Search results for: Imo River Basin

Authors: Esubalew Yehualaw Melaku, Tigistu Haile Eritro

Abstract:

In this study, two basic geophysical methods are applied for mapping the groundwater aquifer system in the Lisana area along the Guder River, northeast of Hosanna town, near the western margin of the Central Main Ethiopian Rift. The main target of the study is to map the potential aquifer zone and investigate the groundwater potential for current and future development of the resource in the Gode area. The geophysical methods employed in this study include, Vertical Electrical Sounding (VES) and magnetic survey techniques. Electrical sounding was used to examine and map the depth to the potential aquifer zone of the groundwater and its distribution over the area. On the other hand, a magnetic survey was used to delineate contact between lithologic units and geological structures. The 2D magnetic modeling and the geoelectric sections are used for the identification of weak zones, which control the groundwater flow and storage system. The geophysical survey comprises of twelve VES readings collected by using a Schlumberger array along six profile lines and more than four hundred (400) magnetic readings at about 10m station intervals along four profiles and 20m along three random profiles. The study result revealed that the potential aquifer in the area is obtained at a depth range from 45m to 92m. This is the response of the highly weathered/ fractured ignimbrite and pumice layer with sandy soil, which is the main water-bearing horizon. Overall, in the neighborhood of four VES points, VES- 2, VES- 3, VES-10, and VES-11, shows good water-bearing zones in the study area.

Keywords: vertical electrical sounding, magnetic survey, aquifer, groundwater potential

Procedia PDF Downloads 79

Authors: Albana Kashtanjeva-Bytyçi, Idriz Vehapi, Rifat Morina, Osman Fetoshi

Abstract:

The purpose of this study is to determine the water quality in Batllava Leka through which a part of the population of the Prishtina region is supplied with drinking water. Batllava Leka is a lake built in the 70s. This lake is located in the village of Btlava in the municipality of Podujeva, with coordinates 42 ° 49′33 ″ V 21 ° 18′25 ″ L, with an area of 3.07 km2. Water supply is from the river Brvenica- Batllavë. In order to take preventive measures and improve water quality, we have conducted periodic/monthly monitoring of water quality in Lake Batllava, through microbiological and physico-chemical indicators. The monitoring was carried out during the period December 2020 - December 2021. Samples were taken at three sampling sites: at the entrance of the lake, in the middle and at the overflow, on two levels, water surface and at a depth of 30 cm. The microbiological parameters analyzed are: total coliforms, fecal coliforms, fecal streptococci, aerobic mesophilic bacteria and actinomycetes. Within the physico-chemical parameters: Dissolved Oxygen, Saturation with O2, water temperature, pH value, electrical conductivity, total soluble matter, total suspended matter, turbidity, chemical oxygen demand, biochemical oxygen demand, total organic carbon, nitrate, total hardness, hardness of calcium, calcium, magnesium, ammonium ion, chloride, sulfates, flourine, M-alkalines, bicarbonates and heavy metals, such as: Fe, Pb, Mn, Cu, Cd. The results showed that most of the physico-chemical and microbiological parameters are within the limit allowed by the WHO, except in the case of the rainiest season that exceeded some parameters.

Keywords: batllava lake, monitoring of water, physico-chemical, microbiological, heavy metals

Procedia PDF Downloads 107

Authors: Ikpesu, Thomas Ohwofasa, Babtunde Ilesanmi

Abstract:

The effects of anthropogenic activities on fish and fisheries products in Niger Delta water bodies were investigated. The rivers were selected based on their close proximity to contaminants and dredging activities. Three stations were chosen per river. The stations chosen to depicting downstream and upstream stations were visited and samples collected on monthly basis. The down streams stations are the polluted and heavily dredged sites, where the upstream station is far, without any evidence of pollution or human activities. During these periods, the fishes of the same species were collected and analyzed for morphological and physiological changes, after which they were returned back to the rivers. The physico-chemicals parameters of these stations were also taken. Morphological changes such as skin ulcerations and other lesions, as well as fungi infections were observed in the down streams fishes. The fish in up streams look healthier and bigger (though the age could not be affirmed) than the downstream fishes. The physico-chemical parameters between the up streams and down streams stations vary significantly (p < 0.01). These anthropogenic effects must have interfere with the normal migration pattern of these fishes, because there were changes in the composition of population and species diversity in the samples sites, with the upstream having true species diversity. The release of pollutants into the water in the Niger Delta areas may triggers off naturally occurring bio toxicity cycles and other fish poisoning. There is risk of biomagnifications of these poisons along the tropic level. This makes the normally valuable food resource dangerous for human consumption and thereby instances of human death caused by such poisoning.

Keywords: anthropogenic, dredging, fisheries, niger delta, pollution, rivers

Procedia PDF Downloads 308

Authors: Abrha Ybeyn Gebremedhn, Yitea Seneshaw Getahun, Alebachew Shumye Moges, Fikrey Tesfay

Abstract:

Rainfed agriculture in Ethiopia has failed to produce enough food, to achieve the increasing demand for food. Pinpointing the appropriate site for rainwater harvesting (RWH) have a substantial contribution to increasing the available water and enhancing agricultural productivity. The current study related to the identification of the potential RWH sites was conducted at the Chacha watershed central highlands of Ethiopia which is endowed with rugged topography. The Geographic Information System with Analytical Hierarchy Process was used to generate the different maps for identifying appropriate sites for RWH. In this study, 11 factors that determine the RWH locations including slope, soil texture, runoff depth, land cover type, annual average rainfall, drainage density, lineament intensity, hydrologic soil group, antecedent moisture content, and distance to the roads were considered. The overall analyzed result shows that 10.50%, 71.10%, 17.90%, and 0.50% of the areas were found under highly, moderately, marginally suitable, and unsuitable areas for RWH, respectively. The RWH site selection was found highly dependent on a slope, soil texture, and runoff depth; moderately dependent on drainage density, annual average rainfall, and land use land cover; but less dependent on the other factors. The highly suitable areas for rainwater harvesting expansion are lands having a flat topography with a soil textural class of high-water holding capacity that can produce high runoff depth. The application of this study could be a baseline for planners and decision-makers and support any strategy adoption for appropriate RWH site selection.

