Combined impact of Climate change and Land use on water quality in the mid-21st century: A modelling study for a highly industrialized stretch of Ganga River

Author(s):  
Sneha Santy ◽  
Pradeep Mujumdar ◽  
Govindasamy Bala

<p>High industrial discharge, excessive agricultural activities, untreated sewage disposal make the Kanpur region one of the most contaminated stretches of the Ganga river. This study analyses water quality for the combined future climate change and land use land cover scenarios for mid-century for a 238km long Kanpur stretch of Ganga river. Climate change projections from 21 General Circulation Models for the scenarios of RCP 4.5 and RCP 8.5 are considered and Land use Land Cover (LULC) projections are made with QGIS software. Streamflow and water temperature are modelled using the HEC-HMS model and a Water-Air temperature regression model, respectively. Water quality analysis is simulated using the QUAL2K model in terms of nine water quality parameters, dissolved oxygen, biochemical oxygen demand (BOD), ammonia nitrogen, nitrate nitrogen, total nitrogen, organic phosphorus, inorganic phosphorus, total phosphorus and faecal coliform. Climate change impact alone is projected to result in degraded water quality in the future. Combined climate change and LULC change may further degrade water quality, especially at the study area's critical locations. Our study will provide guidance to policymakers to safeguard the Ganga river from further pollution.</p>

2017 ◽  
Author(s):  
Anoop Kumar Shukla ◽  
Chandra Shekhar Prasad Ojha ◽  
Ana Mijic ◽  
Wouter Buytaert ◽  
Shray Pathak ◽  
...  

Abstract. For sustainable development in a river basin it is crucial to understand population growth–Land Use/Land Cover (LULC) transformations–water quality nexus. This study investigates effects of demographic changes and LULC transformations on surface water quality of Upper Ganga River basin. River gets polluted in both rural and urban area. In rural area, pollution is because of agricultural practices mainly fertilizers, whereas in urban area it is mainly because of domestic and industrial wastes. First, population data was analyzed statistically to study demographic changes in the river basin. LULC change detection was done over the period of February/March 2001 to 2012 [Landsat 7 Enhanced Thematic Mapper (ETM+) data] using remote sensing and Geographical Information System (GIS) techniques. Further, water quality parameters viz. Biological Oxygen Demand (BOD), Dissolve Oxygen (DO) %, Flouride (F), Hardness CaCO3, pH, Total Coliform bacteria and Turbidity were studied in basin for pre-monsoon (May), monsoon (July) and Post-monsoon (November) seasons. Non-parametric Mann–Kendall rank test was done on monthly water quality data to study existing trends. Further, Overall Index of Pollution (OIP) developed specifically for Upper Ganga River basin was used for spatio-temporal water quality assessment. From the results, it was observed that population has increased in the river basin. Therefore, significant and characteristic LULC changes are observed in the study area. Water quality degradation has occurred in the river basin consequently the health status of the rivers have also changed from range of acceptable to slightly polluted in urban areas.


2018 ◽  
Vol 6 (4) ◽  
pp. 39-47 ◽  
Author(s):  
Firoz Ahmad ◽  
Md Meraj Uddin ◽  
Laxmi Goparaju

AbstractGeospatial evaluation of various datasets is extremely important because it gives a better comprehension of the past, present and future and can therefore be significantly utilized in effective decision making strategies. This study examined the relationships, using geospatial tools, between various diversified datasets such as land use/land cover (LULC), long term Normalized Difference Vegetation Index (NDVI) based changes, long term forest fire points, poverty percentage, tribal percentage, forest fire hotspots, climate change vulnerability, agricultural vulnerability and future (2030) climate change anomalies (RCP-6) of Jharkhand state, India, for a better understanding and knowledge of its vegetation health, LULC, poverty, tribal population and future climate change impact. The long term NDVI (1982-2006) evaluation revealed negative change trends in seven northwest districts of Jharkhand state, these were: Hazaribag, Ramgarh, Palamu, Lohardaga, Chatra, Garhwa and Latehar. The forests as well as the agriculture of these districts have lost their greenness during this period. The forest fire frequency events were found to be more pronounced in the land use/land cover of “tropical lowland forests, broadleaved, evergreen, <1000 m” category, and were roughly twice the intensity of the “tropical mixed deciduous and dry deciduous forests” category. In the nine districts of Jharkhand it was found that 40 % of the population was living below the poverty line which is around twice the national average. The highest poverty districts, in percentage, were: Garwah (53.93), Palamu (49.24), Latehar (47.99) and Chatra (46.2). The southwest and south of Jharkhand state shows a tribal population density of more than 40%. The climate change vulnerability was found to be highest in the district of Saraikela followed by Pashchim Singhbhum, whereas agricultural vulnerability was found to be highest in the district of Pashchim Singhbhum followed by Saraikela, Garhwa, Simdega, Latehar, Palamu and Lohardaga. The temperature anomalies prediction for the year 2030 shows an increasing trend in temperature with values of 0.8°C to 1°C in the state of Jharkhand. The highest increases were observed in the districts of Pashchim Singhbhum, Simdega and Saraikela. Based on these evaluations we can conclude that a few of the districts of Jharkhand, such as Pashchim Singhbhum, Garhwa, Palamu and Latehar need to be prioritized for development on an urgent basis. The outcomes of this study would certainly guide the policymakers to prepare more robust plans when keeping in mind the future climate change impacts for the prioritization of various districts of Jharkhand which suffer from extreme poverty, diminished livelihood and insignificant agricultural productivity for the betterment of the people of Jharkhand based on their adaptive capacity.


