scholarly journals The impact of land use and land cover change on hydrological processes in Brantas watershed, East Java, Indonesia

2021 ◽  
Author(s):  
Mohamad Wawan Sujarwo ◽  
◽  
Indarto Indarto ◽  
Marga Mandala ◽  
◽  
...  

Assessing the impact of land use and land cover change (LULCC) on hydrology is essential for water resource management. The Brantas watershed contributes about 30% of the water supply of the East Java region. The present rapid pace of land occupation for agriculture and settlements is expected to continue to alter flow processes within the watershed. This study aims to simulate LULCC and its impact on the hydrological processes of the watershed. The long-term impact of LULCC is evaluated using the Soil & Water Assessment Tool (SWAT). The analysis model is calibrated using monthly data series from 1996 to 2005 and then validated using data series from 2006 to 2015. Two editions of maps (2001 and 2015) are then used to calculate the LULCC that took place across this time period. The impacts of LULCC on hydrological processes at the sub-basin level are also evaluated. The results show that the variability of rainfall patterns from 2001 to 2015 strongly affected flow variability. The LULCC from agricultural land to other uses (irrigated rice fields, settlements and forests/plantations) is most evident in three sub-basins (sub-basins 2, 9 and 17). However, each sub-basin may respond differently with respect to the LULCC taking place. The increase in area occupied by each class of land use and cover use (LULC) is not always linear to the observed flow, and widely differing LULC classes may display similar flow responses while classes with similar characteristics may have differing impacts on flows within a sub-basin. In other words, the hydrological processes taking place are too complex to be simplified at the sub-basin level.

2021 ◽  
Vol 12 (2) ◽  
pp. 635-670
Author(s):  
Wolfgang A. Obermeier ◽  
Julia E. M. S. Nabel ◽  
Tammas Loughran ◽  
Kerstin Hartung ◽  
Ana Bastos ◽  
...  

Abstract. Quantifying the net carbon flux from land use and land cover changes (fLULCC) is critical for understanding the global carbon cycle and, hence, to support climate change mitigation. However, large-scale fLULCC is not directly measurable and has to be inferred from models instead, such as semi-empirical bookkeeping models and process-based dynamic global vegetation models (DGVMs). By definition, fLULCC estimates are not directly comparable between these two different model types. As an important example, DGVM-based fLULCC in the annual global carbon budgets is estimated under transient environmental forcing and includes the so-called loss of additional sink capacity (LASC). The LASC results from the impact of environmental changes on land carbon storage potential of managed land compared to potential vegetation and accumulates over time, which is not captured in bookkeeping models. The fLULCC from transient DGVM simulations, thus, strongly depends on the timing of land use and land cover changes mainly because LASC accumulation is cut off at the end of the simulated period. To estimate the LASC, the fLULCC from pre-industrial DGVM simulations, which is independent of changing environmental conditions, can be used. Additionally, DGVMs using constant present-day environmental forcing enable an approximation of bookkeeping estimates. Here, we analyse these three DGVM-derived fLULCC estimations (under transient, pre-industrial, and present-day forcing) for 12 models within 18 regions and quantify their differences as well as climate- and CO2-induced components and compare them to bookkeeping estimates. Averaged across the models, we find a global fLULCC (under transient conditions) of 2.0±0.6 PgC yr−1 for 2009–2018, of which ∼40 % are attributable to the LASC (0.8±0.3 PgC yr−1). From 1850 onward, the fLULCC accumulated to 189±56 PgC with 40±15 PgC from the LASC. Around 1960, the accumulating nature of the LASC causes global transient fLULCC estimates to exceed estimates under present-day conditions, despite generally increased carbon stocks in the latter. Regional hotspots of high cumulative and annual LASC values are found in the USA, China, Brazil, equatorial Africa, and Southeast Asia, mainly due to deforestation for cropland. Distinct negative LASC estimates in Europe (early reforestation) and from 2000 onward in the Ukraine (recultivation of post-Soviet abandoned agricultural land), indicate that fLULCC estimates in these regions are lower in transient DGVM compared to bookkeeping approaches. Our study unravels the strong dependence of fLULCC estimates on the time a certain land use and land cover change event happened to occur and on the chosen time period for the forcing of environmental conditions in the underlying simulations. We argue for an approach that provides an accounting of the fLULCC that is more robust against these choices, for example by estimating a mean DGVM ensemble fLULCC and LASC for a defined reference period and homogeneous environmental changes (CO2 only).


2019 ◽  
Vol 11 (24) ◽  
pp. 7083 ◽  
Author(s):  
Kristian Näschen ◽  
Bernd Diekkrüger ◽  
Mariele Evers ◽  
Britta Höllermann ◽  
Stefanie Steinbach ◽  
...  