Keywords: runoff depth, antecedent moisture condition, AHP, weighted overlay, water resource

Procedia PDF Downloads 52

Authors: W. Thongwat, B. Terakulsatit

Abstract:

The study area is Kham Sakaesaeng District in Nakhon Ratchasima Province, the south section of Northeastern Thailand, located in the Lower Khorat-Ubol Basin. This region is the one of saline soil area, located in a dry plateau and regularly experience standing with periods of floods and alternating with periods of drought. Especially, the drought in the summer season causes the major saline soil and saline water problems of this region. The general cause of dry land salting resulted from salting on irrigated land, and an excess of water leading to the rising water table in the aquifer. The purpose of this study is to determine the relationship of physical and chemical properties between the soil and groundwater. The soil and groundwater samples were collected in both rainy and summer seasons. The content of pH, electrical conductivity (EC), total dissolved solids (TDS), chloride and salinity were investigated. The experimental result of soil and groundwater samples show the slightly pH less than 7, EC (186 to 8,156 us/cm and 960 to 10,712 us/cm), TDS (93 to 3,940 ppm and 480 to 5,356 ppm), chloride content (45.58 to 4,177,015 mg/l and 227.90 to 9,216,736 mg/l), and salinity (0.07 to 4.82 ppt and 0.24 to 14.46 ppt) in the rainy and summer seasons, respectively. The distribution of chloride content and salinity content were interpolated and displayed as a map by using ArcMap 10.3 program, according to the season. The result of saline soil and brined groundwater in the study area were related to the low-lying topography, drought area, and salt-source exposure. Especially, the Rock Salt Member of Maha Sarakham Formation was exposed or lies near the ground surface in this study area. During the rainy season, salt was eroded or weathered from the salt-source rock formation and transported by surface flow or leached into the groundwater. In the dry season, the ground surface is dry enough resulting salt precipitates from the brined surface water or rises from the brined groundwater influencing the increasing content of chloride and salinity in the ground surface and groundwater.

Keywords: environmental geology, soil salinity, geochemistry, groundwater hydrology

Procedia PDF Downloads 120

Authors: Noori Shafiqullah

Abstract:

Millions of people reside downstream of river basins that heavily rely on snowmelt originating from the Hindu Kush (HK) region. Snowmelt plays a critical role as a primary water source in these areas. This study aimed to evaluate snowfall and snowmelt characteristics in the HK region across altitudes ranging from 2019m to 4533m. To achieve this, the study employed a combination of remote sensing techniques and the Snow Model (SM) to analyze the spatial and temporal distribution of Snow Water Equivalent (SWE). By integrating the simulated Snow-cover Area (SCA) with data from the Moderate Resolution Imaging Spectroradiometer (MODIS), the study optimized the Precipitation Gradient (PG), snowfall assessment, and the degree-day factor (DDF) for snowmelt distribution. Ground observed data from various elevations were used to calculate a temperature lapse rate of -7.0 (°C km-1). Consequently, the DDF value was determined as 3 (mm °C-1 d-1) for altitudes below 3000m and 3 to 4 (mm °C-1 d-1) for higher altitudes above 3000m. Moreover, the distribution of precipitation varies with elevation, with the PG being 0.001 (m-1) at lower elevations below 4000m and 0 (m-1) at higher elevations above 4000m. This study successfully utilized the SM to assess SCA and SWE by incorporating the two optimized parameters. The analysis of simulated SCA and MODIS data yielded coefficient determinations of R2, resulting in values of 0.95 and 0.97 for the years 2014-2015, 2015-2016, and 2016-2017, respectively. These results demonstrate that the SM is a valuable tool for managing water resources in mountainous watersheds such as the HK, where data scarcity poses a challenge."

Keywords: improved MODIS, experiment, snow water equivalent, snowmelt

Procedia PDF Downloads 69

Authors: Oya A. Urucu, Aslı B. Çiğil, Hatice Birtane, Ece K. Yetimoğlu, Memet Vezir Kahraman

Abstract:

Chlorpyrifos is an organophosphorus pesticide which can be found in environmental water samples. The efficiency and reuse of a molecularly imprinted polymer (chlorpyrifos - MIP) were investigated for the selective removal of chlorpyrifos residues. MIP was prepared with UV curing thiol-ene polymerization technology by using multifunctional thiol and ene monomers. The thiol-ene curing reaction is a radical induced process, however unlike other photoinitiated polymerization processes, this polymerization process is a free-radical reaction that proceeds by a step-growth mechanism, involving two main steps; a free-radical addition followed by a chain transfer reaction. It assures a very rapidly formation of a uniform crosslinked network with low shrinkage, reduced oxygen inhibition during curing and excellent adhesion. In this study, thiol-ene based UV-curable polymeric materials were prepared by mixing pentaerythritol tetrakis(3-mercaptopropionate), glyoxal bis diallyl acetal, polyethylene glycol diacrylate (PEGDA) and photoinitiator. Chlorpyrifos was added at a definite ratio to the prepared formulation. Chemical structure and thermal properties were characterized by FTIR and thermogravimetric analysis (TGA), respectively. The pesticide analysis was performed by gas chromatography-mass spectrometry (GC-MS). The influences of some analytical parameters such as pH, sample volume, amounts of analyte concentration were studied for the quantitative recoveries of the analyte. The proposed MIP method was applied to the determination of chlorpyrifos in river and tap water samples. The use of the MIP provided a selective and easy solution for removing chlorpyrifos from the water.

Keywords: molecularly imprinted polymers, selective removal, thilol-ene, uv-curable polymer

Procedia PDF Downloads 301

Authors: M. J. Matulino, Carissa Ganong, Mark Mills, Jazmine Harry

Abstract:

Large Woody Debris (LWD), defined as wooden debris with a diameter of at least 10 cm and a length of 2 m, serves as a crucial resource and habitat for aquatic organisms. While research on the ecological impacts of LWD has been conducted in temperate streams, LWD's influence on tropical stream biodiversity remains understudied, making this investigation particularly valuable for future conservation efforts. The Sura River in La Selva Biological Station includes both LWD and open channel sites. We sampled paired LWD and open-channel sites using minnow traps, Promar traps, and dip nets. Vertebrates were identified as species, while macroinvertebrates were identified to order level. We quantified abundance, richness, and Shannon diversity at each. We captured a total of 467 individuals, including 2 turtles, 17 fishes, 1 freshwater crab, 39 shrimp, and 408 other macroinvertebrates. Total abundance was significantly higher in LWD sites. Species richness was marginally higher in LWD sites, but the Shannon diversity index did not differ significantly with habitat. Shrimp (Macrobrachium olfersi) length was significantly higher in LWD areas. Increased food resources and microhabitat availability could contribute to higher abundance, richness, and organismal size in LWD environments. This study fills a critical gap by investigating LWD effects in a tropical environment, providing valuable insights for conservation efforts and the preservation of aquatic biodiversity.

