Spatio-temporal characterization of rainfall using an innovative trend and discrete wavelet transformation approaches in Bhakra catchment, India

<p>Using a high-resolution daily gridded rainfall data of 0.25° from the Indian Meteorological Department (IMD), the present study investigates the detailed characteristics of rainfall in the Bhakra Catchment from 1901 to 2019. The long term spatial and temporal rainfall variations in Bhakra Catchment are not well explored. The spatial pattern of rainfall regimes in this catchment is identified by estimating index like the precipitation concentration index (PCI) and seasonality index (SI). Extreme rainfall trends on annual and seasonal basis are examined using the innovative trend analysis (ITA) method. Reliability of ITA was assessed by comparing them with widely applied Mann–Kendall (MK) or modified Mann–Kendall (mMK) test results. Furthermore, the change in two halves of rainfall series is estimated using percent bias technique for estimating changes in rainfall. Changes in slopes are estimated by using Sen’s slope estimator (Q). Discrete wavelet transform (DWT) in conjunction with Sequential Mann–Kendall test (SQMK) is employed to find out the dominant periodicity in rainfall patterns. The effectiveness of the graphical method in qualitative analysis can be seen, while DWT is found efficient in identifying periodicity. Both positive and negative trends are detected in annual and seasonal time series over the study area. The outcomes of this study may be helpful in the planning and management of water resources projects in the catchment along with the planning of mitigation measures to alleviate the effects of climate change under extreme rainfall conditions.</p>

Affinity Propagation Approach for Catchment Classification Applied to Arid Catchments

One of the major issues in the arid region is the availability of hydrological data for hydrological studies of the basins for water resources projects. Since the Kingdom of Saudi Arabia (KSA) is a huge country and contains many arid basins it is awfully expensive and time-consuming to make hydrological networks for studying all these basins. Therefore, the Affinity Propagation (AP) clustering technique is proposed to cluster basins into groups that are similar in morphological, hydrological, and landcover characteristics and defining an exemplar (a representative basin) to each group. This basin is utilized for the installation of a detailed hydrological network. The hydrological response of that basin can be transferred and scaled appropriately to other basins in the cluster since they are hydrologically and morphologically similar. A pilot study is performed on 18 sub-basins in the southwestern part of KSA. GIS software is used to extract basin attributes and the clustering process is performed using the AP cluster packages in R software. The results show that four clusters are obtained based on the morphological attributes (twenty-eight attributes), five clusters based on hydrological attributes (twelve attributes), and three clusters based on land cover and CN (three kinds of landcover as attributes). The AP clustering technique was evaluated by the construction of a correlation matrix that shows a high correlation of 0.817 to 0.999. This study provides a robust technique that is effective and efficient to identify the similarity of catchments and can help hydrologists to develop a catchment management application in arid regions.

Delineasi DAS dan Elemen Model Hidrologi Menggunakan HEC-HMS Versi 4.4

The watershed delineation process is needed and has an essential role in various water resource projects. This study aims to examine the GIS processing function embedded in the latest HEC-HMS software version 4.4 for the delineation of watershed and elements of the hydrological model. In comparison, watershed delineation was also carried out by using ArcGIS software. The area of study is the Bendung subbasin located in Palembang City, where terrain data used is a National DEM data with a spatial resolution of 8 m (0.27 arc-second). The results showed that the boundaries and area of the watershed produced by HEC-HMS 4.4 and ArcGIS showed the same characteristics. The river network produced by the two software shows a slight difference even though the flow patterns are similar. It shows that the level of accuracy and quality of the delineation produced by the HEC-HMS 4.4 is excellent. Besides, elements of the hydrological model can be generated automatically which is not found in previous versions. It allows users to more quickly simulate detailed hydrological models with a large number of elements. Therefore, the use of GIS functions in HEC-HMS 4.4 must be encouraged for various analysis purposes in water resources projects.

Spatiotemporal Variability in the Hydrometeorological Time-Series over Upper Indus River Basin of Pakistan

This paper investigates the spatiotemporal variability in hydrometeorological time-series to evaluate the current and future scenarios of water resources availability from upper Indus basin (UIB). Mann–Kendall and Sen’s slope estimator tests were used to analyze the variability in the temperature, precipitation, and streamflow time-series data at 27 meteorological stations and 34 hydrological stations for the period of 1963 to 2014. The time-series data of entire study period were divided into two equal subseries of 26 years each (1963–1988 and 1989–2014) to assess the overlapping aspect of climate change acceleration over UIB. The results showed a warming pattern at low altitude stations, while a cooling tendency was detected at high-altitude stations. An increase in streamflow was detected during winter and spring seasons at all hydrological stations, whereas the streamflow in summer and autumn seasons exhibited decreasing trends. The annual precipitation showed a significant decreasing trend at ten stations, while a significant increasing trend was observed at Kohat station during second subseries of the study period. The most significant winter drying trends were observed at Gupis, Chitral, Garidopatta, and Naran stations of magnitude of 47%, 13%, 25%, and 18%, respectively, during the second subseries. The annual runoff exhibited significant deceasing trends over Jhelum subbasin at Azad Pattan, Chinari, Domel Kohala, Muzaffarabad, and Palote, while within Indus basin at Chahan, Gurriala, Khairabad, Karora, and Kalam in the second time-series. It is believed that the results of this study will be helpful for the decision-makers to develop strategies for planning and development of future water resources projects.

