Remote sensing estimation of evapotranspiration and ecological water demand in Zhalong wetland under land use/cover change

2021 ◽  
Vol 41 (9) ◽  
Author(s):  
宫兆宁,陆丽,金点点,邱华昌,张强,关晖 GONG Zhaoning
2018 ◽  
Vol 4 (2) ◽  
pp. 378 ◽  
Author(s):  
Gilles A Kandissounon ◽  
Ajay Kalra ◽  
Sajjad Ahmad

The goal of this study was twofold; first analyze the patterns of water consumption in Lagos, Nigeria and use them in a System Dynamics (SD) model to make projections about future demand. The second part used remote sensing to quantify the contribution of extensive land use/cover change to urban flooding. Land use/cover dynamics over the past decade was analyzed using satellite imagery provided by Landsat Thematic Mapping (TM). Unsupervised classification was performed with false color composite using the Iterative Self-Organizing Data Analysis (ISODATA) technique in a Geographic Information Systems (GIS). The study area was divided into four different land use types during image classification: bare land, built-up area, water bodies, and vegetation. For water demand, two different scenarios of population growth including 5.5% and 2.75 % annual increase were considered. The results showed that water demand dropped by 67% of its current value when losses in distribution were reduced by 20% and population annual growth rate kept at 2.75% over the study period. Bare land and water bodies lost 1.31% and 1.61% of their current area respectively while built-up area grew by 1.11%. These changes in land use/cover changes led to a 64% increase in average surface runoff, mostly attributable to increasing surface imperviousness and the absence of an adequate urban drainage system.


Land ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1297
Author(s):  
Ying Xu ◽  
Lei Yao

Land use plays a crucial role in climate change adaptation and mitigation, as the reasonable design of land use distribution can positively impact these things. Therefore, research interest in climate change adaptation and mitigation strategies in land use and management has been growing. However, the adaptation and mitigation strategies have been handled separately at different dimensions and spatial levels. In this study, we presented a modeling framework for land use optimization that integrates climate change adaptation and mitigation, developed the model, and then applied it to Huailai County, wherein environmental and socioeconomic conditions are sensitive to climate change. The regional land use optimization model was combined with a linear programming model and a modified cellular automata model. Subsequently, the climate change adaptation and mitigation constraints, including ecological water demand, spatial suitability, and carbon sequestration, were incorporated into the model. The results indicate that most regions in the study area could adapt to and mitigate climate change with a constant land use pattern, and the land use conversion region under different climate change scenarios was primarily located in the topography transition region. The optimization results also reveal trade-offs between climate change adaptation and mitigation that were manifested with an increase in carbon sequestration and ecological water demand accompanied by decreases in the net income of agricultural production. Thus, it is necessary to simultaneously incorporate climate change adaptation and mitigation into land use optimization and management, and the proposed model provides a feasible method to incorporate them and balance their trade-offs in land use pattern optimization at a regional scale.


2011 ◽  
Vol 356-360 ◽  
pp. 2575-2578
Author(s):  
Feng Gang Dai ◽  
Huan Jie Cai

Ecological and environmental problems become very complex due to regional differences, there are some differences in the concept and the calculation methods of ecological water demand. In this paper,the described method of ecological water demand which combined with GIS technology in the study area is proposed, based on the GIS technology to generate digital land use map, calculated the required extracted land use data. Finally, the application analysis instance of Shijiazhuang to verify this theoretical approach. the results can provide a scientific basis for the calculation of the regional eco-environmental water demand, water allocation and environmental protection.


2012 ◽  
Vol 16 (8) ◽  
pp. 2469-2483 ◽  
Author(s):  
D. H. Yan ◽  
G. Wang ◽  
H. Wang ◽  
T. L. Qin

Abstract. Economic and social development has greatly increased ecological water demand and modified land use of river systems worldwide, causing overall degradation of many of these systems. In this study, theoretical and technical frameworks for regionalization on the eco-environmental function of river systems are formulated and applied to the Luanhe River system. Based on its eco-environmental functions, this river can be regionalized into four types of first-class functional areas: ecological preservation areas, habitat restoration areas, ecological buffer areas and development and utilization areas. Considering the overall eco-environmental functions, we assessed the ecological land use of the Luanhe River system. The total area of basic ecological land use is 876.98 km2; the restrictive ecological land use is 1745.52 km2; ecological land use of the river system returned from farmland is 284.25 km2; and that returned from construction land is 17.35 km2. The average minimum ecological flow of mainstreams in upper and middle reaches of the Luanhe River is 4.896 m3 s−1 based on the habitat method. And the recommended minimum and suitable annual ecological water demand of channels in the lower reaches are 391 million m3 and 819.5 million m3, respectively. The evaporation and seepage consumption and vegetation consumption in riparian zones of the Luanhe River system are approximately 132.6 million m3 and 145.3 million m3 per year, respectively. Our results suggest that is crucial to regulate the instream ecological water use of the Luanhe River's mainstream starting from the Panjiakou-Daheiting Reservoir system. We recommend accelerating ecological land-use planning and strengthening the regulation of ecological water use on this river system focusing on important lower reaches under the condition of competitive water demand.


Author(s):  
H. Lilienthal ◽  
A. Brauer ◽  
K. Betteridge ◽  
E. Schnug

Conversion of native vegetation into farmed grassland in the Lake Taupo catchment commenced in the late 1950s. The lake's iconic value is being threatened by the slow decline in lake water quality that has become apparent since the 1970s. Keywords: satellite remote sensing, nitrate leaching, land use change, livestock farming, land management


2019 ◽  
Vol 47 (11) ◽  
pp. 1847-1856 ◽  
Author(s):  
Li Chen ◽  
Hsiao-Yu Wang ◽  
Tai-Sheng Wang ◽  
Chang-Huan Kou
Keyword(s):  
Land Use ◽  

Geosciences ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 312
Author(s):  
Barbara Wiatkowska ◽  
Janusz Słodczyk ◽  
Aleksandra Stokowska

Urban expansion is a dynamic and complex phenomenon, often involving adverse changes in land use and land cover (LULC). This paper uses satellite imagery from Landsat-5 TM, Landsat-8 OLI, Sentinel-2 MSI, and GIS technology to analyse LULC changes in 2000, 2005, 2010, 2015, and 2020. The research was carried out in Opole, the capital of the Opole Agglomeration (south-western Poland). Maps produced from supervised spectral classification of remote sensing data revealed that in 20 years, built-up areas have increased about 40%, mainly at the expense of agricultural land. Detection of changes in the spatial pattern of LULC showed that the highest average rate of increase in built-up areas occurred in the zone 3–6 km (11.7%) and above 6 km (10.4%) from the centre of Opole. The analysis of the increase of built-up land in relation to the decreasing population (SDG 11.3.1) has confirmed the ongoing process of demographic suburbanisation. The paper shows that satellite imagery and GIS can be a valuable tool for local authorities and planners to monitor the scale of urbanisation processes for the purpose of adapting space management procedures to the changing environment.


Sign in / Sign up

Export Citation Format

Share Document