Hydrology and water resources

Complementary analysis of satellite mission data (altimetry, Moderate Resolution Imaging Spectroradiometers (MODIS)) and climate fields over 2000–2009 was conducted to investigate the variability of the water cover surfaces and the geographical source of water inflowing into the Lake Poopó system. The results suggest that over the time span of 2000–2009 a great part of the variability of the Poopó system originates from geographic sources other than Lake Titicaca. Possible alternative causes include climate change inducing increased temperatures and greater evaporation rates along the Altiplano; increased glacier and snow melting over the Andes Cordillera; and a potential increased anthropogenic water use (such as irrigation, minery, etc.) throughout the path of the Desaguadero River (which connects lakes Titicaca and Poopó). This change in the hydrology of this region could lead to a collapse of water supplies and endanger the already fragile Poopó system as well as the regional socioeconomic system, which closely depends upon it.

The relatively rapid recession of glaciers in the Himalayas and formation of moraine dammed glacial lakes (MDGLs) in the recent past have increased the risk of glacier lake outburst floods (GLOF) in the countries of Nepal and Bhutan and in the mountainous territory of Sikkim in India. As a product of climate change and global warming, such a risk has not only raised the level of threats to the habitation and infrastructure of the region, but has also contributed to the worsening of the balance of the unique ecosystem that exists in this domain that sustains several of the highest mountain peaks of the world. This study attempts to present an up to date mapping of the MDGLs in the central and eastern Himalayan regions using remote sensing data, with an objective to analyse their surface area variations with time from 1990 through 2015, disaggregated over six episodes. The study also includes the evaluation for susceptibility of MDGLs to GLOF with the least criteria decision analysis (LCDA). Forty two major MDGLs, each having a lake surface area greater than 0.2 km 2 , that were identified in the Himalayan ranges of Nepal, Bhutan, and Sikkim, have been categorized according to their surface area expansion rates in space and time. The lakes have been identified as located within the elevation range of 3800 m and 6800 m above mean sea level (a msl). With a total surface area of 37.9 km 2 , these MDGLs as a whole were observed to have expanded by an astonishing 43.6% in area over the 25 year period of this study. A factor is introduced to numerically sort the lakes in terms of their relative yearly expansion rates, based on their interpretation of their surface area extents from satellite imageries. Verification of predicted GLOF events in the past using this factor with the limited field data as reported in literature indicates that the present analysis may be considered a sufficiently reliable and rapid technique for assessing the potential bursting susceptibility of the MDGLs. The analysis also indicates that, as of now, there are eight MDGLs in the region which appear to be in highly vulnerable states and have high chances in causing potential GLOF events anytime in the recent future.

Flooding is usually thought of as a result of heavy rainfall, snowmelt, land subsidence, rising of groundwater, dam failures. Coastal flooding, river flooding, flash flooding, urban flooding , and snowmelt flooding are kinds of flooding. Among them, flash flooding and river flooding occurs often, and negatively impacts human lives and economic asset in Ethiopia. As flood risk and its impacts are increasing from time to time in Ethiopia, the main objective of this paper is to review flooding and it`s coping mechanisms in Ethiopia. The factors affecting flooding are the size of the catchments, the intensity of rainfall and amount of precipitation that fall under the watershed and tributaries, topography, the presence and absence of vegetation, anthropogenic activity within the catchment areas and catchment area are discussed within this paper. And also, the mechanism of reducing flood impacts like flood alert and metrological forecasting agency established but the cop ing and mitigation strategies are very low in Ethiopia. So that, forward suggestions are these strategies need to supplement one another, their coordination must include "multi-actor, multi-level, and multi-sector involvement and is realized for instance, by collaborative leadership. Stakeholder and community involvement and a standard knowledge basis also are fundamental. Check dams, terracing, bunds, percolation tanks, and storage tanks were proposed for various locations across the watershed as effective landscape-based flood risk mitigation strategies. Moreover, the coping strategies are very needed like insurance, perennial crops farming along with flood-prone areas and within the river's bank, and the waterway management is more needed to reducing the river flood inundate. This review recommends new policy approaches that will increase the effectiveness of the present flood coping strategies to sustainably address the impact of flooding on human health.

Enhanced streamflow forecasting has always been an important task for researchers and water resources managers. However, streamflow forecasting is often challenging owing to the complexity of hydrologic systems. The accuracy of streamflow forecasting mainly depends on the input data, especially rainfall as it constitutes the key input in transforming rainfall into runoff. This emphasizes the need for incorporating accurate rainfall input in streamflow forecasting models in order to achieve enhanced streamflow forecasting. Based on past research, it is well-known that an optimal rain gauge network is necessary to provide high quality rainfall estimates. Therefore, this study focused on the optimal design of a rain gauge network and integration of the optimal network-based rainfall input in artificial neural network (ANN) models to enhance the accuracy of streamflow forecasting. The Middle Yarra River catchment in Victoria, Australia was selected as the case study catchment, since the...

In the first multipurpose river valley planning of India, the vast resources of Damodar River Basin (DRB) (eastern India) are not only to be envisioned in their entirety but also to be developed in a unified manner where the water, land, and people are simultaneously bounded in a seamless web. Four large dams (Konar, Tilaiya, Maithon, and Panchet), Durgapur barrage, and Tenughat reservoir are built to tamp the flood-prone Damodar River using water resource in an integrated method. The functionality of Damodar fluvial system is controlled by dams, barrage, weirs, sluices, embankments, and canals, maintaining a dynamic equilibrium between fluvial processes and anthropogenic processes. Carrying more than 50 years of legacy, the existing drainage and flood control system of Damodar Valley Corporation has aggravated a number of hydrogeomorphic problems especially in lower DRB, viz. siltation of river bed and reservoirs, uncontrolled monsoonal stream flow, declining carrying capacity of lower course, drainage congestion, low-magnitude annual floods, channel shifting, de-functioned canals, decay of paleochannels, decline of ground water level, and less replenishing of soils with fresh silts. The present paper is mainly tried to investigate the pre-dam and post-dam hydrogeomorphic variability in relation to flood risk and drawbacks of Damodar Valley Multipurpose Project. Specifically, the annual peak flow of Damodar shifts from August to September due to dam construction and reservoir storage. Applying the annual flood series of log Pearson type III distribution, we have estimated post-dam 5-year peak discharge of above 5,300 m3 s−1 and 100-year flood of above 11,000 m3 s−1. Due to siltation, the bankfull discharges of sample segments are gradually declined up to 4,011 m3 s−1, 2,366 m3 s−1, and 1,542 m3 s−1, respectively, having recurrence interval of 1.18–3.18 years only. With the regulation of monsoon flow, the standard sinuosity index is gradually increased downstream, having high dominance of hydraulic factors in respect of topographic factors. The upstream section of study area (Rhondia to Paikpara) now shows the dominance of aggradational landforms, braiding, avulsion, high width–depth ratio, breaching of right bank, and valley widening, but downstream of Barsul the phenomena of bank erosion, confined sinuosity, low width–depth ratio, and narrowness are more pronounced.

