scholarly journals Confirmation of <i>ACRU</i> model results for applications in land use and climate change studies

2010 ◽  
Vol 7 (4) ◽  
pp. 4591-4634 ◽  
Author(s):  
M. L. Warburton ◽  
R. E. Schulze ◽  
G. P. W. Jewitt

Abstract. The hydrological responses of a catchment are sensitive to, and strongly coupled to, land use and climate, and changes thereof. The hydrological responses to the impacts of changing land use and climate will be the result of complex interactions, where the change in one may moderate or exacerbate the effects of the other. A further difficulty in assessing these interactions will be that dominant drivers of the hydrological system may vary at different spatial and temporal scales. To assess these interactions, a process-based hydrological model, sensitive to land use and climate, and changes thereof needs to be used. For this purpose the daily time step ACRU model was selected. However, to be able to use a hydrological model such as ACRU with confidence its representation of reality must be confirmed by comparing simulated output against observations across a range of climatic conditions. Comparison of simulated against observed streamflow was undertaken in three climatically diverse South African catchments, ranging from the semi-arid sub-tropical Luvuvhu catchment, to the winter rainfall Upper Breede catchment and the sub-humid Mgeni catchment. Not only do the climates of the catchments differ, but their primary land uses also vary. In the upper areas of the Mgeni catchment commercial plantation forestry is dominant, while in the middle reaches there are significant areas of commercial plantation sugarcane and urban areas, while the lower reaches are dominated by urban areas. The Luvuvhu catchment has a large proportion of subsistence agriculture and informal residential areas. In the Upper Breede catchment in the Western Cape, commercial orchards and vineyards are the primary land uses. Overall the ACRU model was able to represent the high, low and total flows, with satisfactory Nash-Sutcliffe efficiency indexes obtained for the selected catchments. The study concluded that the ACRU model could be used with confidence to simulate the streamflows of the three selected catchments and was able to represent the hydrological responses from the range of climates and diversity of land uses present within the catchments.

2010 ◽  
Vol 14 (12) ◽  
pp. 2399-2414 ◽  
Author(s):  
M. L. Warburton ◽  
R. E. Schulze ◽  
G. P. W. Jewitt

Abstract. The hydrological responses of a catchment are sensitive to, and strongly coupled to, land use and climate, and changes thereof. The hydrological responses to the impacts of changing land use and climate will be the result of complex interactions, where the change in one may moderate or exacerbate the effects of the other. Further difficulties in assessing these interactions are that dominant drivers of the hydrological system may vary at different spatial and temporal scales. To assess these interactions, a process-based hydrological model, sensitive to land use and climate, and changes thereof, needs to be used. For this purpose the daily time step ACRU model was selected. However, to be able to use a hydrological model such as ACRU with confidence its representation of reality must be confirmed by comparing simulated output against observations across a range of climatic conditions. Comparison of simulated against observed streamflow was undertaken in three climatically diverse South African catchments, ranging from the semi-arid, sub-tropical Luvuvhu catchment, to the winter rainfall Upper Breede catchment and the sub-humid Mgeni catchment. Not only do the climates of the catchments differ, but their primary land uses also vary. In the upper areas of the Mgeni catchment commercial plantation forestry is dominant, while in the middle reaches there are significant areas of commercial plantation sugarcane and urban areas, while the lower reaches are dominated by urban areas. The Luvuvhu catchment has a large proportion of subsistence agriculture and informal residential areas. In the Upper Breede catchment in the Western Cape, commercial orchards and vineyards are the primary land uses. Overall the ACRU model was able to represent the high, low and total flows, with satisfactory Nash-Sutcliffe efficiency indexes obtained for the selected catchments. The study concluded that the ACRU model can be used with confidence to simulate the streamflows of the three selected catchments and was able to represent the hydrological responses from the range of climates and diversity of land uses present within the catchments.


2020 ◽  
Vol 9 (11) ◽  
pp. 634
Author(s):  
Chengming Li ◽  
Zixian Fan ◽  
Zheng Wu ◽  
Zhaoxin Dai ◽  
Li Liu ◽  
...  