Keywords: large woody debris (LWD), aquatic organisms, ecological impacts, tropical stream biodiversity, conservation efforts

Procedia PDF Downloads 91

Authors: Subagyo Yotopranoto, Sri Wijayanti Sulistyawati, Sukmawati Basuki, Budi Armika, Yoes Prijatna Dachlan

Abstract:

Malaria is a parasitic infectious disease that still remains a health problem in the world, including Indonesia. There is an outbreak happen at West Nusa Tenggara in 2007. A tourist spot in West Nusa Tenggara called West Lombok is mesoendemic area for malaria. Tanjung is the highest malaria morbidity subdistrict in West Lombok. Thus, the research conducted for the presence of a new species of malaria vectors, that are suspected of one factors which caused high morbidity of malaria in this region. The study was conducted in coastal and highland areas. We collected and identified Anopheles larvae from their breeding places. We also collected and identified Anopheles adult mosquitoes with outdoor cow net, indoor and outdoor human bait. In coastal area (Tembobor village), we found Anopheles vagus larvae from rivers as its breeding places. In highland area (Dasan Tengah village), we found An. subpictus from pool, lagoon, and river as its breeding places. In coastal area, with outdoor human bait, we collected An. vagus and An. subpictus adult mosquitoes. With indoor human bait, we collected An. subpictus adult mosquitoes. Whereas with outdoor cow net, we collected An. subpictus and An. maculatus, the first was more dominant. Furthermore, An subpictus strong suspected as malaria vector in coastal area. Anopheles subpictus was an anthropozoophylic mosquitoes, because it was found at indoor and outdoor places.

Keywords: malaria, vector, Tanjung, West Nusa Tenggara

Procedia PDF Downloads 363

Authors: Constantin Haita

Abstract:

The chalcolithic tell settlements from south-eastern Romania, attributed to Gumelnița culture, are characterised by a well-defined surface, marked often by delimitation structures, a succession of many layers of construction, destruction, and rebuilding, and a well-structured area of occupation: built spaces, passage areas, waste zones. Settlements of tell type are located in the river valleys –on erosion remnants, alluvial bars or small islands, at the border of the valleys– on edges or prominences of Pleistocene terraces, lower Holocene terraces, and banks of lakes. This study integrates data on the geographical position, the morphological background, and the general stratigraphy of these important settlements. The correlation of the spatial distribution with the geomorphological units of each area of evolution creates an image of the natural landscape in which they occurred. The sedimentological researches achieved in the floodplain area of Balta Ialomiței showed important changes in the alluvial activity of Danube, after the Chalcolithic period (ca. 6500 - 6000 BP), to Iron Age and Middle Ages. The micromorphological analysis, consisting in thin section interpretation, at the microscopic scale, of sediments and soils in an undisturbed state, allowed the interpretation of the identified sedimentary facies, in terms of mode of formation and anthropic activities. Our studied cases reflect some distinct situations, correlating either with the geomorphological background or with the vertical development, the presence of delimiting structures and the internal organization. The characteristics of tells from this area bring significant information about the human habitation of Lower Danube in Prehistory.

Keywords: chalcolithic, micromorphology, Romania, sedimentology, tell settlements

Procedia PDF Downloads 149

Authors: V. R. Venugopal

Abstract:

Human being evolved 200,000 years ago in an area which is now the Sahara desert and lived all along in the northern part of Africa. It was around 10,000 to15,00 years that he moved out of Africa. Various ancient civilizations – mainly the Egyptian, Mesopotamian, Indus valley and the Chinese yellow river valley civilizations - developed and perished till the beginning of the Christian era. Strangely the regions where all these civilizations flourished are no deserts. After the ancient civilizations the two major religions of the world the Christianity and Islam evolved. These too evolved in the regions of Jerusalem and Mecca which are now in the deserts of the present Israel and Saudi Arabia. Human activity since ancient age right from his origin was in areas which are now deserts. This is only because wherever Man lived in large numbers he has turned them into deserts. Unfortunately, this is not the case with the ancient days alone. Over the last 500 years the forest cover on the earth is reduced by 80 percent. Even more currently Just over the last forty decades human population has doubled but the number of bugs, beetles, worms and butterflies (micro fauna) have declined by 45%. Deforestation and defaunation are the first signs of desertification and Desertification is a process parallel to the extinction of life. There is every possibility that soon most of the earth will be in deserts. This writer has been involved in the process of forestation and increase of fauna as a profession since twenty years and this is a report of his efforts made in the process, the results obtained and concept generated to revert the ongoing desertification of this earth. This paper highlights how desertification can be reverted by applying these basic principles. 1) Man is not owner of this earth and has no right destroy vegetation and micro fauna. 2) Land owner shall not have the freedom to do anything that he wishes with the land. 3) The land that is under agriculture shall be reduced at least by a half. 4) Irrigation and modern technology shall be used for the forest growth also. 5) Farms shall have substantial permanent vegetation and the practice of all in all out shall stop.

Keywords: desertification, extinction, micro fauna, reverting

Procedia PDF Downloads 312

Authors: Ratul Das, Udit Narayan Das

Abstract:

Surface imperviousness in urban area brings significant changes in storm water drainage systems and some recent studies reveals that the impervious surfaces that passes the storm water runoff directly to drainage systems through storm water collection systems, called directly connected impervious area (DCIA) is an effective parameter rather than total impervious areas (TIA) for computation of surface runoff. In the present study, extension of DCIA and TIA were computed for a small sub-urban area of Agartala, the capital of state Tripura. Total impervious surfaces covering the study area were identified on the existing storm water drainage map from landuse map of the study area in association with field assessments. Also, DCIA assessed through field survey were compared to DCIA computed by empirical relationships provided by other investigators. For the assessment of DCIA in the study area two methods were adopted. First, partitioning the study area into four drainage sub-zones based on average basin slope and laying of existing storm water drainage systems. In the second method, the entire study area was divided into small grids. Each grid or parcel comprised of 20m× 20m area. Total impervious surfaces were delineated from landuse map in association with on-site assessments for efficient determination of DCIA within each sub-area and grid. There was a wide variation in percent connectivity of TIA across each sub-drainage zone and grid. In the present study, total impervious area comprises 36.23% of the study area, in which 21.85% of the total study area is connected to storm water collection systems. Total pervious area (TPA) and others comprise 53.20% and 10.56% of the total area, respectively. TIA recorded by field assessment (36.23%) was considerably higher than that calculated from the available land use map (22%). From the analysis of recoded data, it is observed that the average percentage of connectivity (% DCIA with respect to TIA) is 60.31 %. The analysis also reveals that the observed DCIA lies below the line of optimal impervious surface connectivity for a sub-urban area provided by other investigators and which indicate the probable reason of water logging conditions in many parts of the study area during monsoon period.

