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Hydrological responses to large-scale changes in land cover of river watershed: Review

Muhammed Hadi H., Mustafa Andam M., Kolerski Tomasz

Journal of Water and Land Development

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2021

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no. 50

108--121

EN

Despite many studies on the hydrological responses to forest cover changes in micro and mesoscale watersheds, the hydrological responses to forest cover alterations and associated mechanisms through the large spatial scale of the river watershed have not been comprehensively perceived. This paper thus reviews a wide range of available scientific evidence concerning the impacts exerted by the forest removal on precipitation, water yield, stream flow, and flow regimes. It is concluded that there is no statistical correlation between forest cover and precipitation and water yield at the micro and mesoscale. In contrast, there is a relative correlation coefficient (r = 0.77, p < 0.05) between forest cover and water yield at large scales (>1000 km2). These findings help our understanding of the hydrological response to forest disturbance at large and regional scale and provide a scientific perception to future watershed management in the context of human activities and natural hazards.

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A study of thermal controls in rapidly developing city using remotely sensed satellite data: spatiotemporal perspective

Mahmood Khalid, Raza Syed Ahmed, Fatima Syeda Yuman

Acta Geophysica

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2021

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Vol. 69, no. 1

365--379

EN

The unsusual rise in the land surface temperature is playing a vital role toward the rapid and intense changes in global climate. Occurrence of certain land use land cover and alternative changes in them is the prime cause of bringing extreme changes in temperature. In this research, using 30-year long time series (1988–2018) data from Landsat satellites for understanding relation of mean temperature with the two largest and main controlling land use classes (vegetation and built-up) in a rapidly urbanizing district, Lahore. For this purpose, multivariate statistical approaches of scatter plot and correlation coefcient were employed. Temperatures, vegetative and built-up areas were derived using a combination of diferent spatiotemporal tools in a specifcally designed model. Critical analysis suggests breaking up of investigation timeline in two portions based on changing trend. A 23-year period from 1989 to 2011 (Temporal Window-1) and a 6-year period from 2013 to 2018 (Temporal Window-2) were tested separately for the same arguments. Vegetative area showed an increase throughout the temporal window-1 and then a rapid decrease from 2013 to 2018, while built-up area and mean temperature presented an ever-increasing trend during both temporal windows but with much higher rates in second window. Correlation of tempera ture with the both the investigated thermal controls has found getting strong in Temporal Window-2 showing that relation of these landcover areas with temeperature is not linear and severity is increasing with time. Moreover, temperature is found to be strongly dependent upon changes in built-up areas than that of vegetative areas. So, an increase in built-up area has much more devastating efects over the temperature rather than decrease in vegetative area. It was concluded that Lahore district is contributing in global warming more rapidly than it had ever done before.

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Correlating soil and urban planning for sustainable water cycle

Sharma Sheetal

Journal of Water and Land Development

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2019

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no. 40

137--148

EN

Hydrological modelling and processes using modern hydrological models like SCS Curve Number, HCS, HSPF (Hydrologic Simulation Package-Fortran) and kinematic wave models are widely used nowadays in various researches. But using these modelling in drawing the attention of urban planners for challenges and multiple interactions in heterogeneous urban catchments and water systems is still a shortcoming in water sensitive, planning principle. The art of urban planning and technical implementation using behavioural changes in water responses to urban catchments is the need of present urban planning. The complexities of effects and behavioural changes in the water system or urban catchments and incomplete knowledge of these interactions result in failures of sustainable urban developments. Urban planning needs water sensitive methodology to synchronize soil, water and land cover operational with the population over it. The paper reviews the water sensitive urban planning considering the role of soil in urban planning for water and lands correlations, with the purpose of identifying current limitations and opportunities for future urban planning. Data availability and simplified methods are still a strong limitation for urban planners. Therefore, urban hydrology is often simplified either as a study of surface runoff over impervious surfaces or hydraulics of piped systems. Hence the paper provides approach and universal solution to forecast the behaviour of urban catchment for urbanization in terms of natural land-water cycles and its application in planning existing or new urban catchments. The methodology consists of observing Urban watershed catchment areas with different soil groups and built-up induction over them. A detailed study of water levels in hydrological wells and runoff pattern for the period of 40 years have provided a linear correlation of soil, roughness, land cover, infiltration, ground water and built upon the basis of soil behaviours. These correlations conclude to make regression equations as the blueprint for future urban planning norms to be followed by the planners, engineers, and hydrologists for planning.

PL

Modelowanie hydrologiczne za pomocą takich modeli, jak SCS Curve Number, HCS czy Pakiet Hydrologicznych Symulacji Fortran (HSPF) oraz kinematyczne modele falowe są obecnie powszechnie stosowane w różnych badaniach. Nadal jednak brak takiego modelowania w pracy urbanistów stojących wobec wyzwań, stawianych przez wielorakie oddziaływania heterogennych zlewni miejskich z systemami wodnymi. Sztuka planowania urbanistycznego i wdrożeń technicznych korzystających ze zmian reakcji wody na zlewnie miejskie jest potrzebą obecnego planowania miast. Złożoność efektów i zmiany w systemach wodnych lub miejskich zlewniach oraz niepełna znajomość tych interakcji skutkuje niepowodzeniami w zrównoważonym rozwoju miast. Planowanie miast wymaga metodologii wrażliwej na kwestie wodne, aby operacyjnie powiązać glebę, wodę i pokrycie gruntów z populacją ludzką. W pracy dokonano przeglądu planowania urbanistycznego wrażliwego na kwestie wodne z uwzględnieniem roli gleby w planowaniu relacji wody z lądem celem zidentyfikowania bieżących ograniczeń i możliwości przyszłego planowania. Dostępność danych i uproszczone metody to nadal silne ograniczenie urbanistów. Dlatego hydrologia miasta bywa często upraszczana do badania spływów po nieprzepuszczalnych powierzchniach lub do hydrauliki systemów wodociągowych. Niniejsza praca prezentuje sposób podejścia i uniwersalne rozwiązanie służące prognozowaniu zachowania zlewni miejskiej w reakcji na urbanizację w odniesieniu do naturalnej relacji ląd–woda i ich zastosowanie w planowaniu istniejących bądź nowych zlewni miejskich. Metodologia polega na obserwacji 19 zlewni miejskich o różnych typach gleb i zabudowy. Szczegółowe analizy poziomów wody w studzienkach hydrologicznych i schematu spływów wody w okresie 40 lat dostarczyły danych do wyprowadzenia liniowej korelacji między rodzajem gleby, szorstkością podłoża, pokryciem powierzchni ziemi, infiltracją, wodami podziemnymi, wszystkie powiązane z właściwościami gleb. Te korelacje umożliwiły ustalenie równań regresji stanowiących schemat dla przyszłych norm planowania urbanistycznego do wykorzystania przez planistów, inżynierów i hydrologów.