Catchment division constitutes the foundation for urban water flood forecasting but represents a technically challenging task. The accurate division of catchments is significant for precisely forecasting urban waterlogging. However, existing catchment division methods usually lead to produce results that do not accurately reflect the actual land-use distributions. In recent years, most research has been performed in smaller study areas (less than 10 km2), in residential areas, parks and campuses, and usually focused on a single landscape type. However, for large highly urbanized areas with complex land uses, due to the spatial heterogeneity and complexity of such areas in terms of building, traffic network and hydrology, etc., there is few studies on sub-catchment division. Moreover, the division results by using existing method usually have deviate with the actual land-type distributions. To address the above-mentioned issues, a sub-catchment division method was here proposed that accounts for land-use types and flow directions, and it is suitable for large urban areas by introducing an auto-adaptive threshold adjustment in a novel algorithm. First, the study area is divided into first- and second-level (FL and SL, respectively) catchments according to the macroscale features such as natural landforms, canals, and pipe network. Second, an amended DEM (Digital Elevation Model) and flow direction data are used to divide the SL catchments into third-level direction-based (D-B) catchments. Finally, a novel land use-based algorithm is proposed to divide the D-B catchments into the “smallest” catchments (S-catchments). A large-scale area (44 km2) in Dongying City of China was employed to validate the proposed method. The experiment showed that the proposed method is suitable for subcatchment divisions in large regions and can ensure that the subcatchments are consistent with the actual distribution of land uses and runoff directions.


Author(s):  
А.В. Терешкин ◽  
А.Л. Калмыкова ◽  
Т.А. Андрушко

Вертикальное озеленение с участием различных видов лиан в современных условиях имеет важное эстетическое и санитарно-гигиеническое значение. Особо актуально решение вопросов обогащения флоры городских территорий лианами в степных районах в связи с бедным видовым составом и резким ухудшением экологической ситуации. Объектами исследований являлись 7 видов лиан, различных жизненных форм (однолетние, многолетние), произрастающие в населенных пунктах Саратовской области (Аткарск, Саратов). Цель исследований – изучение эколого-биологических особенностей и мелиоративных свойств лиан и выявление перспектив их использования в вертикальном озеленении селитебных территорий Саратовской области. В ходе исследования видового состава, были выявлены наиболее популярные виды однолетних лиан: ипомея красно-голубая (Ipomea tricolor (L.) Roth) и ипомея пурпурная (Ipomea purpurea (L.) Roth), горошек душистый (Lathyrus edoratus L.), настурция (Tropacolum peregrinum L.) и фасоль огненно-красная (Phaseolus coccineus). Большинство (70%) из них произрастают в местах ограниченного пользования. Изученные виды лиан в исследуемых регионах достигают средних природных показателей (при наличии надлежащего ухода), обладают хорошими показателями жизненного состояния, обильно цветут и плодоносят. При воздействии токсикантами различной концентрации на листовые пластинки лиан установлено их степень устойчивости. Выявлено, что однолетние лианы лучше использовать в декоративных целях, а не в санитарно-гигиенических. Сравнительная оценка однолетних видов с многолетними лианами (девичий виноград пятилисточковый и клематис тангутский) показывает устойчивость многолетних видов (в среднем на 3 балла - 40%). Разработаны варианты декоративных композиций с участием травянистых лиан. По степени декоративности выделены однолетние лианы – Ipomea tricolor, I. purpurea (37 – 41 балл), средней степенью отличаются – Lathyrus edoratus (33 балла), Tropacolum peregrinum (30 баллов) и Phaseolus coccineus (20 – 27 баллов). Преимущество многолетних лиан заключается в их устойчивости к резким изменениям климатических условий (на 40 %) по сравнению с однолетними формами. Поэтому они более предпочтительны для озеленения городской среды. Для усиления декоративного эффекта в сезонном аспекте рекомендуются сочетать расширение видового и формового разнообразия растений (многолетние и однолетние лианы, древесно-кустарниковая, цветочная растительность). Установлено, что природно-климатические условия зоны степи и лесостепи в пределах Саратовской области являются достаточно благоприятными для нормального роста и развития древесно-кустарниковой растительности, в том числе травянистых лиан. Таким образом, обоснованное применение древесных лиан в комплексе с традиционными видами насаждений позволит создать комфортные условия проживания населения, регулировать оптимальный температурный баланс и создавать благоприятные микроклиматические условия. Vertical gardening with different types of vines in modern conditions is important aesthetic and sanitary-hygienic value. It is especially important to address the issues of enrichment of the flora of urban areas with vines in the steppe regions due to poor species composition and a sharp deterioration of the ecological situation. The objects of research were 7 species of lianas, various life forms (annual, perennial), growing in the settlements of the Saratov region (Atkarsk, Saratov). The aim of the research is to study the ecological and biological features and reclamation properties of vines and identify the prospects for their use in vertical gardening residential areas of the Saratov region. In the study, species composition was the most popular species of annual vines: morning glory red-blue (Ipomea tricolor (L.) Roth) and purple morning glory (Ipomea purpurea (L.) Roth), the fragrant pea (Lathyrus edoratus L.), nasturtium (Tropacolum peregrinum L.) and runner beans (Phaseolus coccineus). Most (70%) of them grow in restricted areas. Studied species of vines in the study regions reach average natural performance (with proper care), have good indicators of vital condition, bloom abundantly and bear fruit. When exposed to toxicants of different concentrations on the leaf blades of vines established their degree of stability. It was revealed that the annual vines are better used for decorative purposes, and not in the sanitary-hygienic. A comparative assessment of annual species with perennial vines (maiden grapes and clematis Tangut) shows the stability of perennial species (an average of 3 points-40%). The options and decorative compositions with the participation of herbaceous vines. According to the degree of decoration of the allocated annual vine – Ipomea tricolor, I. purpurea (37 – 41 points), the average degree of differ – Lathyrus edoratus (33 points), Tropacolum peregrinum (30 points) and Phaseolus coccineus (20 to 27 points). The advantage of perennial vines is their resistance to sudden changes in climatic conditions (40 %) compared to annual forms. Therefore, they are more preferable for greening the urban environment. To enhance the decorative effect in the seasonal aspect, it is recommended to combine the expansion of species and form diversity of plants (perennial and annual lianas, tree and shrub, floral vegetation). It is established that the climatic conditions of the steppe and forest-steppe zone within the Saratov region are quite favorable for the normal growth and development of tree and shrub vegetation, including herbaceous lianas. Thus, the reasonable use of wood vines in combination with traditional types of plantings will create comfortable living conditions for the population, regulate the optimal temperature balance and create favorable microclimatic conditions.


