboard. Exterior stay vanes, are another distinct characteristic of the device. Therefore, the REEFS differentiating functionality of shore protection cannot be directly extrapolated from detached submerged breakwater studies and the effective energy dissipation capacity of this new WEC taking into account its specific characteristics should be investigated. In this article an experimental investigation of the energy dissipation potential of REEFS WEC was implemented. A small scale physical model (1.5:100) was installed in a piston wavemaker flume and tested under regular wave conditions established by applying Froude similarity to typical West Portuguese sea state conditions. Resistive wave gauges were installed upstream and downstream the device, in order to record water level time series. Discrete Fourier transform technique was used to compute the wave energy spectra (WES). Energy dissipation was evaluated by comparing upstream and downstream WES. Two versions of the device were tested: i) without exterior stay vanes; ii) with exterior stay vanes. Regardless of the version, the REEFS model proved to be able to dissipate part of the incident wave energy. This capacity exhibited a dependence on the wave period, globally decreasing as the wave period increased. The version equipped with stay vanes always exhibited a substantially higher energy dissipation. From a relative point of view, stay vanes showed to be more important for long waves. REEFS energy dissipation was not far from the inferior values reported in literature review for submerged breakwaters of comparable dimensions, confirming the expectations about its shore protection functionality.

ROLE OF EARTH OBSERVATION DATA AND HYDROLOGICAL MODELING IN SUPPORTING UN SDGs IN NORTH WEST HIMALAYA

Abstract. The sustainable usage and accurate assessment of water resources in North West Himalaya (NWH) is very important for respective policy makers. NWH receives precipitation from both southwest and northeast monsoon system. The detailed assessment of current and future water resources and hydrological cycle component for NWH river basins using earth observation (EO) satellites and hydrological models is very critical for attaining United Nations sustainable development goals (SDGs) namely, climate action, affordable and clean energy, clean water and sanitation and building resilient infrastructure. Present work highlights the role of various EO sensors and hydrological models and ground based instruments for improved assessment of water resources of NWH river basins. The complete inventory of NWH surface water (including glacier lakes of UK, HP), snow cover, delta SWE and glaciers database was accomplished with Remote Sensing (RS) datasets. Similarly, glacier velocity was estimated for all major glaciers of NWH using feature tracking and differential interferometry (DInSAR) methods. Fully distributed grid based hydrological model was setup for entire NWH and model calibration/validation was done for Beas, Satluj, Upper Ganga and Jhelum river basins. Quantification of relative contribution of snowmelt, glacier melt and rainfall-runoff was estimated for Bhagirathi basin upto Uttarkashi. An extensive network of automatic weather stations (AWS), 27 nos, 10 snow depth sensors, 04 digital water level recorders, two snow pack analysers and 06 long wave solar radiation sensors were installed in various sites of HP and UK for hydro-meteorological data collection, model simulation and validation. A future climate change simulations were done for Beas and Jhelum basins using CORDEX 4.5 and 8.5 scenarios from 2006–2100. Number of flood peaks were found to be increasing in number as well as decrease in total snow fall.