Keywords: Drainage, imperviousness, runoff, storm water.

Procedia PDF Downloads 351

Authors: N. Y. H. Konagano

Abstract:

Riverside population of Brazilian amazon suffers drinking water scarcity, seeking alternative water resources such as well and rivers, ordinary polluted. Although Amazon Region holds high annual river inflow and enough available of underground water, human activities have compromised the conservation of water resources. In addition, decentralized rural households make difficult to access of potable water. Main objective is to analyze quantitatively the potential of rainwater harvesting to human consumption at Marupaúba community, located in northeast of Amazon region, Brazil. Methods such as historical rainfall data series of municipality of Tomé-Açu at Pará state were obtained from Hydrological Information System of National Water Agency (ANA). Besides, Rippl method was used to calculate, mainly, volume of the reservoir based on difference of water demand and volume available through rainwater using as references two houses (CA I and CA II) as model of rainwater catchment and supply. Results presented that, from years 1984 to 2017, average annual precipitation was 2.607 mm, average maximum precipitation peak was 474 mm on March and average minimum peak on September was 44 mm. All months, of a year, surplus volume of water have presented in relation to demand, considering catchment area (CA) I = 134.4m² and demand volume =0.72 m³/month; and, CA II = 81.84 m² and demand volume = 0.48 m³/month. Based on results, it is concluded that it is feasible to use rainwater for the supply of the rural community Marupaúba, since the access of drinking water is a human right and the lack of this resource compromises health and daily life of human beings.

Keywords: Amazon Region, rainwater harvesting, rainwater resource, rural community

Procedia PDF Downloads 150

Authors: Ime R. Udotong, Justina I. R. Udotong, Ofonime U. M. John

Abstract:

Brass terminal, one of the several crude oil and petroleum products storage/handling facilities in the Niger Delta was built in the 1980s. Activities at this site, over the years, released crude oil into this 3 m-deep, 1500 m-long canal lying adjacent to the terminal with oil floating on it and its sediment heavily polluted. To ensure effective clean-up, three major activities were planned: Site characterization, bioremediation pilot plant construction and testing and full-scale bioremediation of contaminated sediment/bank soil by land farming. The canal was delineated into 12 lots and each characterized, with reference to the floating oily phase, contaminated sediment and canal bank soil. As a result of site characterization, a pilot plant for on-site bioremediation was designed and a treatment basin constructed for carrying out pilot bioremediation test. Following a designed sampling protocol, samples from this pilot plant were collected for analysis at two laboratories as a quality assurance/quality control check. Results showed that Brass Canal upstream is contaminated with dark, thick and viscous oily film with characteristic hydrocarbon smell while downstream, thin oily film interspersed with water were observed. Sediments were observed to be dark with mixture of brownish sandy soil with TPH ranging from 17,800 mg/kg in Lot 1 to 88,500 mg/kg in Lot 12 samples. Brass Canal bank soil was observed to be sandy from ground surface to 3m, below ground surface (bgs) it was silty-sandy and brownish while subsurface soil (4-10m bgs) was sandy-clayey and whitish/grayish with typical hydrocarbon smell. Preliminary results obtained so far have been very promising but were proprietary. This project is considered, to the best of technical literature knowledge, the first large-scale on-site bioremediation project in the Niger Delta region, Nigeria.

Keywords: bioremediation, contaminated sediment, land farming, oily sludge, oil terminal

Procedia PDF Downloads 454

Authors: Bella Japoshvili, Zhanetta Shubitidze, Ani Bikashvili, Sophio Gabelashvili, Marina Gioshvili, Levan Mumladze

Abstract:

Paravani and Saghamo Lakes are oligotrophic lentic systems located in Javakheti plateau (South Georgia) at 2073 m and 1996 m a.s.l. respectively. Javakheti plateau is known as a lakes region as there are located almost 60 small and medium size lakes. Paravani Lake is the biggest lake by its surface area in Georgia, 37 km 2. The Saghamo Lake is smaller and its surface area consists 4.58 km2. These two lakes are connected with Paravani River, because of this the main hydrobiological and ichthyological features are the same. More than 15-30 years were not studied macroinvertebrates of these lakes. Even the existing information is lack and very limited. The aim of our study was to identify main macroinvertebrate groups inhabiting both lakes and to compare obtaining results to existing information. Our investigation was carried out during 2014 and 2015, in 3 seasons of the year, in winter because of severe condition samples were not taken. Kick-net and Petersen grab were used for material collecting, 4 sites from Paravani Lake and 3–from Saghamo Lake were sampled. Collected invertebrates were fixed in ethanol and late taken to the laboratory, where organisms were identified to the lowest taxon possible, usually family. By our results identified 14 taxa for Paravani Lake and 12 taxa for Saghamo Lake. Our results differ from previous information; for Saghamo Lake previously 13 taxa and for Paravani Lake 12 taxa were described. The percentage of the groups also differ from existing information. Our investigation showed that in Paravani Lake most abundant are Apmhipoda, Hydrachnidae, and Hemiptera, in our samples the number of individuals for those 3 taxa was more than thousand, in each. For Saghamo Lake numerous taxon was Amphipoda-36.3%, following by Ephemeroptera-11.37%, Chironomidae-10.5% and Hydrachnidae-7.03% respectively. We also identified the dominant taxon for all studied seasons. Autumn is the period when the diversity of macroinvertebrates are higher in both lakes.