2018 ◽  
Vol 8 (1) ◽  
pp. 16 ◽  
Author(s):  
Irina Matijosaitiene ◽  
Peng Zhao ◽  
Sylvain Jaume ◽  
Joseph Gilkey Jr

Predicting the exact urban places where crime is most likely to occur is one of the greatest interests for Police Departments. Therefore, the goal of the research presented in this paper is to identify specific urban areas where a crime could happen in Manhattan, NY for every hour of a day. The outputs from this research are the following: (i) predicted land uses that generates the top three most committed crimes in Manhattan, by using machine learning (random forest and logistic regression), (ii) identifying the exact hours when most of the assaults are committed, together with hot spots during these hours, by applying time series and hot spot analysis, (iii) built hourly prediction models for assaults based on the land use, by deploying logistic regression. Assault, as a physical attack on someone, according to criminal law, is identified as the third most committed crime in Manhattan. Land use (residential, commercial, recreational, mixed use etc.) is assigned to every area or lot in Manhattan, determining the actual use or activities within each particular lot. While plotting assaults on the map for every hour, this investigation has identified that the hot spots where assaults occur were ‘moving’ and not confined to specific lots within Manhattan. This raises a number of questions: Why are hot spots of assaults not static in an urban environment? What makes them ‘move’—is it a particular urban pattern? Is the ‘movement’ of hot spots related to human activities during the day and night? Answering these questions helps to build the initial frame for assault prediction within every hour of a day. Knowing a specific land use vulnerability to assault during each exact hour can assist the police departments to allocate forces during those hours in risky areas. For the analysis, the study is using two datasets: a crime dataset with geographical locations of crime, date and time, and a geographic dataset about land uses with land use codes for every lot, each obtained from open databases. The study joins two datasets based on the spatial location and classifies data into 24 classes, based on the time range when the assault occurred. Machine learning methods reveal the effect of land uses on larceny, harassment and assault, the three most committed crimes in Manhattan. Finally, logistic regression provides hourly prediction models and unveils the type of land use where assaults could occur during each hour for both day and night.


