Land Use Of Catchment Area Research Articles

Excessive use of chemical fertilizers in catchment areas raises the seasonal pH in natural freshwater lakes of the subtropical monsoon climate region

In recent years, the pH of some oligotrophic natural freshwater lakes in the subtropical monsoon climate region has generally reached an extremely high level of approximately 9.0 during the summer and autumn. It has not been proven that the explanation for why carbon assimilation in productive lakes exceeds carbon supply and causes a rise in pH also applies to oligotrophic freshwater lakes. Regardless, this may have been caused by changes in the solute composition of inflowing rivers as a result of changes in land use in catchment areas. Beimiao Reservoir in Baoshan City, Yunnan Province, where pH has increased significantly in summer and fall over the past few years, was chosen for this research in order to verify this hypothesis. This paper evaluates the status quo of water quality and nutrition in this reservoir. In addition, this paper analyzes the effects of water temperature, the metabolism of aquatic organisms, and river input on the horizontal and vertical spatial differences, diurnal variations, seasonal changes, and annual changes in the pH of the reservoir. It was discovered that one of the primary causes of the pH increase in natural freshwater lakes in the subtropical monsoon climate region during summer and autumn can be summarized as follows: A large amount of nitric acid and sulfuric acid are produced in the soil when chemical fertilizers are overused in runoff areas, particularly during intensive horticultural crop cultivation. Therefore, the subtropical monsoon climate region's soil loses calcium and magnesium ions, whose combined equivalent concentrations significantly exceed those of bicarbonate ions. The combined equivalent concentrations of calcium ions and magnesium ions in the inflowing rivers in summer and autumn are also significantly higher than those in the lake, resulting in the depletion of free carbon dioxide caused by calcium carbonate precipitation and an increase in pH. The conclusion of this research casts new light on the preservation and treatment of the ecological environment of lake water with similar issues.

Internal Loading of Phosphorus from Bottom Sediments of Two Meso-eutrophic Lakes

The aim of the study was to determine the seasonal and spatial variability of phosphorus release from bottom sediments of two lakes in Poland (Wielkopolska Region): Lusowskie Lake and Prawe Lake. The comparison of results from these two lakes could have been reliably made, because they were characterized by a similar trophic state (meso-eutrophic), were located in the same climatic zone, and were examined at the same time but differed in terms of morphometry (area, depth, and shape) as well as land use of catchment area. These dimictic lakes were characterized by hypolimnetic oxygen deficits in summer. The internal loading of phosphorus was analysed on the basis of ex situ experiments with intact cores of bottom sediments sampled at two stations, situated in the profundal (the deepest place in the lake) and in the littoral (2.0 m depth). The results indicated that a higher phosphorus load was released from bottom sediments in the profundal zone than in the littoral zone of both lakes. Phosphorus release from the profundal zone was twofold higher in Prawe Lake than in Lusowskie Lake. It reached 2.6 mg P m−2 d−1 in spring and winter in the larger and deeper Lusowskie Lake, compared to 6.04 mg P m−2 d−1 in autumn in the smaller and shallower Prawe Lake. In the littoral zone, phosphorus release reached 1.67 mg P m−2 d−1 and 0.16 mg P m−2 d−1 in both lakes, respectively. Differences in phosphorus internal loading between the lakes were due to differences in the stability of thermal stratification, time of water mixing and oxygen concentration in the depth profile of the lake.

The characteristic of Natural Organic Matter (NOM) of water from Cikapundung River Pond