Keywords: Georgia, lakes, macroinvertebrates, monitoring

Procedia PDF Downloads 194

Authors: Lin Li, P. G. R. N. I. Pussella

Abstract:

When representing spatial data and their attributes on different types of maps, the scale plays a key role in the process of map generalization. The process is consisted with two main operators such as selection and omission. Once some data were selected, they would undergo of several geometrical changing processes such as elimination, simplification, smoothing, exaggeration, displacement, aggregation and size reduction. As a result of these operations at different levels of data, the geometry of the spatial features such as length, sinuosity, orientation, perimeter and area would be altered. This would be worst in the case of preparation of small scale maps, since the cartographer has not enough space to represent all the features on the map. What the GIS users do is when they wanted to analyze a set of spatial data; they retrieve a data set and does the analysis part without considering very important characteristics such as the scale, the purpose of the map and the degree of generalization. Further, the GIS users use and compare different maps with different degrees of generalization. Sometimes, GIS users are going beyond the scale of the source map using zoom in facility and violate the basic cartographic rule 'it is not suitable to create a larger scale map using a smaller scale map'. In the study, the effect of map generalization for GIS analysis would be discussed as the main objective. It was used three digital maps with different scales such as 1:10000, 1:50000 and 1:250000 which were prepared by the Survey Department of Sri Lanka, the National Mapping Agency of Sri Lanka. It was used common features which were on above three maps and an overlay analysis was done by repeating the data with different combinations. Road data, River data and Land use data sets were used for the study. A simple model, to find the best place for a wild life park, was used to identify the effects. The results show remarkable effects on different degrees of generalization processes. It can see that different locations with different geometries were received as the outputs from this analysis. The study suggests that there should be reasonable methods to overcome this effect. It can be recommended that, as a solution, it would be very reasonable to take all the data sets into a common scale and do the analysis part.

Keywords: generalization, GIS, scales, spatial analysis

Procedia PDF Downloads 328

Authors: I. Ahmad, A. Hannan, S. Ahmad, M. Asif, M. F. Nawaz, M. A. Tanvir, M. F. Azhar

Abstract:

During this research, a comprehensive survey of tree growing areas of Faisalabad district of Pakistan was conducted to observe the symptoms, spectrum, occurrence and severity of A. nilotica and E. camaldulensis decline. Objective of current research was to investigate specific fungal pathogens involved in decline of A. nilotica and E. camaldulensis. For this purpose, infected roots, bark, neck portion, stem, branches, leaves and infected soils were collected to identify associated fungi. Potato dextrose agar (PDA) and Czepak dox agar media were used for isolations. Identification of isolated fungi was done microscopically and different fungi were identified. During survey of urban locations of Faisalabad, disease incidence on Kikar and Eucalyptus was recorded as 3.9-7.9% and 2.6-7.1% respectively. Survey of Agroforest zones of Faisalabad revealed decline incidence on kikar 7.5% from Sargodha road while on Satiana and Jhang road it was not planted. In eucalyptus trees, 4%, 8% and 0% disease incidence was observed on Jhang road, Sargodha road and Satiana road respectively. The maximum fungus isolated from the kikar tree was Drechslera australiensis (5.00%) from the stem part. Aspergillus flavus also gave the maximum value of (3.05%) from the bark. Alternaria alternata gave the maximum value of (2.05%) from leaves. Rhizopus and Mucor spp. were recorded minimum as compared to the Drechslera, Alternaria and Aspergillus. The maximum fungus isolated from the Eucalyptus tree was Armillaria luteobubalina (5.00%) from the stem part. The other fungi isolated were Macrophamina phaseolina and A. niger.

Keywords: decline, frequency of mycoflora, A. nilotica and E. camaldulensis, Drechslera australiensis, Armillaria luteobubalina

Procedia PDF Downloads 369

Authors: Fengxia Li, Lufeng Zhang, Haibo Wang

Abstract:

The tight sandstone gas reservoir in the Xujiahe Formation of the Sichuan Basin has huge reserves, but its utilization rate is low. Fracturing and stimulation are indispensable technologies to unlock their potential and achieve commercial exploitation. Slickwater is the most widely used fracturing fluid system in the fracturing and renovation of tight reservoirs. However, its viscosity is low, its sand-carrying performance is poor, and the risk of sand blockage is high. Increasing the sand carrying capacity by increasing the displacement will increase the frictional resistance of the pipe string, affecting the resistance reduction performance. The variable viscosity slickwater can flexibly switch between different viscosities in real-time online, effectively overcoming problems such as sand carrying and resistance reduction. Based on a self-developed indoor loop friction testing system, a visualization device for proppant transport, and a HAAKE MARS III rheometer, a comprehensive evaluation was conducted on the performance of variable viscosity slickwater, including resistance reduction, rheology, and sand carrying. The indoor experimental results show that: 1. by changing the concentration of drag-reducing agents, the viscosity of the slippery water can be changed between 2~30mPa. s; 2. the drag reduction rate of the variable viscosity slickwater is above 80%, and the shear rate will not reduce the drag reduction rate of the liquid; under indoor experimental conditions, 15mPa. s of variable viscosity and slickwater can basically achieve effective carrying and uniform placement of proppant. The layered fracturing effect of the JiangX well in the dense sandstone of the Xujiahe Formation shows that the drag reduction rate of the variable viscosity slickwater is 80.42%, and the daily production of the single layer after fracturing is over 50000 cubic meters. This study provides theoretical support and on-site experience for promoting the application of variable viscosity slickwater in tight sandstone gas reservoirs.

Keywords: slickwater, hydraulic fracturing, dynamic sand laying, drag reduction rate, rheological properties

Procedia PDF Downloads 75

Authors: Ali Masria , Abdelazim Negm, Moheb Iskander, Oliver C. Saavedra

Abstract:

Estuaries play an important role in exchanging water and providing a navigational pathway for ships. These zones are very sensitive and vulnerable to any interventions in coastal dynamics. Almost major of these inlets experience coastal problems such as severe erosion, and accretion. Rosetta promontory, Egypt is an example of this environment. It suffers from many coastal problems as erosion problem along the coastline and siltation problem inside the inlet. It is due to lack of water and sediment resources as a side effect of constructing the Aswan High dam. The shoaling of the inlet leads to hindering the navigation process of fishing boats, negative impacts to estuarine and salt marsh habitat and decrease the efficiency of the cross section to transfer the flow during emergencies to the sea. This paper aims to reach a new condition of stability of Rosetta Promontory by using coastal measures to control the sediment entering, and causes shoaling inside the inlet. These coastal measures include modifying the inlet cross section by using centered jetties, eliminate the coastal dynamic in the entrance using boundary jetties. This target is achieved by using a hydrodynamic model Coastal Modeling System (CMS). Extensive field data collection (hydrographic surveys, wave data, tide data, and bed morphology) is used to build and calibrate the model. About 20 scenarios were tested to reach a suitable solution that mitigate the coastal problems at the inlet. The results show that 360 m jetty in the eastern bank with system of sand bypass from the leeside of the jetty can stabilize the estuary.