Many parts of sub-Saharan Africa (SSA) are prone to land use and land cover change (LULCC). In many cases, natural systems are converted into agricultural land to feed the growing population. However, despite climate change being a major focus nowadays, the impacts of these conversions on water resources, which are essential for agricultural production, is still often neglected, jeopardizing the sustainability of the socio-ecological system. This study investigates historic land use/land cover (LULC) patterns as well as potential future LULCC and its effect on water quantities in a complex tropical catchment in Tanzania. It then compares the results using two climate change scenarios. The Land Change Modeler (LCM) is used to analyze and to project LULC patterns until 2030 and the Soil and Water Assessment Tool (SWAT) is utilized to simulate the water balance under various LULC conditions. Results show decreasing low flows by 6–8% for the LULC scenarios, whereas high flows increase by up to 84% for the combined LULC and climate change scenarios. The effect of climate change is stronger compared to the effect of LULCC, but also contains higher uncertainties. The effects of LULCC are more distinct, although crop specific effects show diverging effects on water balance components. This study develops a methodology for quantifying the impact of land use and climate change and therefore contributes to the sustainable management of the investigated catchment, as it shows the impact of environmental change on hydrological extremes (low flow and floods) and determines hot spots, which are critical for environmental development.


2017 ◽  
Vol 14 (22) ◽  
pp. 5053-5067 ◽  
Author(s):  
Wei Li ◽  
Philippe Ciais ◽  
Shushi Peng ◽  
Chao Yue ◽  
Yilong Wang ◽  
...  

Abstract. The use of dynamic global vegetation models (DGVMs) to estimate CO2 emissions from land-use and land-cover change (LULCC) offers a new window to account for spatial and temporal details of emissions and for ecosystem processes affected by LULCC. One drawback of LULCC emissions from DGVMs, however, is lack of observation constraint. Here, we propose a new method of using satellite- and inventory-based biomass observations to constrain historical cumulative LULCC emissions (ELUCc) from an ensemble of nine DGVMs based on emerging relationships between simulated vegetation biomass and ELUCc. This method is applicable on the global and regional scale. The original DGVM estimates of ELUCc range from 94 to 273 PgC during 1901–2012. After constraining by current biomass observations, we derive a best estimate of 155 ± 50 PgC (1σ Gaussian error). The constrained LULCC emissions are higher than prior DGVM values in tropical regions but significantly lower in North America. Our emergent constraint approach independently verifies the median model estimate by biomass observations, giving support to the use of this estimate in carbon budget assessments. The uncertainty in the constrained ELUCc is still relatively large because of the uncertainty in the biomass observations, and thus reduced uncertainty in addition to increased accuracy in biomass observations in the future will help improve the constraint. This constraint method can also be applied to evaluate the impact of land-based mitigation activities.


2018 ◽  
Vol 10 (2) ◽  
pp. 56 ◽  
Author(s):  
Marie Caroline Solefack Momo ◽  
Andre Ledoux Njouonkou ◽  
Lucie Felicite Temgoua ◽  
Romuald Djouda Zangmene ◽  
Junior Baudoin Wouokoue Taffo ◽  
...  

This study assesses land cover change of the Koupa Matapit forest gallery, West Cameroon, in relation to anthropogenic factors. Ethnobotanical surveys were conducted to investigate the relationships between the local population and the gallery forest; the spatio-temporal dynamics of the landscapes around the gallery forest were studied from the diachronic analysis of three Landsat TM satellite images of 1984, Landsat ETM + 1999 and Landsat OLI_TIRS of 2016, supplemented by verification missions on field. The satellite images were processed using ArcGIS and Erdas Imagine software. According to surveys, it should be noted that agriculture and livestock are the main economic activities of the population of Koupa Matapit, agriculture and fuel wood collection for energy were the main anthropogenic activities responsible for deforestation and degradation of the forest gallery. The collection of non-timber forest products (NTFPs) would have a significant implication in land use and cover changes. The results indicate that the extension of savannah/agricultural land (from 6989 ha in 1984 to 7604 ha in 2016) and bare soil/built up area (from 71 ha in 1984 to 342 ha in 2016) would have led to the disappearance of much of the forest area (1465 ha in 1984 to 580 ha in 2016). The rapid population growth of Koupa Matapit would be responsible for these pressures. There is an urgent need to implement appropriate land use policy in this area.


2012 ◽  
Vol 3 (2) ◽  
pp. 597-641 ◽  
Author(s):  
A. J. Pitman ◽  
N. de Noblet-Ducoudré ◽  
F. B. Avila ◽  
L. V. Alexander ◽  
J.-P. Boisier ◽  
...  