Natural organic matter (NOM) is an important parameter in drinking water due to its roles as one of main precursors of trihalomethanes (THMs). The characteristic of NOM might be influenced by land use of catchment area. The present study aims to analyse the correlation between various NOM parameters and THMs, and physical characteristics of raw water. The effect of land use around the catchment is also presented. The samples were taken from Cikapundung river pond, which is used by the water company of Bandung City as raw water sources for drinking water. Geographic Information System (GIS) was applied to distinguish anthropogenic and natural land use around the water catchment. The samples were categorised as unfiltered samples and filtered samples to measure dissolved material. Turbidity and conductivity were measured to obtain the physical characteristics of water. NOM parameters were as of TOC, DOC, COD, UV254 and UV355. The turbidity and conductivity of water were 5-34.7 NTU and 132-306 µmhos/cm, respectively. COD was from 32 to 76.8 mg/L. TOC was between 4.22 and 6.92 mg/L. UV254 and UV355 ranged 0.15-0.38 cm-1 and 0.09-0.16 cm-1, respectively. COD and conductivity correlated well in unfiltered (r = 0.923) and filtered sample (r = 0.995). In both unfiltered and filtered samples, UV254 were correlated with UV355 with r of 0.986 and 0.995 respectively. The results revealed that catchments area of the pond was possibly dominated by anthropogenic activities.

Nutrient Limiting Factor for Enabling Algae Growth of Rawapening Lake, Indonesia

Two important issues for establishment of nutrient criteria are identifying which nutrient limits algal growth and determining the concentration of that nutrient enabling nuisance growths. The purposes of this research were: 1) to examine the nutrient (TN, TP, ratio of TN/TP) dynamic in Rawapening Lake spatially and temporally, 2) to identify Nutrient Limiting of Algal Growth in Rawapening Lake, and 2) to determine the nutrient criteria for enabling algae growth in Rawapening Lake. The research was conducted using a survey method in 7 sites from February to August 2016. The result showed that spatially Total Nitrogen (TN) and Total Phosphor (TP) in the lake were not evenly distributed and temporally influenced by the inflow. The development of algae biomass in Rawapening Lake determined ratio of TN/TP. Nutrient criteria as follow: oligotrophic was 5.96 - 14.39, mesotrophic was 14.39 - 42.15, eutrophic 42.15 - 51.65, and hyper-eutrophic > 51.65. These criteria could be used in designing controlling eutrophication problem by arranging nutrient input from both external and internal sources in order to meet those limit. The benefits of research contributes to the development of environmental monitoring methods to assess the trophic status using more appropriate in accordance with the conditions of the tropics region. It also could be used for consideration in policy direction and orientation of land use in catchment areas in relation to water quality of the lake.

Effect of Mughal Road on Land Use of Catchment Area of Rambiara Nallah (Shopian) Jammu and Kashmir, India

Effect of Mughal Road on Land Use of Catchment Area of Rambiara Nallah (Shopian) Jammu and Kashmir, India

Rising floodwaters: mapping impacts and perceptions of flooding in Indonesian Borneo

The roles of forest and wetland ecosystems in regulating flooding have drawn increasing attention in the contexts of climate change adaptation and disaster risk reduction. However, data on floods are scarce in many of the countries where people are most exposed and vulnerable to their impacts. Here, our separate analyses of village interview surveys (364 villages) and news archives (16 sources) show that floods have major impacts on lives and livelihoods in Indonesian Borneo, and flooding risks are associated with features of the local climate and landscape, particularly land uses that have seen rapid expansions over the past 30 years. In contrast with government assessments, we find that flooding is far more widespread, and that frequent, local, events can have large cumulative impacts. Over three years, local news agencies reported floods that affected 868 settlements, 966 times (including 89 in urban areas), inundated at least 197 000 houses, and displaced more than 776 000 people, possibly as many as 1.5 million (i.e. 5%–10% of the total population). Spatial analyses based on surveys in 364 villages show that flood frequency is associated with land use in catchment areas, including forest cover and condition, and the area of wetlands, mines (open-cut coal or gold mines), and oil palm. The probability that floods have become more frequent over the past 30 years was higher for villages closer to mines, and in watersheds with more extensive oil palm, but lower in watersheds with greater cover of selectively-logged or intact forests. We demonstrate that in data-poor regions, multiple sources of information can be integrated to gain insights into the hydrological services provided by forest and wetland ecosystems, and motivate more comprehensive assessment of flooding risks and options for ecosystem-based adaptation.

