Hydrology

A model subglacial drainage system, coupled to an ice-dammed reservoir that receives a time-varying meltwater input, is described and analysed. In numerical experiments an ice-marginal lake drains through a subglacial channel, producing periodic floods, and fills with meltwater at a rate
dependent on air temperature, which varies seasonally with a peak value of Tm. The analysis reveals regions of Tm parameter space corresponding to ‘mode locking’, where flood repeat time is independent of Tm; resonance, where decreasing Tm counter-intuitively increases flood size; and chaotic dynamics,
where flood cycles are sensitive to initial conditions, never repeat and exhibit phase-space mixing. Bifurcations associated with abrupt changes in flood size and timing within the year separate these regions. This is the first time these complex dynamics have been displayed by a glaciohydraulic model
and these findings have implications for our understanding of ice-marginal lakes, moulins and subglacial lakes.

Stretta è la relazione che corre tra lo svolgimento millenario della tecnica di lavoro dell'uomo, e i rapporti con l'ambiente naturale. L'uomo primitivo, come l'animale, raccoglie e consuma frutti spontanei colla semplice operazione prensile, e come l'animale fugge senza controllo davanti al dirompere del fenomeno naturale che ne minacci la vita. Come la produzione artificiale di prodotti pel consumo, e l'accumulazione di riserve di prodotti stessi e di utensili, lo costringe a fissarsi, così lo costringe a difendersi dalle minacce di meteore e sconvolgimento naturali. Una tale difesa, non diversamente da quella contro altri gruppi concorrenti alla sede migliore, o predatori della accumulata riserva, non può che essere collettiva. Da queste esigenze collettive, come tante volte vedemmo, nasce la divisione in classi e lo sfruttamento da parte dei dominatori.

In Marx, "il modo di produzione capitalistico presuppone il dominio dell'uomo sulla natura". Esso presuppone anche la guerra della natura contro l'uomo. Una troppo generosa e prodiga natura non sarebbe ambiente favorevole al sorgere del capitalismo.

Floods are one of the most frequently occurring natural disasters in Indonesia. It is therefore of special concern to reduce the risk of flood fatalities and other damage. The purpose of this study is to design a flood early warning system based on the Internet of Things (IoT). In this work, we use an ultrasonic HC-SR04 sensor to collect information about water levels. Further, we use an MCU8266 node as a microcontroller to analyze the sensor data and test it using a fuzzy inference system (FIS). To monitor the server activities, a Blink application is used as an iCloud IoT to hook up to smartphone devices. The test results show that all the devices function properly and that the system can classify water levels into normal, standby, alert, and danger categories in real time. Thus, the server can send information to the output device before a flood disaster occurs.

The management and maintenance of groundwater quality play a vital role in the development of a region as well as health aspects of living beings in that area. The contamination of groundwater also affects crop yield and production of crop. Hence a systematic study has been carried out to assess the ground water quality in Vallabharaopalem (Latitude: 16.0558 0 N; Longitude: 80.5251 0 E) and Upparapalem (Latitude: 16.0804 0 N; Longitude: 80.5013 0 E) villages of Ponnur mandal in Guntur district, which is a part of western delta of Krishna river in Andhra Pradesh state of India. The formations in the study area belong to recent alluvium. Groundwater occurs under unconfined conditions. The groundwater is analyzed for various physico-chemical parameters. Values of most of these parameters such as electrical conductivity fall beyond the standard limits for drinking water. The chloride-bicarbonate ratio more than 6 as per Revel's classification suggested that the groundwater is injuriously contaminated with saline water. The present attempt is made to understand the contamination in the groundwater quality. Suitable precautionary measures are suggested for sustainable development of ground water quality to maintain the environmental balance in the study area. The present study can be extended in similar critical contaminated areas throughout the world.

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.

Modeling surface water quality using soft computing techniques is essential for the effective management of scarce water resources and environmental protection. The development of accurate predictive models with significant input parameters and inconsistent datasets is still a challenge. Therefore, further research is needed to improve the performance of the predictive models. This study presents a methodology for dataset pre-processing and input optimization for reducing the modeling complexity. The objective of this study was achieved by employing a two-sided detection approach for outlier removal and an exhaustive search method for selecting essential modeling inputs. Thereafter, the adaptive neuro-fuzzy inference system (ANFIS) was applied for modeling electrical conductivity (EC) and total dissolved solids (TDS) in the upper Indus River. A larger dataset of a 30-year historical period, measured monthly, was utilized in the modeling process. The prediction capacity of the develo...

Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of ...