Keywords: Rosetta promontory, erosion, sedimentation, inlet stability

Procedia PDF Downloads 587

Authors: Soheir El-Shazly, Gouda Abdel-Gawad, Yasser Salama, Dina Sayed

Abstract:

Twelve species belonging to genus Carolia Cantraine, 1838 were recorded from nine localities in the Tertiary rocks of the Tethys, Atlantic and Eastern Pacific Provinces. During The Eocene two species were collected from Indian-Pakistani region, two from North Africa (Libya, Tunis and Algeria), one from Jamaica and two from Peru. The Oligocene shows its appearance in North America (Florida) and Argentina. The genus showed its last occurrence in the Miocene rocks of North America (Florida) before its extinction. In Egypt, the genus was diversified in the Eocene rocks and was represented by four species and two subspecies. The paleobiogeographic distribution of Genus Carolia Cantraine, 1838 indicates that it appeared in the Lower Eocene of West Indian Ocean and migrated westward flowing circumtropical Tethys Current to the central Tethyan province, where it appeared in North Africa and continued its dispersal westward to the Atlantic Ocean and arrived Jamaica in the Middle Eocene. It persisted in the Caribbean Sea and appeared later in the Oligocene and Miocene rocks of North America (Florida). Crossing Panama corridor, the genus migrated to the south Eastern Pacific Ocean and was collected from the Middle Eocene of Peru. The appearance of the genus in the Oligocene of the South Atlantic Coast of Argentina may be via South America Seaway or its southward migration from Central America to Austral Basin. The thickening of the upper valve of the genus, after the loss of its byssus to withstand the current action, caused inability of the animal to carry on its vital activity and caused its extinction. The biometric study of Carolia placunoides Cantraine, 1938 from thhe Eocene of Egypt, indicates that the distance between the muscle scars in the upper valve increases with the closure of the byssal notch.

Keywords: Atlantic, carolia, paleobiogeography, tethys

Procedia PDF Downloads 358

Authors: P. Chang, C. Lopez, C. Burbano

Abstract:

Flood protection zones are riparian buffers that are formed to manage and mitigate the impact of flooding, and in turn, protect local populations. The purpose of this study was to evaluate the Guía Técnica de Criterios para el Acotamiento de las Rondas Hídricas in Colombia against international regulations in Canada and Spain, in order to determine its limitations and contribute to its improvement. The need to establish a specific corridor that allows for the dynamic development of a river is clear; however, limitations present in the Colombian Technical Guide are identified. The study shows that international regulations provide similar concepts as used in Colombia, but additionally integrate aspects such as regionalization that allows for a better characterization of the channel way, and incorporate the frequency of flooding and its probability of occurrence in the concept of risk when determining the protection zone. The case study analyzed in Dosquebradas - Risaralda aimed at comparing the application of the different standards through hydraulic modeling. It highlights that the current Colombian standard does not offer sufficient details in its implementation phase, which leads to a false sense of security related to inaccuracy and lack of data. Furthermore, the study demonstrates how the Colombian norm is ill-adapted to the conditions of Dosquebradas typical of the Andes region, both in the social and hydraulic aspects, and does not reduce the risk, nor does it improve the protection of the population. Our study considers it pertinent to include risk estimation as an integral part of the methodology when establishing protect flood zone, considering the particularity of water systems, as they are characterized by an heterogeneous natural dynamic behavior.

Keywords: environmental corridor, flood zone determination, hydraulic domain, legislation flood protection zone

Procedia PDF Downloads 113

Authors: David Maina Muthegethi

Abstract:

The Victoria Basin is associated with gateway for migration to Southern part of Africa. Different communities migrated through the region including the Bantus and Nilotic communities that occupy present day Kenya and Tanzania. A distinct culture of dry-stone technology emerged around 15th century current era, a period associated with peopling of the western Kenya region. One of the biggest dry-stone walls enclosure is Thimlich Ohinga archaeological site. The site was constructed around fourteenth century current era. Architectural design was oval shaped stone structures that were around 4 meters and 2 meters in length and width respectively. The main subsistence strategies of the community that was crop faming, pastoralism, fishing, hunting and gathering. This paper attempts to examine gender dynamics of Thimlich Ohinga society. At that end, attempts are made to infer gender roles as manifested in archaeological record. Therefore, the study entails examination of material evidence excavated from the site. Also, ethnoarchaeological study of contemporary Luo community was undertaken in order to make inferences and analogies concerning gender roles of Thimlich Ohinga society. Overall, the study involved examination of cultural materials excavated from Thimlich Ohinga, extensive survey of the site and ethnography of Luo community. In total, an extensive survey and interviews of 20 households was undertaken in South Kanyamkango ward, Migori County in Western Kenya. The key findings point out that Thimlich Ohinga gender identities were expressed in material forms through architecture, usage of spaces, subsistence strategies, dietary patterns and household organization. Also, gender as social identity was dynamic and responsive to diversification of subsistence strategies and intensification of regional trade as documented in contemporary Luo community. The paper reiterates importance of ethnoarchaeological methods in reconstruction of past social organization as manifested in material record.

Keywords: ethnoarchaeological, gender, subsistence patterns, Thimlich Ohinga

Procedia PDF Downloads 75

Authors: Bua Srikos, Phusit Phukamchanoad

Abstract:

The purpose is to study the model and characteristic of participation of the suitable community to lead to develop permanent water marketing in Bang Noi Floating Market, Bangkonti District, Samutsongkhram Province. A total of 342 survey questionnaires were administered to potential respondents. The researchers interviewed the leader of the community. Appreciation Influence Control (AIC) was used to talk with 20 villagers on arena. The findings revealed that overall, most people had the middle level of the participation in developing the durable Bang Noi Floating Market, Bangkonti, Samutsongkhram Province and in aspects of gaining benefits from developing it with atmosphere and a beautiful view for tourism. For example, the landscape is beautiful with public utilities. The participation in preserving and developing Bang Noi Floating Market remains in the former way of life. The basic factor of person affects to the participation of people such as age, level of education, career, and income per month. Most participants are the original hosts that have houses and shops located in the marketing and neighbor. These people involve with the benefits and have the power to make a water marketing strategy, the major role to set the information database. It also found that the leader and the villagers play the important role in setting a five-physical database. Data include level of information such as position of village, territory of village, road, river, and premises. Information of culture consists of a two-level of information, interesting point, and Itinerary. The information occurs from presenting and practicing by the leader and villagers in the community.All of phases are presented for listening and investigating database together in both the leader and villagers in the process of participation.