Design of Expert System for Managing the System of AthTharthar Lake

The operation and management of water resources projects have direct and significant effects on the optimum use of water. Artificial intelligence techniques are a new tool used to help in making optimized decisions, based on knowledge bases in the planning, implementation, operation and management of projects as well as controlling flowing water quantities to prevent flooding and storage of excess water and use it during drought. In this research, an Expert System was designed for operating and managing the system of AthTharthar Lake (ESSTAR). It was applied for all expected conditions of flow, including the cases of drought, normal flow, and during floods. Moreover, the cases of hypothetical operating of flow under extreme conditions were considered. The results showed a good capability of the designed expert system to operate the potential cases for those discharges and with high efficiency. Also the results showed the inability of AthTharthar Lake System to pass the discharge up to 12600 m3/s during floods. It was recommended to accomplish Tigris River training and increasing the level of levees, reshaping the cross-sections and longitudinal section of the river. It was suggested to expanded AthTharthar Head Regulator and the intake canal to accommodate more flood discharges.

Rainfall-Runoff Modeling of Sutlej River Basin (India) Using Soft Computing Techniques

The prediction of the runoff generated within a watershed is an important input in the design and management of water resources projects. Due to the tremendous spatial and temporal variability in precipitation, rainfall-runoff relationship becomes one of the most complex hydrologic phenomena. Under such circumstances, using soft computing approaches have proven to be an efficient tool in modeling of runoff. These models are capable of predicting river runoff values that can be used for hydrologic and hydraulic engineering design and water management purposes. It has been observed that the artificial neural networks (ANN) model performed well compared to other soft computing techniques such as fuzzy logic and radial basis function investigated in this study. In addition, comparison of scatter plots indicates that the values of runoff predicted by the ANN model are more precise than those found by RBF or Fuzzy Logic model.

Quantification of Environmental Flow Requirement of the Khun Dan Prakan Chon Dam Using Hydrological-Hydraulic-Habitat Simulation Methods

With increased water demand, reservoir operation has become more complex with the need to quantify the exact amount of water needed for each demand sector. The environmental flow requirement, also known as instream flow is regarded as the first-prioritized objective of the multipurpose water resources projects in Thailand. The capability of reservoirs in Thailand to allocate water for environmental needs depends on available supply, strategies and operating policy. Therefore, this study aims to assess the environmental flow requirements of Khun Dan PrakanChon Dam using three methods; 1) the hydrological method (Tennant, Tessmann, 7Q10, FDC, and VMF), 2) hydraulic method (R2CROSS and wetted perimeter) and 3) habitat simu-lationmethod, using the PHABSIM model for physical habitat simulation of aquatic organisms in the Nakhon Nayok River. The hydrological approach was performed under the historically-naturalized flow data of the NY.1B station and established hydrologic flow regime during low flow and high flow months. The environmental flow rates obtained from two hydraulic methods were based upon field observations at the NY.1B station significantly. However, the biological conditions and interactions of aquatic organisms in the river were not principally characterized in hydrologic and hydraulic approaches. In addition, the estimated results performed by habitat simulation model gave an additional meaning of ecological flow needs mainly for aquatic habitat conservation in the river. By integrating the conditions of hydrologic and hydraulic flow regimes as well as the habitat conservation objectives, environmental flow rates of 8-10 cm were recommended to determine the downstream release of Khun Dan Prakan Chon Dam; these recommendations were very close to those derived using the Tessmann, 7Q10 and PHABSIM methods-Tennant and flow duration curve methods.

Estimation of Missing Streamflow Data Using Anfis Models and Determination of the Number of Datasets for Anfis: The Case of Yeşilırmak River

Good data analysis is required for the optimal design of water resources projects. However, data are not regularly collected due to material or technical reasons, which results in incomplete-data problems. Available data and data length are of great importance to solve those problems. Various studies have been conducted on missing data treatment. This study used data from the flow observation stations on Yeşilırmak River in Turkey. In the first part of the study, models were generated and compared in order to complete missing data using ANFIS, multiple regression and Normal Ratio Method. In the second part of the study, the minimum number of data required for ANFIS models was determined using the optimum ANFIS model. Of all methods compared in this study, ANFIS models yielded the most accurate results. A 10-year training set was also found to be sufficient as a data set.

Probable Maximum Precipitation Estimation in a Humid Climate

Due to the importance of probable maximum precipitation (PMP) for designing and planning hydraulic structures, the aim of this study is the estimation of 24-hour PMP (PMP24) by using the statistical and physical methods in a humid climate of Qareh-Su Basin which is located in the northern part of Iran. For statistical estimate of PMP, the equations of empirical curves of Hershfield method were extracted. Then the standard and revised approaches of Hershfield method were written in JAVA programming language, as a user friendly and multi-platform application called the PMP Calculator. Convergence model was considered to calculate PMP by physical method. The depth–area–duration (DAD) curves were extracted to estimate PMP24 using physical method and then PMP24 was estimated for each storm. The results showed that for the standard and revised approaches, Km was found to be varied the range of 17–18.0 and 2.2–5.3, respectively. The maximum values of PMP24 for the first approach was obtained 447.7 mm and for second approach was 200.7 mm. Using the physical method, PMP24 was 143.1 mm. The results of this study will be helpful for planning, designing, and management of hydraulic structures and water resources projects in the study area.