The term morphometry is used in several disciplines to mean the measurement and analysis of form
characteristics. This study incorporates morphometric linear, aerial and relief aspect of fluvial characteristics
of Paisuni river basin. Paisuni river basin covers 571.44 sq km area. Entire drainage network is spread over
Sandstones, Limestone and Alluvium with undulating topography. Paisuni river has dendritic drainage
pattern. Bifurcation ratio is above 3 which indicate that basin has undulating topography. Mean bifurcation
ratio is 3.59 which shows that basin is highly structurally distorted. Relief ratio is 8.8 m/km which shows
moderate to high relief of basin. Drainage density & frequency are more and drainage texture is fine which
shows that basin is impermeable and having low ground water recharging characters with sparse vegetation.
Form factor and circulatory ratio indicates basin shape is elongated. Longitudinal profile shows that basin
has high relief in first order drainages and as drainage order increases, relief decreases and finally converts
into flat basin at the outlet. Present study is useful to identify the sites for artificial recharging structures to
reduce the surface runoff.

Iran, once the pioneer of sustainable water management in the arid region of the world, is now experiencing a serious water crisis, reflected by its drying lakes and rivers, declining groundwater resources and deteriorating water quality. Water supply rationing and disruptions are becoming more frequent, agricultural losses are increasing and ecosystem damages are expanding. While decision-makers prefer to blame the current crisis on droughts, climate change and international sanctions, the dramatic water issues of Iran are rooted in decades of shortsighted and disintegrated planning. The public, experts and media continuously warn about the major water crisis symptoms without seriously discussing the causes. But, what are the main drivers of Iran's water crisis? Crisis driver 1: population growth and spatial distribution Iran has experienced a significant population growth in the last century. Its population almost doubled within the last two decades of the 20th century, right after the 1979 Revolution, which promoted different socioeconomic , cultural and ideological changes in Iran. In addition to a sudden population growth, rapid urbanisation and inappropriate spatial population distribution are challenging Iranian water managers. Th e urban population is currently about 70 per cent, compared to 44 per cent in the 1970s. Eight Iranian cities have a population of greater than one million while the population in metropolitan Tehran has surpassed 14 million (18 per cent of the country's population). Despite the consequences of population growth policies, the government of Iran is now showing a strong interest in boosting the current population growth rate of 1.3 per cent. This interest is rooted in concerns about the projections of age distribution in the future. What is clear though is that Iran definitely lacks the required water resources and infrastructure to satisfy increased water demand. Without strong spatial population distribution adjustments and water consumption reduction measures, population growth can have catastrophic effects.

The Abbay basin is marked by high and rugged mountains, flat topped plateaus, deep gorges, river valleys and plains. The remarkable geographical diversity has implications for the uniqueness of the basin
and in how its watershed needs to be managed in order to ensure sustainable economic development that is resistant to the reality of climate change and global warming on one hand and to enable environmental restoration that can support development aspirations on the other hand.
The Abbay basin provides the major water supply of the Blue Nile river
along with other demographic and ecological assets. The Abbay basin is the most important river basin in Ethiopia and in the rest of sub-Sahara Africa. It accounts 50% of Ethiopia total average annual rainfall runoff. It holds the largest fresh water lake in the country known as Lake Tana and is the home of diverse flora and fauna.
This water atlas describes present factual information on water resources information of the Abbay basin, its spatial and temporal
distribution and uses. The atlas also makes extensive use of illustrations to present facts, characteristics and trends with respect to the water related information of the Abbay basin and serves as shared knowledge base on Abbay.

Generally, low flow in rivers occur as a result of extended period of dryness which is likely attributed to drought. Drought is a natural occurrence as an outcome of reduction in precipitation in a region for a long time. Hence, low flow is a growing concern as there are possibilities of more reduced flows in rivers. However, reservoirs can be utilized to mitigate negative effects on the supply of water in dry periods and supply water for other purposes. This study aims at verifying how the low flow condition of Glomma River in Norway has been progressively sustained by hydropower reservoirs. Water Evaluation and Planning Systems (WEAP) software was used for modelling the natural streamflow condition of Glomma River, which is the longest river in Norway, using two unregulated sub-basins within the Glomma catchment. Findings from this study presents that the period between January and March are critical periods in Glomma River. Results show that the values the annual minimum low flow gotten from the three gauges suggest the flow after regulation has increased significantly as opposed to before regulation. The daily average flow is simulated by WEAP to be an average of 100 m 3 /s during the low flow periods and an average discharge of 350 m 3 /s during the summer. However, the result indicates that the flow in the summer has reduced by 80% in majority of the years. In addition, Nash Sutcliffe efficiency (NSE) for the two sub basins used for this study was 0.9 and 0.76, respectively. Also, the calculation of the coefficient of determination (R 2) resulted in 0.85 and 0.78 respectively for the two sub basins. In particular, findings from this study presents evidence on the low flow condition in Glomma River prior to its regulation and how the regulation has sustained the flow.

L’Encyclopédie de Diderot et d’Alembert consacre quelques lignes à l’Adour qui est défini comme une « rivière de France qui prend sa source aux montagnes de Bigorre, et se jette dans la mer par le Boucaut neuf. Il y a en Gascogne deux autres petites rivières de même nom qui se jettent dans la première.  » Pourtant au XVIIIe la vallée de l’Adour, à partir de Bagnères et plus encore en amont vers Campan, devient un espace majeur dans les récits des voyageurs et explorateurs qui parcourent les Pyrénées. Les descriptions enthousiastes ne manquent pas pour célébrer la richesse et les paysages agrestes d’une « vallée heureuse », « nouvelle Arcadie » ou encore des « Champs Elysées ». Parmi tous les écrits citons, à la suite d’Henri Béraldi, celui de Guibert qui écrit à ce propos dans ses Voyages « La beauté, la richesse extraordinaire de la vallée de Campan, d’où étaient presque tous ces habitants, m’a expliqué ensuite cet air d’une plus grande aisance. J’ai remonté à cheval, et, de Grippe (sic) à Bagnères, traversé la vallée de Campan dans toute sa longueur. J’avais beaucoup entendu parler de cette vallée, et il faut, en effet, que tout lui cède : du moins n’ai-je rien vu dans ma vie d’aussi agréable par le mélange des cultures, par l’industrie des prairies, par le nombre prodigieux d’habitations, par la quantité d’eaux, par la coupe des canaux, et par les sites pittoresques; celui du Prieuré de St. Paul m’a surtout frappé. Cette vallée n’a pas moins de trois lieues de long, sur une de large quelquefois, y compris les pentes, qui remontent aussi haut que la végétation peut atteindre.  » Mais curieusement Guibert pondère son enthousiasme en comparant la vallée de Campan aux « belles vallées de la Suisse »  et nomme la rivière qui y coule le « Gave de Bagnères » ! Force est de constater que le fleuve et ses affluents sont bien souvent secondaires voire absents ! C’est donc à eux que nous allons nous intéresser plus précisément.
L’Adour est certes dans la très grande majorité des territoires qu’il traverse un « cours d’eau gascon » (actuels départements des Hautes-Pyrénées, Gers, Landes et Pyrénées-Atlantiques) mais son embouchure du Boucau-Neuf se trouve dans le Labourd et son nom d’ailleurs a pour origine un terme utilisé par les premières populations qui habitaient ces lieux avant la conquête romaine. Mais l’Adour est plus qu’un cours d’eau, c’est un fleuve et même le second par sa longueur qui naît dans les Pyrénées . Avant de se jeter dans le Golfe de Gascogne, l’Adour prend ses sources dans les montagnes de Bigorre et est formé des Adours de Gripp, de Payolle et de Lesponne dont les eaux servent à irriguer les terres agricoles d’une vallée fertile, a actionné moulins et foulons, puis les industries et usines hydroélectriques. Mais l’Adour a aussi un cours original et pas si tranquille… Parfois il disparaît et réapparaît comme par mystère, à d’autres moments il déborde causant de graves dégâts et emportant tout sur son passage, soudainement il creuse un nouveau lit ! Alors partons à la découverte au fil de l’eau de ce fleuve intranquille…