2011 ◽  
Vol 15 (20) ◽  
pp. 1-25 ◽  
Author(s):  
Roland J. Viger ◽  
Lauren E. Hay ◽  
Steven L. Markstrom ◽  
John W. Jones ◽  
Gary R. Buell

Abstract The potential effects of long-term urbanization and climate change on the freshwater resources of the Flint River basin were examined by using the Precipitation-Runoff Modeling System (PRMS). PRMS is a deterministic, distributed-parameter watershed model developed to evaluate the effects of various combinations of precipitation, temperature, and land cover on streamflow and multiple intermediate hydrologic states. Precipitation and temperature output from five general circulation models (GCMs) using one current and three future climate-change scenarios were statistically downscaled for input into PRMS. Projections of urbanization through 2050 derived for the Flint River basin by the Forecasting Scenarios of Future Land-Cover (FORE-SCE) land-cover change model were also used as input to PRMS. Comparison of the central tendency of streamflow simulated based on the three climate-change scenarios showed a slight decrease in overall streamflow relative to simulations under current conditions, mostly caused by decreases in the surface-runoff and groundwater components. The addition of information about forecasted urbanization of land surfaces to the hydrologic simulation mitigated the decreases in streamflow, mainly by increasing surface runoff.


Climate ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 83
Author(s):  
Geofrey Gabiri ◽  
Bernd Diekkrüger ◽  
Kristian Näschen ◽  
Constanze Leemhuis ◽  
Roderick van der Linden ◽  
...  

The impact of climate and land use/land cover (LULC) change continues to threaten water resources availability for the agriculturally used inland valley wetlands and their catchments in East Africa. This study assessed climate and LULC change impacts on the hydrological processes of a tropical headwater inland valley catchment in Uganda. The hydrological model Soil and Water Assessment Tool (SWAT) was applied to analyze climate and LULC change impacts on the hydrological processes. An ensemble of six regional climate models (RCMs) from the Coordinated Regional Downscaling Experiment for two Representative Concentration Pathways (RCPs), RCP4.5 and RCP8.5, were used for climate change assessment for historical (1976–2005) and future climate (2021–2050). Four LULC scenarios defined as exploitation, total conservation, slope conservation, and protection of headwater catchment were considered. The results indicate an increase in precipitation by 7.4% and 21.8% of the annual averages in the future under RCP4.5 and RCP8.5, respectively. Future wet conditions are more pronounced in the short rainy season than in the long rainy season. Flooding intensity is likely to increase during the rainy season with low flows more pronounced in the dry season. Increases in future annual averages of water yield (29.0% and 42.7% under RCP4.5 and RCP8.5, respectively) and surface runoff (37.6% and 51.8% under RCP4.5 and RCP8.5, respectively) relative to the historical simulations are projected. LULC and climate change individually will cause changes in the inland valley hydrological processes, but more pronounced changes are expected if the drivers are combined, although LULC changes will have a dominant influence. Adoption of total conservation, slope conservation and protection of headwater catchment LULC scenarios will significantly reduce climate change impacts on water resources in the inland valley. Thus, if sustainable climate-smart management practices are adopted, the availability of water resources for human consumption and agricultural production will increase.


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