Abstract. The impact of historical land use induced land cover change (LULCC) on regional-scale climate extremes is examined using four climate models within the Land Use and Climate, IDentification of robust impacts project. To assess those impacts, multiple indices based on daily maximum and minimum temperatures and daily precipitation were used. We contrast the impact of LULCC on extremes with the impact of an increase in atmospheric CO2 from 280 ppmv to 375 ppmv. In general, changes in both high and low temperature extremes are similar to the simulated change in mean temperature caused by LULCC and are restricted to regions of intense modification. The impact of LULCC on both means and on most temperature extremes is statistically significant. While the magnitude of the LULCC induced change in the extremes can be of similar magnitude to the response to the change in CO2, the impacts of LULCC are much more geographically isolated. For most models the impacts of LULCC oppose the impact of the increase in CO2 except for one model where the CO2-caused changes in the extremes is amplified. While we find some evidence that individual models respond consistently to LULCC in the simulation of changes in rainfall and rainfall extremes, LULCC's role in affecting rainfall is much less clear and less commonly statistically significant, with the exception of a consistent impact over South East Asia. Since the simulated response of mean and extreme temperature to LULCC is relatively large, we conclude that unless this forcing is included we risk erroneous conclusions regarding the drivers of temperature changes over regions of intense LULCC.


2018 ◽  
Vol 2 (2) ◽  
pp. 195
Author(s):  
Alfin Murtadho ◽  
Siti Wulandari ◽  
Muhammad Wahid ◽  
Ernan Rustiadi

<p class="ISI-Paragraf">Jabodetabek and Bandung Raya metropolitan region experienced an urban expansion phenomenon that caused the two metropolitan regions to become increasingly connected by a corridor and form a mega-urban region caused by the conurbation process. Purwakarta regency is one of the regions in Jakarta-Bandung corridor that experienced the impact of Jakarta-Bandung conurbation process. This study aims to analyze the level of regional development, to analyze land cover change that occurred, and to predict Purwakarta Regency land use/land cover in 2030. Regional development analysis is done by using the Scalogram method based on Potential Village data of year 2003 and 2014. Land cover change analysis is done through spatial analysis by overlaying land cover Landsat Satellite Image of year 2000 and 2015. Land use/land cover prediction in 2030 is conducted through spatial modelling of Cellular Automata Markov method. Purwakarta Regency experienced an increase in regional development within the period of 11 years (2003 to 2014), which is marked by a decrease in the percentage of the number of villages that are in hierarchy III and increase in the percentage of the number of villages that are in hierarchy II and I. In general, within 15 years (2000 to 2015) Purwakarta Regency has increasing number of built-up area and mixed gardens, meanwhile dry land, forest, paddy field, and water bodies tend to decrease. The results of CA Markov analysis show that the built-up area is predicted to continue to increase from 2000 to 2030, meanwhile paddy fields and water bodies will continue to decrease.</p>


2021 ◽  
Vol 13 (16) ◽  
pp. 3337
Author(s):  
Shaker Ul Din ◽  
Hugo Wai Leung Mak

Land-use/land cover change (LUCC) is an important problem in developing and under-developing countries with regard to global climatic changes and urban morphological distribution. Since the 1900s, urbanization has become an underlying cause of LUCC, and more than 55% of the world’s population resides in cities. The speedy growth, development and expansion of urban centers, rapid inhabitant’s growth, land insufficiency, the necessity for more manufacture, advancement of technologies remain among the several drivers of LUCC around the globe at present. In this study, the urban expansion or sprawl, together with spatial dynamics of Hyderabad, Pakistan over the last four decades were investigated and reviewed, based on remotely sensed Landsat images from 1979 to 2020. In particular, radiometric and atmospheric corrections were applied to these raw images, then the Gaussian-based Radial Basis Function (RBF) kernel was used for training, within the 10-fold support vector machine (SVM) supervised classification framework. After spatial LUCC maps were retrieved, different metrics like Producer’s Accuracy (PA), User’s Accuracy (UA) and KAPPA coefficient (KC) were adopted for spatial accuracy assessment to ensure the reliability of the proposed satellite-based retrieval mechanism. Landsat-derived results showed that there was an increase in the amount of built-up area and a decrease in vegetation and agricultural lands. Built-up area in 1979 only covered 30.69% of the total area, while it has increased and reached 65.04% after four decades. In contrast, continuous reduction of agricultural land, vegetation, waterbody, and barren land was observed. Overall, throughout the four-decade period, the portions of agricultural land, vegetation, waterbody, and barren land have decreased by 13.74%, 46.41%, 49.64% and 85.27%, respectively. These remotely observed changes highlight and symbolize the spatial characteristics of “rural to urban transition” and socioeconomic development within a modernized city, Hyderabad, which open new windows for detecting potential land-use changes and laying down feasible future urban development and planning strategies.


Sign in / Sign up

Export Citation Format

Share Document