Sulistiyono, Heri (2012) Potential impacts of climate change on water resources in Lombok, Indonesia. Doctoral (PhD) thesis, Memorial University of Newfoundland.
- Accepted Version
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Climate change is an issue of current debate around the world. The changes of climatic conditions are evidenced by changes in temperatures and precipitations that may lead to increased risks of floods, droughts, food shortages, diseases, and species extinction. Lombok, a small island in Indonesia and a part of the Nusa Tenggara Barat (NTB) Province, is predicted to suffer extensively in various ways due to climate change. To study the impacts of climate change on water resources on Lombok Island, the Jangkok River with a drainage area of approximately 180 km² has been chosen as a representative catchment for a case study. To date, no research has been conducted in this region to better understand the myriad of climate change impacts especially as it relates to the Island's water resources. In light of these challenges, this thesis aims to address the following five major objectives which are all related to the potential impacts of climate change on Lombok Island, Indonesia: (1) to develop a new downscaling model to provide a higher quality of finer resolution simulated local climatic variables, (2) to modify the commonly used Non Recorded Catchment Area (NRECA) rainfall-runoff model to take climate change into account, (3) to develop a new water index criterion to provide a more accurate assessment of water balance, (4) to develop a water balance optimization model based on the new water index criterion developed in the third objective for water balance assessment of the Jangkok River Basin in Lombok Island, Indonesia for climate change scenarios in the future, and (5) to recommend agriculture and animal farm development policies based on optimum consumptive water uses to sustain future water resources in Lombok due to likely climate change scenarios in Lombok. -- Required data for this research included historical local runoff, rainfall, and climatic data as well as GCM outputs from CGCM2, CSIRO-mk2, and NIES99. Regarding the first objective, results showed that the new downscaling model proposed which is based on a hybrid of algebraic and stochastic approaches (called the HYAS model) is superior to currently used methods. The HYAS model which incorporates multiple variables, successfully simulated realistic values and reproduced changing variance of predicted local hydrological and climatic variables. It is found that impacts of climate change on water resources in the Jangkok River Basin in future include: increases in air humidity, rainfall, as well as air temperature; but decreases in sunshine duration and evapotranspiration. For the second objective, the NRECA model was successfully modified to incorporate climate change in its model input so that it can be used to evaluate the impacts of climate change on the future water availability of the Jangkok River Basin. For the third objective, a new and more realistic water index criterion called the Remaining Water Index Criterion (RWI) which takes minimum water services and the priority of water uses into account was successfully developed to replace the Critical Water Index (CWI), the current criterion, to assess the future water balance of the Jangkok River Basin. Regarding the fourth objective, a water balance optimization model was successfully developed using a Response Surface Methodology (RSM) based on Central Composite Design (CCD). This model applied the RWI criterion. For the final objective, the optimization analysis showed that the population growth rate will be a significant factor in the water balance status after 2050 but the area of agricultural farm development will become a less significant factor in the water balance of the basin after 2080 due to less agricultural water demands and more abundance of water. The development of livestock farms is not a significant factor of the water balance model. Therefore, it is suggested that the Government of NTB Province should: 1) pay more attention to the population growth rate and to strictly maintain the rate at a level of 1.5%or less from now; 2) keep the area of agricultural farms at the level of 51% of the total land or 2295 ha until 2050. This agricultural farm can be developed to approximately 55% of the total land or 2475 ha from 2051 to 2080. It can be further developed in 2081 to approximately 67% or 3000 ha, and finally approximately 81% or 3645 ha can be developed in 21 00; and keep the development of livestock farms at a level of 2% per year.
|Item Type:||Thesis (Doctoral (PhD))|
|Additional Information:||Includes bibliographical references (leaves 166-182).|
|Department(s):||Engineering and Applied Science, Faculty of|
|Library of Congress Subject Heading:||Water-supply--Effect of global warming on--Indonesia--Lombok; Water-supply, Agricultural--Indonesia--Lombok; Runoff--Indonesia--Lombok--Mathematical models; Water balance (Hydrology)--Indonesia--Lombok--Mathematical models.|
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