2019 ◽  
Vol 11 (7) ◽  
pp. 885 ◽  
Author(s):  
Ustaoglu ◽  
Aydınoglu

. Population growth, economic development and rural-urban migration have caused rapid expansion of urban areas and metropolitan regions in Turkey. The structure of urban administration and planning has faced different socio-economic and political challenges, which have hindered the structured and planned development of cities and regions, resulting in an irregular and uneven development of these regions. We conducted detailed comparative analysis on spatio-temporal changes of the identified seven land-use/cover classes across different regions in Turkey with the use of Corine Land Cover (CLC) data of circa 1990, 2000, 2006 and 2012, integrated with Geographic Information System (GIS) techniques. Here we compared spatio-temporal changes of urban and non-urban land uses, which differ across regions and across different hierarchical levels of urban areas. Our findings have shown that peri-urban areas are growing more than rural areas, and even growing more than urban areas in some regions. A deeper look at regions located in different geographical zones pointed to substantial development disparities across western and eastern regions of Turkey. We also employed multiple regression models to explain any possible drivers of land-use change, regarding both urban and non-urban land uses. The results reveal that the three influencing factors-socio-economic characteristics, regional characteristics and location, and development constraints, facilitate land-use change. However, their impacts differ in different geographical locations, as well as with different hierarchical levels.


2020 ◽  
Vol 9 (9) ◽  
pp. 550
Author(s):  
Adindha Anugraha ◽  
Hone-Jay Chu ◽  
Muhammad Ali

The utilization of urban land use maps can reveal the patterns of human behavior through the extraction of the socioeconomic and demographic characteristics of urban land use. Remote sensing that holds detailed and abundant information on spectral, textual, contextual, and spatial configurations is crucial to obtaining land use maps that reveal changes in the urban environment. However, social sensing is essential to revealing the socioeconomic and demographic characteristics of urban land use. This data mining approach is related to data cleaning/outlier removal and machine learning, and is used to achieve land use classification from remote and social sensing data. In bicycle and taxi density maps, the daytime destination and nighttime origin density reflects work-related land uses, including commercial and industrial areas. By contrast, the nighttime destination and daytime origin density pattern captures the pattern of residential areas. The accuracy assessment of land use classified maps shows that the integration of remote and social sensing, using the decision tree and random forest methods, yields accuracies of 83% and 86%, respectively. Thus, this approach facilitates an accurate urban land use classification. Urban land use identification can aid policy makers in linking human activities to the socioeconomic consequences of different urban land uses.


Author(s):  
Maria A. Cunha-e-Sá ◽  
Sofia F. Franco

Although forests located near urban areas are a small fraction of the forest cover, a good understanding of the extent to which —wildland-urban interface (WUI) forest conversion affects local economies and environmental services can help policy-makers harmonize urban development and environmental preservation at this interface, with positive impact on the welfare of local communities. A growing part of the forest resource worldwide has come under urban influence, both directly (i.e., becoming incorporated into the interface or located at the interface with urban areas) and indirectly (as urban uses and values have come to dominate more remote forest areas). Yet forestry has been rather hesitant to recognize its urban mandate. Even if the decision to convert land at the WUI (agriculture, fruit, timber, or rural use) into an alternative use (residential and commercial development) is conditional on the relative magnitude and timing of the returns of alternative land uses, urban forestry is still firmly rooted in the same basic concepts of traditional forestry. This in turn neglects features characterizing this type of forestland, such as the urban influences from increasingly land-consumptive development patterns. Moreover, interface timber production-allocated land provides public goods that otherwise would be permanently lost if land were converted to an irreversible use. Any framework discussing WUI optimal rotation periods and conversion dates should then incorporate the urban dimension in the forester problem. It must reflect the factors that influence both urban and forestry uses and account for the fact that some types of land use conversion are irreversible. The goal is to present a framework that serves as a first step in explaining the trends in the use and management of private land for timber production in an urbanizing environment. Our framework integrates different land uses to understand two questions: given that most of the WUI land use change is irreversible and forestry at this interface differs from classic forestry, how does urban forestry build upon and benefit from traditional forestry concepts and approaches? In particular, what are the implications for the Faustmann harvesting strategy when conversion to an irreversible land use occurs at some point in the future? The article begins with a short background on the worldwide trend of forestland conversion at the WUI, focusing mostly on the case of developed countries. This provides a context for the theoretical framework used in the subsequent analysis of how urban factors affect regeneration and conversion dates. The article further reviews theoretical models of forest management practices that have considered either land sale following clear-cutting or a switch to a more profitable alternative land use without selling the land. A brief discussion on the studies with a generalization of the classic Faustmann formula for land expectation value is also included. For completeness, comparative statics results and a numerical illustration of the main findings from the private landowner framework are included.