An example of carrying out unit hydrograph convolution in order to get the full Hydrograph of a catchment for a given hyetograph is explained in steps. Matrix manipulation using Excel is used for this regard and a simple user defined function is developed to facilitate building the Precipitation Matrix. Using the developed function, it becomes easy to just drag and create the full P matrix in an automated way.

Wang, Lawrence K. and Wang, Mu-Hao Sung (2022). Understanding evaporation, transpiration, evapotranspiration, precipitation and runoff volume for agricultural waste management.  In: "Evolutionary Progress in Science, Technology, Engineering, Arts, and Mathematics (STEAM)", Wang, Lawrence K. and Tsao, Hung-ping (editors).  Volume 4, Number 5, May 2022; pp.81. Lenox Institute Press, MA, USA. STEAM-VOL4-NUM5-MAY2022.  ISBN 978-0-9890870-3-2.  https://doi.org/10.17613/m8tf-zd10. ................ABSTRACT:  This is one of several updated UNIDO (United Nations Industrial Development Organization) training reports which were previously disseminated to developing countries for promoting the US green environmental biotechnology. This publication introduces (a) natural evaporation from water and land surfaces and the evaporation equations using either metric units or the US customary units; (b) natural transpiration and evapotranspiration phenomenon ; (c) the description, applications, limitations, design criteria and performance of evapotranspiration wastewater treatment process; (d) precipitation and the US historical 25-year 24-hour rainfall chart; (e) the parameters of dry-weather flows, runoff from rainfall, runoff from snowmelt, runoff volume (ROV), and total precipitation less evaporation (TPLE) value for storage pond design; (f) the temperature, effect of wind chill and wind chill equations using either metric units or the US customary units; (g) the adjusted mean monthly free water surface (FWS) evaporation for selected US stations; (h) the US annual FWS evaporation chart; (h) the US annual runoff from concrete or unsurfaced feedlots as percent of mean precipitation charts; (i) the US runoff from concrete or unsurfaced feedlots as percent of mean monthly precipitation charts; (j) the US criteria for siting, investigation and design of liquid manure storage facilities; (k) precipitation and condensation calculation; (l) the vapor pressure mathematical model and evaporation analysis for an agricultural storage pond; (m) a runoff determination example; (n) an example of runoff from an agricultural concrete feedlot; (n) an example of runoff from an earth feedlot; (o) an example of agricultural storage pond design ; and (p) glossary terms and research references. The US technical information, charts and examples presented in this publication are typical examples for developing countries to follow, in order to avoid or reduce the unnecessary non-point sources of agricultural pollution, in turn, to achieve the UNIDO's goal of sustainable industrial and agricultural development around the world.

PT Ulima Nitra merupakan salah satu kontraktor pertambangan yang berada di Sumatera Selatan. Secara umum lokasi tambang berada di daerah perbukitan dengan ketinggian antara 40 -90 mdpl dengan curah hujan yang relatif sedang. Dalam metode penambangan surface mining yang diterapkan PT Ulima Nitra, seiring kemajuannya tambang akan menyerupai cekungan besar. Air akan terkonsentrasi di dalam cekungan tersebut dan akan menghambat aktivitas penambangan . Air yang masuk ke lokasi penambangan sebagian besar berasal dari air hujan yang mengalir pada catchment area, untuk mengatasinya dilakukan dengan menerapkan sistem dewatering yang baik agar air tidak menggenangi tambang dan menggangu aktifitas produksi. Untuk perencanaan dewatering di pit PT Ulima Nitra, curah hujan yang direncanakan adalah 38,983 mm/hari dan catchment areanya adalah 27,35 Ha. Berdasarkan perhitungan pompa yang sesuai dengan kondisi di area penambangan PT Ulima Nitra adalah pompa dengan kapasitas debit sebesar 720 m 3 /jam. Jika menggunakan pompa dengan kapasitas 720 m 3 /jam maka, head total pompa adalah 66,6 m dan head aktual adalah 42,47 m pada jalur main sump ke kolam pengendapan lumpur PT Ulima Nitra dengan kecepatan putaran mesin paling efisien sebesar1800 rpm. Pompa yang sesuai dengan debit sebesar 720 m 3 /jam adalah pompa Multiflo type CF-48H.

Hydrological models are vital component and essential tools for water resources and environmental planning and management. In recent times, several studies have been conducted with a view of examining the compatibility of model results with streamflow measurements. Some modelers are of the view that even the use of complex modeling techniques does not give better assessment due to soil heterogeneity and climatic changes that plays vital roles in the behavior of streamflow. In Malaysia, several public domain hydrologic models that range from physically-based models, empirical models and conceptual models are in use. These include hydrologic modeling system (HEC-HMS), soil water assessment tool (SWAT), MIKE-SHE, artificial neural network (ANN). In view of this, a study was conducted to evaluate the hydrological models used in Malaysia, determine the coverage of the hydrological models in major river basins and to identify the methodologies used (specifically model performance and evaluation). The results of the review showed that 65% of the studies conducted used physical-based models, 37% used empirical models while 6% used conceptual models. Of the 65% of physical-based modelling studies, 60% utilized HEC-HMS an open source models, 20% used SWAT (public domain model), 9% used MIKE-SHE, MIKE 11 and MIKE 22, Infoworks RS occupied 7% while TREX and IFAS occupy 2% each. Thus, indicating preference for open access models in Malaysia. In the case of empirical models, 46% from the total of empirical researches in Malaysia used ANN, 13% used Logistic Regression (LR), while Fuzzy logic, Unit Hydrograph, Auto-regressive integrated moving average (ARIMA) model and support vector machine (SVM) contributed 8% each. Whereas the remaining proportion is occupied by Numerical weather prediction (NWP), land surface model (LSM), frequency ratio (FR), decision tree (DT) and weight of evidence (WoE). Majority of the hydrological modelling studies utilized one or more statistical measure of evaluating hydrological model performance (R, R 2 , NSE, RMSE, MAE, etc.) except in some few cases where no specific method was stated. Of the 70 papers reviewed in this study, 16 did not specify the type of model evaluation criteria they used in evaluating their studies, 17 utilized only one method while 37 used two or more methods. NSE with 27% was found to be the most widely used method of evaluating model performance; R and RMSE came second with a percentage use 24% each. R 2 (20%) was recorded as the third most widely used model evaluation criteria in Malaysia, MAE came fourth with 16% while PBIAS is the least with 11%.The findings of this work will serve as a guide to modelers in identifying the type of hydrological model they need to apply to a particular catchment for a particular problem. It will equally help water resources managers and policy makers in providing them with executive summary of hydrological studies and where more input is needed to achieve sustainable development.