The transient response to projected climate change of two ice caps in the central Icelandic highland was simulated with a vertically integrated ice-flow model coupled to a degree-day mass-balance model. The ice caps, Langjökull and Hofsjökull, are of similar size (area ∼900 km2 and volume ∼200 km3) and located only ∼30 km apart. The climate change simulations were started in 1990 from steady states corresponding to the average climate of 1981–2000 and driven with observed weather parameters until 2005. Thereafter, the forcing was according to a Nordic climate change scenario based on the IPCC B2 emission scenario. The simulations during the period 1990–2005 compare reasonably well with observations of mass-balance and glacier extent. Both ice caps are projected to essentially disappear during the next 100 to 200 years. Langjökull, which disappears within the next 150 years, shows larger mass-balance sensitivity to warming than the higher elevated Hofsjökull, where ice on the highest...

The hydraulic performance of round-cornered rectangular labyrinth weirs with varying weir heights and effective lengths has not been explored in the existing literature to the authors’ knowledge. The purpose of this experimental study was to see how the height and effective length of round-cornered rectangular labyrinth weirs affect their discharge efficiency. Nine flat-crested rectangular labyrinth weirs made of high-density polyethylene (HDPE) were tested in a rectangular flume under various discharges to fulfill the goals of this study. The discharge coefficients for the weirs were then calculated. The hydraulic efficiency of weirs with round corners increases as the weir height (P) increases, according to the findings; however, with effective length of the weir to channel width ratios (LC/B) ≤ 1.78, the effect of the weir height diminishes. For the HT/P ranges used in this study, 0.1 ≤ HT/P ≤ 0.65, the round-cornered rectangular labyrinth weirs with higher LC/B ratios (greater M...

The Hindukush Karakoram Himalayan mountains contain some of the largest glaciers of the world, and supply melt water from perennial snow and glaciers to the Upper Indus Basin (UIB) upstream of Tarbela dam, which constitutes greater than 80% of the annual flows, and caters to the needs of millions of people in the Indus Basin. It is therefore important to study the response of perennial snow and glaciers in the UIB under changing climatic conditions, using improved hydrological modeling, glacier mass balance, and observations of glacier responses. However, the available glacier inventories and datasets only provide total perennial-snow and glacier cover areas, despite the fact that snow, clean ice and debris covered ice have different melt rates and densities. This distinction is vital for improved hydrological modeling and mass balance studies. This study, therefore, presents a separated perennial snow and glacier inventory (perennial snow-cover on steep slopes, perennial snow-cover...

Urban flooding is an inevitable problem for many cities around the world. In the present paper, modelling approaches and principles for analyses of urban flooding are outlined. The paper shows how urban flooding can be simulated by one-dimensional hydrodynamic ...

Aquatic coastal systems are affected by high fluctuations in salinity and the zooplankton may rely on dispersal or dormancy to recolonise these environments. Here, we analysed the long-term dynamics of the zooplankton community over 6 years during large salinity fluctuations in a coastal lagoon (Garças Lagoon, Brazil) and the effect of salinity on the hatching patterns of the resting egg bank. We hypothesised that salinity is the main driving factor of the zooplankton community structure, and that increases in salinity reduce the species richness and the abundance of hatchlings. Multiple regression analysis showed that salinity was associated negatively with species richness in the open water, whereas total phosphorus and chlorophyll-a concentrations were negatively and positively related to abundance respectively. Redundancy analysis demonstrated that temporally structured environmental variables (total phosphorus and salinity) were important for zooplankton composition. Periods of...

Afghanistan is highly prone to intense and recurring natural hazards, including earthquakes, floods, flash floods, landslides, avalanches, and droughts. Where 54% of the natural disasters in Afghanistan are water-related and makes the country the second most vulnerable country to floods worldwide. The country is prone to river flooding which cause substantial destruction to crops, human lives, and properties. Helmand River Basin is the largest of the five river basins in Afghanistan. It is a closed basin, which covers the southern half of the country draining to the unique Sistan depression near the Afghan- Iranian Border. About 80% of the population of the basin depends on agriculture and livestock for their livelihood. The middle and lower parts of the basin supports extensive agriculture. Although floods affect almost every part of the basin with varying intensity and frequency, the middle and lower parts of the basin is regarded as one of the most flood vulnerable areas. Unfortunately, residents in the flood prone area are, meanwhile, not sufficiently aware of flooding consequences due to the inadequate information and lack of quality flood data. Thus, the flood prone area has been carelessly developed for settlement and cultivation purposes.
Floods in Afghanistan Rivers are due to convective rainfall or snowmelt and sometimes coupled. Helmand River likewise experiences flood due to intense rainfall and rainfall coupled with rapid snowmelt. Where the intense rainfall-induced floods occur mainly in spring, which lies under the flash flood category. Such flash floods strike the flood prone area for a short duration, whereas the rain and snow-fed coupled floods last for a longer period.