Análise da Influência do Uso da Terra no Microclima Urbano: Caso Irati-PR

A redução das áreas verdes urbanas e o consequente aumento das áreas construídas é um dos temas mais discutidos atualmente. Tanto a dinâmica do uso do solo urbano quanto de mudanças climáticas podem comprovar relações entre diversos usos e ocupações do solo e suas consequências para o microclima local. Este trabalho apresenta uma avaliação da influência do uso da terra no clima urbano em uma cidade de pequeno porte. Foram selecionados 4 pontos abrangendo o perímetro urbano de Irati, no estado do Paraná, com diferentes ocupações, e obtidas variáveis de temperatura e umidade relativa com uso de higrômetros adaptados em abrigos termométricos em 4 horários distintos durante 4 dias. A utilização de imagens orbitais de alta resolução possibilitou o mapeamento do uso do solo urbano de áreas de abrangência num raio de 350 metros dos pontos pré-selecionados. Os resultados comprovaram, estatisticamente, que o uso e ocupação do solo interferem nas variáveis climáticas obtidas.

Urgency for sustainable development in coastal urban areas with reference to weather pattern, land use, and water quality

Water pollution is one of the most critical problems affecting mankind. Weather pattern and land use of catchment area have significant role in quality of water bodies. Due to climate change, there is frequent variation in weather pattern all over the world. There is also rapid change in land use due to increase in population and urbanization. The study was carried out to analyze the effect of change in weather pattern during the monsoon periods of 2008 and 2012 on water quality of a tropical coastal lake system. The nature and extent of variation in different water quality parameters namely electrical conductivity (EC), magnesium (Mg), sodium (Na), chloride (Cl), sulphate (SO4), turbidity, Secchi disk depth, biochemical oxygen demand (BOD), phosphate (PO4), calcium (Ca), and water temperature as well as the effect of various land use activities in the lake basin on water quality have also been studied. There is significant reduction in precipitation, EC, Mg, Na, Cl, SO4, turbidity, and Secchi disk depths whereas a significant rise in the BOD, PO4, Ca, and water temperature were observed in 2012. This significant reduction in electrical conductivity during 2012 revealed that because of less precipitation, the lake was separated from the sea by the sandbar during most of the monsoon period and thereby interrupted the natural flushing process. This caused the accumulation of organic matter including phosphate and thereby resulting reduction in clarity and chlorophyll-a (algae) in the lake. The unsustainable development activities of Thiruvanathapuram city are mainly responsible for the degradation of water bodies. The lack of maintenance and augmentation activities namely replacement of old pipes and periodical cleaning of pipe lines of the old sewer system in the city results in the bypass of sewage into water bodies. Because of the existence of the old sewerage system, no effort has been taken by the individual establishment/house of the city to provide their own treatment system for sewage and sullage and the untreated wastes are discharged into these old sewer pipes and ultimately the wastes reach the water bodies. In this context, decentralized treatment of sewage, sullage, and garbage by individual houses/establishments/hotels/hospitals is a better option for the developing countries. With the rapid developmental activities, and due to the variation of precipitation due to climate change, it is highly essential to provide proper waste treatment/augmentation facilities in urban lake system because a slight variation in the weather pattern can result in serious implications in the already polluted water bodies.

Land use influence on 137Cs levels in perch ( Perca fluviatilis L.) and roach ( Rutilus rutilus L.)

The environmental influence on Chernobyl-derived 137Cs levels in perch ( Perca fluviatilis L.) and roach ( Rutilus rutilus L.) was revealed using partial least-squares regression (PLS). The 53 environmental predictors used describe land use in catchment areas, various catchment area and lake characteristics, lake water chemistry, and fish stock composition. The study showed a profound effect of land use on the 137Cs levels in fish. Radiocaesium deposited on arable land was retained in the soil to a greater extent than was 137Cs deposited on wetlands, which more easily leached out to the lake ecosystems. The 137Cs deposition close to the lakes had a more pronounced effect on 137Cs levels in the fish than did more distant deposition. The radiocaesium bioavailability is mainly governed by lake water cation content, as hardwater lakes had significantly lower 137Cs content in fish. Resuspension of 137Cs contaminated sediments only had a limited influence on the observed levels in fish.