The amount of electricity generation and its availability to the residents of a country reflects its level of development and economic condition. Water being one of the cheapest and renewable sources of energy, is being used to produce one-quarter of the total electricity production in Pakistan. This article presents a forecasting study of hydroelectricity consumption in Pakistan based on the historical data of past 53 years using Auto-Regressive Integrated Moving-Average (ARIMA) modeling. Based on the developed forecasting equation, the hydroelectricity consumption was predicted up to the year 2030. For validating the reliability of the forecasted data, the results were compared to the actual values which showed good fit with minimum deviation. The forecasted values of hydroelectricity consumption revealed an average annual increment of 1.65% with a cumulative increase of 23.4% up to the year 2030. The results were compared with the hydroelectricity generation plans of the Government of Pakistan for its effectiveness. A sensitivity analysis was also performed to study the relation of hydroelectricity consumption to the annual population and GDP growth rate of the country. The research shall significantly prove to be useful in better planning and management of water resources of Pakistan for future.

SEDIMENT YIELDS ESTIMATION AND IDENTIFICATION OF
THEIR SOURCES IN LAKE TANGANYIKA BASIN
The Case of Mulongwe Sub Catchment – Uvira City – DRCongo
Ongezo Muzaliwa Séverin
University of Dar es Salaam, College of Engineering and Technology,
Department of Water Resources Engineering.
Université Officielle de Bukavu (UOB) / DR Congo, B.P 570 BUKAVU
Mail: ongmuzseverin@gmail.com
1. ABSTRACT
Soil erosion / sedimentation are immense problems that have threatened water resources development in the
Tanganyika basin, particularly in the northwest of Lake Tanganyika (Mulongwe sub catchment in Uvira City). This
study was conducted in Mulongwe sub catchment (DRCongo) to set up and calibrate model, to estimate the
sediment yields in the sub catchment and identify the sediment sources. The required input data for this study were
Digital Elevation Model (DEM) with spatial resolution of 30x30m, Land use/cover and soil map for the year 2004.
Eight types of land use/cover have been determined and two types of soil in the study area. The hydro
meteorological observations were set up around the Mulongwe sub catchment. Stream flows and sediment loads
were monitored from two years 1 999 and 2004 at Mulongwe gauging site on the main Mulongwe River. Sediment
sources have been determined by fing printing method and water chemistry.
Model performance evaluation statistics for calibrating daily stream flow and sediment were satisfactory with NSE
and R2 greater than 0.62 and 0.71 respectively. For the validation the NSE and R2 were also greater than 0.56 and
0.63 respectively. Sediment erosion rate were in the range of 0.17-5.23tons/ha/yr with average of 0.53tons/ha/yr and
average amounts of 6,096tons/yr for sediment yields. The sediment sources should be the weathering of rocks,
tectonic effects and anthropic activities in the study area.
Key words: Sedimentation, Erosion, AVSWAT2005, Weathering and Landslide

Hydrological data collection requires deployment
of physical infrastructure like rain gauges, water level
gauges, as well as use of expensive equipment like echo
sounders. Many countries around the world have recorded a
decrease in deployment of physical infrastructure for hydrological
measurements; developing countries especially have
less of this infrastructure and, where it exists, it is poorly
maintained. Satellite remote sensing can bridge this gap, and
has been applied by hydrologists over the years, with the earliest
applications in water body and flood mapping. With the
availability of more optical satellites with relatively low temporal
resolutions globally, satellite data are commonly used
for mapping of water bodies, testing of inundation models,
precipitation monitoring, and mapping of flood extent. Use
of satellite data to estimate hydrological parameters continues
to increase due to use of better sensors, improvement in
knowledge of and utilization of satellite data, and expansion
of research topics. A review of applications of satellite remote
sensing in surface water modelling, mapping and parameter
estimation is presented, and its limitations for surface
water applications are also discussed.

The fate of seasonal river ecosystem habitats under climate change essentially depends on the changes in annual recharge of the river, which are related to alterations in precipitation and evaporation over the river basin. Therefore , the change in climate conditions is expected to significantly affect hydrological and ecological components, particularly in fragmented ecosystems. This study aims to assess the impacts of climate change on the streamflow in the Din-der River basin (DRB) and to infer its relative possible effects on the Dinder National Park (DNP) ecosystem habitats in Sudan. Four global circulation models (GCMs) from Coupled Model Intercomparison Project Phase 5 and two statistical downscaling approaches combined with a hydrological model (SWAT – the Soil and Water Assessment Tool) were used to project the climate change conditions over the study periods 2020s, 2050s, and 2080s. The results indicated that the climate over the DRB will become warmer and wetter under most scenarios. The projected precipitation variability mainly depends on the selected GCM and downscaling approach. Moreover, the projected streamflow is quite sensitive to rainfall and temperature variation, and will likely increase in this century. In contrast to drought periods during the 1960s, 1970s, and 1980s, the predicted climate change is likely to affect ecosystems in DNP positively and promote the ecological restoration for the habitats of flora and fauna.

Land use planners require up-to-date and spatially accurate time series land resources information and changing pattern for future management. As a result, assessing the status of land cover change due to population growth and arable expansion, land degradation and poor resource management, partial implementation of policy strategies, and poorly planned infrastructural development is essential. Thus, the objective of the study was to quantify the spatiotemporal dynamics of land use land cover change between 1995 and 2014 using 5 multi-temporal cloud-free Landsat Thematic Mapper images. The maximum likelihood (ML)-supervised classification technique was applied to create signature classes for significant land cover categories using means and variances of the training data to estimate the probability that a pixel is a member of a class. The final Bayesian ML classification resulted in 12 major land cover units, and the spatiotemporal change was quantified using post-classification and statistical change detection techniques. For a period of 20 years, there was a continuously increasing demand for arable areas, which can be represented by an exponential growth model. Excepting the year 2009, the built-up area has shown a steady increase due to population growth and its need for infrastructure development. There was nearly a constant trend for water bodies with a change in slope significantly less than +0.01%. The 2014 land cover change statistics revealed that the area was mainly covered by cultivated, wood, bush, shrub, grass, and forest land mapping units accounting nearly 63%, 12%, 8%, 6%, 4%, and 2% of the total, respectively. Land cover change with agro-climatic zones, soil types, and slope classes was common in most part of the area and the conversion of grazing land into plantation trees and closure area development were major changes in the past 20 years.

