ICG2022-17

Water is essential for life on earth. It is unequally distributed over the earth surface. Water scarcity occurrs due to both natural as well as anthropogenic causes. One of the major regions behind water scarcity is that its demand has increased twice than earlier as the population growing exponentially. Some of the major causes of water  scarcity are over use of water, pollution of water, drought, ground water pollution. Some problems arise because of water scarcity like lack of access to drinking water, diseases, sanitation issues, distruction of habitats. This paper is an attempt to investigate the causes and consequnces of water crisis. The data for present analysis have been obtained form secondary sources and various agencies. The main objective of the present paper is to attempt evaluation of the water resources. Study reveals that water is rapidly becoming scarce resource in India because the demand of water is increasing due to pressure of population and changing consumption pattern. For instance, in some parts of the study area, there is evidence of progressive declined in the water table due to over pumping by the tubewells. The situation is getting alrming year after year. These problems can be solved conjunctive use of surface and ground water. There is urgent need for the development of surface water irrigation where ground water utilization is high.

How to cite: Raje, A.: Water Crisis in India : An Overview, 10th International Conference on Geomorphology, Coimbra, Portugal, 12–16 Sep 2022, ICG2022-532, https://doi.org/10.5194/icg2022-532, 2022.

The River Murray is Australia’s largest and most important river.  It carries water for irrigation and city supply from the mountains in the east, semi-arid west.  The river crosses a series of low-angle alluvial fans (distributive fluvial systems) in its 1500 km path.  The Barmah Choke is a narrow section of the River Murray’s channel, formed by a Holocene river avulsion, that restricts flow capacity from the upper to lower Murray River.  The flow capacity of the Choke has declined nearly 20% since the 1980s, which imposes a constraint on regulated flows supplied down-valley, and is constraining economic development downstream.  Whilst there could be multiple geomorphic factors explaining the decline, we demonstrate that the most likely cause is a sheet of coarse sand shallowing the river, much of which originated from historical gold mining and catchment erosion in late 1800s.  The sheet of sand is reducing depth diversity, filling pools up to 5m deep, and degrading the ecological and cultural values of the river.  The whole length of the river through the Barmah Forest has shallowed over the last 30 years, aggrading by 1.9 m at the upstream end and 0.70 m in the most downstream section of the Choke (about 10% decrease in area).  The total volume of sand stored between Yarrawonga and Barmah is over 20 million m³, and the average total annual sand load transported into the 82km long Choke ranges between 130,000 m³ in a normal flow year to 500,000 m³ in a flood year (which translates into 2 – 9 cm of aggradation per year).  Surprisingly, overall, long-duration regulated irrigation flows have decreased the rate of sand transport through the Choke.  Decreasing downstream flow capacity across the Barmah Fan is a natural characteristic of this type of distributive fluvial system, but the sand sheet is accelerating the rate of decline.  Without intervention, conveyance through the Choke will inevitably continue to decline until the river avulses into a new channel.  A range of solutions are explored, but all are extremely expensive. 

How to cite: Rutherfurd, I. D., Gower, T., Grove, J., Arrowsmith, C., Vietz, G., Dyer, B., and Sims, A.: How human impacts on geomorphology echo through the centuries: explaining the declining flow capacity in Australia's most important river, the Murray.   , 10th International Conference on Geomorphology, Coimbra, Portugal, 12–16 Sep 2022, ICG2022-181, https://doi.org/10.5194/icg2022-181, 2022.

The present work aims to deepen and discuss the weaknesses of coastal soils in the face of contamination by dumps. Although the dumps were suspended, important areas remained that were contaminated. However, as it is an area that was much explored in more remote times, it is being recovered and with possibilities of urban uses, or even for recovery for use in leisure. Bearing in mind that coastal areas are very important for the economy of the cities located in areas them, mainly because they involve transition areas from coastal to marine environments and many of them may have a geomorphological configuration favorable to ports of flow of national production or receipt of products imported - via ocean. In order to know how the areas contaminated by dumps are being recovered in an environment even more fragile by the genetic characteristics of its soils, waters, relief and landscape, as well as by the dynamic processes arising from the continent, the sea and the atmosphere by the climate. With a case study, we seek to analyze the possibilities of better use in the management of these areas that were once contaminated by dumps and analyze the geomorphological compartmentalization and resilience of this fragile environment. And also describe the methods and techniques applied in these areas for their revitalization.

How to cite: Fierz, M. M.: The Environmental Fragility of The Coastal Area of ​​São Paulo In The Face of Contamination By Landfill: Contribution to the Possibilities of (Management) Decontamination and Reuse., 10th International Conference on Geomorphology, Coimbra, Portugal, 12–16 Sep 2022, ICG2022-252, https://doi.org/10.5194/icg2022-252, 2022.

Evaluation of Changes in landuse due to anthropogenic activities in highly urbanized flood plain of Prayagraj city, Uttar Pradesh, India

                                                                                                                  Dr Mukta Raje – Associate Professor , SPG college Mihrawan,  Jaunpur, Uttar Pradesh , India

Urban settlement along the river Ganga with in Prayagraj city is prevalent since ancient time. Present scenario,both natural landscape as well as cultural settlement are the consequence of centuries long anthropogenic activities. Present study aims to understand the trend in landuse changes from 2000 to 2020 in this highly urbanized flood plain and its relation to geomorphology and anthropogenic activities. The  study adopts a relatively new approach to identify site specific condition for characterizing the landuse changes over a certain region of Ganga Yamuna Doab. The study indicates the best possible landuse conditions for better management and reduction in geo hydrological risk by suggested preventive measures. The research also indicates many landuse variations caused by socio-economic changes.

