No abstract

Measurements of throughfall, stemfiow and interception loss were made in unlogged and logged forest areas of Central Kalimantan, Indonesia. The literature related to interception loss changes due to changes in canopy cover conditions is reviewed and discussed. The characteristics of the experimental site and the various experiments carried out are described in detail. Two methods, the volume balance method and the mass exchange method, were Firstly, I would like to thank Professor Paul Jarvis for his guidance and supervision of the project, and for his extremely thorough editing of this thesis. I would also like to thank Dr Paul van Gardingen, my second supervisor, for his help on various aspects of this thesis, especially on the analysis of gap fraction using hemispherical photography technique, and on practical matters during fieldwork.

No abstract

A barrier to productivity on dryland is limited availability of water during dry season. Heavy rainfall at most in the dryland farming in Indonesia causes high runoff that occurred during precipitations. The huge potential of runoff can certainly be utilized as alternative water sources in the dry season to improve cropping index. The research purposes were to assess the potential of runoff farming system in improving the cropping index on dryland with wet climate. The study was conducted through observation field conditions, rainfall analysis, potential runoff analysis, crop water requirements analysis and water balance analysis in the dryland area. The result of the study indicated that peak of rainfall-runoff started in last decade of December until March. However, entering the second growing season, rainfall occurs until April only. It's implied that during the second growing season has led to a lack of water supply in the peak phase of crop water needs. Rainfall-runoff analysis indicates that surface runoff potential as an alternative source of irrigation in the dryland farming if managed well, one of which uses runoff farming system. With harvest runoff and store it for irrigation in dry season could increase the cropping index. The significant finding of this research was base on supply and demand water analysis shows that to increase cropping index of food crop in dryland with wet climate needed of catchment and cultivation area ratio (CCA ratio) equal to 6.2, to the form of catchment area was arable land with multi-cropping pattern and varies slope.

No abstract

Abstract. Rainfall interception losses were monitored for twelve months and related to vegetation and rainfall characteristics at the Wanariset Sangai on the upper reaches of the Mentaya river, Central Kalimantan. The rainfall interception losses were quantified for one hectare each of unlogged and logged humid tropical rainforests. The results show that interception loss is higher in the unlogged forest (11% of total gross rainfall) than in the logged forest (6%). Interception loss was also simulated by the modified Rutter model and Gash's original and revised models. Both the Rutter and revised Gash models predicted total interception loss over a long period adequately, and resulted in estimates of the interception loss that deviated by 6 to 14% of the measured values, for both the unlogged and logged plots.

Land use and land cover (LULC) changes through built-up area expansion always increases linearly with land demand as a consequence of population growth and urbanization. Cirebon City is a center for Ciayumajakuning Region that continues to grow and exceeds its administrative boundaries. This phenomenon has led to peri-urban regions which show urban and rural interactions. This study aims to analyze (1) the dynamics of LULC changes using cellular automata (CA), artificial neural network (ANN), and ANN-CA; (2) the influential factors (drivers); and (3) change probability in the period 2030 and 2045 for Cirebon’s peri-urban. We used logistic regression as quantitative approach to analyze the interaction of drivers and LULC changes. The LULC data derived from Landsat series satellite imagery in 1999-2009 and 2009-2019, validation of dynamic spatial model refers to 100 LULC samples. This research shows that LULC changes are dominated by built-up area expansion which causes plantations and agricultural land to decrease. The drivers have a simultaneous effect on LULC changes with r-square of 0.43, where land slope, distance from existing built-up area, distance from CBD, and accessibility are significant triggers. LULC simulation of CA algorithm is the best model than ANN and ANN-CA based on overall accuracy and overall accuracy (0.96, 0.75, 0.73 and 0.95, 0.66, 0.66 respectively), it reveals urban sprawl through the ribbon and compact development. The average probability of built-up area expansion is 0.18 (2030) and 0.19 (2045). If there is no intervention in spatial planning, this phenomenon will decrease productive agricultural lands in Cirebon's peri-urban.

ABSTRAK Mekanisme Imbal Jasa Lingkungan (IJL) merupakan salah satu upaya dalam pengelolaan sub-DAS. Mekanisme ini telah diimplementasikan di sub-DAS Cikapundung. Kesepakatan program IJL di sub-DAS Cikapundung terjadi antara kelompok tani Giri Putri : realistic, voluntarily, conditional, dan pro-poor