This study examined the consequence of refuse disposal in Calabar South Local Government Area of Cross River State, Nigeria. This study was conducted in January of 2021. This study targeted staff of the Cross Rivers Urban Development Agency (CUDA) and heads of households within Calabar South for sampling. Seven major streets were selected for sampling based on population density and the large amounts of waste generated. The streets comprised Palm Street, Main Avenue, Goldie Street, Afokang Street, Edibe Street, New Airport Street and Howkins road. The research used a table of random numbers to conveniently select 30 households from each street, which amounted to 210 households. Heads of households irrespective of gender constituted the responds for this study. Data collection was guided by the checklist method in Tong et al (2007). All the authors of this study comprised members of the survey team for this study. Data collection was by means of reconnaissance survey of the study area, taking of photographs using digital camera, key informant interviews on CUDA officials and questionnaire administration on heads of households. The research employed a survey approach, and a simple percentage that was used to analyzed the questionnaire with photographs that provided a qualitative analysis. The study revealed that, dumping of refuse on drainage pathways has effect on the environment and man. however, the research recommend that waste management agencies should always embark on awareness programs, provision of bigger waste bins should be made available and located close to residents, more funds should be allocated to waste management agencies.
Keywords: domestic waste management, refuse disposal, drainage system, Calabar South Nigeria, household hazardous wastes (HHW)

In this study, morphometric analysis and prioritization of the four sub catchments of Vashishthi Watershed located between Ratnagiri district in Maharashtra state, India is carried out by employing Remote Sensing and Geographic Information System (GIS) techniques using satellite imageries and topographic maps on a scale map of 1:50000. Vashishthi watershed has dendritic drainage pattern. The morphometric parameters are discussed about Linear, Aerial and Relief aspect. The drainage density of the study area varies from 0.730 to 0.742 Km/km 2 which observed that high permeable subsoil. The bifurcation ratio varies from 1.9 to 2.6 which indicates geology is reasonable homogeneous and no structural disturbances. The morphometric analysis explains sub catchment 3 shows lower values of drainage density and stream frequency, and sub catchment 1 shows lower values of form factor, texture ratio and elongation ratio. The compound parameter values are calculated and the lowest compound parameter value is given the highest priority. The results of this analysis would be useful in distribution of streams network with respect to sub watersheds and determine the effect of characteristics of the catchments such as shape, size, slope.

Major river valleys (e.g. Ganga, Brahmaputra, Narmada, Godavari, Kosi etc.) of India have remained as cradles of human livelihood and achievements throughout the course of human history. In the same way, contributing with floods the Damodar valley of eastern India is nurturing its civilization in different phases through almost 3,500 year. Documented history of ruinous extreme floods is more than 347 years old (1665 – 2012) in the Damodar River. It is true that when this river is in the extreme phase, none can withstand against its power. Still we are not now fully capable to manage the adamant nature of river particularly in the monsoon period. Simultaneously the uncertain event, e.g. cloud burst, heavy monsoon rainfall and cyclones etc., and resultant flash floods are not forecast accurately. As the catchment of Damodar has good physiographic and hydro-meteorological potentiality of floods, it is imperative to know the current status of flood probability and risk. So here an attempt is made to investigate the temporal variation (i.e. natural phase – without dams and controlled phase – with dams) of annual peak flows understanding the dam induced flood hydrological changes in the Damodar River. Using the quantitative techniques, viz., Flood Potential Index (FPI), Flash Flood Magnitude Index (FFMI) and Flood Frequency Analysis (FFA), the magnitude of flash floods and channel dimensions are analyzed to derive significant explanation and prediction about the flood risk in the lower segment of Damodar River.

Abstract
In East Africa where wetlands are becoming essential systems for waste water treatment and potable water supply, hydrological characterisation is crucial to understand the dynamics of their functioning on a spatial and temporal scale. Beside ecosystem services, basic ecological properties such as vegetation structure and nutrient cycling of wetland ecosystems depend on hydrology. Nabajjuzi wetland, in central Uganda, East Africa is internationally recognised as a Ramsar site and currently used for potable water supply in addition to other essential ecological and social economic services to the riparian communities. To contribute to the limited and scanty information of this ecosystem, the study focussed on hydrological and water quality characterisation using a water-nutrient mass balance as the major output. Also, the flow dynamics of Fe and allochthonous suspended solids loading into the wetland were investigated.

Results show that the water balance of Nabajjuzi wetland is dominated by surface flow, which is influenced by rainy and dry periods. During peak flow, the estimated hydraulic retention time was found to be 1 month compared to 1.5 months during the low flow period. Also, water loss flux due to evapotranspiration in this region is high and in Nabajjuzi wetland, it is twice the daily rate of abstraction. Analysis of long term flow data also revealed that the current water abstraction rate can potentially result in hydrological stress to the system during extremely low flow periods. However, the wetland N and P loading is very low compared to other urban disturbed wetlands. Consequently, high concentration of Fe and suspended solids loading are the major constraints to the surface water quality hence potable water supply. Generally, there is need for a more comprehensive hydrological-water quality study and careful planning of the future catchment land use strategies. This can enhance management and conservation of the wetland to guarantee the crucial ecosystem services it provides.

Keywords: Hydrology, Riverine wetland, Hydrological gradient, Surface-flow, Nutrients, Iron, Mass-balance, Lake Victoria basin.

In the first multipurpose river valley planning of India, the vast resources of Damodar River Basin (eastern India) are not only to be envisioned in their entirety; these are to be developed in a unified manner where the water, land and people are simultaneously bounded in a seamless web. Four large dams (Konar, Tilaiya, Maithon and Panchet), Durgapur barrage and Tenughat reservoir are built to tamp the flood prone Damodar River using water resource in an integrated method. The functionality of Damodar fluvial system is controlled by dams, barrage, weirs, sluices, embankments and canals, maintaining a dynamic equilibrium between fluvial processes and anthropogenic processes. Carrying more than fifty years of legacy, the existing drainage and flood control system of Damodar Valley Corporation (DVC) has aggravated a number of hydrogeomorphic problems especially in lower Damodar River Basin, viz., siltation of river bed and reservoirs, uncontrolled monsoonal stream flow, declining carrying capacity of lower course, drainage congestion, low-magnitude annual floods, channel shifting, de-functioned canals, decay of palaeochannels, decline of ground water level and less replenishing of soils with fresh silts etc. The present paper is mainly tried to investigate the pre-dam and post-dam hydrogeomorphic variability in relation to flood risk and drawbacks of Damodar Valley Multipurpose Project. Specifically the annual peak flow of Damodar shifts from August to September due to dam construction and reservoir storage. Applying the annual flood series of log Pearson type III distribution we have estimated post-dam 5 years peak discharge of above 5,300 m3 s-1 and 100 years flood of above 11,000 m3 s-1. Due to siltation the bankfull discharges of sample segments are gradually declined  up to 4,011 m3 s-1, 2,366 m3 s-1 and 1,542 m3 s-1 respectively, having recurrence interval of 1.18 to 3.18 years only. With regulation of monsoon flow the standard sinuosity index is gradually increased downstream, having high dominance of hydraulic factors in respect of topographic factors. In the upstream section of study area (Rhondia to Paikpara) now shows dominance of aggradational landforms, braiding, avulsion, high width-depth ratio, breaching of right bank and valley widening, but downstream of Barsul the phenomena of bank erosion, confined sinuosity, low width-depth ratio and narrowness are more pronounced.

