45 research outputs found
Tropical Agrarian landscape classification using high-resolution GeoEYE data and segmentationbased approach
We examine the use of high spatial resolution âGeoEYEâ imagery for land use classification in a tropical landscape. Image objects (I-Os) derived from features identification provide a basis for segmentation process and the Geographic Object Based Image Analysis (GEOBIA) framework. eCognition software with I-Os as classification unit and maximum likelihood algorithm facilitated the process. Supervised classification approaches (SCA) and rule set classification approach (RSCA) were used and performance and transferability of two approaches compared. Main conclusions: (a) high degree of details in GeoEYE data enables delineation of diverse land use zones, and (b) segmentation based analysis is more effective to tackle spatial intermixing. © 2016 by the authors.BMB
The co-constitution of regional politics and massive infrastructures in the Transaqua water project
Large-scale water infrastructure projects have seen a sudden surge to the top of the political agenda in many countries as a means of addressing developmental goals at both national and regional levels, despite a decline in funding for these projects in the 1990s and 2000s. The Transaqua inter-basin water transfer (IBWT) project, a 2400 km-long canal aiming to connect the Lake Chad and Congo River basins, has been recently hailed by the Lake Chad basin countries, international and regional organizations, and the private sector as the most feasible solution to revitalize Lake Chadâs declining water levels. It has also started to reconfigure the regional politics of two of Africaâs largest basins. This article focuses on this case study and analyses how regional features shape Transaqua and how it simultaneously reconfigures regional politics. Based on concepts such as âregionâ, âregionalismâ and âregionalisationâ within the international relations discipline and applying mixed methods of discourse, document and media analysis, we show how the project is influencing regional dynamics, alliances and power relations in the Lake Chad and Congo River basins, and how the Transaqua discourse evolves along with regional features such as droughts, water abundance and regional insecurities, despite being in the planning stage
Impacts of salinity parameterizations on temperature simulation over and in a hypersaline lake
In this paper, we introduced parameterizations of the salinity effects (on heat capacity, thermal conductivity, freezing point and saturated vapor pressure) in a lake scheme integrated in the Weather Research and Forecasting model coupled with the Community Land Model (WRF-CLM). This was done to improve temperature simulation over and in a saline lake and to test the contributions of salinity effects on various water properties via sensitivity experiments. The modified lake scheme consists of the lake module in the CLM model, which is the land component of the WRF-CLM model. The Great Salt Lake (GSL) in the USA was selected as the study area. The simulation was performed from September 3, 2001 to September 30, 2002. Our results show that the modified WRF-CLM model that includes the lake scheme considering salinity effects can reasonably simulate temperature over and in the GSL. This model had much greater accuracy than neglecting salinity effects, particularly in a very cold event when that effect alters the freezing point. The salinity effect on saturated vapor pressure can reduce latent heat flux over the lake and make it slightly warmer. The salinity effect on heat capacity can also make lake temperature prone to changes. However, the salinity effect on thermal conductivity was found insignificant in our simulations. © 2015, Chinese Society for Oceanology and Limnology, Science Press and Springer-Verlag Berlin Heidelberg
Incorporating Ecosystem Services into Water Resources ManagementâTools, Policies, Promising Pathways
Ecosystems provide a range of services, including water purification, erosion prevention, and flood risk mitigation, that are important to water resource managers. But as a sector, water resources management has been slow to incorporate ecosystem protection and restoration, for a variety of reasons, although related concepts such as nature-based solutions and green infrastructure are gaining traction. We explain some of the existing challenges to wider uptake of the ecosystem services concept in water resources management and introduce some promising avenues for research and practice, elaborated in more detail through 12 papers, spanning five continents and a variety of contexts, which make up a Special Issue on âIncorporating Ecosystem Services into Water Resources Managementâ. Cross-cutting themes include (A) ecosystem services as a flexible concept to communicate with stakeholders; (B) participatory processes to involve stakeholders in research; (C) multiple values, and valuation methods, of water-related services; and (D) applications of decision-support tools. We conclude with a summary of research gaps and emphasize the importance of co-producing knowledge with decision makers and other stakeholders, in order to improve water resources management through the integration of ecosystem services. © 2022, The Author(s)
Wetland dynamics: Links with spatial, ecological and socio-economic related issues in the western coastal belt of Sri Lanka
WetlandsAssessmentLagoonsMarshesEcologyEcosystemsSocial aspectsEconomic aspects
Impacts of the Two Biggest Lakes on Local Temperature and Precipitation in the Yellow River Source Region of the Tibetan Plateau
The Tibetan Plateau harbors thousands of lakes; however few studies focus on impacts of lakes on local climate in the region. To investigate and quantify impacts of the two biggest lakes (Ngoring Lake and Gyaring Lake) of the Yellow River source region in the Tibetan Plateau on local climate, two simulations (with and without the two large lakes) from May 2010 to July 2011 are performed and analyzed using the WRF-CLM model (the weather research and forecasting model coupled with the community land model). Differences between simulated results show that the WRF-CLM model could provide realistic reproduction of surface observations and has better simulation after considering lakes. Lakes mostly reduce the maximum temperature all year round and increase the minimum temperature except in March due to the large heat capacity that makes lakes absorb (release) more energy for the same temperature change compared to land. Lakes increase precipitation over the lake area and in the nearby region, mostly during 02-14 BT (Beijing Time) of July to October when the warm lake surface induces the low level horizontal convergence and updraft over lake and provides energy and vapor to benefit the development of the convection for precipitation
Recommended from our members
Ten new insights in climate science 2020 â a horizon scan
Non-technical summary
We summarize some of the past year's most important findings within climate change-related research. New research has improved our understanding of Earth's sensitivity to carbon dioxide, finds that permafrost thaw could release more carbon emissions than expected and that the uptake of carbon in tropical ecosystems is weakening. Adverse impacts on human society include increasing water shortages and impacts on mental health. Options for solutions emerge from rethinking economic models, rights-based litigation, strengthened governance systems and a new social contract. The disruption caused by COVID-19 could be seized as an opportunity for positive change, directing economic stimulus towards sustainable investments.
Technical summary
A synthesis is made of ten fields within climate science where there have been significant advances since mid-2019, through an expert elicitation process with broad disciplinary scope. Findings include: (1) a better understanding of equilibrium climate sensitivity; (2) abrupt thaw as an accelerator of carbon release from permafrost; (3) changes to global and regional land carbon sinks; (4) impacts of climate change on water crises, including equity perspectives; (5) adverse effects on mental health from climate change; (6) immediate effects on climate of the COVID-19 pandemic and requirements for recovery packages to deliver on the Paris Agreement; (7) suggested long-term changes to governance and a social contract to address climate change, learning from the current pandemic, (8) updated positive costâbenefit ratio and new perspectives on the potential for green growth in the short- and long-term perspective; (9) urban electrification as a strategy to move towards low-carbon energy systems and (10) rights-based litigation as an increasingly important method to address climate change, with recent clarifications on the legal standing and representation of future generations.
Social media summary
Stronger permafrost thaw, COVID-19 effects and growing mental health impacts among highlights of latest climate science
Modeling the distribution of Pterocarpus dalbergioides (Padauk) at landscape level using a geospatial approach, in Andaman- Bay Islands - South Asia
In Dayawansa, N. D. K. (Ed.). Geoinformatics for Environmental Conservation and Management: Third National Symposium on Geoinformatics, Sri Lanka, 25 August 2006. Peradeniya, Sri Lanka: Geo-Informatics Society of Sri Lank