GeoScape ◽  
2021 ◽  
Vol 15 (2) ◽  
pp. 104-119
Author(s):  
Navid Forouhar ◽  
Amir Forouhar ◽  
Mahnoosh Hasankhani

Abstract Land-use planning generally aims to manage the development of urban areas to address the needs of the communities. In this regard, the multiple and often competing environmental, economic and social conflicts complicate the process of land-use planning. Commercial development in residential neighbourhoods is a common type of land-use conflict that can dramatically exacerbate these potential conflicts. Over the recent decades, many affluent neighbourhoods of Tehran Metropolis (the capital of Iran) have been confronted with an unbridled development of commercial activities within the residential areas. This paper seeks to understand the process of land-use change and its impacts on the residents’ quality of life in an affluent neighbourhood of Tehran Metropolis (Gisha Neighbourhood) by adopting a combination of quantitative and qualitative methods of impact assessment including semi-structured interview, purposeful field survey, and traffic survey. The results yield that incompatible land-use policies of the Tehran Comprehensive Plan and structural defects in the land-use change regulations led to an unbridled process of commercialisation which intensified non-local activities with city/regional service coverage along the main streets of Gisha Neighbourhood. The analysis demonstrates that despite improving the accessibility of residents to urban facilities and reducing their travel time/cost, the process of land-use changes in Gisha Neighbourhood declined the residents’ quality of life by its considerable negative effects on socio-cultural structures, landuse patterns, traffic flow, and human health in the residential areas of the neighbourhood.


2013 ◽  
Vol 5 (2) ◽  
pp. 71-79 ◽  

This paper investigates the hydrological effects of specific land use changes in a catchment of the river Pinios in Thessaly (Ali Efenti catchment), through the application of the Soil and Water Assessment Tool (SWAT) on a monthly time step. The model's calibration efficiency is verified by comparing the simulated and observed discharge time series at the outlet of the watershed, where long series of hydrometrical data exist. The model is used to simulate the main components of the hydrologic cycle, in order to study the effects of land use changes. Three land use change scenarios are examined, namely (A) expansion of agricultural land, (B) complete deforestation of the Trikala sub-basin and (C) expansion of urban areas in the Trikala sub-basin. All three scenarios resulted in an increase in discharge during wet months and a decrease during dry periods. The deforestation scenario was the one that resulted in the greatest modification of total monthly runoff.


Land ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 17
Author(s):  
Camelia Sabina Botezan ◽  
Andrei Radovici ◽  
Iulia Ajtai

Urban growth triggers massive changes in land use cover, exacerbating extreme natural and technological events. In order for land use planning to be efficient, it requires the integration of comprehensive risk and vulnerability assessment. This paper aims to create a bridge between the existing vulnerability theories and their implementation in land use planning policies and proposes an innovative approach to determine whether the changes in the territorial dynamics of cities draw considerable changes in communities’ social vulnerability. The methodology identifies and selects three case studies from the Urban Atlas inventory, representative of the dynamics of large Romanian cities, taking into consideration the following hazards: earthquakes, floods, and technological hazards. Vulnerability was then assessed by assigning each land use class a specific vulnerability level. The methodology involved assessing the level of vulnerability specific to the situation in 2018 compared to 2006. The results showed that major changes in land use are related to the transition of areas with a low level of vulnerability to areas with a higher level of vulnerability as a result of the urban areas expansion to the detriment of natural and agricultural areas. This is generally translated into a higher degree of vulnerability due to an increased density of artificial elements and of population in the residential areas. The findings of the study of territorial dynamics in the proximity of large industrial operators did not reveal a tendency that differed from the general trend. Although many territorial changes have been observed in the period 2006–2018, it is necessary to extend the analysis, with the issue of the new versions of the Urban Atlas, to confirm the identified trends and to express the up-to-date situation.


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