A B S T R A C T Flooding is the most devastating hydro-meteorological hazard in Togo. For instance, communities in the Lower Mono River Basin needs attention because they suffer the impacts almost every year. This paper focused on assessment and mapping of social flood risk in the Lower Mono River Basin, West Africa. The study combined GIS, Remote Sensing, and indicator-based flood risk assessment techniques in mapping flood disaster risk. The Risk Assessment Framework of Davidson (1997) and Bolin et al. (2003) that comprises Hazard, Exposure, Vulnerability and Capacity was adopted for the study. The resultant risk map shows that all the communities are exposed to flood risk but particular ones such as Agbanakin, Azime Dossou and Togbavi are found in areas with relatively high flood risk levels. Positive attitude towards early action and early warning systems, collaboration among disaster relief institutions and appropriate building codes are recommended for reduction of flooding disaster risk.

Genale-Dawa River Basin is one of the largest and most drought prone regions in Ethiopia. As a result a search for alternative source of water has always been a major issue in the region. This study therefore, aims at characterizing and evaluating the ground water potential resource of the river basin. The delineation and numerical discretization of the river basin were primarily done for the proper development of the problem domain. And the groundwater governing equation was solved at individual nodal points of the discre-tized region using a 3-D numerical ground water model called TAGSAC. This resulted in monthly average groundwater table fluctuation and replenishable ground water potential estimation. Hydrogeological classification was also done based on hydraulic conductivity values obtained from model calibration .

The time series being rainfall data is a typical seasonal series of one-year period. The time-plot of the realization herein called GASR and its correlogram are as expected, reflecting seasonality of period 12. For instance, the autocorrelation function is oscillatory of period 12. A 12-point differencing yields a series called SDGASR with a generally horizontal secular trend. It is adjudged stationary by the Augmented Dickey Fuller unit root test. Its correlogram gives an indication of stationarity as well as an involvement of the presence of a seasonal moving average component of order one and a seasonal autoregressive component of order two. This autocorrelation structure suggests three multiplicative SARIMA models, namely: (0, 0, 0)x(0, 1, 1) 12 , (0, 0, 1)x(0, 1, 1) 12 and (0, 0, 1)x(2, 1, 1) 12. The first model is adjudged the most adequate. Its residuals have been observed to be uncorrelated. It may be the basis for the forecasting of rain in the region for planning purposes.

The global terrestrial land surface has been affected by the changing land cover/land use over years. The continuous changes in land cover/land use have also affected the water balance of major watershed by changing the magnitude and pattern of the stream flow of major rivers in Kenya. Land use and land cover changes in Kimondi watershed has caused serious hydrological changes on Kimondi River thereby affecting the entire hydrological regime of the whole of Yala Basin. The study was necessary to evaluate the stream flow responses to land use/land cover changes in the upstream of Yala River.These findings provides invaluable insights to the Yala watershed conservationists, the Nandi county and the government of Kenya in conserving the water resources, monitoring of watershed conservation and ensuring environmental sustainability. This is will provide effective upstream response measures in ensuring reduced magnitudes and frequency in surface runoff and increased groundwater recharge in Kimondi watershed. The extent of land use and land cover changes in the watershed was examined through analysis and classification of SPOT images using ENVI 5.3. Descriptive analysis of data collected from KII and questionnaires was done using SPSS and Ms Excel. The evaluation of variations and responses in river flow and rainfall was done using linear regression and correlation methods. Weibull's method was used in the analysis of extreme (Max Q and Min Q) hydrological data as well as determine the return periods. The Flow Duration Curve examined the historical variability of observed stream flow. The study revealed that there were major land use and land cover changes in Kimondi watershed such as uncontrolled human encroachment in King'wal wetland due to search of land for agriculture and settlement, decrease in natural forests, and increase in growth of eucalyptus as well as rainfall variability. The study revealed an increase in agricultural area (4.8%), bare ground (3.97%), settlement (12.46%), planted forest (9.59%) and shrubs (1.66%), and decrease in area under natural forest (28.94%) and shrinking in size of King'wal Swamp (3.63%). Trend analysis of the hydrographs revealed, for annual and monthly daily stream flows, as statistically significant at p-value ≤ 0.05 with monotonic trend. Trends and variations in river flow indicated periods of low dry season flows and peak wet season flows between the 1990 and 2015 mainly attributed to both land use/land cover changes and climate variability. The Flow Duration Curve revealed an 11.3% exceedance for Q 25 and 0.74% exceedance for Q 95. Weibull's analysis showed a 1.8% and 2% return period in 53 years for maximum discharges and minimum discharges respectively.

Observed changes in precipitation patterns, rising surface temperature, increases in frequency and intensity of floods and droughts, widespread melting of ice, and reduced snow cover are some of the documented hydro-logic changes associated with global climate change. Climate change is therefore expected to affect the water supply-demand balance in the Northeast United States and challenge existing water management strategies. The hydrological implications of future climate will affect the design capacity and operating characteristics of dams. The vulnerability of water resources systems to floods and droughts will increase, and the trade-offs between reservoir releases to maintain flood control storage, drought resilience, ecological flow, human water demand, and energy production should be reconsidered. We used a Neural Networks based General Reservoir Operation Scheme to estimate the implications of climate change for dams on a regional scale. This dynamic daily reservoir module automatically adapts to changes in climate and readjusts the operation of dams based on water storage level, timing, and magnitude of incoming flows. Our findings suggest that the importance of dams in providing water security in the region will increase. We create an indicator of the Effective Degree of Regulation (EDR) by dams on water resources and show that it is expected to increase, particularly during drier months of year, simply as a consequence of projected climate change. The results also indicate that increasing the size and number of dams, in addition to modifying their operations, may become necessary to offset the vulnerabilities of water resources systems to future climate uncertainties. This is the case even without considering the likely increase in future water demand, especially in the most densely populated regions of the Northeast.

Land use land cover change is the general term for human and natural modification of the earth's terrestrial surface at a variety of spatial and temporal scale. This change lends the need of knowing the type of change, when and where they occur with their extent and rates. Hence, effective information regarding the environmental responses of land use land cover changes are important to hydrologists, land use planners, watershed management and decision makers to formulate and implement effective and appropriate response strategies to minimize the undesirable effects of future land use land cover change. Consequently, this study was aimed at assessing the land use land cover changes of Gilgel Gibe catchment between 1987, 2001 and 2010. Particularly, the study have analyzed land use land cover changes that were assumed to take place in the Catchment for the past 24years. The Land use maps of 1987, 2001 and 2010 were derived from satellite images and processed using ERDAS Imagine 9.1 and ArcGIS10.1 software. Change detection analysis and accuracy assessment was done after Image processing and classification with spatial analysis tools. The outcome of land cover change analysis shows an increment of agricultural land from 54.51% to 56.54%, Urban and built up area from 2.22% to 4.06%, range land from 30.02% to 31.55% while decreasing proportion of forest land from 12.82% to 7.63%, Water body from 0.42% to 0.22% for the recent period between 2001 and 2010. The accuracy assessment of land cover classification indicates an overall accuracy of 83.87%, 82.18%, 89.29% and kappa coefficient of 0.7848, 0.7691, and 0.86 respectively for 1987, 2001 and 2010 map.