Keywords: participation, community, sustainable development, encouragement, tourism

Procedia PDF Downloads 347

Authors: Javed Iqbal

Abstract:

Filling of Xiangjiaba Reservoir Lake in Southwest China triggered and re-activated numerous landslides due to water fluctuation. In order to understand the relationship between reservoirs and slope instability, a typical reservoir landslide (Dasha landslide) at right bank of Jinsha River was selected as a case study for in-depth investigations. The detailed field investigations were carried out in order to identify the landslide with respect to its surroundings and to find out the slip-surface. Boreholes were drilled in order to find out the subsurface lithology and the depth of failure of Dasha landslide. The in-situ geotechnical tests were performed, and the soil samples from exposed slip surface were retrieved for geotechnical laboratory analysis. Finally, stability analysis was done using 3D strength reduction method under different conditions of reservoir water level fluctuations and rainfall conditions. The in-depth investigations show that the Dasha landslide is a bedding rockslide which was once activated in 1986. The topography of Dasha landslide is relatively flat, while the back scarp and local terrain are relatively steep. The landslide area is about 29 × 104 m², and the maximum thickness of the landslide deposits revealed by drilling is about 40 m with the average thickness being about 20 m, and the volume is thus estimated being about 580 × 10⁴ m³. Bedrock in the landslide area is composed of Suining Formation of Jurassic age. The main rock type is silty mudstone with sandstone, and bedding orientation is 300~310° ∠ 7~22°. The factor of safety (FOS) of Dasha landslide obtained by 3D strength reduction cannot meet the minimum safety requirement under the working condition of reservoir level fluctuation as designed, with effect of rainfall and rapid drawdown.

Keywords: Dasha landslide, Xiangjiaba reservoir, strength reduction method, bedding rockslide

Procedia PDF Downloads 162

Authors: Satish Kumar, Spandan Sahu, Sarjati Sahoo, K. K. Khatua

Abstract:

An experimental investigation has been carried out in a tilting flume of 2 m wide, 13 m long, and 0.3 m deep to study the effect of flow on the formation of braided channel pattern. Sediment flow is recirculated through the flume, which passes from the headgate to the sediment/water collecting tank through the tailgate. Further, without altering the geometry of the sand bed channel, the discharge is varied to study the effect of the formation of the braided pattern with time. Then the flow rate is varied to study the effect of flow on the formation of the braided pattern. Sediment transport rate is highly variable and was found to be a nonlinear function of flow rate, aspect ratio, longitudinal slope, and time. Total braided intensity (BIT) for each discharge case is found to be more than the active braided intensity (BIA). Both the parameters first increase and then decrease as the time progresses following a similar pattern for all the observed discharge cases. When the flow is increased, the movement of sediment also increases since the active braided intensity is found to adjust quickly. The measurement of velocity and boundary shear helps to study the erosion and sedimentation processes in the channel and formation of small meandering channels and then the braided channel for different discharge conditions of a sediment river. Due to regime properties of rivers, both total braided Intensity and active braided intensity become stable for a given channel and flow conditions. In the present case, the trend of the ratio of BIA to BIT is found to be asymptotic against the time with a value of 0.4. After the particular time elapses off the flow, new small channels are also found to be formed with changes in the sinuosity of the active channels, thus forming the braided network. This is due to the continuous erosion and sedimentation processes occurring for the flow process for the flow and sediment conditions.

Keywords: active braided intensity, bed load, sediment transport, shear stress, total braided intensity

Procedia PDF Downloads 131

Authors: Asibor Godwin, Adeniyi Funsho

Abstract:

This study was carried out to investigate the impact of biological treated effluent on the physico-chemical properties of receiving waterbodies and also to establish its suitability for other purposes. It focused on the changes of some physic-chemical variables as one move away from the point of discharge downstream of the waterbodies. Water samples were collected from 14 sampling stations made up of the untreated effluent, treated effluent and receiving streams (before and after treated effluent discharge) over a period of 6 months spanning the dry and rainy seasons. Analyses were carried out on the following: temperature, turbidity, pH, conductivity, major anions and cation, dissolved oxygen, percentage oxygen Saturation, biological oxygen demand (BOD), solids (total solids, suspended solids and dissolved solids), nitrates, phosphates, organic matter and flow discharge using standard analytical methods. The relationships between investigated sites with regards to their physico-chemical properties were analyzed using student-t statistics. Also changes in the treated effluent receiving streams after treated effluent outfall was discussed fully. The physico-chemical water quality of the receiving water bodies meets most of the general water requirements for both domestic and industrial uses. The untreated effluent quality was shown to be of biological origin based on the biological oxygen demand, chloride, dissolved oxygen, total solids, pH and organic matter. The treated effluent showed significant improvement over the raw untreated effluent based on most parameters assessed. There was a significant difference (p<0.05) between the physico-chemical quality of untreated effluent and the treated effluent for the most of the investigated physico-chemical quality. The difference between the discharged treated effluent and the unimpacted section of the receiving waterbodies was also significant (p<0.05) for the most of the physico-chemical parameters.

Keywords: eflluent, Opa River, physico-chemical, waterbody

Procedia PDF Downloads 261

Authors: Mostafa Zandi, Ramin Mansouri

Abstract:

Spillways are one of the most important hydraulic structures of dams that provide the stability of the dam and downstream areas at the time of flood. Morning-Glory spillway is one of the common spillways for discharging the overflow water behind dams, these kinds of spillways are constructed in dams with small reservoirs. In this research, the hydraulic flow characteristics of a morning-glory spillways are investigated with CFD model. Two dimensional unsteady RANS equations were solved numerically using Finite Volume Method. The PISO scheme was applied for the velocity-pressure coupling. The mostly used two-equation turbulence models, k- and k-, were chosen to model Reynolds shear stress term. The power law scheme was used for discretization of momentum, k , and  equations. The VOF method (geometrically reconstruction algorithm) was adopted for interface simulation. The results show that the fine computational grid, the input speed condition for the flow input boundary, and the output pressure for the boundaries that are in contact with the air provide the best possible results. Also, the standard wall function is chosen for the effect of the wall function, and the turbulent model k -ε (Standard) has the most consistent results with experimental results. When the jet is getting closer to end of basin, the computational results increase with the numerical results of their differences. The lower profile of the water jet has less sensitivity to the hydraulic jet profile than the hydraulic jet profile. In the pressure test, it was also found that the results show that the numerical values of the pressure in the lower landing number differ greatly in experimental results. The characteristics of the complex flows over a Morning-Glory spillway were studied numerically using a RANS solver. Grid study showed that numerical results of a 57512-node grid had the best agreement with the experimental values. The desired downstream channel length was preferred to be 1.5 meter, and the standard k-ε turbulence model produced the best results in Morning-Glory spillway. The numerical free-surface profiles followed the theoretical equations very well.