How to cite: Raje, M.: Evaluating Landuse Changes due to Anthropogenic Activities in Highly Urbanized Flood Plain of Prayagraj city, Uttar Pradesh India, 10th International Conference on Geomorphology, Coimbra, Portugal, 12–16 Sep 2022, ICG2022-613, https://doi.org/10.5194/icg2022-613, 2022.

The geomorphological and geological characteristics of karst regions are very specific and complex, affecting the hydrological processes significantly. Due to the enormous heterogeneity and non-linearity of karst terrains, the hydrodynamic functioning of karst watersheds considerably differs from non-karst watersheds. Quantifying and understanding the influence of these watershed characteristics in the hydrodynamics of karst and non-karst areas is crucial for managing water resources and extreme hydrological episodes, particularly in the present scenario of hydroclimatic variability and uncertainty.

The present study establishes a comparison between two watersheds: (i) a karst basin (Anços) composed of Middle Jurassic karstified limestones, dominated by a rough plateau that promotes the infiltration, and (i) a non-karst basin (Arunca) characterized by Upper Jurassic and Cretaceous marly limestones, and Cenozoic thick mudstones deposits (low permeability promoting surface runoff). The rivers' water level was logged every 20 minutes by a gauge station from 2010 to 2020, and the rainfall was also registered for the same period.

The objectives of this study are (i) to examine, from a quantitative perspective, the influence of geomorphological and geological characteristics on the runoff coefficient using statistical analysis; (ii) to quantify the rainfall-runoff lag time and the recession coefficients from the analysis of storm hydrographs simultaneously in both watersheds; (iii) to deepen the knowledge about the behavior of each watershed in flood episodes through hydrological simulation.

The results showed that geomorphological and geological watershed characteristics play an essential role in the hydrodynamic functioning of the Anços and Arunca watersheds. Furthermore, the outcomes of this study revealed a pronounced contrast between the two watersheds in the reaction to rainfall and mainly in the first stage of the recession limb. It should be highlighted that the non-karst watershed presents a faster and more extreme hydrological behavior expressed in a peak hydrograph. On the reverse, the karst watershed demonstrated a higher storage capacity, revealed by the shape of the recession curve.

How to cite: Paiva, I., Pinto dos Santos, P., Pardal, J., Cunha, L., and Tavares, A.: Geomorphology and lithology as factors influencing hydrological dynamics. Comparative analysis of karst vs. non-karst watersheds in the central-western region of Portugal, 10th International Conference on Geomorphology, Coimbra, Portugal, 12–16 Sep 2022, ICG2022-646, https://doi.org/10.5194/icg2022-646, 2022.

Khagrachari and Mohalchari Upazilas (sub-district) of the Khagrachari hill district are located and characterized by a series of parallel hills that tend to be NNW-SSE, situated in the central part of the eastern fold belt of Bangladesh. The central part of the hills features a series of medium high mountains, including the mysterious Alutila cave of Matiranga area of Khagrachari A cave formed in an around 1000 m high hill named as Alutila (potato hill) or Arbari hill. A vast network of streams and valleys flows down the slopes of the hills and represents a well-developed drainage system in the study area. The drainage system in the study area possess dendritic pattern. The Chengi River of the study area is running almost E-W trend cutting across the hill ranges of Khagracahri. There are also a large number of streams (chara or chari in local term) and large lake named ‘Mataipukhiri (Debota Pukur)’ which was naturally formed above 491 msl. The surficial deposit in the study area has been divided into: Dihing Formation, Undivided Dihing and Dupitila Formation, Dupitila Formation, Girujan Clay Formation, Tipam Sandstone Formation, Bokabil Formation and Bhuban Formation. According to laboratory analysis, Dihing sandstone is composed of very fine to medium-sized sand and is poorly sorted. Dupitila sandstone is composed of medium to fine sand and is moderately sorted. Tipam sandstone layer consisting of fine sand. Bokabil sandstones range from fine sands to very fine sand. Various types of sedimentary structures have been observed for example, cross-stratification, cross-lamination, wavy stratification, clay gall, calculus and nodular structure. The concentration of heavy minerals in the sedimentary rocks of the Khagrachari and Mohalchari areas are not significant. However, the heavy mineral concentration gradually increases from the Ding Formation (1.74 to 2.14)%, the Dupitila Formation (1.81 to 2.67)%, the Tipam Formation (1.55 to 3.92)%, and the Bokabil Formation (3.58 to 4.01)%. The identified minerals are quartz, muscovite, biotite, augite, hornblende, garnet, epidote, rutile, tourmaline, actinolite, tremolite, zircon, monazite, kyanite, sillimanite, apatite and other opaque minerals. The analyzed samples have very high abundance of augite, hornblende, and kyanite. The presence of white clay and glass sand has been investigated at Manikchari area in the Kagrachari hill area. The results of the chemical analysis show the percentages of SiO₂ (63.4-82.0)%, Al₂O₃(5.78-18.51)%, Fe₂O₃(0.45-17.93)%, Na₂O (0.160.80)%, K₂O (0.403.24)%, MnO is (0.162)%, CaO is (0.03-0.93)%, and ignition loss is (1.60-7.58)%. The existence of quartz sand (silica enriched) and white clay had also been confirmed adjacent to the surveyed area. Investigations of lithology, minor sedimentary structures and grain size parameters infers that the overall paleoenvironment was a transition from shallow waters condition prevailed during the early sedimentation phase of the area.

How to cite: Saha, R. K.: Geomorphic and Sedimentological Evolution of Khagrachari-Mahalchari hills of Bangladesh, 10th International Conference on Geomorphology, Coimbra, Portugal, 12–16 Sep 2022, ICG2022-728, https://doi.org/10.5194/icg2022-728, 2022.