In this research paper exhaustive review is conducted on artificial neural network (ANN) which is employed in the field of hydrological related problems, whereas the conventional approaches are cumbersome and complex in view of computational analysis. Artificial intelligence operation can be well exemplified through application in rainfall-runoff modelling, modelling streamflow, water quality modelling, and application in ground water. A good physical understanding of the hydrologic process being modelled can help in selecting the input vector and designing a more efficient network. This review provides examples for ANN model that provides reasonable accuracy for hydrological problems, and a more effective tool for engineering applications.

A three-phase study was initiated as a way to promote Integrated Catchment Management approaches in
the Limpopo River basin. This paper presents the situational assessment, which should enable De Beers
to understand how their Venetia Mine operations are located within a broader and highly dynamic socioeconomic
and ecohydrological landscape as it pertains to water risks. The second phase, Risk assessment,
aims to develop conservation interventions in the identified areas; the third phase will develop mechanisms
for implementing water stewardship schemes to mitigate the shared water risks.
Analysis of the social-ecological system (hydrological, climatic, ecological, socio-economic and
governance systems) of the Limpopo River basin indicates that the institutional arrangement of the
Limpopo River basin is neither simple nor effective. The basin is rapidly approaching closure in the sense
that almost all of the available supplies of water have already been allocated to existing water users. If
the proposed ecological flow requirements were to be met for all of the tributaries, the basin would be
‘closed’. On-going and projected land use changes and water resources developments in the upper
reaches of the basin, coupled with projected rainfall reductions and temperature increases, and allocation
of the flows for the ecological reserve, are likely to further reduce downstream river flows. The
coupled increase in temperature and decrease in rainfall is of great concern for everyone in the basin,
especially the poorer communities, who rely on rain-fed agriculture for their livelihoods. Increased
temperatures also lead to increased evaporation from reservoirs and therefore result in a decrease in
water availability. This will lead to increased abstraction of groundwater, especially from alluvial aquifers,
and consequently an increase in river transmission losses and a decrease in river flows.

Approximately 40 per cent of the world’s population
lives in river and lake basins that comprise two or more
countries, and perhaps even more significantly, over 90
per cent lives in countries that share basins. The existing
263 transboundary2 lake and river basins cover nearly
one half of the Earth’s land surface and account for an
estimated 60 per cent of global freshwater flow. A total
of 145 States include territory within such basins, and
30 countries lie entirely within them. In addition, about
2 billion people worldwide depend on groundwater,
which includes approximately 300 transboundary
aquifer systems.

For determining of Muskingum model coefficients, requires to an output hydrograph. Such hydrograph is not available in most rivers. In this research, the Muskingum's new coefficients are determined by the method that which is not require to output hydrograph and its accuracy is high. This coefficient is determined based on kinematic wave model with suitable scheme. The comparison between results of Muskingum model with new coefficients and dynamic wave model, showed that the new coefficients, are valid at special conditions. The new coefficients were adjusted by optimization technique for all conditions. The new adjusted coefficients are function of bed slop, bottom width and Manning's roughness coefficient for the river. The results of these coefficients were validated by dynamic wave model.

Study region: Osun Drainage Basin, Nigeria.

Study focus: Estimating spatial and temporal patterns of recharge is important for sustainable groundwater resources management. This is especially true for data poor regions, such as the Basement Complex in Nigeria, which has shallow aquifers, a proliferation of wells and no efficient groundwater monitoring network. This study evaluates the performance of a spatially distributed monthly water balance model (WetSpass-M) in estimating groundwater recharge. The WetSpass-M model has moderate data demands, which allows for comprehensive assessment of recharge.

New hydrological insights for the region: 27 % of the rainfall in Osun drainage basin becomes recharge, while the remaining is lost through evapotranspiration (43 %), surface runoff (21 %) and interception (9 %). September is the month with highest recharge, ranging between 0 and 73 mm in the north and 129 up to 213 mm in the south and northeast of the basin. The study revealed the significance of the applied water balance model in understanding the spatial and temporal status of recharge. Therefore, the spatial and temporal patterns of recharge should be taken into consideration in preparing a sustainable groundwater resources management plan for the Osun drainage basin. Artificial recharge might be adopted to store storm water runoff during wet periods to improve the groundwater supply in dry months. Also, monthly groundwater withdrawals should be regulated in relation to spatial and temporal recharge patterns.

Groundwater models which realistically represent the hydrogeology of a complex system, like the Unkheltseg Basin, are critically important to Mongolia. They have flow on benefits to research, governments, management strategies and commercial development within the country. Limited case studies of calibrated 3-D numerical transient simulations in fault-controlled connection between basins, similar to the Unkheltseg Basin, are available in the public domain and the model presented here aims to address this problem. This basin is uniquely geologically controlled and a key water supply resource for future economic development in the Taikh Valley. Commercial exploration projects have produced the high-quality geological and hydrogeological data gathered, necessary for successful model simulation at a basin-wide scale. Using the ''DRAIN Package'' and ''Fracture-Well Package FW4'' in MODFLOW-SURFACT, the spatial discretization necessary to fully represent horizontal and vertical flow direction was achieved to effectively constrain recharge and discharge across the fault barrier. This model is an important tool for establishing a long-term monitoring programme in a fault-controlled basin, which predicts regional impacts, both short and long term.

This book synthesises archaeological and historical research in order to investigate Maltese water management technology and rural landscape development between AD 900 and 1900. Maltese terrestrial geological formations and stratification are a determining factor in conditioning the formation of subterranean aquifers, water-harvesting and storage, landscape development and utilisation. Central to this publication are reservoirs, cisterns, wells and perched aquifer galleries, which have for centuries provided farmers tilling arable land with a supplementary water source other than the limited and erratic seasonal rainfall. The data and conclusions presented in this book are the result of extensive personal field and archival research and include an assessment of the available documentary sources of evidence including place-names and cartographic sources. Comparative research suggests that a number of perched aquifer subterranean galleries share common characteristics with qanat technology of the Islamic and the Roman worlds and in a Maltese context, were possibly part of a new agricultural and technological package introduced during the Muslim or the post-Muslim period between the eleventh and the fourteenth centuries AD.

Published in: BAR International Series 2829
ISBN: 9 781407 316291

In this study, morphometric analysis and prioritization of the four sub catchments of Vashishthi Watershed located between Ratnagiri district in Maharashtra state, India is carried out by employing Remote Sensing and Geographic Information System (GIS) techniques using satellite imageries and topographic maps on a scale map of 1:50000. Vashishthi watershed has dendritic drainage pattern. The morphometric parameters are discussed about Linear, Aerial and Relief aspect. The drainage density of the study area varies from 0.730 to 0.742 Km/km 2 which observed that high permeable subsoil. The bifurcation ratio varies from 1.9 to 2.6 which indicates geology is reasonable homogeneous and no structural disturbances. The morphometric analysis explains sub catchment 3 shows lower values of drainage density and stream frequency, and sub catchment 1 shows lower values of form factor, texture ratio and elongation ratio. The compound parameter values are calculated and the lowest compound paramet...