Keywords: morning-glory spillway, CFD model, hydraulic characteristics, wall function

Procedia PDF Downloads 77

Authors: Asselah Amel, Affif Chaouche M'yassa, Toudji Amira, Tazerouti Amel

Abstract:

This study covers two aspects ; the biodegradability and the performances in corrosion inhibition of a series of synthetized surfactants namely Φ- sodium methyl ester sulfonates (Φ-MES: C₁₂-MES, C₁₄-MES and C₁₆-MES. The biodegradability of these organic compounds was studied using the respirometric method, ‘the standard ISO 9408’. Degradation was followed by analysis of dissolved oxygen using the dissolved oxygen meter over 28 days and the results were compared with that of sodium dodecyl sulphate (SDS). The inoculum used consists of activated sludge taken from the aeration basin of the biological wastewater treatment plant in the city of Boumerdes-Algeria. In addition, the anticorrosive performances of Φ-MES surfactants on a carbon steel "X70" were evaluated in an injection water from a well of Hassi R'mel region- Algeria, known as Baremian water, and are compared to sodium dodecyl sulphate. Two technics, the weight loss and the linear polarization resistance corrosion rate (LPR) are used allowing to investigate the relationships between the concentrations of these synthetized surfactants and their surface properties, surface coverage and inhibition efficiency. Various adsorption isotherm models were used to characterize the nature of adsorption and explain their mechanism. The results show that the MES anionic surfactants was readily biodegradable, degrading faster than SDS, about 88% for C₁₂-MES compared to 66% for the SDS. The length of their carbon chain affects their biodegradability; the longer the chain, the lower the biodegradability. The inhibition efficiency of these surfactants is around 78.4% for C₁₂-MES, 76.60% for C₁₄-MES and 98.19% for C₁₆-MES and increases with their concentration and reaches a maximum value around their critical micelle concentrations ( CMCs). Scanning electron microscopy coupled to energy dispersive X-ray spectroscopy allowed to the visualization of a good adhesion of the protective film formed by the surfactants to the surface of the steel. The studied surfactants show the Langmuirian behavior from which the thermodynamic parameters as adsorption constant (Kads), standard free energy of adsorption (〖∆G〗_ads^0 ) are determined. Interaction of the surfactants with steel surface have involved physisorptions.

Keywords: corrosion, surfactants, adsorption, adsorption isotherems

Procedia PDF Downloads 97

Authors: Zeinu Ahmed Rabba, Derek D Stretch

Abstract:

Remote sensing contributes valuable information to streamflow estimates. Usually, stream flow is directly measured through ground-based hydrological monitoring station. However, in many developing countries like Ethiopia, ground-based hydrological monitoring networks are either sparse or nonexistent, which limits the manage water resources and hampers early flood-warning systems. In such cases, satellite remote sensing is an alternative means to acquire such information. This paper discusses the application of remotely sensed rainfall data for streamflow modeling in Gilgel Ghibe basin in Ethiopia. Ten years (2001-2010) of two satellite-based precipitation products (SBPP), TRMM and WaterBase, were used. These products were combined with the PyTOPKAPI hydrological model to generate daily stream flows. The results were compared with streamflow observations at Gilgel Ghibe Nr, Assendabo gauging station using four statistical tools (Bias, R², NS and RMSE). The statistical analysis indicates that the bias-adjusted SBPPs agree well with gauged rainfall compared to bias-unadjusted ones. The SBPPs with no bias-adjustment tend to overestimate (high Bias and high RMSE) the extreme precipitation events and the corresponding simulated streamflow outputs, particularly during wet months (June-September) and underestimate the streamflow prediction over few dry months (January and February). This shows that bias-adjustment can be important for improving the performance of the SBPPs in streamflow forecasting. We further conclude that the general streamflow patterns were well captured at daily time scales when using SBPPs after bias adjustment. However, the overall results demonstrate that the simulated streamflow using the gauged rainfall is superior to those obtained from remotely sensed rainfall products including bias-adjusted ones.

Keywords: Ethiopia, PyTOPKAPI model, remote sensing, streamflow, Tropical Rainfall Measuring Mission (TRMM), waterBase

Procedia PDF Downloads 285

Authors: Wen Feiming

Abstract:

As the ecological barrier of the Yangtze River, the ecological security of the Parallel Range-Valley area is very important. However, the unique geomorphic features aggravate the contradiction between man and land, resulting in the encroachment of ecological space. In recent years , relevant researches has focused on the single field of land science, ecology and landscape ecology, and it is difficult to systematically reflect the regularities of distribution and evolution trends of ecological patterns in the process of urban development. Therefore, from the perspective of "Production-Living-Ecological space", using spatial analysis methods such as Remote Sensing (RS) and Geographic Information Systems (GIS), this paper analyzes the evolution characteristics and driving factors of the ecological pattern of mountain towns in the parallel range-valley region from the aspects of land use structure, change rate, transformation relationship, and spatial correlation. It is concluded that the ecological pattern of mountain towns presents a trend from expansion and diffusion to agglomeration, and the dynamic spatial transfer is a trend from artificial transformation to the natural origin, while the driving effect analysis shows the significant characteristics of terrain attraction and construction barrier. Finally, combined with the evolution characteristics and driving mechanism, the evolution modes of "mountain area - concentrated growth", "trough area - diffusion attenuation" and "flat area - concentrated attenuation" are summarized, and the differentiated zoning and stratification ecological planning strategies are proposed here, in order to provide the theoretical basis for the sustainable development of mountain towns in parallel range-valley areas.

Keywords: parallel range-valley, ecological pattern, evolution characteristics, driving factors

Procedia PDF Downloads 104