Considering the peculiarities and large variation in the nature of problems associated with water resources planning, development and management, the issues involved in research related to particular region and specific project, there is a provision under National Hydrology Project (NHP) of India is to take up applied and action-oriented R&D studies by the implementing agencies. This article presents the details of purpose driven studies taken up by various implementing agencies under the National Hydrology Project of India.

The study demostrated that integration and spatial analysis with relevant socioeconomic sources and physical parameter from different sources can be evaluated for the interpretation of filling station sites planning. This has demostrated the effectiveness of the application of Geographic Information System (GIS) in predicting and determining of site criteria for filling stations facilities development, most especially in areas of competing land uses that require sustainability, environmentally sensitive development solutions, environmental safety, and consumer accessibility. A stratified sampling technique was used to select the sample size and administration of questionnaire. The data collected was analyzed using descriptive statistics such as frequency distribution, bar chart, pie chart and percentage while Chi-square statistical technique was used in testing the hypothesis. Spatial analysis (such as query and buffer) was also employed to assess the distribution pattern of filling stations in the study area.The result shows that siting of filling station in unsuitable site usually accompany with dangers.

Study region: 26 boreal catchments (mid-Norway). Study focus: We performed regional flood frequency analysis (RFFA) using the L-moments method and annual maximum series (AMS) of mean daily streamflow observations for reliable prediction of flood quantiles. We used similarity in at-site and regional parameters of distributions, high flow regime and seasonality, and runoff response from precipitation-runoff models to identify homogeneous catchments, bootstrap resampling for estimation of uncertainty and regression methods for prediction in ungauged basins (PUB). New hydrological insights for the region: The rigorous similarity criteria are useful for identification of catchments. Similarity in runoff response has the least identification power. For the PUB, a linear regression between index-flood and catchment area (R 2 = 0.95) performed superior to a power-law (R 2 = 0.80) and a linear regression between at-site quantiles and catchment area (e.g. R 2 = 0.88 for a 200 year flood). There is considerable uncertainty in regional growth curves (e.g. −6.7% to −13.5% and +5.7% to +24.7% respectively for 95% lower and upper confidence limits (CL) for 2–1000 years return periods). The peaks of hourly AMS are 2–47% higher than that of the daily series. Quantile estimates from at-site flood frequency analysis (ASFFA) for some catchments are outside the 95% CL. Uncertainty estimation , sampling of flood events from instantaneous or high-resolution observations and comparative evaluation of RFFA with ASFFA are important.

Climate change has become a challenge for the globe and impacting various systems. This study evaluated the seasonal and annual variabilities and trends of rainfall, temperature, and potential evapotranspiration for the period 1985-2019 over Bilate basin of Rift Valley Lakes basins in Ethiopia. Twenty rain and eleven temperature gauge stations datasets were used. Coefficient of variation and precipitation concentration indices were used for variability analysis, whereas Mann-Kendall test and Sen's slope estimator were used for trend detection and magnitude. The short and main rainy seasons characterized the basin with a bimodal rainfall pattern. Variability indices revealed dry Bega season with significant rainfall variability. In the dry season, higher relative variability is exhibited in the upstream north and lesser in the downstream south which flips in the main rainy season. Internal climate variability evaluation with indices showed a weak correlation with the observed rainfall variabilities for seasons. Inter-annual and seasonal anomalies characterize inconsistent wet and dry years, which uncertainly impact climate-sensitive rainfed agriculture. The areal weighted average rainfall shows negligible declining trend (α = 0.05) with a magnitude of 2.45 mm/year and 2.60 mm/year for annual and Belg, respectively. The minimum average temperature was relatively more variable than the maximum average temperature. Most of the stations established warming trends either negligible or significant. Potential evapotranspiration exhibited less variability with negligible trends in the majority of the stations. Therefore, rainfed agricultural practices and water resources use in the basin should adapt with supplementing measures to respond to uncertain variabilities and minor changes.

Integrated Socio-Ecological History of Residential Patterning, Agricultural Practices, and Water Management at the “Classical” Burmese (Bama) Capital of Bagan, Myanmar (11th to 14th Century CE): Report on the 2018 IRAW@Bagan Field Season. Edited by Gyles Iannone, Pyiet Phyo Kyaw, and Scott Macrae.

Trent University Occasional Papers in Anthropology No. 20
ISSN 0825-589X
Peterborough Ontario

https://irawbagan.wordpress.com/

Accurate estimation of point rainfall at ungauged locations from the measurements at surrounding sites is critical in obtaining a continuous surface of rainfall information. This can be accomplished through numerous interpolation methods, which have different strengths and weaknesses. The accuracy of the resulting continuous surface of rainfall information depends on the density of the point data and observational errors, which in turn affect the integrity of hydrological studies that utilize the data as input. In this study, four interpolation methods—Thiessen polygon, inverse distance weighting (IDW), thin plate, and Kriging—were evaluated at an experimental catchment in South West England at three gauge densities through the leave-one-out cross-validation (LOOCV) method. The numbers of rain gauges used for the three densities were 49, 28, and 10, which were translated to 2.75, 4.82, and 13.5  km2 per gauge since the area of the catchment was 135.2  km2. The gauge density was found to have an effect on the accuracy of the interpolated results as there was a gradual improvement in the error statistic with a corresponding increase in the gauge density. The results also showed that IDW and Kriging were better than the Thiessen polygon and thin plate methods at all the three gauge densities. The performances of IDW and Kriging were similar, suggesting that Kriging, though complex in nature, does not show greater predictive ability than IDW. It is important to note that there is a significant difference in R2 between the cross-sectional approach and longitudinal approach.

Hydrology is a relatively new science and a truly ancient one (Biswas 1970). It is fascinating to consider that the word hydrology, which refers to the study of water flows from precipitation to infiltration, groundwater, evapotranspiration, and runoff, only developed in the eighteenth century (Perrault and Perrault 1721). Even then it was regarded by some as the "wisdom of God," as well as an empirical science (Tuan 1968). The scope of hydrologic science has been shaped by a combination of direct observation, remote sensing, practical action, and cultural beliefs. It is interesting to try to push the origins of hydrologic science back to include relationships between hydroclimatic phenomena and prehistoric human settlement (e.g., Magill, Ashley, and Freeman 2013). One may even wonder whether other species evolved sophisticated water finding, navigation, and regulatory capacities as hydrologic agents (Finlayson 2014). In each of these respects, the history of hydrology has far greater historical depth than is commonly perceived. The benchmark study on this topic is Asit Biswas's (1970) History of Hydrology which drew together a rich array of sources to survey the field. His volume begins with ancient archaeological and historical innovations from antiquity to 600 BCE and then proceeds to the classical world of Greece, Rome, and the Hellenistic empire. After an understandably short chapter on the medieval period (though see Magnusson 2001), the greater part of the